Microplastics, PFAS, and phthalates: health risks & minimizing exposure (AMA 67 sneak peek)

1. 0:00 – 0:12

   Intro

   1. PAPeter Attia0:00

      [upbeat music] Hey, everyone. Welcome to "The Drive" podcast. I'm your host, Peter Attia.

   2. SPSpeaker0:10

      Peter, thanks for coming back

2. 0:12 – 5:49

   The complexity of the topic of microplastics & associated chemicals

   1. SPSpeaker0:12

      for another AMA. How are you doing?

   2. PAPeter Attia0:14

      Good. Thank you for having me.

   3. SPSpeaker0:16

      Before we get started today, quick question. Do you have a beverage in front of you?

   4. PAPeter Attia0:20

      I do.

   5. SPSpeaker0:21

      What type of glass is that in? Is it a plastic? Is it glass?

   6. PAPeter Attia0:26

      It is plastic.

   7. SPSpeaker0:27

      Huh. Okay.

   8. PAPeter Attia0:28

      [chuckles]

   9. SPSpeaker0:29

      Interesting then. That will be, uh, interesting for this AMA, which is gonna cover one topic, which is something that seems to be growing in interest. We've been getting a ton of questions on, ton of conversation online. That's microplastics and other chemicals such as BPAs, PFAS, and phthalates. So, what we did, gathered all these questions that have come through, pulled them together, and are ultimately gonna try and help people understand should they be worried, what should they be worried about, what's dangerous. Based on all that, what can they do about it? So, before we get started, anything you want to add?

   10. PAPeter Attia1:10

       Yeah. I, I think there's actually a lot I need to say before we dive into this for context. Um, so I'll, I'll preface maybe by saying the following. Um, obviously, people who are regular listeners of the AMA can appreciate that these are not, you know, sort of, um, you know, uh, off, off-the-cuff remarks that we make here, and we, we put a lot of work into doing this. Uh, when I, when I sit up here and do these AMAs, I'm, I'm doing them based on the work that, that me and a team of analysts have done for usually about a month in preparation for them. I think it would be safe to say that in the six years we've been doing this, or is it seven or eight now? I've lost track. Um, to date, at least, this will go down as the AMA that has required the most work, uh, that has probably generated the most swear words, uh, and probably resulted in the secretion of the most, uh, uh, adrenergic compounds from, uh, f- from the adrenal glands. In, in other words, this has been a royal pain in the ass to prepare for. And as recently as last night at ten o'clock, I was emailing you saying, "What the F? Why are we doing this?" It's a never-ending morass of information, most of which is incomplete. Uh, uh, you know... Anyway, there, there's so much I could say on this. And then the most wonderful thing happened, which always happens after... Any- anyone has experienced this if they think back to being in college where you sort of, the, even the night before the exam, you're like, "I don't know what the hell is going on." And the best advice is usually just go to bed, get a good night's sleep, get up nice and early, fresh cup of coffee. And, um, and I think that sort of happened this morning, right? You know, me and a couple of the other analysts sort of went to bed, got up this morning, and all of a sudden, I just had more clarity about what, you know, in my words, how, how to land the plane. Um, and I, and I took to writing a couple of pages out, and I think I've got kind of a, a sensible way to, to make sense of something that is incredibly noisy. So what I'm gonna say at the outset is, um, if you are listening to this thinking that there is a punchline and a one-word answer, I, I'm gonna spare you the disappointment. This is a very nuanced topic. If I could answer this in a word, I promise you I would, and I would never try to go through the 75 pages of notes that our team has assembled to help me think about this topic. I swear to you, there are 100 things I'd rather be doing right now than, than going through this. However, it is important in, in an area where there is so much uncertainty, so much asymmetry, uh, and such complete and incomplete information that we have to understand the boundary conditions so that we can each make a reasonably informed decision. So, so with that as my sort of preamble, um, I, I think let's, let's do our best to, to guide people on a, on a journey that we've been on, um, and, uh, and acknowledge our shortcomings, acknowledge where we wish we knew more, where maybe others do know more, um, but leave people with a framework such that at the end of this AMA, which will hopefully be sometime today and not tomorrow, um, everyone can sort of make a risk-based decision for themselves, for their families.

   11. SPSpeaker5:10

       Yeah, definitely. And it kind of reminds me of what Bob Kaplan always used to say, right? Which is, further from the shore, the deeper the water. So as we've kind of like gone deeper and deeper on this, it seems more complicated, more complicated. The last question I'll ask before we get started, that coffee you drank this morning, was that in a glass mug or like a Starbucks kind of like paper mug with the plastic lid on top?

