Note: The Paleologix supplements discussed in this post are no longer available. Please click here to view the products recommended as substitutes.
In this episode, I share my thoughts on Paleofantasy and review new research on Cholesterol numbers and BPA toxicity.
In this episode, we cover:
4:00 What did Chris eat for breakfast?
7:57 Book Updates!!
22:04 Thoughts on “Paleofantasy”
42:34 The latest research on Cholesterol numbers
49:08 BPA Toxicity Research Updates
Links We Discuss:
Full Text Transcript:
Steve Wright: Hey everyone, welcome to another episode of the Revolution Health Radio Show. This show is brought to you by ChrisKresser.com. I’m your host, Steve Wright from SCDLifestyle.com, and with me is integrative medical practitioner and healthy skeptic Chris Kresser. So Chris, how’s your day going?
Chris Kresser: It’s great. It’s a rainy, cloudy day here in Berkeley, and I’ve just been getting a lot of work done.
Steve Wright: Fair enough.
Chris Kresser: It’s nice that it hasn’t slowed down my activity, though, thanks to the old treadmill desk. I’m at about 14,000 steps right now and it’s 1:00, so it’s a good day so far.
Steve Wright: Well, you got me beat. I hit 11,000 today.
Chris Kresser: That’s pretty good. Last time I talked to you, you were getting pretty beat up at the higher levels. It sounds like your endurance has improved.
Steve Wright: Yes, mostly my ability to carve out the opportunities to get more steps has improved.
Chris Kresser: OK, that’s good.
Steve Wright: Just making a little more effort.
Chris Kresser: Do you have a treadmill desk, or are you just walking more?
Steve Wright: No, I’m just saying: Nope, that’s it, time to go for a walk, and just going for walks.
Chris Kresser: Yeah. You know, I just discovered — maybe you already knew about this — this really cool app called Time Out. It’s only for Mac, but I guess there’s one called Workrave for Windows. But it’s perfect for what we’re trying to do here because it reminds you to take breaks throughout the day. It has micro breaks and macro, longer breaks. Micro breaks are like 15 seconds every 10 minutes, and then the longer breaks are like every 45 minutes for maybe 10 minutes. You can completely control it and make the intervals whatever you want, but after 10 minutes, you’ll see this little notification come up and the whole screen kind of grays out, and it shows a progress bar for the break. And during those really short micro breaks, I just turn my head away from the screen and look at a far distance or a closer distance, because one of the harmful things about looking at a screen for so long is that we’re not really adapted to focusing on one horizontal plane visually for an extended period of time like you do when you’re staring at a screen, so even just turning your head away and taking a little eye break can be really helpful. Or I’ll use one of those opportunities to just stand up, stretch, shift my position, something like that, maybe go do a quick set of pull-ups or push-ups or resistance training or running in place or mountain-climbers or something like that. And then the longer breaks, I’ll get up and walk around or do more conditioning or strength training or maybe do some meditation or stress management or something like that. I was pretty good before about remembering to do that on my own, but I’ve just found that Time Out makes it super easy. You know, there is a little skip button that you need to be careful of because it can be easy to just hit that, but so far I’ve been pretty disciplined about whenever the break thing pops up, just do it, and it’s been helpful. You should check it out if you haven’t already.
Steve Wright: Yeah. I haven’t heard of that. What was the name again?
Chris Kresser: It’s called Time Out. That’s for Mac. And the Windows version, although it’s not the same, is Workrave.
Steve Wright: All right, I will look into those. I can use all the help I can get as far as keeping me on schedule.
Chris Kresser: Yeah, it’s great.
What Did Chris Eat for Breakfast?
Steve Wright: Cool. So our listeners want to know, Chris, when you woke up this morning, what did you have for breakfast?
Chris Kresser: Well, actually recently I’ve kind of gotten off the intermittent fasting kick and I was having three meals a day again, but this morning I was back on it, so I didn’t eat until about 10:30. I had some mostly decaf coffee with cream first thing in the morning, and then I ate some leftover ground beef that was cooked in a bunch of different spices, almost like a taco seasoning with paprika and cumin and coriander, some black pepper, salt, and then simmered in homemade chicken broth and tomatoes, like an organic tomato puree that we buy in a jar. And then I had some plantains fried in a blend of ghee and coconut oil and then this killer new batch of sauerkraut with cabbage and beets and ginger and carrots that Elanne, my wife, made. It’s the best that we’ve ever made. It’s really crunchy and good. I should clarify probably, too, that when I say we’re eating — I think most of the listeners know this, but some don’t apparently on Facebook. People were saying: How can you eat sauerkraut with breakfast? And it became clear that they were thinking it was the sauerkraut that you buy like in the condiment section of the supermarket. That really mushy —
Steve Wright: Gross.
