Joe Rogan Experience #1175 - Chris Kresser & Dr. Joel Kahn

1. 0:00 – 15:00

   Five, four, three, two,…

   1. JRJoe Rogan0:02

      Five, four, three, two, one. (claps) Gentlemen, thank you very much for being here. I really appreciate it. Dr. Kahn, uh, before we get started, why don't you tell everybody what your background is. Uh, you will be representing the vegan portion of this discussion. Uh, tell people about yourself a little bit.

   2. JKDr. Joel Kahn0:22

      Thank you. I feel like the head broccoli in the United States today. But I am from Motown, Motor City, badass. Uh, born and raised University of Michigan School of Medicine, summa cum laude, internal medicine training, cardiology training in Dallas, Texas. Very hard to be vegan in Dallas, but I did it in the '80s, because I've been doing this 42-year vegan.

   3. JRJoe Rogan0:41

      42 years?

   4. JKDr. Joel Kahn0:42

      42-year vegan, thank you.

   5. JRJoe Rogan0:43

      That's impressive.

   6. JKDr. Joel Kahn0:44

      Age 18. And then, uh, Kansas City, Missouri, another tough town to eat plants in, only the steakhouse, KC Masterpiece. Did, uh, training in stenting. I was blasting open heart attacks from 1990 on. Came back to Michigan, very active cath lab, heart attack, you're dead, I bring you back practice, 24 hours a day with great partners. And about three to four years ago, I used all these decades of plant-based medicine I've been basically bringing my family up with and teaching patients, but opened a completely preventive cardiology practice. And along the way with my wife and son, we now own three plant-based restaurants, two in Detroit, one in Austin, Texas. Write books, do TV, write blogs, teach, teach, teach. Not gonna stop till I'm 150.

   7. JRJoe Rogan1:29

      And-

   8. JKDr. Joel Kahn1:29

      Because there's a lot of erectile dysfunction to stamp out. That's my passion.

   9. JRJoe Rogan1:33

      That?

   10. JKDr. Joel Kahn1:34

       Oh my God, what else? What better purpose in life?

   11. JRJoe Rogan1:37

       Um, well, okay, we can get to that later.

   12. JKDr. Joel Kahn1:40

       Heart, heart, heart, heart dise-

   13. JRJoe Rogan1:41

       (laughs)

   14. JKDr. Joel Kahn1:41

       Heart disease is somewhere in that mix too.

   15. JRJoe Rogan1:43

       Okay, and, uh, if people want to read more about you, website is?

   16. JKDr. Joel Kahn1:48

       Yeah, uh, D-R-J-O-E-L K-A-H-N, drjoelkahn.com.

   17. JRJoe Rogan1:53

       And you've written a ton of books, right? How many books?

   18. JKDr. Joel Kahn1:55

       Five books.

   19. JRJoe Rogan1:55

       Five books.

   20. JKDr. Joel Kahn1:56

       And a bunch of medical papers.

   21. JRJoe Rogan1:57

       Okay.

   22. JKDr. Joel Kahn1:57

       And a whole lot of blogs.

   23. JRJoe Rogan1:58

       Awesome. And Chris?

   24. CKChris Kresser2:01

       Yeah, Chris Kresser. Um, I did my undergrad at UC Berkeley, and, um, then got a Master's of Science and, um, Co-Director of the California Center for Functional Medicine, which is a functional medicine clinic in, in here in California, up in Berkeley. And, uh, I came to this from my own experience with chronic illness. I- as, as you know, Joe, got really sick, uh, back in my early 20s when I was traveling around the world, and, uh, you know, conventional medicine didn't have much to offer for me. And so, that led me on a path of trying to figure out the best approach from a diet and behavior and lifestyle perspective to heal from my own chronic illness, and then that evolved into, um, me starting to write, you know, I started a blog and a website. And then, um, wrote a couple of books and now have, uh, an organization that trains practitioners in functional medicine and also trains health coaches.

   25. JRJoe Rogan3:00

       And you, at one point in time, were vegan?

   26. CKChris Kresser3:03

       I was a macrobiotic vegan. I was apprenticing with a macrobiotic, uh, chef. So, uh ...

   27. JRJoe Rogan3:09

       What's the difference between a macrobiotic vegan, for folks, and a regular vegan?

   28. CKChris Kresser3:13

       Uh, it, macrobiotic is a particular philosophy, it's a particular approach that came from Japan, and, um, it's vegan, but it's, it's, you know, it's, it's heavily influenced by Japanese, uh, tradition and cuisine, and it has some kind of different beliefs than a, a typical vegan approach. So I was, uh, when I was originally studying Chinese medicine, I was working and, and apprenticing with a macrobiotic vegan chef, and we were going around cooking for people who were really ill, often people with cancer who were following a macrobiotic diet. And before that, I had been a vegetarian for quite a while as well. Wh- when I was traveling around the world and got sick, actually, I was, I was a vegetarian at that point too.

