Longevity Doctor: "1 Cup Everyday"... Melt Fat, Reverse Brain Decline & Unclog Arteries | William Li

Dr. Rangan Chatterjee 0:00 You know, we don't naturally, I think many of us think about food and blood vessels, but we do think about our brain health, our cognition, our mood, our skin health, our immune system, without realizing that, wait a minute, what underpins all of them? Well, if you don't have healthy blood vessels, you're not gonna be delivering oxygen to all of those critical things. So healthy blood vessels mean a healthy heart, a healthy brain. I, I think it's, um, it's such a core tenet of optimal health to have healthy blood vessels. Of course, many people talk about exercise and actually moving your body is gonna help, um, maintain those blood vessels or, or certainly it's one factor, but I've heard you say in one interview that one of your pet hates is when you hear about exercise being the only thing that's good for your heart's health because, of course, the food you consume is also very important with these blood vessels as well. So perhaps you can give some examples of what kinds of foods directly impact the health of our blood vessels.

Dr. William Li 1:05 Well, one thing we talked about already is olive oils, uh, uh, olive oil, but I also wanna actually back that up and just say, look, and what about olives? You can just eat the whole olive, and now you get the fiber from the olive, and you'll actually get the other polyphen-- more polyphenols from the flesh of the olive. Uh, other things that... Other foods that are, um, clearly very health- heart-healthy are the leafy green foods that have dietary fiber and all these other polyphenols, so the Brassica family. Now, I like to cook, so, you know, when you get me talking about foods, I, I'll usually start talking about the foods, and most people think about broccoli, okay? Um, uh, I will tell you broccoli, like other Brassica veg-- family of vegetables, have isothiocyanates. These are the class of molecules that create sulforaphanes, and sulforaphanes, um, are great for our metabolism. They help to lower, um, uh, our-- uh, burn down our harmful body fat. They lower inflammation, which is really, really critical. And many of the Brassica family of vegetables, you're talking about broccoli, you're talking about kale, you're talking about Brussels sprouts, you're talking about bok choy, you're talking about Swiss chard. You know, I mean, these are, uh, vegetables that are growing in the summer gardens and, you know, take a little extra olive oil, saute some garlic on it, and just, just throw the vegetables in there, um, hit them with a little bit of, uh, spice, and you've got very quickly a delicious, uh, uh, warm cooked vegetable dish, uh, that, that's tasty. Squeeze a little lemon. You want a little red pepper flakes.

Dr. Rangan Chatterjee 2:31 What is that doing for our blood vessels? If we-- I mean, it sounds delicious. My stomach's-

Dr. William Li 2:34 Yeah

Dr. Rangan Chatterjee 2:34 ... watering already at the thought of that. But what, what does that actually do to the-- to our blood vessels?

Dr. William Li 2:39 What's happening is that they're-- when you're eating it, when you're eating that delicious food, the, the polyphenols and the sulforaphanes get absorbed into our bloodstream, all right, uh, from your stomach. Uh, and those, uh, those, the-- they, they serve a number of functions that help protect your heart. Number one, they lower oxidative stress. Uh, while they're s-- while, while these molecules are coursing through your blood vessels, 'cause they've been absorbed, uh, after you've eaten them from your stomach, they're protecting the walls of your blood vessel from damage. So if there's oxidative stress, they actually protect your cells, the lining, the, the, the smooth lining of your blood vessels. Number two, they actually lower inflammation as well. So, uh, the, the, the, the sulforaphanes in, uh, leafy greens lowers inflammation. Inflammation itself can damage the ice. They can scrape up the lining of the blood vessels, lowers inflammation. Uh, uh, the other thing about these leafy greens is they have dietary fiber, which don't get absorbed into your bloodstream, but that tumbles all the way down through your gut, down to your gut microbiome.

Dr. Rangan Chatterjee 3:41 Mm.

Dr. William Li 3:41 We haven't had a chance to talk about that yet. But gut health, turns out feeding dietary fiber from our food to our healthy gut bacteria leads our own bacteria, healthy gut bacteria, to produce, um, substances, short-chain fatty acids-

Dr. Rangan Chatterjee 3:57 Mm

Dr. William Li 3:57 ... that then lower inflammation further. Inflammation is super damaging to our blood vessel health, right? So if you have-- If you're inflamed, and you've got inflammatory markers, I mean, we can measure, uh, in the lab, if you take a vial blood, you measure your C-reactive protein as a marker for inflammation. Listen, that's-- that inflammation, if your CRP, if your levels of inflammatory markers are high, you got inflammation everywhere in your body-

Dr. Rangan Chatterjee 4:24 Mm

Dr. William Li 4:24 ... including in the lining of your blood vessels. That's sixty thousand miles worth of inflammation. That's actually a really bad thing to be carrying around. So this is how leafy greens with their polyphenols and their dietary fiber can all conspire in a beneficial way or collaborate in a beneficial way to be heart healthy-

Dr. Rangan Chatterjee 4:42 Mm

Dr. William Li 4:43 ... starting with improving the healthier blood vessels.

Dr. Rangan Chatterjee 4:46 Yeah. Super interesting. Any, any other foods that we forget about when thinking about our blood vessels that you would like to highlight and encourage us to bring into our diets?

Dr. William Li 4:57 Yeah. Well, you know, it turns out that two beverages, tea and coffee, have polyphenols that are heart healthy and beneficial. All right? Uh, tea has catechins, and the specific catechin that has been best studied is called EGCG, epigallocatechin-3-gallate. Uh, and again, I encourage people not to get, uh, hung up on the technical stuff unless you're a science geek, but, um, just know that we, we know these things. Uh, in coffee, there's many different polyphenols. One of the best studies called chlorogenic acid.

Dr. Rangan Chatterjee 5:31 Mm.

Dr. William Li 5:31 Um, and both of these are heart-healthy and blood-- vascular-healthy, blood vessel-healthy, uh, for similar reasons. They protect your blood vessels against oxidative stress. They, um, lower inflammation.

Dr. Rangan Chatterjee 5:42 Yeah.

Dr. William Li 5:42 They're good for gut health. They improve your metabolism by helping your body burn down harmful excess body fat, which then contributes to inflammation. So, um, uh, so it-- they're, they're powerful levers-

Dr. Rangan Chatterjee 5:55 Yeah

Dr. William Li 5:55 ... that can actually help us, uh, in-- And if you-- By the way, if you combine this Over the course of the day with eating some leafy greens, and, uh, and, and then you have some of these blood vessel regenerative foods like the barley with the beta-glucan or the mushrooms, um, that, that we talked about earlier, or a little bit of dark chocolate, high quality dark chocolate. You see, it's the net consumption-

Dr. Rangan Chatterjee 6:17 Yeah

Dr. William Li 6:17 ... of the things that we're eating all day long that expose our blood vessel, that extraordinary network, to help u- us maintain the roads in our body-

Dr. Rangan Chatterjee 6:29 Yeah

Dr. William Li 6:29 ... and that's our circulation.

Dr. Rangan Chatterjee 6:30 You mentioned some of the benefits of green tea there. I know you often speak about these drinks that, you know, all the longevity populations consume tea, coffee, and water. You also made a video recently on your YouTube channel about drinks that we can consume that help us with our metabolism and help us perhaps remove visceral fats from, you know, organs like the liver. It's quite an interesting concept that for people, because I think if most people think about their weight and excess fats that may have built up on their body, I think there's a widespread view out there that the main thing that matters is being in some form of calorie deficit. So essentially, you are consuming less than you're burning off, so over time you start to lose some of that excess fat. Now, I know your, your last book covered this in a lot of detail, but just help us understand how important what I just said is versus particular drinks like green tea or coffee that can really help boost our metabolism. Can you help us sort of find a way through that in case anyone's getting confused there?

Dr. William Li 7:46 Yeah. There's a lot of ways to help our body optimize its metabolism. We, we talked about one earlier, which is don't overconsume calories, and whatever you do consume, uh, make it high quality. So that kind of, that snapshot can- captures a lot of what we talked about earlier. But, you know, there is a hidden mechanism, a hidden trigger in our body that can help burn down extra harmful body fat that, um, allows us to eat foods in order to burn fat. Now, that sounds like a contradiction in terms, right? If you wanna lose fat, you wanna not eat, right?

Dr. Rangan Chatterjee 8:22 Mm-hmm.

Dr. William Li 8:22 Nope. Actually, there are some foods, and this is a big surprise, and I wrote about this in my book, Eat to Beat Your Diet. There are some foods that actually trigger fat burning. Now, now to, to... Before I tell you the foods, I gotta tell you how this works. You know, um, uh, the popular, uh, fad that people have been doing these days, like cold plunges, right? And cold plunges being, uh, a healthy for your metabolism and other things. Well, actually, it does work, and I'll tell you why it works. When you expose your body to cold, it-- the temperature drop actually triggers, uh, a special kind of body fat that's not harmful, but really beneficial, and it's called brown fat. And brown fat is not a fat that most people are familiar with. Most people are familiar with, um, white fat. We call it white fat. They're two different color... Th- this is what these-- this is what this tissue looks like under the microscope, okay? White fat looks white under the microscope if you're in a lab, and brown fat looks brown-

Dr. Rangan Chatterjee 9:22 Mm-hmm

Dr. William Li 9:22 ... uh, under the microscope. White fat is the, uh, h- is sort of the fat that we normally think about. It's lumpy, bumpy, wiggly, jiggly. It can be under the skin, subcutaneous white fat. It's under our arms, under our chin. It's the muffin top that people don't like or the thigh fat or butt fat. Okay. But white fat is also, uh, not only under the skin, but it's packed inside the tube of our body. Our body's a tube. So i- if you look inside the tube of our body, um, where our organs are, our gut, our viscera, if fat growing there, called visceral fat, can be extraordinarily dangerous-

Dr. Rangan Chatterjee 9:58 Mm-hmm

Dr. William Li 9:58 ... because as it expands, it sort of expands like a glove wrapping around your organs, and it can be highly inflammatory.

Dr. Rangan Chatterjee 10:05 Mm.

Dr. William Li 10:05 And that it when-- and so our body's kind of evolved a natural way to tame that kind of extra visceral fat, and it's through brown fat. There's other kind of fat. Now, brown fat is not lumpy, bumpy, wiggly, jiggly. Brown fat is thin as a sheet, and it's not n- it's not close to the skin. In fact, it's close to the bone.

Dr. Rangan Chatterjee 10:26 Mm.

Dr. William Li 10:27 It's like, it's like attached to the muscle deep underneath your skin, and we got a little bit on the side of our neck, we have a little bit under our breastbone. We got a little bit between our shoulder blades, and it's scattered in our belly a little bit. All right? And what brown fat does, it just kinda hangs out quietly in the background. But if there's really cold temperatures, okay, cold temperatures will trigger it to fire up and generate heat, right? Um, uh, and, and, uh, when it generates heat, this, this evolved in animals, uh, who are, that are hibernating, right? You get that woodchuck-

Dr. Rangan Chatterjee 11:02 Mm

Dr. William Li 11:02 ... gets n- nice and fat in the fall and into the winter, and then it waddles into the cave, and then it's not coming out. It, it's gotta stay warm in the winter. Why doesn't it freeze to death? Well, because the brown fat of those hibernating animals, when the w- weather gets really cold, f- triggers thermogenesis, thermal heat, genesis, generating heat, and that brown fat actually fires up and keeps the animal warm all winter long, provides it energy. Where does it get the energy from? The brown fat in hibernating animals has to, uh, sustain the heat-making fuel. Okay, the fuel. We'll talk about fuel again. It draws it down from the white fat. So that's why animals start the winter hibernating as big, round, you know, fat balls, and by the time spring comes around, they've consumed most of the energy, they've lost most of that fat-

Dr. Rangan Chatterjee 11:51 Mm

Dr. William Li 11:51 ... by generating heat. Well, guess what? Humans also have that same mechanism. In fact, it wasn't until 1930s and before, until we realized that humans also have brown fat. And it's in the locations I mentioned, around your neck, behind the breastbone, and so on and so forth. Cold weather will actually fire it up. And we discovered this, by the way, it was published in the New England Journal of Medicine, um, in an analysis of PET scans. Now, PET scans pick up metabolism.

Dr. Rangan Chatterjee 12:19 Mm-hmm.

Dr. William Li 12:19 When you're generating heat, when brown fat's generating heat, it'll actually light up because of the higher metabolism. It was picked up in PET scans, um, uh, in New England, which is an area in the United States that gets cold winters. Um, and, uh, people were just-- were looking for, um, uh, uh, uh, tumors, and they found ins- instead of a tumor, they found, um, something lighting up in the body that turned out to be brown fat. Uh, it wasn't a tumor, it was brown fat. People hadn't noticed it before. No one had noticed it before. But then when they actually looked at when PET scans showed the brown fat firing up, it was only during scans taken in people who were getting the scans in the winter-

Dr. Rangan Chatterjee 13:01 Hmm

Dr. William Li 13:01 ... not in the summer. And so seasonally, our brown fat lights up, which makes sense, just like those hibernating animals. So cold plunges actually are beneficial for your metabolism by firing up your brown fat to burn down your harmful white fat. So brown fat is good fat, burns down extra white fat, which is bad fat and visceral fat, and lowers inflammation. Now, temperature does it. That's pretty cool. There are some drugs that will do it. I don't recommend it because they, they all have side effects. But guess what? It turns out that there are certain foods that you can eat that turn-

Dr. Rangan Chatterjee 13:37 Mm-hmm

Dr. William Li 13:37 ... on brown fat and, uh, and, and cer- certain beverages. And two of them we talked about, green tea and, uh, uh, and coffee, uh, both contain the polyphenols that light up your brown fat to burn down harmful excess white fat. So the two beverages, and there's a whole other foo- bunch of foods as well, can actually help to stimulate your metabolism by lighting up your brown fat. One last thing I'll tell you that, that is-- that people will like, uh, I can't remember, which is the brown fat, which is the white fat. I'll tell you what-- how you can remember brown fat. You know, people are talking about mitochondria now these days-

Dr. Rangan Chatterjee 14:12 Mm-hmm

Dr. William Li 14:12 ... in the, in the health and wellness world. Well, mitochondria are the little tiny batteries, batteries in our cells that give us energy. Um, I remember when I was in medical school, I'm sure, uh, you had a similar experience memorizing all the different parts of the cell.

Dr. Rangan Chatterjee 14:27 Yeah.