Chris Kresser: Disgusting, stinky stuff. And I was like: Eww. It’s true. I couldn’t imagine eating that for breakfast or any other time, for that matter. So this is raw homemade sauerkraut — a completely different thing. And then I had about a cup of kefir to wash it all down. So that was my breakfast, and Sylvie and I had breakfast together. She sat in the high chair right next to me, and she had some of the ground beef as well, but I chopped up some steamed broccoli with some butter, and I mixed it into the ground beef. That’s one of the ways that she likes to eat broccoli — with beef. Who doesn’t? And then she is on a raspberry kick right now, so she had some raspberries, and then she also had some sauerkraut, which as a lot of listeners know, is one of her favorite foods. So that was her breakfast.
Steve Wright: That sounds pretty delicious. Yeah, I mean, one of my favorite things to do is literally scramble up some whole eggs and just salt and pepper and then pile on the real, raw sauerkraut and just eat that.
Chris Kresser: Um-hum. Eggs and sauerkraut are a great combo. I agree.
Steve Wright: Awesome. Well, you’ve been pretty busy lately, and you have a lot of balls in the air, so I think you’re probably due for some updates, right?
Chris Kresser: Yeah. Should we do that now or start the show and do that afterwards? What do you think?
Steve Wright: Well, how about you think about when you’d like to do it, and in the meantime while you’re thinking and the gears are working, I’m going to tell the listeners about Beyond Paleo. If you’re new to the paleo diet or if you’re new to this show or just interested in optimizing your health, you’re going to want to go and check out what over 30,000 other people have signed up for. This is called Beyond Paleo, and it’s a free 13-part email series that Chris has put together on his best tips and tricks for burning fat, boosting energy, and preventing and reversing disease without drugs. So head over to ChrisKresser.com. There’s a big red box when you get there. Go ahead and put your name and email in those boxes, and Chris is going to start sending you those free emails right away.
So, Chris, what’s your preference? Should we do it now or later?
Chris Kresser: Yeah, let’s do it. I just want to give a few updates. Lots of interesting stuff going on — at least to me! I mean, it’s definitely keeping me busy, so PaleoFX is coming up next week, coming up quickly actually, and I’m headed out there on Thursday. It’s going to be kind of a shorter trip for me because of everything else that’s going on, but I’m arriving Thursday, I’m on some panels on Friday, and then I’m doing my talk on Saturday morning and then leaving not too long after that and coming back. My talk is going to be similar to what I did at the Weston A. Price Foundation on the gut-brain-skin axis. I’ve just continued to research that. It’s really fascinating to me, and I think it’s a great subject for a lot of people, and frankly I just have not had time to prepare an entirely new presentation on a completely new topic from scratch. It’s really time intensive the way I put the presentations together, and you know, how much research I review as part of that process, it’s a little bit overwhelming, especially with the book and everything else that’s going on and AHS coming up. But I don’t think there’s that much crossover between PaleoFX and the Weston A. Price conference last year. I apologize to the few people that will be there that have already seen the talk. Hopefully, you’ll pick up some good new nuggets that I’ve added, but I think others will enjoy it who haven’t seen it yet.
And I have some bad news, which is that I just heard from the organizers of AHS that due to some kind of miscommunication with the media crew, my talk on iron overload was not recorded from AHS last year, so that was a real disappointment for sure and especially because I get several emails a week from people asking when that’s going to be available. So here’s what I’m going to do: I’m going to record my voice over the slides and maybe even get a transcript done for it and then just make it available for free through my website or something like that. It’s an important subject. I want it to be out there and available, and I thought it would be and it’s not, so I’m definitely going to do it. I can’t promise a delivery date on that just because of everything else that’s going on, so just be patient for a little bit longer, and hopefully I’ll be able to knock that out in the not-too-distant future. It’s about a 40-minute talk, so it’s not impossible to find the time, but even 40 minutes right now is difficult, and of course, all the other things that go into that, recording it and producing it and stuff like that.