   29. JRJoe Rogan3:55

       And you discovered through your own personal ... What are you doing over there, buddy? (laughs)

   30. JKDr. Joel Kahn4:01

       (laughs)
2. 15:00 – 30:00

   So this is an…

   1. CKChris Kresser15:00

      who are overweight and obese. So if you... If calories are that much under-reported, all nutrition comes through calories. Everything we get, fat, protein, carbohydrates, micronutrients, they all come through calories. So if, if calories are that under-reported, that completely invalidates the data set.

   2. JRJoe Rogan15:18

      So this is an obesity study, so they're, they're under-reported because of shame?

   3. CKChris Kresser15:21

      It's not an obesity study.

   4. JRJoe Rogan15:22

      Oh.

   5. CKChris Kresser15:22

      It's just every... Americans are overweight and obese.

   6. JRJoe Rogan15:26

      Right. Yeah.

   7. CKChris Kresser15:26

      The majority of Americans are overweight and obese, so in any data set of Americans, you're gonna have the majority of them overweight or over obese, so, or, or, or obese. So that's the first problem. The second problem is a healthy user bias, which I know we talked about before. But it's basically the idea that because, you know, when someone engages in an unhealthy and a behavior that's perceived as unhealthy, they are more likely to engage in other behaviors that are perceived as unhealthy and vice versa. So let's say you do a study of people who ate, eat more red meat. Well, red meat has been perceived as unhealthy for a long time. And so what we know is that in those observational studies, the people who eat more red meat are also smoking more, they have higher body mass index, they're eating less, fewer fruits and vegetables, they have a lower level of education, they're less physically active. So how do you know that it's the red meat that's causing the problem and not those other things? You don't, because they cannot control for all of those potential confounding factors. The third problem with observational research, and maybe the biggest, is that the, the, the relative risks in nutrition are so low that they're indistinguishable from chance. So in fields outside of nutrition and epidemiology, nobody would consider a relative risk, an increase in risk less than 100%, a doubling, to be really worth paying attention to. So to put this in perspective, the observational studies that Joel was referring to that confirm that y- s- that cigarette smoking led to lung cancer, that showed an, uh, a one- between a 1000% and 3000% increase in s- uh, lung cancer in smokers. Okay? And the studies that have shown that eating aflatoxin, which is a mycotoxin, increase liver cancer risk, that's 600% increase. Okay? The IAR- the IARC, the WHO report that suggested that processed red meat was a carcinogen, that was 18% increase. Most epidemiologists-

   8. JKDr. Joel Kahn17:31

      Hmm.

   9. CKChris Kresser17:31

      ... you talk to will say, "That is so low that it's really indisting- uh, indistinguishable from chance, especially given the healthy user bias and the problems with the data collection that I mentioned before."

   10. JRJoe Rogan17:42

       So the studies that are cited, so when people are talking about red meat causes cancer, they're literally talking about something that showed an 18% increase.

   11. CKChris Kresser17:51

       Yeah. Right.

   12. JRJoe Rogan17:52

       And-

   13. CKChris Kresser17:52

       Yeah.

   14. JRJoe Rogan17:52

       ... this is over-

   15. CKChris Kresser17:53

       Which-

   16. JRJoe Rogan17:53

       ... people that are also-

   17. CKChris Kresser17:54

       That-

   18. JRJoe Rogan17:54

       ... consuming sugar, other-

   19. CKChris Kresser17:55

       So that, so that, that translates into four and a half, there were four and a half cases of cancer out of 100 in people with no, lowest intake of processed meat, and that went up to 5.3 cases out of 100 in people with the highest intake of processed meat. So, you know, there are quotes like y- if you, if you look even 20 years ago, like, there's an article in Science, um, the journal Science, and Marcia Angell, who was the former editor of New England Journal of Medicine, was quoted as saying, "We wouldn't even accept a paper for publication if it didn't have at least a 200% increase, especially if it was a new association or the, the, the biological mechanism wasn't known." And here we are today.

   20. JKDr. Joel Kahn18:40

       ... saying that, you know, this increase that by 7% or by 10%, and when you consider that the data is usually questionnaires of what people ate, and all of these confounding factors like exercise and, and fruit and vegetable consumption and things like that are not accounted for, then we're really just playing games with numbers. Is part of the problem as well that there's this clickbait culture now in terms of journalism- Well, sure. ... where they just want to publish something that says- Of course. ... a study shows, you know, 18% of people eat red meat get cancer?

   21. CKChris Kresser19:14

       Yeah.