Dr. William Li 14:27 Man, there are so many different parts of the cell. How, how on earth are you gonna memorize them? So I always remember mitochondria as mighty chondria, these little tiny little things that are small but mighty, and they generate energy.

Dr. Rangan Chatterjee 14:38 Yeah.

Dr. William Li 14:38 And so brown fat has a lot of mitochondria, okay, the cell-- fat cells, and that's why they're able to generate the heat. They're like loaded with batteries, okay? And they, the batteries generate heat. They draw down the fuel from the white fat. Well, mitochondria have a lot of iron in them. Iron, the same kind of iron that you'd have in nails, like, you know, like for construction. Now, what happens when you take a bunch of silver nails and you stick them outside in your front deck for, uh, uh, a, a few days or a week? They're gonna turn brown-

Dr. Rangan Chatterjee 15:09 Hmm

Dr. William Li 15:09 ... 'cause they oxidize, right? Rusty nails. And that's what actually happens in our brown fat, is that the iron attached to other mitochondria, and there's a lot of mitochondria, which means there's a lot of iron, all right? Gets oxidized, and it gets rusty, and that's why brown fat is brown and white fat doesn't have that. So that's the reason that there's white fat and brown fat.

Dr. Rangan Chatterjee 15:29 Yeah. I love it. So if someone is trying to lose excess fat on their body-

Dr. William Li 15:34 Hmm

Dr. Rangan Chatterjee 15:34 ... yes, they need to think about how many calories overall they're consuming. We've covered that a little bit on the show already. But-

Dr. William Li 15:42 Mm-hmm

Dr. Rangan Chatterjee 15:42 ... I guess people really do struggle to, you know, lose weight and keep that weight off in the modern food environment. So you're saying yes, pay attention to how much you're consuming, but also if you are consuming the right kinds of foods and drinks like green tea and coffee, and I know tomato juice we haven't mentioned today, but those things can also help activate brown fat, which is-- it's all gonna help basically. You know, instead of just taking one approach, you're saying-

Dr. William Li 16:15 Yeah

Dr. Rangan Chatterjee 16:15 ... why, why just stick to one? Why not do everything that you possibly can to-

Dr. William Li 16:19 Yeah

Dr. Rangan Chatterjee 16:19 ... increase the chances of success?

Dr. William Li 16:22 That's right. And, and, you know, and do it in ways that are kind of natural, uh, and don't, don't force you to take it, go to extremes. So one thing is just putting less on your plate. It's eas-- That's a-- that's low-hanging fruit. That's easy to do. Um, whatever you put on your plate, make it plant-based and as healthy as possible. Don't eat too much saturated fat. Don't eat too much salt. Don't, don't, and don't have added sugars. Uh, listen, that's, uh, that's also pretty easy. You just gotta remember the details on that. So again, less fuel, high-- but high quality fuel, that makes a lot of sense. Um, now if you wanna actually add to this, uh, you know, this idea of like, uh, uh, burning down fat, now you can actually think about swapping out the foods that-

Dr. Rangan Chatterjee 17:10 Mm-hmm

Dr. William Li 17:10 ... grow fat, in fact, um, that build fat, and swapping them out for foods that burn down fat.

Dr. Rangan Chatterjee 17:16 Mm-hmm.

Dr. William Li 17:16 So swap your soda for tea or coffee. All right?

Dr. Rangan Chatterjee 17:21 Yeah.

Dr. William Li 17:21 And now, rather than building up your, uh, fat with empty calories, uh, you know, with extra calories from the soda, uh, or destroying your gut microbiome with the diet soda, now you're actually drinking a beverage that traditional and, you know, uh, tastes great-

Dr. Rangan Chatterjee 17:38 Yeah

Dr. William Li 17:38 ... uh, to, to most people, uh, that actually will light up your brown fat at the same time and to burn down harmful visceral fat. So simple swaps can, you know, swap out something that's not good for you, that builds your fat, with something that actually can burn down your fat. That's a simple, uh, uh, thing as well. But, you know, and then, but if you think about like, what about planning a meal, right? Like, oh my gosh, you know, I gotta-- If you have to do your meal plan for the week, you know, think about what you're gonna shop on, sh- shop for. That can... And then you want to choose healthy. Oh man, that's another layer I gotta actually deal with to figure out, like what should I buy that's healthy? Well look, let me kind of run down some interesting foods that can, have been shown in human studies to burn down harmful body fat. All right? And, and let me challenge you, if you're gonna listen to this, to write it down on your grocery list and see if this is something you might consider buying. All right? As long as you don't eat too much of it. All right. Onions. Onions have quercetin, mostly packed on the outer layer of the onion. So we- once you peel the onion, um, don't throw away, don't peel off too much of the outer layer, 'cause most of the fat burning quercetin, brown fat lighting up quercetin, is on the outer layer. Red onions got more of the good stuff than, uh, uh, yellow onions. Uh, but yellow onions are also good. Uh, what about, um, tomatoes? Turns out lycopene in tomatoes, which helps to make the tomato red, uh, actually, uh, can burn down extra body fat. It can actually burn down visceral fat by, through thermogenesis, that can actually shrink your waistline. Your, uh, you know, you're, you're not stretching out the tube of your body as much. It'll shrink it down. This has been studied in humans. Um, what about, uh, strawberries? Strawberries, ripe strawberries have been shown to actually, um, burn down harmful visceral fat. A can of inexpensive white beans has been studied. Just eating, you know, a can of beans, uh, uh, for five days out of seven days, been shown to shrink your waistline by one inch by burning down harmful body fat. Uh, what's in a bean? Well, diet- a lot of dietary fiber, some healthy, uh, fat, fats from the legumes. Obviously how you cook the beans gonna make a difference. You know, if you want to stew them, add a little extra virgin olive oil, and now you've ganged up 'cause olive oil can also burn down harmful body fat as well. Carrots can burn down harmful visceral fat. All you need to eat, and this has been studied, is the equivalent of three medium-sized carrots a day-

Dr. Rangan Chatterjee 20:00 Sorry to interrupt. If you're enjoying this video and you want to learn more, then do check out my free special guide, which contains the six crucial steps you need to take in your life to not only build healthy habits, but also to make them stick. If you want to get hold of this free guide, all you have to do is click on the link in the description box below

Dr. William Li 20:22 Can actually turn on your thermogenesis.

Dr. Rangan Chatterjee 20:24 Wow.

Dr. William Li 20:25 Gonna make a salad, gonna roast some carrots. Hey, you know what? Um, I, I'm just giving you a partial grocery list, but if you, if you think you can take that and run with it... Oh, what about seafood? Let's say that you do eat seafood. All right? Um, listen, I'm an omnivore. I, I pretty much eat anything. I try to eat healthy things. I, I try to mostly eat plant-based foods. I eat r- uh, uh, actually only a very tiny amount of meat. Um, and I try to choose high quality whatever it is I am, am eating. But seafood actually contains omega-3 fatty acids. Guess what? That's another healthy fat. Actually, omega-3s, a lot of people don't realize, are originally coming from plants. They come from algae, all right? Uh, so, uh, the plants of the sea is where they're originally coming from. Uh, and they wind up in seafood. Most people think, oh, I gotta eat salmon. I'm sick of salmon, or, I gotta eat tuna. It's expensive. You know what? Actually, it turns out that lesser fish, more inexpensive fish, uh, and shellfish, uh, also have omega-3s. Um, and so sure, salmon has a lot. Um, uh, but you can actually look at cod or flounder or other types of, of... Or Mediterranean sea bass. They all have omega-3s, uh, that are, uh, healthy for you, and so do mussels and clams. If you eat, uh, shellfish and squid and octopus and shrimp, okay? They all have omega-3s.

Dr. Rangan Chatterjee 21:48 Yeah.

Dr. William Li 21:48 And that's another way, if you live near the coast or you're somebody who enjoys cooking, and you wanna kind of live it up with, uh, uh, you know, some seafood-

Dr. Rangan Chatterjee 21:58 Yeah

Dr. William Li 21:58 ... there, you know, that, that's also a way of turning on your good, beneficial brown fat to burn down your harmful excess white fat. The underscore here though, I want to say, even though I've mentioned a lot of ingredients, you gotta remember, how you prepare the food is important. If you don't wanna be putting a lot of butter into it, you don't wanna putting a lot of salt into it that can damage your blood vessels. You don't, you know... Cook in a healthy way. You don't need to steam everything, but you wanna actually be mindful you're not gonna fry everything either.

Dr. Rangan Chatterjee 22:27 Yeah. Dr. Li, you have such a wonderful way of talking about food. You clearly explain the science, but your passion infuses through everything, and it, it kind of leaves us all with this idea that the foods we choose can be a creative pursuit for us. Yes, it's for our health, but there's a, it's like an artistic endeavor that we can play with to actually find the things that we can utilize to improve our health. So I really, really appreciate that. I also appreciate that list at the end there. Many of those foods that you recommended were very, very affordable, which I think is, uh, a, you know, something to be very aware of these days.

Dr. Rangan Chatterjee 23:07 To finish off, Dr. Li, if someone has heard our conversation and they're like, "Okay, Dr. Li, I hear what you're saying. I understand the science there, but I don't really need to change much. My life is going pretty well. I think I'm of a decent weight. I can function at work. Why should I start changing the food that I put on my plate?" What would you say to them?

Dr. William Li 23:33 Well, listen, I, I, you know, uh, my, uh, current research, the area that I am working on, I, you know, my books are all about the work, the research I'm doing.

Dr. Rangan Chatterjee 23:41 Mm-hmm.

Dr. William Li 23:42 I'm, I'm not, like, I'm not reaching for topics to cover. I, I'm, I'm writing about what I'm re- researching. And right now, I'm researching about aging, healthy aging, including longevity, and I'm re- I'm researching brain health and all the things connected to brain health. And one of the reasons that I, I, you know, to answer to somebody who's asking the questions that you just stated, I would say, listen, if you are doing pretty well now, keep it up. All right? But- What the exciting research is showing is that if you push a little bit harder and try to, uh, buff up some of those areas, even a, by a little bit, you could actually be doing yourself a service to improve your brain health as you get older in remarkable ways. Like, for example, here's one. Um, uh, you know, I'm eating plenty of fruits and vegetables. I'm fine. Well, you know what? Uh, you might be amazed to know that, um, strawberries, even a cup, one cup of ripe strawberries a day, all right, has been shown to actually reduce, uh, cognitive decline, uh, in, in human clinical studies, and also reduce the, uh, depression that comes with cognitive decline. What's in a strawberry? You got ellagic acid and anthocyanins. These are natural molecules that we're discovering, and so we're discovering the benefits to brain health-

Dr. Rangan Chatterjee 25:00 Mm-hmm

Dr. William Li 25:00 ... of ripe strawberries. So, you know, maybe you're eating healthy, but maybe the next time you go, uh, by a market and you just are walking by those strawberries, you might wanna do a double take and go back and say, "You know, I'm gonna try some of those now." And so these little, tiny extra tweaks, if you're somebody who's already healthy. Think about what you're doing. If, if you feel, like, pretty good now, great. Now it's time to actually level up, to actually see if you can do something to make yourself even better in the future. And so I think thinking about our, uh, what we do now having an impact in the future is kind of like saying rather than, uh, put all of my money under my mattress, which is sort of a Depression-era thing, why don't we invest our money in some good things? I mean, you're gonna have the money anyway, but we- where are you gonna put it? Under your mattress, or are you gonna invest it in something that's gonna grow? And I think that making healthy food choices are a way of growing our health, and this is where my research is now. By growing your health, you know, you're, you're, you're really investing and you're becoming wealthier, uh, inside out, um, uh, in terms of brain health, which is a huge dividend for you.

Dr. Rangan Chatterjee 26:14 Yeah.

Dr. William Li 26:14 Uh, I mean, think about it. The thing that all this discussion about longevity and mitochondria and glucose spiking and, you know, and, and, and trying to get your sirtuins and, you know, like, all the millions of things that people are talking about now, I have one thing to say to that. Who wants to live longer if you're not able to have good brain health? You could live to 150, 200, go for it, but if your brain isn't working, it's not worth living for.

Dr. Rangan Chatterjee 26:43 Yeah.

Dr. William Li 26:43 And so that's why I think that in this, accompanying this quest to live long, we want to live well, and the choices that you're making now, the research is finding, remarkably, that we can actually improve our future us as well in ways that are profoundly important. Our vision, our brain, you know, our muscle strength, uh, our ability to enjoy life. Um, you know, you, you talked, you mentioned the word passion. We want to actually really enjoy-

Dr. Rangan Chatterjee 27:15 Mm-hmm

Dr. William Li 27:15 ... every year that we get.

Dr. Rangan Chatterjee 27:17 So in terms of categories and types of foods that we should think about limiting or avoiding, the first thing you went to was those drinks with added sugar, soft drinks, fizzy drinks, soda. How, you know, in whatever country you're in, however you like to refer to it, I hope it's generally well-known that actually those things are damaging for our health, our immune system, our teeth, and you beautifully explained why that is. Now, before we go to diet drinks, 'cause I'm really glad you brought that up, full sugar fizzy drinks. Is it just the sugar that's causing problems because it overwhelms our system and we can't process it, or is it something else? Is it the sugar and the chemicals and the impact they have on other aspects of our body's health, and potentially, those five defense systems that you've written beautifully about in your book? What's going on there? Is it just the sugar, or is it something else?

Dr. William Li 28:14 Yeah. The soft drinks, the sodas that we see so commonly around us, it's part of everyday modern life, you know, for the last hundred years or so. It's interesting. The, the history of soda is really fascinating. It dates back into Europe where, um, people were trying to find additional ways to be, uh, surprised and delighted by beverages, right?

Dr. Rangan Chatterjee 28:35 Yeah.