So yeah, hopefully that won’t happen this year. I’m really excited about my talk at AHS this year. The title is “Are Parasites Paleo? The Hidden Cost of Modern Hygiene,” and I’m going to talking about the hygiene hypothesis, which is now called the old friends hypothesis, which is the idea that we co-evolved with a number of different organisms, including parasites, that may actually have a beneficial impact on our immune system and that modern sanitation and hygiene, although it has undoubtedly had a lot of benefits, like reducing infection, has perhaps contributed to the epidemic rise of autoimmunity, allergies, asthma, and other conditions involving immune dysregulation.
And in fact, we’re going to have Moises Velasquez-Manoff as a guest on the show for the next show, which is really exciting because he wrote the kind of definitive layperson text on this subject, the book called An Epidemic of Absence, which I know a lot of listeners have read, and if you haven’t, you should definitely check it out. But he’s going to be a guest on the show, and he’s actually moving to Berkeley, I heard, so I’m excited to meet him. We’re going to have lunch and talk shop and totally geek out about the immune system and old friends. So that’s exciting. He’s really gracious to join us on the show, and I think everyone’s going to enjoy that a lot.
Book news: After a long process of deliberation and exploration, I just earlier this week signed with an agent named Richard Pine at InkWell Management, and he represents some people you’ve probably heard of, like Andrew Weil and Mark Hyman and Martin Seligman and Wayne Dyer and some other pretty heavy hitters in the health and nutrition space. That was a really interesting process. Definitely when I started this whole journey of deciding to write a book, I was originally thinking I might self-publish, and then there was the idea of publishing with a smaller publisher, and then there was an idea of going for one of the ‘Big Six’ main publishers without an agent, and then after going to New York and meeting with a bunch of different agents and talking to several people, I decided that a really skilled, experienced agent has a lot to bring to the table and especially with how full my plate is in other ways, I just want to focus on being an author and not being a publisher or an agent myself at this point, and so I’m really excited about that. And I have some offers from some publishers and will be going back to New York again in April to meet with some other publishers, so hopefully by the end of April or maybe May I’ll have a verbal deal and then looking at publication maybe in early 2014 or spring 2014. The good news is I’ve been writing all along the way here. I have about 90,000 words, so that’s about three-quarters finished, and the next three months I’m really going to have to just put my head down and try to finish it off because I’d like it to be published as early in 2014 as possible. We’ll see how that goes.
Steve Wright: Well, that’s awesome. Congratulations, Chris. I think I can say that for myself and Jordan and all of our listeners. It’s amazing to hear you go through this process and have you share it with us, and I know we all can’t wait to see the manuscript or the book, I guess, when it comes out. That’s really exciting. And a total bummer on the AHS talk, because I was there and it was a great talk, but I guess when you do it yourself and you screencast it, you can take your wakey breaks and maybe you’ll be really refreshed for it.
Chris Kresser: Yeah. I mean, arguably it’ll be better for people because they’ll be able to see the slides more clearly and we can get maybe a transcript or something like that, but it is a bummer, you know, just from a timing perspective for me. Stuff happens. I’m not bitter about it or anything like that. It’s just an unfortunate thing.
So there’s one more announcement, and then we’ll go on and get into the show. There are a couple new programs coming soon that I’ve been working on, and I think I’ve mentioned one of them before. It’s called the Personal Paleo Launch Pad, and basically one of the main requests that we’ve had from blog readers, podcast listeners, people who’ve purchased Healthy Baby Code or High Cholesterol Action Plan or the Personal Paleo Code or even the Meal Plan Generator is more support. It’s really difficult when you’re starting a whole new diet and lifestyle and especially if you’re the only one in your family or your circle of friends that’s doing it and you don’t have a lot of experience, maybe, with food preparation or making these kinds of transitions. It can be pretty intimidating, and I’ve just seen in my work with patients and just my experience in this space that the people who succeed and do the best are usually the people who have some kind of support system.
So I’ve been thinking for a while about how to provide that in a way that’s accessible to the greatest number of people, and so the Personal Paleo Launch Pad is what we’ve come up with. And what it is, is it’s basically a collection of tools and resources. It includes the Meal Plan Generator, which, as I’m sure most of you know, is a web application that allows you to generate full meal plans for a day or a week that include only the ingredients that are safe for you. So if you’re on a GAPS Diet, you can generate a GAPS meal plan. If you’re on a low-carb or very-low-carb diet, you can do that. If you’re doing a 30-day challenge or reset, the autoimmune version, you can do that. We’re getting a low-FODMAP version ready. There’s a quick-meals option for people who are really busy and only want recipes that take about 15 to 20 minutes to prepare. It also has an index so, like, if you have some beef on hand, you can look up “beef” and it will show you all the recipes that we have in there. There are about 700 recipes in there now from some of the best recipe sites in the paleo world, like Nom Nom Paleo and Health-Bent, and some original recipes from myself and my team. So that’s the Meal Plan Generator, and then there’s the progress tracking tool, which is a web application that helps you track your progress, your weight, your waist-to-hip ratio, and then a bunch of other categories, like digestion and sleep, energy levels, blood sugar, skin. And so it charts out your progress over time so you can stay on track and stay inspired as you move through the transition period.