   22. JKDr. Joel Kahn19:14

       That's a huge problem, and there is a study that was done that showed that 43% of findings that came from observational studies were portrayed in the media as being causal. Mm. Which, which any epidemiologist would tell you that that's-

   23. CKChris Kresser19:30

       Yeah.

   24. JKDr. Joel Kahn19:30

       ... a faux pas, you can't do that. But nobody is gonna click on a headline that says, you know, "Small association between these two variables seen. We don't know what it means." Right. (laughs)

   25. CKChris Kresser19:43

       Yeah.

   26. JKDr. Joel Kahn19:43

       "But please read th- this story, it's really interesting." Right. So, so let me just grab a couple. (clears throat) And again- Sure. ... a lot of respect and agreement, but if we throw epidemiology away, we've thrown away about 80% of nutrition knowledge, 'cause that is the most common kind of study. And that still leaves us with basic science, which is rocking. It leaves us with, um, randomized clinical trials, which are very hard in nutrition, and they're very expensive, and there's less than we need. And it finally leaves us with studying old, healthy people, centenarian studies. We'll just go to Loma Linda. 10 times more people in Loma Linda are over 100 than there are in Los Angeles. 10 times more.

   27. CKChris Kresser20:16

       Really?

   28. JKDr. Joel Kahn20:16

       That's by definition, yeah. It's called the Blue Zone, and we'll talk about Blue Zone. But that doesn't- Well, it was discovered in the 1950s. If you lived in Loma Linda, you were living 12- Where is Loma Linda? Loma Linda's an hour east of here. What, what's going on over there? Well, it's a center of the Seventh-Day Adventist Church- Oh. ... which teaches people eat your veggies, don't drink, don't smoke, and exercise. Oh. So it's an amazing lifestyle-oriented, uh, a- aspect of the Christian church. And they, in 1958, got huge funding from the government to explore why the heck are they living 12 years, eight years, 10 years longer, and they've parsed that out in probably 1,000 publications. They're, uh, you know, it's not a randomized study, you know, it wasn't LA versus Loma Linda, we'll feed you different diets and follow up. Won't ever happen. But it is, you know, a reliable, longterm peer review. This stuff's published in, uh, the finest of journals, and it at least lets you ask questions. I mean, why is there a 104-year-old cardiac surgeon, Elliott Warsham, walking around doing his gardening and he just finished operating on heart patients? I mean, it's insane. At 104? 104, Elliott Warsham, love you buddy. Oof. Rolling dice. So but let me go back for a minute. If we throw epidemiology out, we are left with basically biochemical energy- Uh, I'm not suggesting that, by the way. (laughs) No, I know, I know, I know. But so food f- this is all technical stuff and, but you've got a sophisticated audience. Food frequency questionnaires, what Chris said, is the source of a lot of these epidemiology studies. You fill out a four page, a 40 page at, in Loma Linda, it's a 58 page survey. But it, you do it once, that's called the pure study. The headlines, you've seen them. Cheese, eggs, meat are good for your heart. It's been in the news the last two weeks. That comes from a giant international study. They did one food frequency questionnaire at the beginning, 12 years later they're reporting the data, it's all clickbait headlines. It's like you say, people love to see this stuff. So if we throw out some studies, we have to throw out the largest nutritional study that's been reported and the most recent one that's getting all the headlines. It's gotta be played fair. Now, you go to Loma Linda, it's every four years they're asking. You got to Harvard School of Pub Health, every four y- they update the data. So if you change your diet, that's the weakness. You fill out the survey and then you get healthy or you get sick, and you make changes and then they're counting if you're dead or alive. Well, it might be what you did year six, not what you filled out year one. So there are- So- ... there are better and worse forms. The second I'd say healthy user bias is the idea that people pick a certain diet and might have other lifestyles that might be as or more important. Well, it's gonna be true of the paleo group. I mean, these guys are, you know, look at Chris, he looks wonderful. He's healthy, he's thin, he's not the obese American, the 75% that are overweight and obese. I mean, that's true in the, uh, plant community to some extent. We have chubby vegans, oh my God. But, but there's no observational studies with significant numbers of paleo dieters, Joe. Oh, I know, I know that.

   29. CKChris Kresser22:50

       So, so the-

   30. JKDr. Joel Kahn22:50

       So we-
3. 30:00 – 45:00

   Can I quick little…

   1. CKChris Kresser30:00

      So-

   2. JKDr. Joel Kahn30:00

      Can I quick little thing now?

   3. CKChris Kresser30:02

      Please.

   4. JRJoe Rogan30:02

      Mm-hmm.