Dr. William Li 28:35 So the traditional drinks were always tea or coffee. Of course, the most popular beverage in the world was just drinking water, um, the most important one actually as well, uh, tea and coffee following close behind, and then there was, uh, wine, right? I mean, these were for thousands of years sort of the, the elixirs, so to speak, of our beverages. And carbonation was actually added to fruit juice. First it was a mistake, I think, that was made when they invented it, but then actually it became something to delight folks. You know, kind of like in a, you go to a carnival, you know, and, and you see some spectacle that actually is just some... You walk by and you think, "Oh, my gosh, that's so unusual. That's delightful." That's how sodas were actually, um, uh, drank. And then once actually the, the big industries came in and turned it into a marketing buzz, it started to take on a life of its own. And here's where it morphed. Went from fruit juices that actually had some carbonation, which is just gas, you know, CO2, and that's okay. But what wound up happening is that they started to have less fruit, but they figured out how to put chemical flavorings that actually mimic the f- fruit flavoring. And then of course, nobody really wants to have just a plain, watery-looking carbonated drink, so then they started to add artificial coloring, and then they started to add preservatives. And this goes to the importance of reading a label. Whenever I actually pick up something to drink, you know, from a store, a grocery store, I, you know, uh, uh, I, I, I'm an explorer, so I love to actually try new things. If I saw a drink in a store that seemed appealing or attractive or intri- intriguing to me, I might pick it up. But the first thing I do is I take a look at the label. What is in there, right? So it should be mostly water, so I look for that. And then most, many people don't know this, but the order in which the ingredients appear on a label, at least in the United States, is, um, is synonymous with their c- relative concentration-

Dr. Rangan Chatterjee 30:26 Yeah

Dr. William Li 30:26 ... in the drink. And so what you wanna do is it's usually water, and then it's sugar, all right? So we ta- just talked about that, or artificial sweetener, and then you start seeing the other things behind it. And I think most people will be astounded and, um, disappointed, rightfully so, that natural fruit juice is usually pretty low on the list of-

Dr. Rangan Chatterjee 30:49 Yeah

Dr. William Li 30:49 ... 10 or 20 ingredients. And so if you're creeped out by not being able to pronounce, understand, identify the ingredients on, on s- on a, on a beverage, your, you should follow your instincts. That's probably not something you wanna put in your body, because your body's not hardwired to handle those chemicals.

Dr. Rangan Chatterjee 31:09 Yeah. I think that's great advice, something I use with my patients as well. People say there's always exceptions. Yeah, there are exceptions, but as a general principle when looking at ingredient labels, I, I completely echo that. If you don't recognize it, you know, maybe give it a miss and choose something else instead. You also mentioned marketing there when you were talking about fizzy drinks, and that really is something that we're fighting. You know, you are trying to promote all this incredible colorful food, but what we're fighting is this marketing machine, and, and particularly around, I guess, soft drinks and fizzy drinks and sodas. It's, it's really tragic to see sports stars who are looked up to by children, you know, you certainly have seen this in the UK for many years. You see this in a big way in India, where, like, the big cricket stars are often sponsored and are seen drinking a can of soda. And actually, I think this is one of the big problems we're up against, because that just infuses into these young kids' mind that actually I wanna be like that person, or they're drinking that drink, oh, I wanna drink that and be like them. How much of a problem do you think marketing is? You know, sponsorship, product placements, commercial deals. Is that something we need to be fighting against?

Dr. William Li 32:25 I think that we all have the freedom, most of us, to make our own choices. And I try to think about any argument, um, such as the one we're discussing now, from both sides of the coin. If you run a company, and your, and, and your company's making a product, your job is to market it, whether it's a soda or whether it's a tennis shoe or whether it's a wristwatch, right? On one hand, I, I don't blame companies for actually doing marketing, and the ones that actually do it really well, hey, you know what? That's, that's their job, okay? On the other hand, I think that the fight that we're actually having is not really against the company. The fight is really against the inertia that many of us have in the community to do our homework on, and to get back in touch with our body. Because I think that if we actually, you know, took a look in the mirror and started to, um, reacquaint ourselves with what our body is telling us. I mean, you know, look, here's how I think about it. In the mor- you get up in the morning, you take a shower, you step out of the shower, you look, you're gonna see the mirror. You look in that mirror. Most people aren't that happy. Most people are not that happy with what they see. They can always find something wrong with themselves, you know? And then, you know, and then you might step on a scale, and you might not like that number, okay? Um, and then you realize, uh, those are the few moments of clarity in a day where you might actually be thinking about yourself.

Dr. Rangan Chatterjee 33:44 Yeah.

Dr. William Li 33:44 And then we get dressed, and we go off, and we're just swept up with the rest of, um, our lives, whether it's our jobs, whether it's our families, whether it's other responsibilities, and we leave ourselves behind. Oftentimes, we deprioritize what our body needs. And I think that one of the things, the inertia we're fighting against, is actually all those other distractions in our life. I o- I actually think that, you know, one of the things that we could do to teach children, and one of the things we could do to teach young parents, one of the things we could do to help teachers, whether it's grade school, high school, or college or beyond, is to really reemphasize the fact that we all need to be in touch with our bodies. We need to know ourselves first. Knowing yourself first allows you to then discern whether or not a message that you're seeing on television or being promoted by a sports star, or whether something that is being marketed to you in a grocery store is something that you wanna partake in, right? And so I think that, yes, we should, um, be vigilant, and we should enact policies that prevent predatory marketing practices to people that are uninformed and are, uh, highly vulnerable, like marketing to children, you know, with, uh, uh, certain ads like that. I think that's, that is something that works, and therefore it's something that really we need to, we do need to actually push back against. But on the other hand, you know, I think companies are just doing their job. I think that we have our own decision. We need to push back on the predatory practices, um, of companies that are preying on the vulnerable, and we also need to be able to lift up the consumer so that they are smarter, wiser, more in touch with themselves, and then they actually can discern-

Dr. Rangan Chatterjee 35:26 Yeah

Dr. William Li 35:26 ... what they should be ordering, uh, or buying, uh, that can actually help themselves.

Dr. Rangan Chatterjee 35:31 Yeah, I really appreciate that nuanced answer, looking at it from both sides.

Dr. Rangan Chatterjee 35:37 You mentioned sugar and these soda drinks that we know, uh, certainly even small amounts [laughs] consumed regularly can be quite damaging for our health. And then you went to artificial sweeteners in these diet drinks. Now, I share the same perspective as you do on this, but it does appear to be a very divisive topic with the public, but even within science and within medicine. This whole topic of whether artificial sweeteners are good, bad, or neutral seems to get a lot of people's backs up. I know Professor Tim Spector, who has been on the show before, and he's pretty clear as well that we should be avoiding them. You seem to be pretty clear on that. I certainly take the precautionary principle with my patients to say, "Listen, I've seen enough data that suggests it's having a negative impact on the gut microbiome," so I would prefer to take that precautionary approach to say, "Let's try something else." What is your view on that, and why do you think it's such a divisive topic?

Dr. William Li 36:38 Well, first of all, every kid loves candy, right?

Dr. Rangan Chatterjee 36:42 [laughs]

Dr. William Li 36:43 Me, me as well. I remember when I was a child, you know, uh, in the US, you know, we had Halloween, and who, who didn't look forward to collecting all the candy from the neighbors? And, and I think that, you know, sugars, the candies, the- they're delightful, and there's nothing wrong with being delighted, and I think we carry with us lots of pleasant, fun memories. I think brain's also hardwired to actually go after sweet things.

Dr. Rangan Chatterjee 37:06 Yeah.

Dr. William Li 37:07 Right? I mean, it's part of our instinct as animals to, you know, to just like the, the, the lion on the savanna goes after the antelope, I think humans, you know, on the street [laughs] go after candy. It's one of those things that just we're, we're hardwired to go after sugar. I think there are industrial interests that actually, you know, pose, uh, counter arguments to the harm of sugars and artificial sweeteners. And by the way, I do wanna actually bring this up, 'cause I think it's, it's important. Let's not character assassinate categories. I think that's really important. So artificial sweeteners, let's be specific.

Dr. Rangan Chatterjee 37:39 Okay.

Dr. William Li 37:40 What I was referring to are things that are not refined sugars, the powdery white stuff that you would buy in a supermarket. The artificial sweeteners are the ones that are chemically synthesized, not natural, that actually have been designed to, um, activate the sugar receptors on your tongue and mimic sweetness.

Dr. Rangan Chatterjee 37:59 Right.

Dr. William Li 37:59 Okay? And there's many different kinds, and so I think that if anybody were to go to Google and look up categories of artificial sweeteners, you'll start seeing this is not one product. It's, uh, many different types. Some people could consider artificial sweetener stevia. Now, stevia's a natural sweetener-

Dr. Rangan Chatterjee 38:15 Yeah

Dr. William Li 38:15 ... but it's still artificial when you compare it to refined sugar. And so... And what about, you know, like some people use monk fruit, which is also a natural sweetener, which isn't the same thing as refined sugar. It also activates your sugar taste buds. It's more natural. And then what about aspartame and sucralose, and what about all those, um, other kind of chemical names that you can't pronounce? And so I think a- as we're talking about this now, we need to say categorically, you know, I think, um, excess natural sugars in product form added to food, as in added sugars, um, tend to be unhealthy if you over-consume that. And soda is, is just one of many examples with lots of added sugar. Artificial sweeteners is not one category. It's a lot of different types of-

Dr. Rangan Chatterjee 39:01 Yeah

Dr. William Li 39:01 ... things that, that are used in place of refined sugar. And what I would say to be a savvy consumer, you know, um, just know that there are more natural versions of those. I think stevia is fine. However, there are stevia, um, that actually are not really all stevia. You pick up the package, you look at the ingredients, and you find even though it says stevia, you look at the ingredients and you actually see that there are other things that are added to it. We cannot forget when you buy ultra-processed food in a package, stuff has been added to it almost certainly-

Dr. Rangan Chatterjee 39:34 Yeah

Dr. William Li 39:34 ... even to preserve it on the shelf, that may or may not be good for you. And one of the big advantages we have right now, every one of us carries around one of these, a mobile phone. Um, and so if you don't recognize something and you're curious, go ahead and type it in and search that chemical just to learn something about it. That could actually make the difference between whether you put it in your cart or not.

Dr. Rangan Chatterjee 39:54 Yeah, I love that. Very empowering way of looking at this, to put the information in the consumer's hands and say, "Right, you start as much as possible to make these better decisions, because you know that this one's gonna lead to health. This one's probably gonna not promote my health over a period of time." Sorry to interrupt. If you're enjoying this video and want to dive deeper into the topic of sleep, I have created a free special guide containing my top five science-backed tips to help you get your best night's sleep and reduce fatigue. If you wanna get hold of this free guide, all you have to do is click on the link in the description box below.

Dr. William Li 40:31 I mean, look at, look at what happens when we sit down at a restaurant, right? Um, you open a menu, and the waiter comes over and says, uh, "Do you have any questions?" And so, uh, w- all of us have done this. You pick one that kind of seems interesting to you, and, and you ask... What's that question we ask? You ask the waiter, "Hey, what's in this?" All right? "What's in this dish?" And they tell you, and on the basis of the information that you asked for as a consumer for, on, on food that you're about to purchase and eat, you might say, "Oh, well that sounds pretty good. I'll have it." Or you might say, "Hmm. You know, that doesn't sound so great to me. I think I'll choose something else." And I think that that, the power, you know, the power's in the pocket of the consumer.

Dr. Rangan Chatterjee 41:11 Yeah.

Dr. William Li 41:11 And it's our money, our resources that we're spending. And, and by the way, I mean, you can see this now with, you know, global and the geopolitical events that are happening. If we choose not to support something, it can have a powerful impact, and that impact actually comes from our pocketbooks.

Dr. Rangan Chatterjee 41:27 Yeah.

Dr. Rangan Chatterjee 41:27 Apart from these drinks that we've covered so far, any other sorts of foods that we should generally try and avoid, let's say, when we're in the grocery store or the supermarkets? Anything we should think about?

Dr. William Li 41:39 Yeah. Yeah, so I think, you know, largely for the same reasons of having chemicals being put in our body that we don't really want, ultra-processed foods, foods that come in a box, foods that got lots of ingredients and lots of preservative and chemicals inside them, things that, um, uh, that, uh, they say that your grandmother, if you showed her, might not recognize as food, or great-grandmother perhaps. The ultra-processed foods as a group tend to be associated when we look at populations with poorer, uh, health outcomes from diabetes, obesity, cardiovascular disease, and even cancer. And so again, you know, I, even though I said we should be careful not to overgeneralize, it is true, things in a box, things in a can, things, you know, that are manufactured at scale and intended to sit on the shelf for months or maybe even years tend to draw the attention, my attention anyway, um, that r- it really is worth reading the label and knowing what it is you're putting in your body. So ultra-processed foods. I think, uh, uh, alcohol is another thing that is a, is popular. It's social. I mean, look, um, if you look at beer and wine- These go back millennia as part of human culture. People sat and, and distilled and fermented beer and wine for thousands of years. Uh, you know, in the Colosseum in Rome, they're still doing excavations to figure out what the gladiators actually, uh, ate and drank, and they found, they find inside there, you know, wine casks and, and things like that. Like, it, it was a, it was a, it's a, it's a cherished tradition of, of humans. But what we do know is that it's easy to over, uh, consume, and we do know that there are, while there are healthful properties in the liquid of wine due to the fermentation, it pulls things out of the red grape skin, or pulls things out of the barley hops in the case of beer, like xanthohumol in beer or resveratrol in red wine. The fact of the matter is that none of the benefits that you get from any alcoholic beverages come from the ethanol, the alcohol itself. The thing you get the buzz from does nothing for your health. Okay? Um, some of the other things that happen to be in the broth of the fermentation might be good for you. And so that's, uh, something that, you know, like, like, oh, well, they've found that... And I think recently there was research showing that, you know, even one glass of red wine, uh, could have an impact on brain health-

Dr. Rangan Chatterjee 44:03 Yeah

Dr. William Li 44:03 ... as well. And I think that, you know, we have to be... I, I'm really careful about not chucking a spear, you know, at every food that, you know, we wanna kind of, um, malign, uh, for a health reason. I think wine is a cherished tradition. Alcohol is a cherished tradition. But people should know that the benefits of it... And it's okay to have a glass or two every now and then, but I think that the, the people who really go after it hard, look, besides the obvious liver disease, and the problems of nutrition, and the brain health, I mean, alcohol is a toxin to your brain. Um, uh-

Dr. Rangan Chatterjee 44:34 Yeah

Dr. William Li 44:34 ... we do wanna actually be mindful about the amounts that are consumed. You know, processed meats are another food product that actually are classed as a carcinogen by the World Health Organization. Now, what kind of processed meats are we talking about? We're not talking about the, the air-cured salami from Sardinia, you know, that, you know, that have been made in the same way for thousands of years, that people eat sparing amounts of, you know-

Dr. Rangan Chatterjee 44:58 Mm

Dr. William Li 44:58 ... as part of a more well-balanced Mediterranean traditional meal. I'm talking about the deli foods. You go in there and they're slicing stuff, you know, from a big lump that, that looks nothing like the animal from which it came.