And then there’s going to be a moderated forum, which I’m really excited about. I’ve had a lot of requests to put a forum on my public website, ChrisKresser.com, and who knows? I may do that at some point, but the reason that I’ve not done that for such a long time is that I really don’t like a lot of the public forums. I think they’re rancorous, and the kind of general tone is hostile and not very helpful. There’s a lot of name calling and personal attacks and a lot of contradictory and conflicting information, and a lot of my patients just have complained about how confused they get when they go onto some of these forums and get seven different answers all saying different things. It’s not that I don’t think that some of these forums can be helpful. It’s just that I think in some way they might do as much harm as they do good, and in any event, I’m not comfortable with the tone and the way that a lot of conversations happen on forums like that. So I always knew that if I was going to do a forum it would be a moderated forum with a really civil dialogue, a supportive vibe with a lot of people who are just most interested in helping each other out and not in intense debates and driving their own agendas and being right.
So the forum is going to be moderated by four or five paleo ambassadors, which are volunteers from the community that have a lot of experience in the paleo world and who just genuinely want to give back to the paleo community, and then there’s going to be Kelsey, our licensed paleo RD, who is going to be one of the supervisors and Laura who is getting her RD now and will have it pretty soon, also extremely knowledgeable, and both of them are trained in the Personal Paleo Code approach. So I’m really excited about the forum component of this.
And there’s going to be a biweekly Q&A with Kelsey and Laura and with guest appearances by me, so people will have another way of getting their questions answered about the Personal Paleo Code or just the paleo diet and lifestyle in general. There will be a monthly seminar on special topics of interest in this genre with myself and then special guests and luminaries in the paleo/real food genre. And then there will be a discount on Paleologix supplements for anyone who is signed up for that. So it’s going to be a monthly subscription. It’s going to be a little under $10 a month, and it’s going to be launching, I think, in the second week of April or something like that. So I’m really, really super excited about that. [Note: The Paleologix supplements discussed in this post are no longer available. Please click here to view the products recommended as substitutes.]
Steve Wright: Yeah, it sounds very cool, and I want to echo — I think you’re a couple years ahead of me, Chris, not like light years, but I started out kind of the same fashion, bumping around on various sites and trying to find info, and the wrong message board can do as much harm as one good message board can do for the whole Internet, so I’m really happy to hear that you’ve constructed it this way, and I think it’s going to help a lot of people.
Thoughts on “Paleofantasy”
Chris Kresser: OK, so I know we’re 20-something minutes into this, and I imagine some people are getting antsy to hear about some other stuff, so let’s move on. The first thing I want to talk about is Marlene Zuk’s book called Paleofantasy. I’m sure a lot of people have seen references to this online. It’s caused quite a splash in the paleo community. She’s an evolutionary biologist. I think she works at the University of California, Irvine. And she’s written some articles before this book on the same subject. I haven’t actually read the book. I’ve read her articles. There was one in The New York Times. And then I’ve read some reviews of her book by John Hawks and then one in The Wall Street Journal. And her claims, at least in the articles that I’ve read and based on the reviews that I’ve read, as they relate to the paleo diet and lifestyle, can be boiled down to these three concepts: One is that she says the idea that human evolution stopped in the Paleolithic Era is false and that it may, in fact, even be faster now than it’s ever been before. Number two, that there never was a time where humans were perfectly adapted to their environment. It’s always been a messy, kind of chaotic transition, and it’s more of a fluid process than a static event, this idea of adaptation. And number three, that there never was a single paleo diet or lifestyle or environment, and that when you look back in the late Paleolithic, the diversity of diet and lifestyle among different groups around the world was probably much greater than the diversity that exists between diets and lifestyles in modern times in different parts of the world.