   5. JKDr. Joel Kahn30:02

      Quick, quick little thing. I just wanna go back for a minute to meat and cancer. World Health Organization is not a vegan group, it's not a nothing group. You know, it's a fairly well-respected international organization that puts out health, uh, claims. So although I ... absolutely, Chris had the data right. 18% increase in cancer risk with processed red meat. I wanna make that clear. I hope you don't eat too many hot dogs, salami, baloney, pepperoni. That's the, uh-

   6. JRJoe Rogan30:26

      Nitrates.

   7. JKDr. Joel Kahn30:27

      Yeah. Uh, well, it may be more than nitrates, but it's just a whole-

   8. JRJoe Rogan30:30

      Preservatives.

   9. JKDr. Joel Kahn30:30

      ... it's the salt, it's the preservatives, it's junky pieces of the animal that they're putting into a hot dog. That was a group. That's an 18% increase. You can go 4.5% to 5.5%. That's still 50 to 60,000 people a year that get colon cancer if that data's right. They wouldn't get colon cancer if they just would stop eating hot dogs. At a minimum, and I know Chris will agree, frigging hospitals are serving hot dogs and the data's out there that it promotes cancer to people getting chemotherapy with the IV pole. It's insanity. So, 50,000 people avoid colorectal cancer with small differences that the World Health Organization suggests. It was 800 papers and 22 world experts. There's no perfect study, but when they announced that October 25th, 2015, the world was shocked. You just said that processed red meat causes cancer. They didn't say related. They were strong enough data to say cause. They've been beat up. They published more data. They haven't backed down. I just wanna put that out. The healthy user bias will exist in the paleo community when the study's done 'cause they ... I mean, look at Paleo FX. They're ... it's everything, and I honor that. I mean, we should promote healthy lifestyle. Food's only one part of this. I mean, we will all at this table live longer than the average American. We're not smoking two pack a day. We don't have 38-inch waistlines, the whole deal. We're doing the whole thing. Hopefully you guys are enjoying a little cabernet now and then, or ... uh, that's always on the list. Just don't overdo it. But the healthy user bias, that particular ... that health food study paper, it's 1996, it's a pretty old paper. In the paper in the limitations, they beat themselves up. "We were missing this or that." Anybody just read the paper. It's not that it doesn't bring up an interesting point, but to say that we, again, throw away all these papers 'cause they are biased. Lastly, and I'm done. Multivariate analysis. Chris was just talking about better studies that factor all this stuff. Let's not bore your audience with statistics, statistics. But there's certainly the ability now to say, does animal protein associate with an increased risk of cancer? And put in smoking and weight and diabetes and blood pressure and vegetable intake and alcohol intake and family history, and then you just isolate the one thing.... is there foibles, are there downsides? Of course. But all modern epidemiology does multivariate analysis to try and isolate it. You know, you can cast stones everywhere, but, you know, there are, you know, the World Health Organization, I mean, there's 21 organizations say, "Limit your saturated fat in your diet," and none that are international societies say, "Increase it." So you put, uh ... Nutrition science needs to incorporate as much as you can with as much reliability, and at the end of the day, you can see we'll still have questions.

   10. CKChris Kresser32:54

       Well-

   11. JKDr. Joel Kahn32:54

       But I can't throw-

   12. CKChris Kresser32:56

       ... the organi- the US used to say, "Don't eat much cholesterol." Now they don't. They used to say, "Limit your total fat," and now they don't.

   13. JKDr. Joel Kahn33:02

       That's wrong.

   14. CKChris Kresser33:02

       Because they've gone out ... It's not wrong, actually.

   15. JRJoe Rogan33:05

       Well, it is wrong.

   16. JKDr. Joel Kahn33:05

       Well, the USDA says in the guideline-

   17. CKChris Kresser33:07

       But, b- but-

   18. JKDr. Joel Kahn33:07

       ... "Eat as little cholesterol as possible."

   19. CKChris Kresser33:08

       ... it says, "Cholesterol is not a nutrient of concern" in that sentence.

   20. JKDr. Joel Kahn33:10

       Because they couldn't identify the exact milligram to recommend. It used to be 300. They said-

   21. CKChris Kresser33:14

       Because the science doesn't support-

   22. JKDr. Joel Kahn33:16

       No, it's 'cause inter-

   23. CKChris Kresser33:17

       ... limiting dietary cholesterol anymore. Let me go back and, and to the ... this question of-

   24. JKDr. Joel Kahn33:22

       That's wrong. They say, "Limit cholesterol."

   25. CKChris Kresser33:23

       Hold on. You-

   26. JKDr. Joel Kahn33:23

       They say, "Limit cholesterol to as little as possible." I mean-

   27. JRJoe Rogan33:25

       But who, what, what's this th- they? Who is they and-

   28. JKDr. Joel Kahn33:28

       USDA. USDA.

   29. JRJoe Rogan33:29

       ... the USDA?