Dr. Rangan Chatterjee 45:10 Yeah.

Dr. William Li 45:10 And some of these cured sausages, if you visit a sausage factory... I had a, I had a patient once who actually worked as an inspector-

Dr. Rangan Chatterjee 45:18 Oh, wow

Dr. William Li 45:19 ... in a, a commercial sausage plant, and he told me that he has to, he used to have to change his boots every month, rubber boots, walking in there, because the, the stuff that's splashed out of the pool in which the sausages were essentially, um, uh, embalming in for preservatives and for flavorings would actually dissolve the sole of his rubber boots.

Dr. Rangan Chatterjee 45:41 Oh, man.

Dr. William Li 45:42 That made such an impression on me. I'm still talking about it 20 years later.

Dr. Rangan Chatterjee 45:46 Yeah. And we're sort of removed from that process, aren't we? We don't see that. We don't see that on videos. We just see the nice packaging and, uh, the clever marketing copy on there. And so I think that's really, really important. And I, I really like the way you made that distinction there. Also, you know, when talking about things like alcohol or anything, it depends not just on that one thing, it depends on everything else that's going on in your life as well. We like to take these things in isolation, good or bad. It's like, well, it kinda depends, doesn't it? In our first conversations together, which, if people haven't heard, I'd highly recommend they go back and listen to, one of the things I really liked about your approach was you said, "Well, let's put into our body foods that support these five defense systems. And if we can do that and support them, we raise the bar. We become more resilient, therefore we've got more headroom to actually deal with the insults that are going to come in in life, whether that's DNA insults from pollution, or whether it's the odd thing that we creep into our diet that we probably know isn't the best thing for us, but, you know, we just fancy it now and again." And I really like that approach. And, and I know we're starting off this conversation focusing on some of the things to avoid. We're very quickly gonna get onto the things that people can put in, but yeah, I really, really appreciate that.

Dr. William Li 47:04 The most important thing that we as doctors can do is to listen to our patients and hear them out, and try to understand where they're coming from and what's important to them. I always ask my patients, um, you know, "What do you eat? What do you like to eat? What, what brings you joy when it comes to food?" Though the an- That question usually can elicit an answer. Like, I never, I try to, I'm very careful not to ask that question judgmentally.

Dr. Rangan Chatterjee 47:29 Mm.

Dr. William Li 47:29 What kind of negative foods do you... How much steak do you eat? Like, I, I don't, I never ask that. I always sort of say, like, "Tell me about what do you enjoy eating? What brings you joy? What are some of the favorite things that you like to eat?" And you know, again, it's that conversation that invites someone to look deeply within them. I think that, um, you know, uh, I, I, when I was a kid, I studied martial arts and, uh, and, um, one of the greatest martial arts artists ever was Bruce Lee, who I actually read a lot of his writings. He wrote in a philosophical sort of way, and he wrote, "One of the most important things that, if to succeed in life, whether it's martial, in martial arts or otherwise, is to know yourself, to truly know yourself." And I think that so often we get distracted. We don't have that opportunity to ask ourselves something simple like, so if we had a choice, what would we want to eat? What brings us joy? And my, my strong belief is if we want people to get on a better diet, to get them started and to keep them going on it, we want them to actually feel like it's not a heavy lift, it's something that's doable. And I think there's nothing easier than to say, "Hey, you know what? Something that you already brings you pleasure and joy, something that you enjoy to eat already is healthy. So let's start with those things, because you already know you love them." So, and so what I-

Dr. Rangan Chatterjee 48:44 Yeah

Dr. William Li 48:44 ... in my book, Eat to Beat Disease, I have lists of, like, 200-some foods. I always tell people, you have my book, get a Sharpie. Okay? Uh, I, I say a Sharpie, like the marker, permanent marker-

Dr. Rangan Chatterjee 48:54 Yeah

Dr. William Li 48:54 ... because it's permanent. You have to make a commitment. All right? Take a Sharpie, a black Sharpie, and circle the foods that you enlist that you already like. No, actually, that you love. All right? And, and, and I, I don't care if it's just one or two, almost everyone I've met has been able to circle, like, 10 of them, so I- or more. But if you find a food that you already love that's healthy and good for you, that activates your health defenses, you are already way ahead of the game.

Dr. Rangan Chatterjee 49:20 Love that. Very empowering approach to people.

Dr. Rangan Chatterjee 49:23 Oils. Oils are something that can cause a lot of confusion. I know you're a big fan of olive oil. I wanna talk about olive oil and why it's so beneficial. But before we get to olive oil, in the spirit of the kind of foods that we should think about limiting when we are in our supermarket or our grocery store, and we're looking around to purchase oils to cook food in, to sprinkle on food, to pour on our salads, what kind of oils should we try and avoid? And then what sort of oils should we try and buy instead?

Dr. William Li 50:01 You know, so this, like the debate about artificial sweeteners, um, is a loaded topic. And so I, I wanna just start, you know, this component of our conversation by saying the jury is still very much deliberating what oils are harmful to you and, and are most harmful to you. Um, but I think that it's less controversial what, uh, oils are better for you-

Dr. Rangan Chatterjee 50:30 Yeah

Dr. William Li 50:30 ... and good for you. I wanna, you know, for your listeners, I wanna kind of give people some real practical things-

Dr. Rangan Chatterjee 50:35 Yeah

Dr. William Li 50:35 ... and not just kind of dive into the science of petroleum products, which is what oil, oils are. Let's talk about this. Rule number one, regardless of what oil you actually have, what I would say is don't have too much of it because oils are fats, and fats can be healthier, but there really isn't such a thing as a healthy fat that you should, like, drink lots of it every single day, okay? So the point is that there are healthier oils, but you should, we should all limit the amount of oil that we actually intake into our body. All right? Number one. Number two is that, and this is actually broadly speaking, is don't reuse your oil. Okay? Most oils that are reused, when we heat them to cook, whether we're actually, you know, uh... I mean, again, deep-frying is generally something that's not very healthy. The process of deep-frying actually changes the chemical, the natural chemicals that make up oil in the oil itself and then paint it onto the food, stick it onto the food. So we're eating some of the changed chemicals when we actually eat deep-fried food. Now look, I mean, I, I've had, I've had some awesome fish and chips, um, uh, when I visited England before. Um, and, and, again, and again, as we talked about, you know, every now and then, if you're, you spend most of your time shoring up your health defenses, raising your own bar, you know, having a rare treat is totally fine. But when you fry things in hot oil, you're also changing the chemical structure of things. That entire browning, golden browning, crisping of food actually changes the chemical structure-

Dr. Rangan Chatterjee 52:07 Yeah

Dr. William Li 52:07 ... of the food itself in, in ways that are potentially carcinogenic, and so just need to be careful about that. The third, re- uh, so, so a thing, you know, like reusing oil. Here's a thing that's kind of like a little risky. You go to a restaurant to eat. You have no idea if they're reusing their oil over and over and over again. You know? Um, I mean, think, think about in, uh, Asian restaurants. Whether it's an Indian restaurant or a Chinese restaurant, they've got these gigantic vats where they're frying tasty little bits up. Um, but they may be reusing that oil for days. So, um, uh, reused oil, not good for you, for sure. And, and the stuff that's fried in oil can also change in time. So let's start now talking about just, like, the o- the properties of oils themselves. This is where I think rather than kind of walk into the quicksand of trying to say, "Is palm oil better than corn oil? Is coconut oil dangerous for you?" You know, like, we can wade into that jungle with, you know, but I think you need a machete to cut your way out of it.

Dr. Rangan Chatterjee 53:01 [laughs]

Dr. William Li 53:02 And so the best way to think about it, to help to give clarity is, you know, are there any healthier oils to use and how to use them? And this is where I think olive oil really stands out.

Dr. Rangan Chatterjee 53:13 Yeah.

Dr. William Li 53:13 Number one, it's part of a healthy pattern of eating that's been revered for thousands of years, and that's in the Mediterranean, traditional Mediterranean diet. And the olives are seasonal. They're pressed. The extra virgin olive oil contains not just fat, poly and mono unsaturated fatty acids, which are better for your body and less damaging for your cardiovascular health, but there's a lot of polyphenols that come from the olive itself. Now, a lot of people don't understand this, but when you look at olive oil, the reason we say extra virgin olive oil, EVOO, you know, that's what the, that's what supermarkets and what restaurants are proud to use now, is because it's not just fat. It contains the polyphenols from the oil. So if you were to actually... By the way, this is a good experiment to do for, for your lis- listeners. Buy a little container of olives from your grocery store, de-pitted, make it easy for yourself, and literally, you know, take it home and, and take a, a heavy glass or take a, a board, like a, like a heavy cutting board, and press those olives yourself. And you'll actually see, if you press hard enough, you'll see some oil come out of it.

Dr. Rangan Chatterjee 54:22 Yeah.

Dr. William Li 54:22 Now, in a f- in an olive oil factory, I mean, that, that's, that's-- So you can actually appreciate where your food comes from, where your olive oil comes from. Now, when you actually press it, you'll see that you've crushed the olives, and some of the bits from the olives are actually in the olive oil. The reason that olive oil tastes so good, it's got that, you know, kind of, um, peppery, vegetal kind of quality to it, um, it's got a umami flavor. It's not because the fat is flavorful. It's because the bits of olives that were crushed in there-

Dr. Rangan Chatterjee 54:53 Mm

Dr. William Li 54:53 ... are actually in there flavoring it. Now, those bits and the stuff that comes from the meat of the olives contain the polyphenols, one of which is hydroxytyrosol. Hydroxytyrosol sounds like a very ca- complicated chemical name. You don't, your listeners don't need to memorize it by any means. But you should know that that comes from the olive. Now, uh, olive oil will have some of it. Only about 20% of the, of, of it. But if you actually press that olive, 80% goes into the olive water and, and it's stuck in the pulp. And so one of the things that I always say is that, you know, if you really love olive oil and you wanna get the most out of it, um, just eat the whole olive, you know? And you can actually cut up an olive, and you'll get a little bit of fat, you'll get all that flavor, and you'll get a lot more of the polyphenol. Now, if you're gonna cook with olive, olive oil, I, I, I always say go for extra virgin because of that reason. I would say don't deep-fry, but, but you can sp- you can put, put some on, uh, to food. You can actually saute with it. Not too much. All the studies show that about three tablespoons of olive oil, uh, sort of like what you ... Probably that's around the max of what you'd want a day. So nobody's drinking olive oil. And then the other thing that is, uh, if you wanna choose which olive oil, because I get overwhelmed when I walk into a store and I see all these, like a whole wall full of olive oils, right? Everybody's marketing. Here's what I do, again. I pick up the olive, uh, an oil, and I look at the ingredients. What do I look for? I look for mono-varietal olive oil. Mono-varietal means it's made with just one kind of olive, and I look for the one kind of olive that, that it, that oil's made from, from three different varieties of olive. In Spain, Spanish olive oil, I look for Picual, P-I-C-U-A-L. Picual olives, h- among the highest in, in polyphenols in the oil. So the olive oil will be loaded. Second, um, Greek olive oil. Um, the Koroneiki olive, which is from the Peloponnesus. It ... Well, both the Picual and Koroneiki are very common olives, so that's a good news. It's not very expensive. Highest amount of poly- One of the top three polyphenols. And the third, if for Italian olive oil, I look for, um, uh, oil that's been pressed from a mono-varietal called Moraiolo, and that comes from Umbria. And there, that's less common, harder to find, a little pricier. But I just gave you three olives, uh, Picual, Koroneiki, Moraiolo, uh, that are not ... Most of them are not good eating olives, but they're great for olive oil. They're packed with polyphenols. If you get, uh, olive oil that is mono-varietal, pressed only from each of those, you can be guaranteed that you're getting sort of the top, the sort of the capo di capo of the polyphenols in the olive oil.

Dr. Rangan Chatterjee 57:39 What about olive oil? Does that have any relationship with our stem cells?

Dr. William Li 57:43 Absolutely. So olive oil, uh, uh, is a healthy fat, as they say. It's a plant-based food, comes from plants, the olives. Uh, and it, uh, contains bioactives, many bioactives. Some of them have been identified. The ones that actually, uh, have been best studied, one of them is called hydroxytyrosol. The other one's called oleocanthal. And, you know, for people who are listening, you know, if you're a science geek, you can write all this stuff down, but just know that there are these natural substances that have powerful effects on our body. And for example, hydroxytyrosol, and, a- as a molecule, uh, uh, but olive oil as a food substance, all right? Um, has been shown to be protective of our stem cells, meaning when you, uh, consume olive oil and you get these polyphenols, the hydroxytyrosol, oleocanthal, in our bloodstream circulating around. Look, there's a lot of stuff in our bloodstream, uh, uh, that, that's going on, a lot of exposures that we have. And when you've got hydroxytyrosol from olive oil in the bloodstream along with your stem cells, they sort of act as police escorts to help your stem cells get to where they go-

Dr. Rangan Chatterjee 58:53 Mm-hmm

Dr. William Li 58:53 ... in a safer way. Uh, they're, they're, they're, uh, they're escorted to where they're needed. They're protected. And so why do they need to be protected? Well, if you think about it, there's a lot of oxidative stress that can be in our bodies. You know, um, oxidative stress can come from, uh, fumes that you breathe, from vaping, from, uh, off-gassing from carpets, from, uh, artific- artificial, uh, flavorings and, uh, preservatives that you have in your food, um, fr- uh, from cleaning materials that you're actually having. All these chemical exposures cause oxidative stress in our blood, which can damage your stem cells. Hydroxytyrosol, again, is one of those natural molecules that have been shown to protect your stem cells against oxidative stress. So literally, it's like a police escort that helps your stem cells, um, uh, get to where it needs to go, uh, uh, in sort of a safe and efficient manner.

Dr. Rangan Chatterjee 59:46 So when you think about olive oil, there are multiple reasons to consume olive oil. You just mentioned the research around stem cells. I'm sure if I asked you about longevity or inflammation or blood vessels, you could also talk to me about the benefits of olive oil. Sorry to interrupt. If you're enjoying this video and want to dive deeper into the topic of nutrition, I have created a free special guide which contains the five most important changes I think we all need to make when it comes to our diet. If you wanna get hold of this free guide, all you have to do is click on the link in the description box below.