So those were her three arguments, and her conclusion was that because of all those three things, the basic premise behind following a paleo diet and lifestyle is fantasy and unscientific and should be thrown out, essentially. Actually I agree with many of her points, and that might not come as a surprise to some of you who have read a lot of my work, because I’ve written and spoken about these things before. And I even agree with some aspect of her conclusion, but not all of it. I think there’s a little bit of a straw man argument going on here. Another phrase that comes to mind is throwing the baby out with the bathwater. John Durant had a bit of a scathing critique of the book and a very pithy tweet that said Paleofantasy should’ve been a blog post in 2010 rather than a book in 2013. And what he meant was that some of these critiques that she’s making have already been widely addressed in the paleo community and discussed a lot, and it doesn’t in any way invalidate what we’re doing here. So let’s take a look at each of her three may claims, and I’ll tell you a little bit about what I think of each of them, and then we’ll talk about her conclusion.
The first claim is that evolution didn’t stop in the Paleolithic. I think that’s absolutely true. I’ve talked about that a lot before. Mat Lalonde and I talked about that in our interview. I’ve written a few articles about that on my blog. I’ve used lactase persistence as an example, as she did in her articles and in her book. She uses that as an example of how evolution has continued in such a way that it can help us adapt to new foods that weren’t around during the Paleolithic area. I’ve also mentioned, and Mat and I talked about this, epigenetics. Changes in gene expression can happen in as little as one generation, and that can actually make us more or less tolerant of a certain food and cause other pretty profound changes. I’m not sure if she goes into epigenetics in her book, she didn’t in the articles that I read, but that’s another way that genetic or epigenetic changes can make us more or less fit for a modern environment in a really short time. However, on the other hand, we have to consider that lactase persistence is a really crude mutation. We normally have a gene that turns off our ability to digest lactose right after weaning or around the time that we’re weaned. And what lactase persistence is as a mutation is it just breaks that gene. It breaks that gene so that our ability to digest lactose doesn’t get turned off. So that’s a pretty crude or shallow mutation involving one single gene. It’s a lot easier to break something than it is to create something from scratch, so more complex mutations that would involve several different genes, which would be necessary for us to completely adapt to eating and processing cereal grains or legumes, for example, that would take a long time, and there’s not much debate about that. Those kinds of genetic changes take tens, hundreds of thousands of years or more to become fixated in a particular population. The example that Mat Lalonde used was, like, growing wings. Something on that level is going to take probably millions of years to evolve. It can’t happen in a few generations. It can’t even happen in a few thousand years. So we have to consider the scale and the complexity of the mutations that we’re talking about.
Some simple mutations definitely have occurred that might make some of us more or less tolerant of Neolithic foods, like dairy, which is one of the reasons why I’m always talking about the importance of individual variation and experimentation, but that doesn’t mean that none of the rules of evolutionary biology are true anymore and we’ve magically had all these complex mutations that would help us adapt to a modern environment. That’s a huge exaggeration, and it’s just not true. And even with lactase persistence, as quickly as that’s gone in the last 10,000 years, still only a third of the global population has that mutation, so still the majority of people in the world can’t digest lactose in adulthood very well.
The second idea is that humans never were adapted to a paleo lifestyle, or there wasn’t a kind of fixed period of adaptation where everything was hunky-dory. I think that’s true, too, but on the other hand, you have to consider that people living in the Paleolithic Era had a million and a half years, really, to adapt to the basic diet, which was vegetables, fruits, tubers, meat, fish, nuts, and seeds. Those foods have been a part of our evolutionary milieu for a very long time, and we had a long time to adapt to those. So even if the environment was changing a lot and the exact composition of those foods was changing a lot — which it was — and different groups in different parts of the world ate different compositions of those foods — which they did — You know, we have evidence even of modern hunter-gatherers, which I’ve talked about numerous times, that some people like the Kitava eat just a little bit of fish and a lot of tubers and fruit. People like the Tukisenta have even more of their calories from tubers, like 97% or something like that. And then you have the Inuit, who get most of their calories from fish and fat or sea mammals. And then there are a lot of examples in between. So it’s true that there was never a typical paleo diet and that there was always a process of evolution and adaptation going on, but it’s also true that neither the Inuit, nor the Kitava, nor the Tukisenta, nor the Okinawans, nor any of their ancestors anywhere in the world — We can say without a doubt that they weren’t eating Twinkies, they weren’t eating Cheez Doodles, they weren’t drinking Super Big Gulps or donuts. They also weren’t consuming grains or legumes as staples. There’s some recent evidence that suggests that some groups as far back as the Neanderthal time were eating some cooked grains or legumes, but most of the evidence suggests that those were not staples for most people. So again, there’s a middle ground here where we can say: Yes, there was never a time of complete adaptation, but there are foods that we’re much better adapted to eating than others, and those are the foods that form the paleo template that we talk about so much.