   30. JKDr. Joel Kahn33:29

       The guidelines come out every five years, and they are im- uh, used for school menus and hospital menus. It was a big buzz in 2016 when it was announced. They no longer were giving a so many milligrams of cholesterol a day you'd never exceed.
4. 45:00 – 1:00:00

   So these organizations, Joel,…

   1. CKChris Kresser45:00

      and saturated fat. And in fact, two tablespoons of olive oil has more saturated fat than a seven-ounce pork chop. That's a little-known fact. Um, the, the oily fish, mackerel, you know, which all of these health agencies that Joel is talking about advises us to eat, has twice the total fat and one-and-a-half times the saturated fat that we're, of the meat that we're told to avoid. Um, does it make sense that nature, you know, would include, th- that you could eat, uh, uh, you know, mackerel and the polyunsaturated fats in it are good for you, but the saturated fat in it is bad for you? That's kind of nonsensical. But, you know, t- let's talk a little bit more about the research. So, um, there never really was good evidence to suggest that dietary cholesterol and saturated fat are connected to heart disease. And, uh, Zoe Harcombe, who's a, has a PhD, a nutritional researcher, she wrote her thesis, her PhD thesis, on the evidence back in the '70s that led to the restrictions on, uh, saturated fat and cholesterol. And then she also reviewed the evidence year, y- uh, all the way up until 2016. And, and if, uh, I have th- um, this information on my website, if you go kresser.co/rogan, you can find it. And what you'll find is, there never was en- really good, uh, evidence to support the limitations on di- on saturated fat and cholesterol. And people have started to look at this more recently and, uh, for example, you have a meta-analysis of observational studies, including about 350,000 participants recently that found no relationship between saturated fat intake and cardiovascular disease. You have an exhaustive review of studies, something like 25 randomized controlled trials, gold standard of clinical evidence, and s- almost 40 observational studies involving 650,000 participants. And I'll read you a quote from the conclusion. "Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of saturated fatty acids." Now, look, one of my favorite quotes is the ph- the philosopher Anatole France: "Even if 50 million people say a foolish thing, it's still a foolish thing." And the other thing to consider is that the history of science is really the history of most scientists being wrong about most things most of the time. And, uh, you know, sci- i- in science, we have to continually challenge our, our hypotheses and try to falsify them, and that's how the scientific process moves forward. And that's why in 2010, the US, uh, federal government removed restrictions on total fat, whereas before there was a restriction on total fat, because they, they acknowledged that the research was showing that not all fat is the same and that, y- you know, we don't need to be restricting fat from avocados and things like that. And then in 2015, they removed the restriction on dietary cholesterol. Now, they did that fairly quietly, because how do you think it looks when people have been told to, you know, limit their fat and limit their cholesterol, and then the, the federal agency goes back on that lim- th- that recommendation after so many years of telling people to do that? People lose faith in the agencies that are, that are issuing these guidelines, you k- I ... And don't take it from me. You know, I'm, I'm, I'm not expecting anyone to believe me, and that's why I've put all of the, the studies and the research supporting this at kresser.co/rogan. But how about John Ioannidis, who's one of the most renowned epidemiologists in the world? He's a professor of medicine at Stanford, and he has wrote some, written some scathing critiques of nutritional research recently that have been published in JAMA and British Medical Journal. So here's a quote from one of them: "Some nutrition scientists and much of the public often consider epidemiological associations of nutritional factors to represent causal effects that can inform public health policy and guidelines. However, the emerging picture of nutritional epidemiology is difficult to reconcile with good scientific principles. The field needs radical reform." (laughs) And he goes on to point out that meta-analyses of observational studies have found that almost all foods are associated with a higher risk of death if you crunch the data in certain ways. So, uh, it's not enough to say that d- you know, governments are recommending this or that. We have to look at the science and what the science is saying. And as I said, you, two recent meta-analyses covering over a million people are not showing a relationship between saturated fat and heart disease, and they're not showing any benefit from replacing saturated fat with polyunsaturated fats.

   2. JRJoe Rogan49:44

      So these organizations, Joel, that-

   3. CKChris Kresser49:46

      Yeah.

   4. JRJoe Rogan49:46

      ... you were describing, why do you think that they recommend ... Based on what Chris has just said, why do you think that they recommend reducing your saturated fat, reducing your cholesterol?

   5. JKDr. Joel Kahn49:55

      Okay. Um, and thank you. And, you know, the, the importance here, we're s- we are, you know, technical in the weeds, but I wanna bring it back. This discussion is, do you have a stroke, heart attack, erectile dysfunction, lose a leg, or do you not, because at least one factor in development of these horrible medical problems that are 80% preventable, at least one of it is your nutrition and the content of your nutrition? I mean, there's no doubt. It's the single most important factor. It's never been the only factor.