Dr. William Li 1:00:24 Yeah, yeah.

Dr. Rangan Chatterjee 1:00:25 But how do you recommend people consume it? Are you a fan of it being cold on salads and vegetables? Or are you someone who says, "Yeah, it's okay to actually cook with olive oil as well"? Because this is a area of a little bit of confusion and controversy online, so I'd love to get your take on this.

Dr. William Li 1:00:42 Yeah. I, I wanna be very clear about this. Olive oil is, of all the cooking oils, uh, a healthier choice to be able to have with a meal. You can ... You don't have to cook with it, but you can cook with it. Um, there's a myth that olive oil, uh, has a low smoke point, so you shouldn't do high-heat cooking. As it turns out, olive oil's, uh, smoke point is almost the same as canola oil, uh, which is, uh, uh, used for frying. It's pretty close. You, you shouldn't reuse, uh, olive oil at a hot heat, but, but cooking with it in a, in a wok, if you're using, doing Asian cooking, is perfectly fine. Actually, you just have to like the taste of the olive oil, uh, in cooking it. So again, that, that's a little bit of a myth. You can actually cook with olive oil at, at, in, at pretty high heat, and you're fine. Certainly, sauteing is no problem. Frying is ... Stir-frying is no problem. And by the way, in the Mediterranean, uh, I don't encourage people to eat a lot of fried foods because the frying creates these little side products called acrylamides-

Dr. Rangan Chatterjee 1:01:39 Mm

Dr. William Li 1:01:39 ... which, you know, are potentially carcinogenic. But everyone likes ... Occasionally, people like crispy food. Um, you know, in the Mediterranean, how they fry foods, they fry them in olive oil. All right? And in fact, the polyphenols get into the- ... food that you fry.

Dr. Rangan Chatterjee 1:01:55 Mm-hmm.

Dr. William Li 1:01:55 So it actually makes something that's not that healthy a little bit healthier with the polyphenols in it. Um, I would say, so you can actually cook with it. I'm not saying you should eat... You should fry with it or eat fried foods, but cooking with it is fine. Ea- uh, using olive oil, uh, um, cold, plain, is, is, is also fine if you wanna dip it in some bread or, uh, put it in a salad dressing. Um, I, uh, think the quality of the olive oil is really, really important, okay? And a lot of people don't appreciate this, but when you go out to buy olive oil, what do most people do? Well, you know, if, if you, if you are for the first time buying olive oil, it's overwhelming how many different choices you have.

Dr. Rangan Chatterjee 1:02:33 Yeah.

Dr. William Li 1:02:33 So you might go for the less expensive one, or you might go for the one that's got a more attractive label on it. Um, I'll tell you the way that, uh, I recommend doing it and what I do myself. I always want to, um, get the highest quality olive oil. Uh, so, um, what, what I look for are olive oils that are made with... pressed with only one kind of olive. It's called monovarietal olive oil. And there's two reasons for that. When you're... When olive oil makers make olive oil, they're picking olives when they're ripe off the tree and literally just crushing it and then spinning it in a basket, and so it whips out all the fluid, and the oil floats to the top, uh, and then the, the watery stuff goes to the bottom, and the chunks f- go to the bottom, uh, and they just scoop the olive oil off. They don't filter it, and so that's why you wind up getting, uh, little bits that are green.

Dr. Rangan Chatterjee 1:03:27 Mm-hmm.

Dr. William Li 1:03:27 So extra virgin first press olive oil's always gonna be tastier. You're gonna get that peppery, you know, uh, sometimes peppery, uh, taste to it. By the way, those... that's what the polyphenols are.

Dr. Rangan Chatterjee 1:03:39 Mm-hmm.

Dr. William Li 1:03:39 They're actually giving you that taste sensation, a great taste sensation of olive oil. All right, um, many olive oil makers, and you can look this up on Google, there's a whole scam in the olive oil industry where people who are labeling olive oil are in fact adding other oils to it.

Dr. Rangan Chatterjee 1:03:57 Yeah.

Dr. William Li 1:03:57 It has some olive oil, and they cut it. Um, and so, um, that's not good. You're, you're getting who knows what other kind of olive oils. It's, it's a whole scam. The other, other times, people are mixing different types of olive oils together, sometimes the cheapest ones they can find together to serve it up to you. And so the way to get around that is to look for monovarietal olive, olive oils pressed with only one variety of olives. These are gonna usually be coming from a single farm. All right? It could be a large farm, but a single farm. And this also not only guarantees the quality of the olive oil because it's not gonna be cut with other things.

Dr. Rangan Chatterjee 1:04:36 Mm-hmm.

Dr. William Li 1:04:36 Uh, monovarietal, it's a label. Um, uh, mono one, varietal type of olive. Um, but I look for a monovarietal's olive oils coming from one of three different kinds of olives that you can actually find very easily-

Dr. Rangan Chatterjee 1:04:49 Mm

Dr. William Li 1:04:49 ... in the store. And the reason I look for them is 'cause they have the highest levels of polyphenols of all the olives. All right, so if you like Spanish olive oil, all right, I look for monovarietal Spanish olives made with the type of olive, the variety of olive called picual, P-I-C-U-A-L, picual olives. Fortunately, it's a very common olive in Spain, and fortunately, that olive, you can easily find picual monovarietal olive oil, and it's not that expensive, all right? Uh, if you like Greek olive oil, I love Greek olive oil, um, the, uh, uh, the olives that have highest polyphenols among Greek olives are called koroneiki, K-O-R-O-N-E-I-K-I, koroneiki olives.

Dr. Rangan Chatterjee 1:05:33 Mm.

Dr. William Li 1:05:34 It's come from the Peloponnesus. Fortunately, a very common, uh, olive in Greece, monovarietal, highest polyphenols, taste amazing, great for whatever you're cooking or grilling or salad dressing. And then Italian, if you like Italian olive oils, in Umbria, the highest m- uh, polyphenols have been found in moraiolo olives, M-O-R-O-A-I-L-O, moraiolo olives, which is found in Umbria. It's a less common olive. It's gonna be more expensive, but again, tastes great, highest polyphenols. And so I kinda tell people, "Look, if you're gonna go buy olive oils, why not get the highest quality? It's fuel." And if you're gonna... And, and it's gonna t- you wanna be able to have it taste great if you're gonna use it and dip some bread or whatever it is, sourdough bread or whatever, something healthy i- in it, or you're gonna dribble it on some, uh, uh, some pasta or whatever you're cooking with it. Why not get the best? And why not get the best with the high... not only best taste but also pure-

Dr. Rangan Chatterjee 1:06:34 Yeah

Dr. William Li 1:06:34 ... and also with the highest polyphenols? And that's how I actually choose with olive oil. By the way, some people have reported, I heard this before, that olive oils are not good for your blood vessels. They actually damage the lining of your blood vessels. That's all bunk. I'm a blood vessel expert, and I'm also an expert on food as medicine. We've studied this. It's a theoretical thing that got put together that winds up actually not being true. Well-intentioned people try to put science together, and if not real scientists and they don't know the data, it- it's understandable how they may come up with it, but olive oil is perfectly fine. In fact, it's very healthy for your blood vessels, quite the opposite. Now, how much to eat? You know, there's a lot of studies out there of olive oil. On average, if you take a look at all the studies, the average amount of healthy oil to consume per day is about three to four tablespoons worth of olive oil, okay? That's a fair amount of olive oil if you're not an olive oil consumer, but if you think about the Mediterranean, three to four tablespoons. Go ahead and take a measuring, uh, a, a, a spoon out in your, in your kitchen and t- take out three to four tablespoons and put it into... on a dish. It's not that much. And if you are, um, scrambling your eggs with it, all right, if you like eggs, um, instead of butter, and at lunch if you're making a salad dressing with it- And you're gonna put some salad dressing on. And then at, at dinner, if you're gonna roast some vegetables, uh, or, or grill some vegetables and you're gonna put some olive oil on it, you will easily get three to four, uh, tablespoons of olive oil into your system.

Dr. Rangan Chatterjee 1:08:08 Okay, brilliant. That's super practical. So essentially, a lot of advice there on olive oil. If people are struggling with the cost of things, as many people are these days, is your advice to get the best quality olive oil that you can afford?

Dr. William Li 1:08:25 Yeah, absolutely. And, and by the way, you know, I would say it's, it's a buyer's world out there, particularly because you could buy things on the Internet as well.

Dr. Rangan Chatterjee 1:08:34 Mm-hmm.

Dr. William Li 1:08:34 If you search for, um, monovarietal, uh, Picual or Koroneiki or Moraiola olive oil, and you just let the Internet show you what's the cheapest one, you know, and do a little review to make sure that they're, you know, a good quality manufacturer or supplier. Order it, buy it, you know?

Dr. Rangan Chatterjee 1:08:53 Yeah.

Dr. William Li 1:08:53 Um, that- that's the fastest way to actually get high quality. Listen, people, people spend a lot of money on a lot of different things, right? But then you actually... Again, take a, take a look at your own lifestyle. I can tell you the best investment you can make is getting high quality food for yourself. And in, in, in Europe, it's a lot better than the United States. I mean, people buy junk stuff for food, and they spend their money on things that are unhealthy, um, uh, uh, as well. They get-- They buy cheap, unhealthy things, and they spend money on healthy- unhealthy things. I think food is one-- Getting healthy food, high quality food is one of the best investments you can actually make.

Dr. Rangan Chatterjee 1:09:28 Yeah. Hear, hear. Completely agree. And I think, you know, everyone does have different financial situations and different means, no question. But I think something quite profound happens when you internally, going back to what we were talking about before, about, you know, tuning into yourself, listening to your body's own signals. Like, when you consciously make that decision, not like an opinion, a decision that, you know what, the food I put in my mouth now is of top importance. You know, I made that decision a few years ago. Like, I internalized that, you know, if I'm gonna be the best human being that I can be, the best father, the best husband, the best capable human being as I age, well, the quality of the food I put into my mouth day in, day out is important. It doesn't mean you're never gonna go off track, but there's something really, I think, powerful about when you make that decision. And y- once you make that decision and you live with that decision for a while, you know, other things start to change. So, you know, I love eating out as much as the next person, Dr. Li, but I will say that I've become a lot fussier these days, and I actually prefer eating in. I much prefer eating in because when you really tune into what good quality food tastes like, often when you're out, not always, there are some great restaurants out there and great cafes for sure, I just don't feel that good afterwards a lot of the time when I go out. It could be the oils they're using to fry or whatever it might be. So again, I'm not saying that applies to anyone else, but for me, I much prefer to eat in these days when I can.

Dr. William Li 1:11:13 I, I totally agree. And, and by the way, I think the, the, the companion piece that I add, 'cause I'm like you. I, you know, I sort of, I, I, I try to find what makes me feel good, uh, and, and stick to that. But I also think that, you know, having some self-compassion is an important-

Dr. Rangan Chatterjee 1:11:34 Yeah

Dr. William Li 1:11:34 ... component to that as well. So if you've decided that you're gonna just try to be as healthy as you can, um, don't feel like it's a strict religion or a s- you're not in a military camp where you can-

Dr. Rangan Chatterjee 1:11:47 Yeah

Dr. William Li 1:11:47 ... only do one thing. We're all human. We have to enjoy ourselves. We have to have enough compassion to realize that it's okay every n- every now and then-

Dr. Rangan Chatterjee 1:11:57 Yeah

Dr. William Li 1:11:58 ... to, you know, kind of wander off the path. As long as you get back on the path, you're gonna be just fine. And I try to kind of lower people's stress level-

Dr. Rangan Chatterjee 1:12:05 Yeah

Dr. William Li 1:12:06 ... in trying to live a healthy life by also saying, "You know, look, these are guidelines. Y- you know that they're good for you. You, you should feel, you should feel better when you're doing them. Um, it's up to you to actually take that path." And, and rather than make people feel fear, guilt, shame when it comes to food, I try to give people permission to live a little, you know?

Dr. Rangan Chatterjee 1:12:27 Yeah.

Dr. William Li 1:12:27 Every now and then, you're gonna do something you're gonna really enjoy. Listen, if you spend more time doing things that are good for you, your body's gonna be strong enough to be able to rebound from something occasionally you do that's not so good for you. It's like driving on a road, right? I mean, look, you know the rules. Following the rules of the road are actually gonna help keep you a safe driver so that you're gonna be accident free. But look, who doesn't speed every now and then? And you know speeding can kill you, right? So, but every now and then, you need to get someplace quickly.

Dr. Rangan Chatterjee 1:12:56 Yeah.

Dr. William Li 1:12:56 You're gonna go a little bit faster than the speed limit. It's okay.

Dr. Rangan Chatterjee 1:12:59 Yeah.

Dr. William Li 1:12:59 It's okay. And so I, I kind of try to give people permission to, um, and I encourage them to be self-compassionate and give them permission to feel the liberty to choose-

Dr. Rangan Chatterjee 1:13:09 Yeah

Dr. William Li 1:13:10 ... with the en- with the encouragement to make more good choices more often.

Dr. Rangan Chatterjee 1:13:16 Let's take something like an apple or a carrot. Let's say a carrot, for example. There's all kinds of phytonutrients and beneficial compounds within that carrot. So what happens when we start to peel off the skin off that carrot? Because my view would be, well, a lot of the beneficial properties are in that skin, right? That's what's had to protect itself from the environment, from bugs, as you've just mentioned. So when we are peeling off that skin, yes, people may wanna do it for a taste profile, I understand. But aren't we reducing how beneficial that food could be by taking off the outside?

Dr. William Li 1:14:04 Yeah, I'm glad you described the fact that we might wanna remove the peel for aesthetic purposes, uh, maybe for taste purposes or texture purposes. But the fact of the matter is we know for a fact that skin does actually have good stuff. I'll give you a great example, like in an apple or a pear or a peach. Okay? Um, those are all fruits that, you know, if you took the time to peel it, um, you'll, you'll have a more homogeneous, you know, kind of, uh, looking piece of fruit. But most mothers will tell their kids, "If you eat, if you eat it with the skin, you'll get more stuff," and it's actually true. There's not only more fiber oftentimes in the outer layers, 'cause you're talking about outer, outer layers.

Dr. Rangan Chatterjee 1:14:44 Yeah, yeah.