And kind of getting back to what I was saying before, just because we’ve had some minor adaptations to some aspects of the modern lifestyle, that doesn’t mean we just throw out the entire concept of mismatch, which holds that we’re genetically and biologically adapted to a general paleo type of template. I think that’s still a very valid concept. It still can really help guide our exploration into nutrition and health. And even if there’s plenty of room for individual variation within that and even if there are examples where we might be adapted to certain parts of the modern lifestyle, it doesn’t invalidate everything else we can learn from looking through that lens.
So I think we’ve pretty much covered all of the arguments there. Essentially, my take on it is Paleofantasy is a really catchy title, it’s probably a good way to sell books, but it’s a big of an exaggeration, and it maybe refers to an earlier argument for the paleo diet that didn’t incorporate these distinctions that we’ve been talking about, and I don’t think it’s any cause for concern or in any way threatens the message that we’re trying to get across.
Steve Wright: Yeah. I think we should all pour a glass of your favorite drink, whatever that might be, and then toast her, because I think she’s doing us a lot of good by stirring the pot and getting us a bunch of publicity because it appears that she’s just not up on how the evolution of paleo and eating what I would see as a low-inflammation, low-allergy diet and the various references and reasons why you might want to do that. So I think this is just a great sign that we’re reaching more and more people, and I guess she’s going to make money on some books, and hopefully the people that buy her book will also buy some other books.
Chris Kresser: Yeah. If we were in a room talking about this stuff, I’d probably agree with her more than I would disagree with her, but there are some key points of disagreement, which I hope I made clear. I also just want to end this by just shifting gears completely and saying that I think we can justify the paleo nutrition approach without even resorting to the evolutionary argument whatsoever, and I’m going to do this in my book. You can look at paleo nutrition just strictly using modern research, and you can make an argument for it, and people like Mat Lalonde these days are almost exclusively talking about it in these terms to avoid the kind of misunderstanding that can happen that we’ve just been talking about. But if you think about maximizing nutrient density, so making your diet focus on the most nutrient-dense foods and eating less of the least nutrient-dense foods, what do we see if we do that? Well, guess what foods are the most nutrient dense, Steve?
Steve Wright: Uhhhh, wheat.
Chris Kresser: Haha, either that or beef liver, organ meats. I’m referring to this in my book. It’s a peer-reviewed study using a scale of nutrient density that is actually even stacked against animal products because they penalize foods for saturated fat and cholesterol and salt. But even considering that, even with the deck stacked against them, animal products are still number one on the list. So organ meats were number one in terms of nutrient density, and then muscle meats and fish and poultry were number two in terms of nutrient density. The next category is vegetables. And then after that, you have fruits and nuts, depending on the fruits and nuts switching places. And then whole legumes are after that, and then whole grains. And then you have processed, refined grains and sugar at the bottom of the list and seed oils. So if you evaluate foods just on the basis of nutrient density using modern, clinical, peer-reviewed research, the paleo diet still looks pretty good.
And then the next thing would be minimizing toxins, and using that same argument, we look at foods that have immunogenic or allergenic proteins. We look at things like phytic acid, which can inhibit mineral absorption. Phytic acid is in a lot of foods, including good foods like spinach and greens. In fact, there’s more phytate in spinach and greens than in some grains and legumes, so it’s not that we need to avoid that entirely, but the reason it’s not as much of a problem in greens is that the greens are just so nutrient dense that we’re going to absorb a lot of other nutrients from the greens that aren’t inhibited by phytate. So it’s not that phytic acid withdraws any nutrients that are already stored in your body. It just prevents you from absorbing certain nutrients, primarily minerals, in the foods that you eat.
So it’s about maximizing nutrient density and minimizing toxins. It’s not eliminating toxins, because that’s pretty much impossible to do. And it doesn’t mean only eating liver either. It’s a spectrum or a scale. But if you look at the foods that have the lowest levels of toxins, they’re often the most nutrient-dense type of paleo foods that we talk about as well, and grains and legumes have relatively low nutrient density and relatively high toxin levels, so that makes them subpar foods. Does it mean we should never, ever eat them? It’s hard to make that argument. It’s hard to make an argument that if someone eats a diet of whole grains and legumes and animal products and vegetables and fruits — let’s face it; that’s a pretty healthy diet. It’s unlikely that that diet is going to be associated with a lot of disease. But can we improve on that? Well, one way to improve on that right off the bat is soaking the grains and legumes to minimize the toxins and improve bioavailability of nutrients. And in my opinion, another way to improve on that further is to just decrease your intake of those foods and step up your intake of foods that are more nutrient dense. The problem with eating a lot of grains and legumes is it means you’re probably going to eat less of foods that are more nutrient dense. It’s not even necessarily that the grains and legumes are super problematic on their own, especially if they’re prepared properly.