   6. JRJoe Rogan50:19

      Okay, but why do you think these organizations-

   7. JKDr. Joel Kahn50:21

      So the stuff matters. Right.

   8. JRJoe Rogan50:22

      ... are saying this if he's saying-

   9. JKDr. Joel Kahn50:23

      Okay. So-

   10. JRJoe Rogan50:23

       ... that the studies don't support that?

   11. JKDr. Joel Kahn50:25

       Well, uh, I disagree that the science ... And I wanna be s- very specific. Let's talk about cholesterol and let's talk about saturated fat.

   12. JRJoe Rogan50:31

       Okay.

   13. JKDr. Joel Kahn50:31

       So stay with saturated fat, 'cause there is differences there. They're-

   14. JRJoe Rogan50:34

       Okay.

   15. JKDr. Joel Kahn50:35

       ... both, uh, you know, c- contents of food, fatty contents of food, but they're chemically different and the volume weight is very, very different. Um, cholesterol only comes from animals. Saturated fat is in animals and plants, uh, depending on the food source. So when this rise in heart attacks developed, research began, 1948, 1950, 1958. There were observations made that carefully done dietary logs suggested, these were hypotheses, there might be a connection between what you eat and heart attacks, and then it's centered on, um, you know, is it foods high in protein, foods high in sugar, foods high in fatty sources? Ultimately, they got sophisticated. Foods high in-... plant fat sources, foods high in animal fat sources. So by the late 1950s, there was a very strong consensus already that foods high in animal products with saturated fat, they go together, we're talking meat, egg, and cheese, may be a role. Why? L- let me give you a great example. In 1959, you grew up in Japan, you have a cholesterol of 120, you almost never see a heart attack. You move to Hawaii because there's migration. Your cholesterol rises to 180. Welcome to America. Your heart attack risk triples. You move to this great city, Los Angeles, this was published in 1959, your cholesterol's now 210. You have 10 times the heart attack risk that you had when you lived in Japan. Genetics don't change that quick. This was within one generation. They're called Nisei, people that leave Japan to move to California, the Nisei, and there's the Nisei-Han study that tracked these people. Now, is it the air? Is it that they adopted other bad habits? Sure, it could be, but within a very short time, they had 10 times the risk of heart attack. So public research and dollars, this stuff matters.

   16. JRJoe Rogan52:13

       But why is this correlated with animal fats and proteins-

   17. JKDr. Joel Kahn52:16

       'Cause they're, yeah.

   18. JRJoe Rogan52:16

       ... and why isn't it correlated with sugar-

   19. JKDr. Joel Kahn52:18

       Right.

   20. JRJoe Rogan52:18

       ... and refined carbohydrates?

   21. JKDr. Joel Kahn52:19

       So, carefully done studies say, and I think we all agree, more so now 'cause we're overweight and now we're more insulin resistant and added sugars in the diet are more important in 2018 than they were when the country was thin in 1960. They weren't good then, they aren't good now. But when you parse it out, multivariate analysis, there's a stronger relationship between the number one food in studies like this is usually butter, more than red meat, it's actually butter. That's just an R value. It's called statistic. I don't wanna go so deep into statistics. It is. Somewhere there is sugar. I'll give you a classic study. If you could hold sugar the same and increase dietary saturated fat, heart disease rockets. If you could hold saturated fat the same and increase sugar in these manipulations, coronary heart disease doesn't increase. Let's point something out. I've been inside of hearts 15,000 times, I've never scooped sugar out of a blocked artery. I scooped cholesterol out of blocked arteries. 20% of every blockage in a heart is cholesterol. It's a fact that was discovered in 1910. It's never varied. Then we fed animal, uh-

   22. JRJoe Rogan53:18

       Let's pause for a second.

   23. JKDr. Joel Kahn53:19

       Yeah.

   24. JRJoe Rogan53:19

       Chris, do you have something to say about that?

   25. CKChris Kresser53:20

       Yeah. So that doesn't mean that the cholesterol is there because people were eating it, Joel. You know that.

   26. JKDr. Joel Kahn53:25

       It could be though.

   27. JRJoe Rogan53:26

       But hold on.