Dr. William Li 1:14:44 Um, but there's also more, uh, phytonutrients and these bioactives. In apples, in pears, and in peaches, there is actually a substance called ursolic acid that's much more concentrated in the outer layer. And ursolic acid is one of these bioactives that stimulates blood vessel growth. It helps us heal. It stimulates angiogenesis so that if we have an injury, um, our bodies will more, will, will speed its healing up. That's could be really important for our cardiovascular system, for example. It helps to promote the growth of blood vessels in beneficial, uh, sort of ways. Now, that's actually on the peel. So, okay, so how can you eat fruit peel? Well, uh, look, uh, if you had to eat six apricots or six pears, uh, or six peaches, you know, that might take a little work. Or eat six apples, that- that's, that's a pretty commit- that's a good commitment to eat six apples, [laughs] um, uh, even in a day. But on the other hand, if you actually get dried fruit, the dried fruit will take a big fruit and shrink it really small. So take a look at an apricot. I could, I might not be able to, I might not feel like eating six apricots, whole apricots from the tree, but I could easily eat six dried apricots, you know, uh, sort of in a, in a, in a, in a dried fruit mix. And so again, if you want the skin, it's not just, you know, eating the li- the fresh fruit, which you can do, um, but you can also get it in a dried form. Now, back to the fresh for a second. This, this, this would be a good reason to buy organic as well, because, you know, when you spray with pesticides, for fruits and foods with very thin skins-

Dr. Rangan Chatterjee 1:16:18 Mm

Dr. William Li 1:16:18 ... um, I mean, for carrots, you're really, there's not a skin, it's really just an outer kind of layer of the carrot. The, the fact of the matter is, is that, that, um, if there's pesticides in that area, it's very hard to scrub them, uh, off. I learned, by the way, from a food safety expert at the U- US Department of Agriculture who teaches food safety, even for a regular piece of produce, to wash all the potential pathogens, bacteria, listeria, all these other things that could happen, it's recommended that you actually rinse, whether it's organic or not, you rinse it under cold running water for 60 seconds. I did not realize that.

Dr. Rangan Chatterjee 1:16:55 Wow.

Dr. William Li 1:16:55 That, that's been shown. And by the way, another thing I didn't realize is that even, like, an onion you're supposed to rinse off before you actually cut it. Now, I, I, I had previously never really washed my onions. I just figured if I peel off the skin, what's underneath there is pretty clean. But it, and I was told, "No, no, you, you should see the research. You really wanna be able to wash that onion. 60 seconds in cold running water-

Dr. Rangan Chatterjee 1:17:16 Wow

Dr. William Li 1:17:17 ... is what you wanna do." So again, back to the fruit skin. Um, a great reason to buy, good to have, good to eat, nutritious, more phytonutrients, phytochemicals. Um, a good reason to get organic is because it's harder to wash the pesticides off of it. And, and dried f- dried versions of fruits are also ways of actually getting the skin as well, and that's the other reason to get, if you get dried fruit, get dried organic fruit.

Dr. Rangan Chatterjee 1:17:41 Yeah. Super interesting. I'm conscious of time. There's so much I wanna talk to you about. Um, yeah, let's go here.

Dr. Rangan Chatterjee 1:17:49 Autoimmune disease is on the rise massively across the world, frankly, and I'd love to hear a little bit from you about the relationship between foods and the development of autoimmune disease. And I wanna just add there, before you respond, that, you know, I've been practicing now as a medical doctor for almost 21 years, and, you know, maybe 10 years ago as I started to really get tuned into how you might start to use food as a therapeutic tool with your patients, I've noticed that when certain patients with certain autoimmune diseases, like I can remember one clearly, this lady with hypothyroidism. She was on levothyroxine, but she still didn't feel very good at all. When I changed her diet, I helped her change to a completely whole food diet from, like, a standard Western diet that she was at that time consuming, her symptoms went right down. We could halve the dose of levothyroxine I think within a few months. It was really incredible. So maybe, you know, speak to that if you can a little bit about the relationship a- and potentially why that could have worked with that patient.

Dr. William Li 1:19:00 Yeah. I mean, I, you know, so I've noticed this as well, you know, over the, uh, decades of my clinical practice, that autoimmune diseases, which by the way, uh, let's just make sure our audience, uh, uh, the listeners actually, uh, appreciate this, it's not one disease. It is dozens, scores of actually different types of diseases that all share kind of a common denominator that in auto- the autoimmune part of it is that somehow, for some reason, the immune system is triggered in ways that actually the immune response causes, um, harm to your body itself. It's sort of the body attacking the body or the body re- responding, the immune system responding in ways that causes incredible distress at the organ level, right? And so, um, it could be lupus, it could be rheumatoid arthritis, it could be psoriasis, it could be Hashimoto's, it could be celiac. Those are some of the more common ones that people actually talk about. But in fact, there's probably a lot of autoimmune diseases that we don't even recognize yet. And a new one, by the way, which is coming down the pipe, which we believe is long COVID, which many, many people, uh, do have already, and pro- I think we're gonna see a whole other-

Dr. Rangan Chatterjee 1:20:09 Mm-hmm

Dr. William Li 1:20:09 ... emergence of, of long COVID as a significant medical problem, uh, in the coming decade. Uh, that also seems to be autoimmune as well, where the body's immune system has overreacted or is overreacting to attack ourselves, our healthy selves. Okay, so if, if we're talking about a- ... panoply of different diseases that share this common denominator. Um, w- what's the, what's the role of food? Well, one thing that actually we do know, as celiac's a great example of this, gluten sen- gluten, um, enteropathy, is that some foods, in, in the case of celiac it's gluten, which is in wheat, uh, and whole grains. Um, uh, for reasons that we don't fully understand, the body sees that and just has a bad reaction. It's kind of like that, you know, the, the, the family member that, you know, the, the black sheep in a family that comes over for your family holiday gathering, and, like, you just don't have a good reaction to them. Every- We all have, we all have one or two of those people in our families.

Dr. Rangan Chatterjee 1:21:07 [laughs]

Dr. William Li 1:21:07 Um, and that's how your immune system kind of reacts to something in food that it just doesn't like, and it gets pissed off. And when it gets angry, it actually starts to have this reaction that makes the entire body unpleasant, just like that visitor to your home that you just d- don't, don't react well to. Like, you wanna stay in a different room. Well, that reaction is what autoimmune diseases are, and that's why when you talk about, um, you know, the levothyroxine, just to, so your listeners know, like, that's actually trying to replace something that is damaged because of this reaction. You wanna actually see if we can, um, undo the damage a bit, right? And autoimmune diseases are often treated with steroids. What do steroids do? They shut down, they turn down the volume of the immune system. Hey, this rock music is too loud. Let's turn it. The house music's too loud. Let's turn it down a little bit. Okay, so that's what steroids do. It turns out that if you go back, back, back, back to look at what might be some of the root causes, increasingly we're wondering if some of these chemical additives in ultra-processed foods are actually triggering, um, uh, immune responses that are unintended. These are unintended consequences. And so there's a, um, theory that in people who say that they're, they've got gluten, uh, or celiac disease, um, they're actually don't, they don't actually have full-blown celiac disease, but they're al- they're res- reactive, allergic. They're im- immuno, uh, respon- reactive to something that's in packaged food that also has gluten in it. And so, uh, so you're, you're, you're sort of, um... There are things that in these chemical-laced foods that we may not fully appreciate yet. Now it goes back to what your observation with your patient is. So what happens when we take people, and there's many people who spend most of their lives eating things out of a box, right?

Dr. Rangan Chatterjee 1:22:56 Yeah.

Dr. William Li 1:22:56 Out of convenience. Uh, it comes from a factory, sits on the shelf for months or years, and you change it to a whole plant-based diet. Mostly plant-based, or a whole foods diet. Okay, now you're talking about not shopping in the middle aisle of the store. And I have nothing against the middle aisle. There's good treasures in there. But you're spending time in the produce. Or, you know, if you live in a village, you're going to the village market and-

Dr. Rangan Chatterjee 1:23:16 Yeah

Dr. William Li 1:23:16 ... going first to the fruit and vegetable and herb stand. And you're buying all the stuff, and now you're getting fresh foods that have all these phytonutrients. Um, you're having to take the time to prepare them in tasty ways. Um, you're staying away from that, the boxed, canned, preserved, chemically preserved foods. You're allowing your immune system to, to, um, calm, and you're allowing the phytonutrients to also lower inflammation, and we're getting back to a more natural state.

Dr. Rangan Chatterjee 1:23:47 Mm.

Dr. William Li 1:23:47 Like, that's how I, that's how I explain the kind of broad observations that you actually had, is probably allowing, un- unburdening the body, uh, pissing it off less, and allowing the body to actually get back to a more natural state that's, where it's capable of being less inflamed. Allow the health defenses to reassert themselves.

Dr. Rangan Chatterjee 1:24:07 Yeah. I love that explanation. And moving to a whole food diet, no matter who you are, no matter what your current state of health, there's very little side effects, or negative side effects, I should say. There's many effects, [laughs] mostly beneficial effects. Very, very few negative side effects of doing that.

Dr. Rangan Chatterjee 1:24:25 One thing I must ask, uh, Dr. Li, before we end this conversation is, in our first chat you mentioned many foods which have super helpful properties. Two that come to mind are kiwi fruit. You mentioned how they can actually help repair DNA, which is remarkable. The amount of people who've stopped me in the streets since then to say, "Dr. Chatterjee, since that conversation, I've been buying kiwi. I've been buying kiwi." I've heard it over and over again. So that's credit to you, Dr. Li. But also tomatoes you mentioned. I know we covered lycopene in this conversation as well. But many people contacted me, including some family members, to say, "Listen, I don't tolerate kiwis. Like, I get a really bad reaction when I have them. I don't tolerate tomatoes. I get a really bad reaction when I have them." And of course, this is individual, because not everyone has intolerances or reactions to certain foods. But for people who've heard your great advice and wanted to bring those in, but thought, "Well, I can't have that," how would you respond to them? Like, what would you say to them to, to give them some sort of hope?

Dr. William Li 1:25:30 Yeah. Well, look. Uh, what I always tell people is when it comes to food and health, it's not just about the food or any single food, whether it's a kiwi or a tomato. It's really about how our body responds to what we put inside it. So if you, um, uh, don't like kiwis, can't find kiwis, or are allergic to kiwis, all right? Those are three easy reasons. Or can't afford a kiwi. Um, you can do a swap out. Okay? So what's, what is, what are in kiwis? Kiwi's got vitamin C. It's got fiber. What are some other foods that actually have vitamin C that also have fiber? Red bell pepper can actually have that. Um, what if you're like, "Well, I'd like, I'd like something a little sweet"? Okay, guava. That also has vitamin C, and it's also got fiber as well. Now, the research that we discussed last time about the kiwi was research done with kiwi itself. But the properties of the kiwi, which is vitamin C and fiber and some of the other phytonutrients, um, those can be found in other fruits as well. So kiwi, I always say, like, if you wanna kind of stick with the research, you gotta go with the food that was actually studied. But the properties and the principles allow you to actually think about how to swap things out. What are... Tomato. Great example. I don't really like tomatoes. Um, I'm allergic to tomatoes. Some people have hypersensitivities, like a histamine reaction to tomatoes. I have, I, I remember in college, I had a, um, classmate who, um, would never go to the salad bar. She would stay as far away as possible because, um, tomatoes kind of gave her this, um, super histamine mast cell reaction. Her whole face would puff up, uh, when she actually had anything that had tomatoes on it. And, um, um, well, guess what? Lycopene. If you wanna get the lycopene benefits, you know, lowers risk of breast cancer by 20%, lowers risk of prostate cancer by thir- almost 30%, protects your DNA against sunlight. What else is lycopene? Watermelon

Dr. Rangan Chatterjee 1:27:16 Yeah

Dr. William Li 1:27:17 Watermelon has lycopene as well. So maybe you don't like tomatoes, maybe you can't get tomatoes. Well, what about a slice of watermelon?

Dr. Rangan Chatterjee 1:27:22 Yeah.

Dr. William Li 1:27:23 And so again, these swap outs are, are really-- And this is something I think is so important, and, and this is what I hope to be able to convey through my book. And I, you know, I, I created a, a free master class. I've been trying to teach people periodically online, um, how, how to do this, is, is think about why something is beneficial for you, and then if you can get that food, that's perfectly fine. If you need to swap it out 'cause you can't find that food or can't afford that food, think about what else might be a good standard.

Dr. Rangan Chatterjee 1:27:52 Yeah.

Dr. William Li 1:27:53 Right? And at the end of the day, it still has to taste good for you. So maybe you don't like tomatoes, but you like watermelon.

Dr. Rangan Chatterjee 1:27:57 Yeah.

Dr. William Li 1:27:57 Maybe you don't like kiwi, but you actually like guava. I'm a scientist. I study blood vessels. That's where my, my root as a scientist is, by circulation. Uh, and in fact, our blood vessels are remarkable. We've got sixty thousand miles worth of blood vessels packed inside our body. Four hundred of those miles are actually in our brain. So, uh, the-- our circulation is really super important. And as a researcher, I began appreciating that our, uh, this incredible maintenance of the blood-- of our circulation, which are, after all, the highways and byways that deliver the oxygen we breathe and the nutrients that we eat, that these roads, these blood vessels need to be maintained just like, uh, a road, uh, you know, in the countryside. If you don't maintain the road, it's gonna break down over a period of time. And one of the things as a, as a vascular blood vessel researcher, angiogenesis researcher, um, we discovered early on is that stem cells in our body contribute to building and repairing blood vessels. So that was sort of-

Dr. Rangan Chatterjee 1:28:59 Hmm

Dr. William Li 1:29:00 ... how I became interested in, and, and quite familiar and, and actually worked on stem cell research in the lab. Um, we, we actually discovered many chemical substances that can stimulate stem cells to help do their repair. And so when I began studying food as medicine, one of the things that, uh, it was remarkable to discover is that some of the synthetic chemicals that you could order from a, a research shop could actually stimulate stem cells. But then it was really jaw-dropping to me. In fact, one of the most, um, light bulb going off moments that I had as a food as medicine researcher to discover that natural substances in our food can similarly activate our stem cells and call them into action. And without necessarily putting out a distress call, we can just gently coax our body's own reserve into action to help repair ourselves in a more robust way.

Dr. Rangan Chatterjee 1:30:03 So which are some of the top foods that we can choose to put inside our mouths that are going to do this?