That brings me back to another point about nutrient density. The studies that examine nutrient densities, like the one that I just referred to, they don’t even take bioavailability into account. So not only is the deck stacked against animal products by the fact that anything with saturated fat and cholesterol and salt is penalized on these scales, it’s also the fact that bioavailability of nutrients is not taken into account also makes the differences seem less than they would be otherwise. If we consider bioavailability, organ meats and animal products and vegetables would be even further ahead of grains and legumes because the nutrients in them are so readily available and absorbable by the human body.
And then there are several other categories that I’m going to mention in my book that aren’t so specific to paleo, like the difference between eating organic and local produce and pasture-raised meat and wild fish from conventional varieties and the importance of eating from nose to tail, like eating all the different parts of the animal, and then the discussion on fats, you know, saturated and monounsaturated fat and omega-3’s and omega-6. So if we use completely modern research, all peer-reviewed evidence, we can make a very strong argument for a paleo template type of diet without ever even referring to the anthropological evolutionary argument. So that’s going to be a big focus of my book, is making a kind of modern argument for the paleo template approach using the latest genetic research that we’ve been discussing, addressing and including all of Marlene’s critiques, which we’ve talked about before, and then making a really strong argument for paleo just from a modern scientific perspective.
Steve Wright: Well, I’m very excited for that book, and that’s why I eat Paleo/Specific Carbohydrate Diet/Weston A. Price — whatever you want to call it — real food diet. Obviously the anthropological stuff is cool to speculate on, but I’m bigger on the hard sciences as well, and I think it’s overwhelming at this point. We just need to get more people to know about it.
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The Latest Research on Cholesterol Numbers
Chris Kresser: Yeah, exactly. I couldn’t agree more. So let’s do one more thing before we finish. I’m going to be writing a blog post about this. I think it’s scheduled for April. I’ve already written it actually. I think it’s scheduled for April 12 or something like that. I read a pretty interesting study — This is kind of a sidetrack but it relates, so I’ll make it relevant. — I have a newsfeed that pulls articles about cholesterol and heart disease. As I’m sure many of you know, that’s been a longstanding interest of mine. So there was a recent article talking about the superiority of testing LDL particle number, not particle size, like large fluffy or small dense, but the actual number of LDL particles as being the most important risk factor for heart disease. I talk about this at length in the High Cholesterol Action Plan. In fact, that’s one of the main reasons I created that course, because it’s such a profoundly important thing to understand. And I’m going to be writing a series on my blog about this soon just to bring everything up to date.
So these authors were saying it’s now abundantly clear from all of the research that’s been done that we should be measuring LDL particle number to gauge people’s risk for heart disease and not LDL cholesterol or total cholesterol, which is still what everyone is getting measured when they go to see their doctor. That’s by far, I’d say 99.9% of doctors, that’s what they’re doing to gauge heart disease risk, and it’s not really even controversial at this point in the scientific literature that LDL particle number is much more predictive of heart disease. So the difference, to use an analogy, is that if your blood stream is a river, the LDL particles are like boats that navigate around the river and the cholesterol is like cargo inside of those boats. When you get total cholesterol and LDL cholesterol measured at the doctor, that is looking at the amount of cargo inside of the boats, whereas we should be measuring the number of boats. Why? Because atherosclerosis is a gradient-driver process, and the more LDL particles you have in your blood stream, the more likely it is that they’re going to penetrate the fragile endothelial lining and start the whole process of plaque formation.
So that was kind of a long preface, but I wanted to read you this quote at the end of the paper as a kind of lead-in to this brief discussion we’re going to have about BPA, bisphenol A. So the quote is:
Some have expressed concern that introducing [LDL particle number] into clinical practice will result in confusion to both physicians and patients, and that the public may lose confidence in the healthcare system if cholesterol, which has been emphasized for decades, is challenged as the primary means of risk assessment.
So essentially they’re saying that some doctors are worried that if we tell you the truth, you’re not going to trust the medical system because we’ve been telling you something that’s not true for decades as a kind of justification for not telling the truth, which is just mindboggling to me. It’s absolutely crazy. I mean, I think they’re right. People will lose confidence in the healthcare system, but that’s not an excuse for not giving people information that could potentially save their lives and avoid a lot of unnecessary treatment.