   28. CKChris Kresser53:27

       And, and let me... Let's say, let's look at the, what the research says again here. So they've done controlled feeding studies where they fed people two to four eggs a day, and those show that in 75% of cases has zero impact on blood cholesterol levels. For the other 25% of people, they're termed hyper-responders. And in that group, dietary cholesterol r- r- does modestly increase LDL cholesterol, but it also increases HDL cholesterol and it does not increase the risk of heart disease. This is why the, the guidelines were changed on dietary cholesterol, is there is no evidence that, that consuming dietary cholesterol increases the risk of blood cholesterol in most people. And even when it does, there's no evidence that it increases the risk of a heart attack, which is again, why the dietary guidelines changed. For saturated fat, again, it... Most of the studies that showed harm were short-term studies. These, uh, longer term studies have shown that on average, eating saturated fat does not increase the saturated fat levels in the blood. And of all of the long-term studies that looked at this, only one showed any association between saturated fat intake and, uh, cholesterol levels in the blood. Then we have a meta-analysis, lots of meta-analyses actually, but one of the, uh, best known meta-analyses was of 17 randomized controlled trials of low-carb diets that were high in saturated fats in... Published in the journal Obesity Reviews, and they found that low-carb diets neither increased nor decreased LDL cholesterol, but what they did find was that low-carb diets were associated with decrease in body weight, improvements in several cardiovascular risks, risk factors, including triglycerides, fasting glucose, blood pressure, body mass index, abdominal circumference, plasma insulin, C-reactive protein, as well as an increase in HDL cholesterol. Now, there have now been 10 meta-analyses of randomized controlled trials looking at low-carb diets for weight loss. All 10 showed that, uh, the low-carb diet either outperformed in most cases or was, was on the s- at the same level as low-fat diets. There have been several meta-analyses now, you can see them all at kresser.co/rogen, that have looked at, um, low-carb diets for diabetes and even cardiovascular risk markers, and all of these meta-analyses have found that low-carb diets are superior for glycemic control, for reducing insulin, for reducing triglycerides, and have beneficial effects across the board without increasing cardiovascular risk markers. So we're now... We're t- we're talking about (laughs) randomized controlled trials, which is the best form of evidence that we have, and we're not seeing any harm from incr- you know, increased consumption of saturated fat. So-

   29. JRJoe Rogan56:14

       So is the problem that you're citing epidemiology studies from the 1940s and the 1950s?

   30. JKDr. Joel Kahn56:19

       Well...
5. 1:00:00 – 1:15:00

   Okay, I gotta stop…

   1. JKDr. Joel Kahn1:00:00

      Okay, so everything's, like, stirred up and 2014, a guy named Chowdhury publishes a similar analysis that is the reason that Time magazine put on the cover, "Butter Is Back" because it was not new research. It's a meta-analysis. It's all following this Mexico City, uh, effort to, uh, fund dairy positive publications, a, a study so bad that both the journal required them to adjust and republish the data 'cause of mistakes. The Harvard School of Public Health said, "Take this thing away. Statistically, this is nonsense." Since those two times, and that's just the bottom line, we have had confusion in the public. We've got experts like Chris, experts like me, experts like Dr. Mark Hyman, experts like Dr. Walter Willett, on and on. There is a quote from the tobacco industry that our product is confusion. They didn't care about, you know, winning the battle when the public's confused, they're just gonna keep on doing habits they have. And that is-

   2. JRJoe Rogan1:00:54

      Okay, I gotta stop you- ... 'cause now we're in the weeds with conspiracy theories.

   3. JKDr. Joel Kahn1:00:57

      Yeah.

   4. JRJoe Rogan1:00:57

      I'd like to go back-

   5. CKChris Kresser1:00:58

      Oh, it's uh, so no, I mean, so I, I, I-

   6. JKDr. Joel Kahn1:00:59

      Well, that's when the pendulum of 1950, 1960, 1997, 395 of the best done studies in the world say, "You eat more saturated fat, your cholesterol goes up."

   7. CKChris Kresser1:01:09

      No, it's, it's actually-

   8. JKDr. Joel Kahn1:01:10

      "You eat more saturated fat, coronary heart disease goes up." It was crystal clear and the guidelines said it. The guidelines still say it, the guidelines still say limit saturated fat.

   9. JRJoe Rogan1:01:18

      Are you, are you suggesting that the same science from the 1950s and the 1940s is-

   10. JKDr. Joel Kahn1:01:23

       Who, who-

   11. JRJoe Rogan1:01:23

       ... is applicable today?

   12. JKDr. Joel Kahn1:01:24

       If it's, in retrospect, valid. Here, let's point out one that's not.

   13. JRJoe Rogan1:01:28

       But is it?

   14. JKDr. Joel Kahn1:01:29

       Yeah, absolutely.

   15. JRJoe Rogan1:01:30

       Do you think it is?

   16. CKChris Kresser1:01:30

       No.

   17. JKDr. Joel Kahn1:01:31

       Absolutely. I abs-

   18. JRJoe Rogan1:01:32

       Why, why do you think it's not?

   19. CKChris Kresser1:01:33

       What, what's changed?

   20. JRJoe Rogan1:01:33

       Because we keep bringing this up. Why do you think it's not?