Dr. William Li 1:30:11 Yeah. Okay. So first of all, this is-- we're at the beginning of, you know, a new era looking at regenerative foods, foods that can stimulate regeneration. So I don't have like the, uh, wrapped gift box to give you of a laundry list of all the foods known to man.

Dr. Rangan Chatterjee 1:30:28 Mm-hmm.

Dr. William Li 1:30:28 We're still doing research on this, but I'll tell you-- I'll give you some examples because, um... And when I talk, by the way, uh, Rangan, I, I really refer, uh, uh, to both laboratory, but also to human evidence, which I think is really important.

Dr. Rangan Chatterjee 1:30:41 Hmm.

Dr. William Li 1:30:42 You know, something we see in the lab is interesting, and they can let you raise an idea. But at the end of the-- at the end of the day, it's whether or not it works in people that makes all the difference in the world. So I'm gonna kind of, um, flip back and forth a little bit, but always emphasize what we know in people. So first of all, um, you might, uh, not be surprised that the source of stem cell activating, uh, substances are plant-based foods. Mother Nature's sort of, uh, uh, uh, uh, medicine cabinet are fruits and vegetables, nuts and legumes, and healthy oils and seeds, you know, omega-- sources of omega-3s. Um, uh, so, uh, researchers have been actually mining the same, uh, uh, pharmacopoeia, uh, pharm with an F, not a PH, um, looking at what substances are in nature that can stimulate stem cells. So I'll give you an example. We know that there's a, uh, a, a natural bioactive, a natural chemical found in plants called ursolic acid, okay? That's U-R-S-O-L-I-C, ursolic acid. It's found in fruit peel, right? The peel of an apple, the peel of a pear, uh, the peel of, uh, uh cranberries, a peel of bl- a peel of blueberries, right? These are fruit peels. And most likely, if you have eaten an apple, you're not-- I mean, unless you were a kid and, and your grandmother peeled the apple for you [chuckles] , you just take an apple and clean it, and then just eat the whole thing, right? The peel's got good source of dietary fiber and ursolic acid. Ursolic acid has been shown to stimulate stem cells to come out of the bone marrow and help to stimulate regeneration and to repair blood vessels, for example. Quite amazing.

Dr. Rangan Chatterjee 1:32:26 Hmm.

Dr. William Li 1:32:27 All right? That's an example. Um, there's another substance that has been discovered called beta-D-glucan. Now, this is a soluble fiber, which we know is good for gut health. Um, and it does a lot of other interesting things too that are beneficial for the body. But beta-glucan has been discovered to stimulate stem cells. Now, where do you get beta-glucan? You can find them in, uh, mushrooms. Both the cap and the stipe, the stem of the mushroom, has beta-glucan. In fact, the, the, the stem of the mushroom has twice as much beta-glucan as the cap of the mushroom.

Dr. Rangan Chatterjee 1:32:58 Hmm.

Dr. William Li 1:32:58 So I always tell people, if you're actually preparing food, um, and you know, you're, you're preparing, you're cooking mushrooms, please don't throw the stems away because they have a lot of goodness to them. Um, uh, you can utilize them. It's sustainable cooking. Keep all the food parts and use them, and they're good for you. Um, oats also has beta-D-glucan. You know, if you're actually having, um, steel-cut oats for breakfast, for example, uh, uh, is another source of beta, uh, glucan. And barley. Now, barley has actually been studied, uh, with beta-glucan- To look at stimulating the stem cells that can regenerate your circulation, that can help to repair and grow new blood vessels where they're needed, and this is exactly in my wheelhouse, to study circulation. So we took this even further to look at the role of other foods that can stimulate stem cells, and one of them is dark chocolate. Dark chocolate has a very particular benefit because first of all, chocolate is a confection. It's a candy. It's made, you know, uh, it's crafted to be sweet and delicious, and most people like dark chocolate, but it is... contains a plant-based, uh, food ingredient, and that's cacao. Cacao comes from a tropical tree where the seed pod of the cacao is, is shaped like an American football. It can be bright yellow. It could be brown. If you pick one up, it's kinda heavy. You shake it, and you can feel the heavy chestnut-like seeds shaking around. And that, that, those seeds are the ones that are, um, uh, dried, fermented, ground into a powder, and used, uh, by percent to actually make chocolate. So if you have a 50%, uh, cacao chocolate, it's got half of the cacao. If you got 80%, it's got a lot more, 90%, et cetera. Well, what's-- research that's been done shown that 80% or higher cacao puts enough of a natural plant-based bioactive called proanthocyanidin into your bloodstream, so this has been measured, and in, in the clinic, if you actually give people who have, let's say, coronary artery disease, so they've got narrowing of their blood vessels and stiff, hard blood vessels, all right? So these are, these are not, these are not people at their optimal state of health. If you, um, measure their stem cells and then, then see how many stem cells are floating around in their blood, which is not many, and then you were to actually, um, do a simple test called flow-mediated dilation, FMD, um, to check how resilient their blood vessels are. Basically, it's a blood, blood pressure cuff. You blow it up, and you put an ultrasound, uh, in your, uh, uh, in the crook of your arm, and then you let the blood pressure, uh, cuff, uh, deflate quickly. You see what happens to your-- how well your, uh, circulation, your blood vessels recover from compression from the cuff. That's a reflection of vascular blood vessel circulatory health. If you do that at baseline to see, um, how well, uh, the blood vessels in these people are doing, not that well. Then, uh, researchers have given them two cups of dark chocolate in the form of hot, hot chocolate. That's it, two cups, uh, to have a day for thirty days, and at the end of thirty days, you measure-- take out your blood and measure the stem cells again, and then do that flow-mediated dilation resiliency test again of the blood vessels to see have they changed. This is what's amazing that's been found, that dark chocolate, the an- proanthocyanidins, not only got into the bloodstream, but they doubled the number of stem cells circulating in your blood vessels, and they doubled the resiliency, improved, uh, the, by, by twofold, the resiliency of your blood vessels just over the course of a month with as little as two cups of hot chocolate that's dark.

Dr. Rangan Chatterjee 1:37:02 Wow. That, that, that's a really interesting point, what you said there at the end there. The quality matters, doesn't it? Because you could get, I guess, a hot chocolate powder from the supermarket which was full of additives and full of sugar and has a very low concentration of cacao, or you could get a completely different one, which is, you know, a lot of, you know, minimal ingredients, uh, high levels of cacao, as you say, eighty percent plus. That's the nuance I think sometimes that we're missing, aren't we, when we talk about food? Hot chocolate is not just hot chocolate. It depends on the-

Dr. William Li 1:37:41 Right

Dr. Rangan Chatterjee 1:37:41 ... quality, right?

Dr. William Li 1:37:43 That's right, and the stuff that you get in a packet at the grocery store that's inexpensive and, and it might taste really great. It, it might be the stuff that we had when we were kids. I, I know I did. Um, if you now take a look at the ingredient label-- I tell people anytime you're buying anything that's prepackaged, please take a look at the ingredient label before you put it in your grocery cart, because if you start seeing the added sugar and then the emulsifiers and all the artificial chemicals and preservatives and the stabilizers, that's probably not something that you want to actually put in your body. And if it, if the ingredient label creeps you out, put it back and just look for another choice that, as you say, has minimal numbers of ingredients, or even better yet, I mean, and I, I say this to people who are really committed to using a natural way to improve their health, put it together yourself. I mean, you can even make it without dairy, which is really interesting, without any type of, of, um, milk product at all. Uh, uh, you can make yourself a really tasty, um, uh, uh, super dark chocolate, and in fact, a lot of people don't know this, but the history of cacao and chocolate goes all the way back to the Aztec civ- civilization, where at some point, they actually considered, um, chocolate was used as currency. It was so valuable, and at a certain point of time, it was used for its medicinal and ceremonial value. And so this is why, you know, like we go, you know, you're ta-taking a trip in an airport, and you're passing by the, uh, uh, the, the newsstand and, you know, it's so tempting to buy a bottle of water and get a chocolate. The, the, you know, the, the, the healthful chocolate we're talking about is really paying attention-

Dr. Rangan Chatterjee 1:39:24 Yeah

Dr. William Li 1:39:24 ... to the details of the quality of what you're actually gonna put into your body, because that's gonna influence how your body responds to it.

Dr. Rangan Chatterjee 1:39:31 Yeah, it's really fascinating. I was reflecting with a friend over the summer on how certain things, let's say cacao, let's even say alcohol as well, were often used in traditional cultures in very different ways to the way we consume them today, or they're often consumed today. You know, it was ritualistic, ceremonial. Cacao probably, from what I understand, wasn't used daily. It was now and again for celebration, for ritual, and I think the same thing also from what I understand with alcohol. Yet we love to take those things and then shove them in every day now, and it ... I, I, I feel that we do that with lots of things. We change the way we consume them compared to how we have done so traditionally.

Dr. William Li 1:40:18 Absolutely, because if you think about, uh, uh, the way that we approach, uh, the, the, the foods around us, uh, today, uh, so often it's really ... The food is treated as a commodity.

Dr. Rangan Chatterjee 1:40:32 Mm.

Dr. William Li 1:40:33 You know, we, we have this consumer mentality where we just go out to look for the cheapest, most convenient, most tasty thing, so influenced by advertising, and we've gotten further and further away from what I think is absolutely central to our humanity when it comes to food, which is to have some appreciation, uh, of our food, to, to really savor our food, respect our food. A- and frankly, you know, if you take a look at some of the broader planetary concerns in terms of how we grow our food, how we treat the land that our food's grown on, how we, you know, uh, how we farm our food, all of those implications, uh, uh, th- of the degradation-

Dr. Rangan Chatterjee 1:41:13 Hmm

Dr. William Li 1:41:14 ... uh, of the food system comes from the fact that, you know, we, we don't respect it so much anymore and [laughs] so we're just stripping away the land. We're getting the cheapest food possible, the fastest possible. We're packaging it into things that are not very costly, put colors on them-

Dr. Rangan Chatterjee 1:41:28 Mm-hmm

Dr. William Li 1:41:28 ... you know, cheap things to attract. You know, sort of like the clickbait, uh, idea of, uh, of, uh, of our, of nutrition and, and our food. I think it takes us further away from our humanity, and I'm, I'm bringing that up because, you know, as you're talking about tradition and ritual, uh, and ceremonial, I think one of the things that we're beginning to perhaps appreciate as things are becoming so distressed around the world is that, you know, there's a, there is really great value and calming value to be able to be more appreciative to the things that we do have and to respect when it comes to food-

Dr. Rangan Chatterjee 1:42:08 Mm

Dr. William Li 1:42:08 ... to really start thinking of our food in a different way, including where it comes from and how it's handled, and then ultimately how we're preparing it and putting it into our body. It's a, it is a continuum that pays off when it comes to our health.

Dr. Rangan Chatterjee 1:42:22 Yeah, for sure. Thank you for sharing that. Now, Dr. Li, so far the foods we've mentioned in relation to stem cells I think are ursolic acid, which you can get in fruit peels. You mentioned beta-D-glucan, which you can get in mushrooms and oats and barley. You, you've also mentioned about cacao and dark chocolate and how beneficial that can be.

Dr. Rangan Chatterjee 1:42:46 One thing I've always noticed with your approach, you make food something that I think excites people. You talk about all these different foods and all these different pathways and how we can, you know, be active participants in our health by choosing foods that are gonna activate all these incredible pathways. How do you square that alongside the fact that many people these days eat an excess of calories? If someone hears what you're saying, and they're already eating an excess of calories, and they start adding in, uh, dark chocolates, um, hot chocolates, um, oats, barley, right? H- how do you help people tease through that? Because obviously an, a calorie excess is problematic for health even if you are adding in some of these powerful foods.

Dr. William Li 1:43:42 Yeah, no, I mean, th- this is a great topic of discussion. I'm very passionate about this idea of not overeating, not overconsuming, okay? 'Cause we're, we're, you know, we're here, we're talking about, uh, how we have gotten further and further away from traditions and rituals and, and, and mindfulness. Uh, look, uh, overconsumption is a relatively recent phenomenon, let's say within the last 70, 80 years, uh, within the last 100 years for sure, um, uh, of modern society. You know, because if you go further back than that, most people were, most people were still scrabbling around-

Dr. Rangan Chatterjee 1:44:24 Mm

Dr. William Li 1:44:24 ... to actually get enough food.

Dr. Rangan Chatterjee 1:44:25 Yeah.

Dr. William Li 1:44:25 They were hungry most of the time, all right? It's only really in our modern day and age and, you know, sort of post-World War II where, uh, relative prosperity, especially in modern countries, developed countries, actually allowed us to essentially, um, overconsume, uh, food f- on a regular basis. And so I wanna talk about metabolism for a moment-

Dr. Rangan Chatterjee 1:44:48 Sure

Dr. William Li 1:44:48 ... because this is actually where this squares away with healthy eating, uh, and, and overeating. Okay, so, uh, I w- I want people to think about, uh, uh, metabolism, which has to do with weight gain, which has to do with obesity, which has to do with, uh, uh, diabetes and metabolic diseases and, and other chronic diseases ranging from cardiovascular disease to cancer to dementia. So it's all connected together. Um, uh, uh, our metabolic health is maintained by our body like a machine, and in fact it's like the operating ... Our, our metabolism is like the operating system on your computer, like on your laptop. And, you know, there's all these myths about metabolism, and one of the myths is that- Uh, our metabolism is just the roll of the dice. We get it from our parents. We- we're, we're born with whatever metabolism we're, we're, we're b- born with, and that's actually not correct. Um, you know, people-- How, how many people have heard, "Oh, my sister was so lucky. She was born with a fast metabolism. She's skinny as a stick, and she can eat anything." Um, me, I've actually was born with a slow metabolism. I've had to fight with food my whole life-

Dr. Rangan Chatterjee 1:46:01 Mm

Dr. William Li 1:46:02 ... and I've had trouble with my weight. That's not me, but I'm, I'm saying what, what people have-- what I hear people saying. And it's just the luck of the draw, so therefore, they give up and they say, you know, "This is my fate. Wasn't my fault. I was born-- I, I, I drew the short end of the stick." No, it's not true. What... You know, if, if we are born and our kidneys work the same and our eyesight works the same and our nerves work the same, what makes you think that metabolism in the human body is a crapshoot and just, uh, and it's, it's, it's, it's ramshackle and just a game of chance, um, who gets a fast or slow metabolism? No. Our metabolism is an operating system the same as in your laptop. And, uh, Rangan, if you went to buy the same model of laptop I have-

Dr. Rangan Chatterjee 1:46:46 Mm-hmm

Dr. William Li 1:46:46 ... we bought them from the same store at the same time, you and where you live and me where I live, and we plug it in, charge it up, and then hit the button at the same time, boot it up, the operating system of your laptop where you live and where I live, it's gonna be exactly the same out of the box. So the human metabolism is hardwired in our body to operate exactly the same way. I-

Dr. Rangan Chatterjee 1:47:08 Mm.