   12. PAPeter Attia5:36

       It was actually in a metal Yeti, you know, kind of camping coffee cup. That's sort of my favorite way to drink coffee.

   13. SPSpeaker5:45

       All right. So you redeemed yourself a little bit there, which is good.

   14. PAPeter Attia5:47

       [chuckles]

   15. SPSpeaker5:48

       Um,

3. 5:49 – 12:12

   Definitions: microplastics, BPA, PM2.5, phthalates, & more

   1. SPSpeaker5:49

      starting off, I think it'd be helpful, as we kind of typically do, definitions. What are microplastics? What's BPA? What are these chemicals we're talking about? Let's just define them now, so as we say them going forward, people understand what we're talking about.

   2. PAPeter Attia6:05

      Yeah. I mean, part of this is you just have to kind of get suck it up through the semantics. And part of the challenge is that some of the definitions are not very helpful. So starting with microplastics, you know, they're, they're typically defined, um, as any particles of plastic that are smaller than five millimeters. Now, again, I realize that not everybody is facile with the metric system, but, but anybody who is will realize five millimeters is huge, right? Like you can see five millimeters, that's half a centimeter. Um, so we're not really talking about that. Um, I, I think most current studies would, would really classify microplastics as those smaller than one millimeter, one tenth of a centimeter, about one twenty-fifth of an inch. Um, and then of course, we talk about what are called nanoplastics, which are particles that are smaller than one micrometer or micrometer. Um, so, so one one-thousandth of a meter. So we abbreviate these as MNPs or micro nanoparticles. And we should just acknowledge that these things are completely ubiquitous. They're found anywhere that we have looked for them, uh, which is to say we find them in water, we find them in food, we find them in fruit, on fruit, in vegetables, on vegetables, in meat, in the air. Um, and, and therefore micro nanoplasticals or MNPs are completely ubiquitous. Okay, you asked about BPA. BPA is a-- th-this is-- now there are lots of these, uh, bisphenol chemicals, but bisphenol A or BPA is the one that most people are familiar with. Um, ironically, uh, the presence of BPA at least, uh, being used actively, uh, has been reduced quite a bit over the past fifteen years. But just understand that there's a whole family of these, uh, bisphenols, and typically we substitute one for the other. Um, but what are they, right? They're chemicals that are used to make polycarbonate plastic. Polycarbonate plastic is the hard plastics we have in our world. So if you think about all the places where you use plastic and it's hard, uh, I think of kind of the Nalgene type water bottles, epoxies, resins, things like that. That's where you're gonna have historically found a lot of BPA. Of course, today this is less the case. Uh, but the truth of the matter is they're now replaced by other, uh, bisphenols, so BPS and BPF. And the truth of the matter is not clear that we know if those are any better than BPA. So, um, when I say BPA, I think it's just easiest to sort of think of the broad category of these families. Um, another thing that we-- we're going to talk a, a bit about, and I've talked quite a bit about this in the past, is actually particulate matters, uh, of the two point five or smaller variant. These are abbreviated PM2.5, and again, it refers to, um, particulate matters in the air that are smaller than two point five micrometers. Um, so again, why is that important? Well, there's, there's something relevant about a particle that's that small, which is that if inhaled, it has the potential at least to become systemic. And the reason for that has to do with the anatomy of the lung and the size of, uh, both the alveolar air sacs and the epithelial linings of them, which again, it's not necessarily that intuitive that you could breathe something, but that it is small enough that it could actually get across a cell barrier at the innermost part of the lungs and enter the systemic circulation just as though it had been injected into you. So again, um, a, a PM2.5 refers to any particulate matter that is inhaled in the air that is of that size or smaller. Now, are there some microplastics or micro nanoplastics that fit that description? Yes, but most are not. So most PM2.5s, um, are not microplastics. I forget the exact number. I know it's somewhere-- Uh, we, we did look it up. It, it's, it's on the order of a few percent. Um, I would say that the greatest contribution to PM2.5s probably come from air pollution. So anything that has to do with, you know, you know, when there's a fire, you know, burning wood, obviously burning fossil fuels, but coal being hands down the, the leader of this. I mean, uh, natural gas combustion, uh, produces much less of this. Um, okay. And then, and then we'll talk about, um, phthalates, which are another class of chemicals that are kind of like, um, the-- I think of them as sort of the opposite of the, of the BPAs. So these are the things that are used in plastics to make plastic more flexible, uh, and to, to, to have more kind of bend in it. They're also found in products that we use like shampoos, lotions, laundry detergents. Uh, it makes fragrances last longer. Um, now there's been a constant regulatory shuffling around all of these things, and I'm not going to get into it because honestly, it's not that-- I mean, I could just put everybody to sleep right now. We're going to leave a ton of this in the show notes section where we're going to kind of go through the regulatory machinations on this and which of these products were banned and when and what got substituted in. Um, but the bottom line is that the use of phthalates are still currently allowed in food content application, um, but many companies have undergone voluntary reductions in this. Um, there doesn't appear to be any restriction in the use of phthalates for personal care products. Um, and, um, a-again, I think this is probably where people are going to see their greatest exposure to them. So, um, I guess I'll stop there, Nick, but that's, that's kind of the, the, the whirlwind tour of what, what all these different compounds are.