   21. CKChris Kresser1:01:35

       So we're, we're, we're going back to observational studies done 50, 60 years ago that suffer from all of the problems that I mentioned to begin with, and several more that we didn't have time to go into. Um, we have randomized controlled trials now, and you know, observational studies were never meant to prove a hypothesis. They're meant to generate a hypothesis. And it's true that in some cases it's not possible to do a randomized controlled trial, like with cigarette smoking. You'd have to, you know, do, have the trial last for so long and you'd have to isolate people in a ward so they weren't exposed to air pollution and other factors that could affect the result. You can't do that. But in that case, the risk was 1000 to 3000% higher. So there are criteria called the Bradford Hill criteria, which you can use and apply to observational studies to assess the chance that there's a causal relationship. And in the case of smoking, which actually was when the Bradford, Bradford Hill criteria were created, that relate, that meets many of those criteria. In the case of nutrition research, very seldom did they meet more than a couple of the Bradford Hill criteria. Now observational research, in order to be valuable, needs to be confirmed. You know, it, the, the results need to be replicated in a randomized control trial. That's how science is supposed to work. But there was one analysis that found that zero of 52 claims that were made in observational nutrition studies were replicated when they were tested later. And in fact, five were replicated in the opposite direction. In other words, they, when they did an experiment, they found the opposite result to what the observational study suggested. So good examples of this are...... observational studies originally suggested that beta carotene, an antioxidant, that s- people with the highest intake of beta carotene had something like a 30% reduced risk of death, which is not really plausible anyways. But then when they started doing trials where they were giving people beta carotene supplements, not only did it not improve their lifespan, they got more cancer. It increased the risk (laughs) of cancer. So, this is why it's so important not to rely just on observational data and to do these experiments. Now, going back to saturated fat, as I said, we've got a 2013 meta analysis of 20 randomized controlled trials that found that low carb/high protein diets led to greater improvements in glycemic control compared to low fat, American Heart Association, American Diabetic Association diets. We've got a 2014 meta analysis of 10 randomized controlled trials that showed that low carb diets are more effective than high carb diets for patients with type 2 diabetes. And we've got another meta analysis of 25 randomized controlled tri- uh, trials just published in 2018 that found the same thing. So, you know, science marches on. We, we, we learn more, we change, and now we've got randomized controlled trials that are replacing some of the observational evidence from the '50s and '60s and '70s, which b- which, by the way, in, in, in Dr. Harcombe's paper you'll see that that evidence was never strong to begin with. And this is what we should be looking at.

   22. JRJoe Rogan1:04:37

       So, why are you consistently bringing up these studies from the '50s?

   23. JKDr. Joel Kahn1:04:40

       Well, 'cause Chris is mixing everything up. He's talking low carb data. "Let's talk low carb diet. That's keto diet, that's low carb diet, let's be like that."

   24. JRJoe Rogan1:04:47

       B- but before we go to that-

   25. JKDr. Joel Kahn1:04:47

       But we, hey, yeah, I know, I know.

   26. JRJoe Rogan1:04:48

       ... b- before we go to that-

   27. JKDr. Joel Kahn1:04:48

       Well, that's what he, right-

   28. JRJoe Rogan1:04:49

       ... but I, but you, you consistently bring up these studies from the 1950s and the 1960s. These-

   29. CKChris Kresser1:04:53

       Low carb diets are high in saturated fat.

   30. JRJoe Rogan1:04:55

       Okay, so that's-
6. 1:15:00 – 1:16:18

   Joel?…

   1. CKChris Kresser1:15:00

      increase in ch-... And then when they looked at... They just took cholesterol out of the equation. Let's just look at, is there an increase in heart attacks or death from eating saturated fat? When they did that, there's no increase. And, and, and these are, uh, that... Those are observational studies and we have all these randomized controlled trials that are showing no, no increase in cholesterol, no increase in insulin levels, and actually a decrease in all of those markers.

   2. Joel?

   3. JKDr. Joel Kahn1:15:27

      ... um, important stuff and a lot of stuff was said. And I doubt, unless you're really high level, you understood. I just wanna pick out one thing Chris said. Does anybody know what the Cochrane Database, a word that flew out of his mouth ... Cochrane, C-O-C-H-R-A-N-E, is a group of scientists that try and be very objective, very independent, don't have any emotional, any books, any supplements, any food and nothing. And we all love supplements around this table, but let's get outta that. Cochrane Database, every five years, comes out with a statement, "Does saturated fat relate to the risk of heart disease?" In 2015, the most recent, Hooper... Look up Hooper, look up Cochrane Database. Yes, it does. Chris said it, but he flew by it. No, it wasn't powerful enough that your choice of butter, eggs, meat, and cheese necessarily predicted your total lifespan, but it absolutely predicted your risk of developing a heart attack and stroke, according to this independent database. That's the-

Episode duration: 3:47:38