Dr. William Li 1:47:08 And I'm telling you this because it's very important to think about the consequences of abusing our metabolism over a period of time.

Dr. Rangan Chatterjee 1:47:17 Mm-hmm.

Dr. William Li 1:47:18 All right? And when you abuse your metabolism, uh, you can actually slow it down. You can actually cause problems with your metabolism. You could derail your metabolism, and overconsumption of calories is one of the things that you can do to, uh, to abuse your metabolism. So think about it. You, Rangan, are, are, um, uh, uh, take exceptional care of your laptop. You know, you, uh, have it in a case. You clean it afterwards. You shut it off at night. Um, you use an antivirus program to make sure, you know, you make sure you don't-

Dr. Rangan Chatterjee 1:47:47 Mm

Dr. William Li 1:47:47 ... uh, have malware on it, viruses on it. Okay. Me, I'm, I'm not so careful. I, I travel with it. Sometime it gets dropped. I just clo-- I, I shove it-- I just throw the laptop in the back of my car. Um, oops, I spill coffee on it every now and then, water. I mop it up, and I, and I never turn it off, and, and I'm downloading stuff all the time off the internet, okay? Now, what do you think is gonna happen to that same operating system-

Dr. Rangan Chatterjee 1:48:12 Yeah

Dr. William Li 1:48:12 ... in your laptop versus my laptop? Yours is gonna be functioning a lot better than mine. And if you think about taking in calories, when you overconsume calories, among other things that you can do, uh, uh, what that does is that puts a stress on your metabolism, uh, and if you overload your metabolism by eating more calories. Now, calories are basically-- Look, food is, food is our fuel. We call-- And our fuel, just like in your car, uh, uh, is something that we absolutely need, so you need calories.

Dr. Rangan Chatterjee 1:48:44 Mm.

Dr. William Li 1:48:44 Food is our fuel, and in our body, we, we call it calories, all right?

Dr. Rangan Chatterjee 1:48:48 Mm.

Dr. William Li 1:48:48 So this is the similar way, and we l-- and just like you're filling up your car with fuel, uh, we fill up our bodies with fuel, uh, by the, with the food that we eat. If you overload the fuel in your car, what's gonna happen? I mean, usually the gas station, the petrol station has a clicker to prevent you from overloading your gas tank. In the body, we don't have s- we h- we do not have that clicker, so we can easily overload, overflow our gas, uh, our own bodies' co- fuel tanks.

Dr. Rangan Chatterjee 1:49:19 Yeah.

Dr. William Li 1:49:19 Fuel tanks are fat. When you overload your fat, okay, you're gonna keep on filling up fat and filling up more fat. You need more fat. Our stem cells will create more fat, more fuel tanks, and you keep on eating, you keep on overloading. That caloric load, overload, puts a stress on our metabolism, all right? And that then starts to derail our health. And so I don't care if you eat, and, uh, uh, eating healthy food or junk food. Now, obviously, just like petrol, fuel that you put in your car, if you care about your car, if you're very conscientious about the, uh, about the, the longevity of your car, the, the health of your car, your automobile, all right, uh, uh, you are going to actually try to choose higher quality fuel to put in it.

Dr. Rangan Chatterjee 1:50:07 Mm.

Dr. William Li 1:50:07 Put some crummy fuel in it once in a while, once, once or twice, no problem. Your car's not-- It'll survive it. You put crummy fuel in your car, low quality fuel, the cheapest fuel in your car every single day, I guarantee you your car is not gonna last as somebody who's as w- as long as somebody who's, who takes really good care of a car and put good quality fuel. So the quality of the fuel, the quality of the food matters for the engine of our body.

Dr. Rangan Chatterjee 1:50:32 Mm.

Dr. William Li 1:50:33 Okay? Um, and if you overload fuel in our body, you overload our metabolism, and it doesn't matter whether you actually have good quality fuel or bad quality fuel. Overloading is not good. But whatever fuel you have, you would prefer to have good quality fuel. So this is back, go back to your point of overconsumption. I always tell people, you know, who are struggling with, "Okay, there's so much information out there, uh, Dr. Li. How do I get started?" And the first thing I say is that, you know, take stock with the quality of the food that you eat. What quality fuel are you loading into your, the, the, the vehicle of your body? And, you know, if they take a food diary, record, you know, for a few days or a week everything they eat-

Dr. Rangan Chatterjee 1:51:19 Mm

Dr. William Li 1:51:20 ... then they can read it and say, "Oh man, you know, this isn't so good. I shouldn't be eating this." Or-- And sometimes people surprise themselves. "You know, actually, I, I eat pretty well on average." Um, but they can identify some of the low quality fuel items that they actually are putting in. Then I ask them to say, "How much do you actually eat?" Now, this is a trickier question because most people overeat. You know? And I, we're trained to, or almost trained to overeat. And so if you are, uh, uh, loading your own plate, uh, uh, I always tell people, take only two-thirds of what you would normally take. So if you're, if you're, if you're serving yourself at dinner, uh, from the, the, the platter, whatever you would normally take, as a f- just have an instinct to say, "Nope, I'm just gonna take... I'm gonna leave a third of it back in the platter."

Dr. Rangan Chatterjee 1:52:13 Mm-hmm.

Dr. William Li 1:52:13 "I'm gonna take only two-thirds and put it on my plate." All right? I always say load the vegetables on first.

Dr. Rangan Chatterjee 1:52:18 Yeah.

Dr. William Li 1:52:19 Uh, then take, uh, then take only the, ta- then remove a third of it as a start. All right? Then I always say, uh, uh, if you are f- if you... And eat slowly, and if you're feeling full, stop eating. You don't have to clean your plate. It's okay if you don't clear, clear everything on your plate. That's a good health habit. And then I always tell people, uh, try not to snack after dinner, because snacking after dinner is another opportunity to actually overload your-

Dr. Rangan Chatterjee 1:52:48 Yeah

Dr. William Li 1:52:49 ... uh, your body. And so these are all little tips that I think people always try to get into like, "So how do I do this? Like, I, I wanna choose good healthy food, but it's more than that. I, I can't, I don't wanna overeat the food. How do I start?" So I, I give people these sort of like, uh, little easy tips of how to, how to take those first steps in their health journey.

Dr. Rangan Chatterjee 1:53:11 Yeah. I really appreciate that. It's really, really useful because you, you mentioned quite a few things there that are, are worthy of conversation, I think. One was about the wealth of information that now exists for people, the overload of information, even good quality information. It's a bit like the overload of good quality healthy food. If you are, you know, overeating lots of healthy foods, and you know, that analogy with the car is a, is a really nice one because as you say, you can't really overload your car fuel tank 'cause there is a, a stopper. It, it just won't allow you to do it. But just imagine that wasn't there. If you start spraying petrol all over the internal workings of your car, even if it was premium fuel-

Dr. William Li 1:53:59 Yeah

Dr. Rangan Chatterjee 1:53:59 ... well, it's a little bit like when we have visceral fat accumulating in our body, isn't it? You know, this harmful fat certainly beyond a certain point where it's starting to send out inflammation and damage those organs and increase our risk of early death and disease.

Dr. Rangan Chatterjee 1:54:13 So I think it's a really, I think it's a great analogy. I wanna talk about this era of information overload because I think people can consume all kinds of information now. They can read books, they can watch your YouTube channel or my YouTube channel, and they can get all this information. Yet I still think with all this information, so many people are confused, and they go, "Well, yeah, Dr. Li, you're saying this. Someone else is saying this. Someone else I, I followed online is saying this." And my feeling, and I'd love to know your perspective on this, is that, yes, we wanna listen to experts. We wanna get their advice and hear about the science and the research, but then we also have to then go inwards and go, "Okay, which bit of this advice works for us? I heard Dr. Li say this. I heard Dr. Chatterjee say this. I heard Dr. Whoever else say this. But actually, you know what? When I eat like that, that's when I feel good." And I feel we're missing that these days. We, we've outsourced our inner expertise about our own bodies far too much to external experts, and I think that is a massive problem these days that we're not talking about enough.

Dr. William Li 1:55:27 Yeah, no. Uh, our own health is incredibly personal. What makes me feel good when I make a food decision, when I sit down to make a meal or, or even how I prepare a meal, for example, or if I sit at a restaurant, uh, where, where I naturally kind of gravitate in terms of ordering food, that's very personal to me. And how I feel about, uh, uh, how I eat and how much I eat and when I eat, these are all, uh, very important factors for health, but, uh, uh, uh, but how it works for me is gonna be different than how it works for you-

Dr. Rangan Chatterjee 1:55:59 Mm-hmm

Dr. William Li 1:55:59 ... for example, or, or anybody who's listening. So knowing thyself, like self-knowledge is true knowledge. Every individual needs to reckon and recognize their own self-knowledge, as well of, of self-knowledge, self-limitation, uh, in order to be able to actually advance. And, and you're right. We spend so much time externally consuming information and not enough time, uh, contemplating how we, what makes us tick, how are we actually doing it. You know, there are, uh... Taking a walk is a solo a- can be a solo activity that allows you to exercise and be in motion. But if you do it by yourself, I mean, some people like to walk with others-

Dr. Rangan Chatterjee 1:56:45 Mm

Dr. William Li 1:56:45 ... but if you do it by yourself, it's an opportunity to actually calm your mind from other people and think-

Dr. Rangan Chatterjee 1:56:52 Mm-hmm

Dr. William Li 1:56:52 ... about yourself.

Dr. Rangan Chatterjee 1:56:53 Yeah.

Dr. William Li 1:56:53 If you meditate, it's another way to actually... Um, and, and practice breathing exercise, it's another way to actually center yourself. And I think that, you know, one of the things, even though we talk about healthy foods and we talk about exercise, all these-- We give a lot of recommendations, right? And I wanna talk about the information overload sources in, in just one second. But, you know, we give a lot of advice, recommendations because part of our mission, your mission and mine, is to get useful information out to people. But, you know, that's still an external thing-

Dr. Rangan Chatterjee 1:57:24 Yeah

Dr. William Li 1:57:24 ... to somebody listening to us. What's really important, e-equally important, is that, uh, anybody who wants to pursue better health, take the time to really get to know, uh, uh, how they feel, uh, when they're healthy and how they feel when they're not feeling so healthy, and how individual moves make them feel-

Dr. Rangan Chatterjee 1:57:49 Mm

Dr. William Li 1:57:49 ... to, to find out what their own path is. Everyone's got their own path. A-And by the way I, I would, I would say this again, I mentioned it briefly, personalized medicine is where all medicine is going.

Dr. Rangan Chatterjee 1:58:00 Yeah.

Dr. William Li 1:58:00 So I don't care if you're in oncology and cancer-- treating cancer, cardiology, treating, you know, blockages of your blood vessels in your heart. The bottom line is that we're all realizing one size doesn't fit all.

Dr. Rangan Chatterjee 1:58:10 Yeah.

Dr. William Li 1:58:11 All right? And every individual's going to be different and respond differently to the same treatment that we might... Listen, medicine, when, when you were training and I was training, I'm, I'm sure we had some very, very common patterns and themes. One of the themes is that you take an antibiotic, you say-- get right the same dose, and you treat for the same number of days, and you're done. It's like a cookbook that's just supposed to work the same way for everyone, and it's just not so. It's not true in medicine, it's not true in nutrition, and it's not true in exercise either.

Dr. Rangan Chatterjee 1:58:40 Yeah.

Dr. William Li 1:58:40 And so I think that this whole idea of personalization, uh, having, uh, individuals know themselves is absolutely vital.

Dr. Rangan Chatterjee 1:58:49 Yeah.

Dr. William Li 1:58:49 Vital to-- as a, as a, as a start. And then I wanna say just one more thing about this whole information overload. You know, this is true for children, uh, who are consuming, uh, uh, information, uh, uh, in a very particular way, right? So typical kid in high school is-- or junior high school or maybe even younger, is on their phone scrolling all day long. They're watching TikTok, they're watching-- looking at various things, they're communicating with, in, with Snapchat and quick, you know, communication. It's, it's very externally focused, and it's consumptive. There's an algorithm that, that feeds you more of what you seem to be enjoying seeing or looking at longer.

Dr. Rangan Chatterjee 1:59:31 Mm-hmm.

Dr. William Li 1:59:31 But that doesn't actually help you get to know yourself.

Dr. Rangan Chatterjee 1:59:34 Yeah.

Dr. William Li 1:59:34 And, uh, and it, it also, uh, doesn't force you to consider the source of your information. I think another really, uh, important thing for anybody who is interested in health information from experts is first, try not to listen to everybody and everything. You know, try to pick a few people who, um, are trusted voices. It's up to you to decide how you connect to them. One of the big challenges I think of the online community, whether it's YouTube or, uh, Instagram or these other media platforms, is that anybody can actually deliver information. And any-- And, and, and I think that one of the things that I believe is that people who are trained in health and who do research and who are very careful in their communication and how-- what they're actually projecting, um, uh, because words matter.

Dr. Rangan Chatterjee 2:00:36 Yeah.

Dr. William Li 2:00:36 I think that that's really important, uh, from a, from a source perspective, so you can actually narrow yourself down. Um, you know, pick two or three people that you feel you resonate with, you like their voice, but, but do check into their backgrounds to see if you think that that person should be a trusted resource.

Dr. Rangan Chatterjee 2:00:55 Yeah.

Dr. William Li 2:00:55 Um, so you're not getting, uh, wild ideas that may not actually be correct.

Dr. Rangan Chatterjee 2:01:01 If you enjoyed that conversation about the foods to stop eating, I think you are really going to enjoy this one that's all about inflammation.

Dr. William Li 2:01:08 Chronic inappropriate inflammation is at the root of a lot of our cancer, coronary artery disease, obesity, type II diabetes, hypertension, and so forth