4. 12:12 – 14:39

   The reasons behind the increase in microplastics in our environment & the surge in interest in them

   1. SPSpeaker12:12

      And do we have any idea why it seems like we're now hearing about microplastics being everywhere? Like, it doesn't seem like that was always the case. So do we know why there's been this huge uptick in this?

   2. PAPeter Attia12:28

      Yeah, I think there's two things going on. So the first is that obviously plastics are relatively new, um, didn't really exist much prior to the 1950s. Um, and the, the-- you know, if you think about it, I mean, they, they were pretty remarkable, right? So incredibly lightweight, uh, remarkable strength to weight ratio, um, resistant to rotting and corrosion and shattering. I mean, there are lots of reasons we've, we use plastic. Um, and so when you combine the fact that they've been increasing in their proliferation over the past seventy years, uh, that would certainly explain why, uh, we might be seeing more of them. But there's also a little bit of the, uh, what's the, what is the expression? The, the drunk under the streetlight problem, right? Like, people are also looking at this more and more and more. In fact, um, if you don't mind, if you could pull up, there's a figure we've got that shows the number of scientific publications focusing on microplastics in the last twenty years. Um, so if you go back, it's, you know, showing basically twenty-- you know, two thousand to twenty twenty. Um, it's a linear scale, uh, so, you know, but it's still pretty remarkable, right? It still looks like you're basically watching Bitcoin from, uh, you know, two thousand and ten to two thousand and twenty. That's, that's, that's effectively what's been going on. So a-again, I don't doubt that we're s- that there are more and more microplastics accumulating in the environment. Um, that, that's likely. But, um, we can't lose sight of the fact that we're also looking for it nonstop. Um, so, uh, you know, o-one of the questions that I don't, I didn't come up with a satisfactory answer to was, if you just look at the last five years, are we seeing a true increase, right? I wouldn't doubt that there's more twenty twenty versus nineteen eighty, right? That strikes me as, hey, over that forty-year period, I could really see it going up. But twenty twenty to twenty twenty-five, is that a real increase, uh, or is that, is that sort of a, um, a, a, a, an artifact of observation?

5. 14:39 – 17:15

   The various ways that humans are exposed to microplastics & nanoplastics

   1. SPSpeaker14:39

      And you touched on a teeny bit when you were kind of going over the definitions, but I think it'd be helpful to just dive into it a little deeper, which is how are humans being exposed to microplastics currently?

   2. PAPeter Attia14:51

      Yeah. So again, I, I think it, it, it's-- it-- we should, we should always be thinking about this through the lens of relevant versus not so relevant exposure. But, but again, we're gonna always try to focus on a relevant exposure, which is an exposure that has the potential to accumulate. Um, so the most common route of human exposure is, is from inhaling plastic dust and fibers, uh, and from consuming food and beverages that contain, you know, these micro, nanoplastics. And again, that's why I, I prefer to talk about MNPs rather than just microplastics. Why? Because, um, my concern about consuming, um, you know, like a five millimeter piece of plastic is nil because it can't be absorbed. It's gonna come right out my body the next day. This is not the thing that we need to be afraid of. So what are, what are the foods and, you know, beverages we need to be concerned with, right? So the, the, the highest places we tend to see these are in seafood, salts, water, uh, both tap water and bottled water, um, but also in, in fruits, vegetables, meats, um, even beverages like milk, beer, and wine, which obviously are, you know, primarily, uh, made, you know, con-contain water as well. Um, nanoplastics in soil can accumulate within plants, um, and obviously the exposure gets magnified as you go up the food chain. Uh, this again explains why we would see it in, in seafood given that we understand the role of plastics in the oceans. Um, and, and that's why obviously you can see, um, you know, seafood and land animals accumulating these as well. So, um, the epithelial barrier is the first line of defense. Uh, and again, remember, there's an epithelial layer on the outside of your body that we can see, but there's also an epithelial layer on the inside of your body, right? Everything between your mouth and your anus is also an epithelial layer. Um, and that's why generally micro, nanoparticles don't enter the body through the skin or through the gut unless they are small enough, right? So again, we've already talked about it. The pulmonary epithelium requires them to be smaller than two point five, uh, microns, um, and in the lining of the gut, they could probably be as big as, uh, a hundred and fifty microns to be absorbed.

   3. SPSpeaker17:13

      And do we

6. 17:15 – 21:45

   Volume of plastic consumed by humans, & how the body eliminates or absorbs microplastics

   1. SPSpeaker17:15

      know how much plastic humans actually consume, and is it even knowable? You, you often hear numbers thrown around a lot, and so curious what we know on that.

   2. PAPeter Attia17:26

      I think it is a-- it's, it's difficult to know, but I think we can, I think we can probably put some, put some brackets around it. So, um, first there's a, you know, just a huge amount of variability, um, that based on a, a lot of factors. So where you live, uh, what type of food you eat, and what your source of drinking water is would probably be the three biggest determinants of your exposure to MNPs. Um, again, that's, that's, that's, that's worth noting again, and I think it's worth stating, right? So just your geography, your source of food, your source of water plays the biggest role. Um, if you aggregate the data from all of the studies, it would suggest that humans are consuming, and this is a broad range, so I think that's just unfortunately the nature of, of this stuff. Somewhere between 10 and 300, uh, micrograms a week. Again, these are, you know, this is 10 to 300 thousandths of a gram per week. Um, now, a study that was published in 2021 estimated that on average we consume about four, uh, microns per week from, um, or micrograms, sorry, per week from fish, uh, and, you know, other, other sea things like crustaceans, mollusks, tap water, bottled water, beer, et cetera, et cetera. Um, the study simulated the expected exposure to amounts, um, that agreed with measured quantities in microplastics in school. Now, uh, in stool rather. So I, I think this is probably an underestimate given that it didn't look at some of the other areas, um, that we've-- that have already been found to ex- it contain some MMPs such as fruits, meat, vegetables, um, you know, potentially plastic off cutting boards, utensils, you know, again, the plastics that may come from, uh, you know, things we'll talk about like reheating food and things like that. So, um, the, the, the point is that the, the, the mass of these things is pretty small and that might not be kind of the right way to, to think about it and, you know, we can, we can talk about some of the misinterpretations of that stuff. Um, there was a recent study published in 2023, um, it was in Korea, and it estimated that the population was consuming somewhere between 140 and 310, uh, micrograms per week. Um, and again, I, I think that's, you know, that's a, that's a nice narrower band. It also ports with largely the upper limit of the, of the US-based study as well. Um, so yeah, I mean, I, I think that's probably the, the, the, the ballpark of where people are consuming.

   3. SPSpeaker20:16

      And how do those numbers compare to, you know, like the credit card worth of plastic that was all over the news, right? So I think you couldn't go anywhere without seeing that we're eating or consuming a credit card worth of plastic a week. So the numbers that we're seeing in those studies compared to what that would be, how do those compare?

   4. PAPeter Attia20:39

      Yeah, not even in the same zip code. So that soundbite that humans consume a credit card worth of plastic, uh, refers to a report that estimated weekly consumption was five grams of MMPs. Um, that has been largely debunked, uh, despite, you know, what you've said, which is the prevalence in, in popular media. But, you know, as-- And I don't remember who, who, um, who, who, who, who, um, who famously stated that the, uh, a lie will travel around the world or halfway around the world before the truth has a chance to pull its boots on. Um, I, I, I don't even need to go into that. We'll, we'll link in the show notes to, um, both the, uh, the original analysis which came out of the University of Newcastle, commissioned by the, the WWF, was released I think in 2019. Um, and then obviously the, um, uh, the cor- sort of the rebuttals to that. But yeah, the, the long and short of it is that that's, um, that I, I don't think any serious, uh, person believes that, that we're consuming five grams of plastic a week.

7. 21:45 – 27:37

   How microplastics accumulate in the body, the variability in tissue accumulation, & the challenges in studying their long-term health effects

   1. SPSpeaker21:46

      And then based on what we consume, what do we know about how they're eliminated from our body?

   2. PAPeter Attia21:53

      Yeah. So again, the main way that these things are eliminated is, is, is largely through coughing and sneezing them out, right? So, so anything that's coming into our lungs, we can get it out by a cough or a sneeze, uh, as well as urine and stool. Um, so again, the largest particles, those that are greater than, you know, 10, 10, uh, uh, microns, um, will generally be removed, uh, with, with relatively high efficiency, uh, regardless of how they enter the body. It's really the smaller particles that are eventually, uh, gonna make their way to the immune system. Um, you know, if you were gonna do a mass balance on this stuff, the majority, like to the tune of 99% of ingested microplastics are, are gonna be eliminated through, through stool. And, um, you know, this is a relatively short transit time. We're talking about 24 to 72 hou- hours. Um, and again, the plastics have a very difficult time crossing the GI epithelium. Um, so when you look at animal studies, we would see that, um, it's about 0.3%, maybe with a ceiling of about 1.7% of microplastics have the capacity to be absorbed across, uh, the GI epithelium. And of course, it's heavily, heavily size dependent. So it's the particles that are gonna be less than 10 microns, which remember that that's, that's, um, that's four times larger than what is required to get into the lung. So again, just think in the lung we're anchoring to 2.5 microns or less. In the gut, um, even though in theory the gut could absorb something close to maybe 100, we just don't, uh, you know, I think that's more theoretical, and in practical terms, we tend to see it as, as 10 micron or four times that size. Um, so the bottom line is this: if you're encountering a microplastic that's less than 2.5 microns, you could absorb it both in your gut or via your lungs. Um, now again, um, when, when we, you know, go through this type of analysis, um, in, in urine, we, we again see that, that there are als- al- we also excrete microplastics through, through the urine, but this is less than what we do through the gut.

   3. SPSpeaker24:15

      And for the things that are not eliminated, where do they end up, and why are there growing concerns about that?

   4. PAPeter Attia24:25

      Yeah. So this is really the crux of what's going on. Thank you for listening to today's sneak peek AMA episode of The Drive. If you're interested in hearing the complete version of this AMA, you'll want to become a premium member. It's extremely important to me to provide all of this content without relying on paid ads. To do this, our work is made entirely possible by our members, and in return, we offer exclusive member-only content and benefits above and beyond what is available for free. So if you want to take your knowledge of this space to the next level, it's our goal to ensure members get back much more than the price of the subscription. Premium membership includes several benefits. First, comprehensive podcast show notes that detail every topic, paper, person, and thing that we discuss in each episode. And the word on the street is nobody's show notes rival ours. Second, monthly Ask Me Anything or AMA episodes. These episodes are comprised of detailed responses to subscriber questions, typically focused on a single topic and are designed to offer a great deal of clarity and detail on topics of special interest to our members. You'll also get access to the show notes for these episodes, of course. Third, delivery of our premium newsletter, which is put together by our dedicated team of research analysts. This newsletter covers a wide range of topics related to longevity and provides much more detail than our free weekly newsletter. Fourth, access to our private podcast feed that provides you with access to every episode, including AMAs, sans the spiel you're listening to now and in your regular podcast feed. Fifth, The Qualies, an additional member-only podcast we put together that serves as a highlight reel featuring the best excerpts from previous episodes of The Drive. This is a great way to catch up on previous episodes without having to go back and listen to each one of them. And finally, other benefits that are added along the way. If you want to learn more and access these member-only benefits, you can head over to peterattiamd.com/subscribe. You can also find me on YouTube, Instagram, and Twitter, all with the handle PeterAttiaMD. You can also leave us a review on Apple Podcasts or whatever podcast player you use. This podcast is for general informational purposes only and does not constitute the practice of medicine, nursing, or other professional healthcare services, including the giving of medical advice. No doctor-patient relationship is formed. The use of this information and the materials linked to this podcast is at the user's own risk. The content on this podcast is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard or delay in obtaining medical advice from any medical condition they have, and they should seek the assistance of their healthcare professionals for any such conditions. Finally, I take all conflicts of interest very seriously. For all of my disclosures and the companies I invest in or advise, please visit peterattiamd.com/about where I keep an up-to-date and active list of all disclosures. [outro music]

Episode duration: 27:37