So what I wanted to talk about is the importance of maintaining an open mind and a spirit of curiosity when you’re involved in scientific research, because if you really think about it, the history of science is really the history of most scientists being wrong about most things most of the time. At some point, everyone thought the world was flat and the sun revolved around the earth and it was heresy to think otherwise. We all know the connection between cholesterol and heart disease, the connection between salt and hypertension, the connection between stress and ulcers, this idea that low estrogen in menopausal women was causing heart disease and that if we gave them estrogen they would get better. Of course, they didn’t; they got worse and had more heart disease. There are so many examples of where we were wrong and we later found out that we were right, and what’s crazy to me is that we look back like a hundred years ago and laugh at the theories from that time, but we forget that people in a hundred years are going to be looking back and laughing at our theories!
Steve Wright: Yeah.
Chris Kresser: So a little humility, I think, would be really helpful for all of us in the research community and clinicians and scientists because why do we think it’s going to be different for us? A lot of what we believed even 10 or 15 years ago is turning out to not be true. And it may not be completely false, but we expand our knowledge all of the time. For me, three or four years ago, I didn’t know about LDL particle number. I knew that something was wrong with the typical way of looking at things with cholesterol and that the amount of cholesterol in the particles was not the driving factor of heart disease, but I wasn’t aware of all of the research — and there wasn’t as much of it then — linking particle number to heart disease. And so perhaps I went too far from being a cholesterol believer too far to the other end of the spectrum of being a skeptic. I mean, I still am a cholesterol skeptic, but to say that lipids have nothing to do with heart disease is a gross exaggeration and misunderstanding.
BPA Toxicity Research Updates
I want to bring this back into the context of BPA because that’s what I originally set out to talk about. I’m sure a lot of you have heard and maybe even read on my blog that bisphenol A, or BPA, is a harmful chemical that has estrogenic effects, and because of its estrogenic activity, it leads to numerous health problems ranging from obesity to infertility. And there was tons of animal evidence that supported that idea, and there were big scientific and environmental organizations that came out and made consensus statements about how harmful BPA was, and there were tons of media reports suggesting that. And I came across some research recently and have been looking into it further that is definitely challenging that view and changing my take on it, at least in terms of its estrogenic effects. A lot of that animal research was probably not reliable because the researchers used doses of BPA that could never be obtained by humans in a free-living environment. They also used methods of administration like injection or implanting BPA that don’t reflect real-world routes of exposure, and that’s important because we have some defense mechanisms, like the gut and mucosal barriers that help mitigate exposure to toxins.
And one of the main principles of peer-reviewed research is that initial result has to be repeated in larger studies by other labs in other places, and in terms of BPA’s estrogenic effects, that doesn’t seem to have happened. The follow-up large studies have found that even at levels 4000 times higher than the maximum exposure that humans get in the general population, there are no discernible estrogenic effects, and studies conducted by other groups on oral exposure to BPA at doses that are obtained in everyday life have also failed to find any negative effects on reproductive health or sexual development.
The guy that published this commentary in the journal called Toxicological Sciences is named Dr. Richard Sharpe. He is a global expert on male reproductive health. The article was great, but what I was most fascinated by in the article was his commentary on science and the importance of realizing that science is a kind of messy process that involves a lot of gray area and very little black and white, so I want to read you a quote from his commentary. He says:
Anyone involved in biomedical research knows that scientific “facts” that remain untouched by the ravages of further research are a rare commodity. Usually, most facts change their form with time (evolve), and their meaning, and probably their importance, will also change. Disappointing as this may be for our scientific egos, it represents something far more important — scientific progress. It is inevitable that scientific progress, in the form of new facts, will trample over our bright ideas, hypotheses, and even over our results. This apparently destructive process is in fact constructive, and as scientists, we have to embrace this evolution and accept that the sacrifice of our initial beliefs (and our precious results and interpretations) is part and parcel of advancing understanding.
So this guy is one of my new heroes. It’s one of the most refreshing and honest passages I’ve ever seen in a scientific paper, and it feels like that should be some kind of mandatory reading for anyone who’s working as a scientist or going into science. I think a lot of scientists do understand that, but maybe policy makers and the media and clinicians and the general public want certainty and black-and-white answers because those are things that we can act on and create policy around and make treatment decisions based on, so it’s completely natural and I understand why people crave that kind of certainly, but unfortunately that’s just not the way science works for the most part. Here’s another section:
What is never stressed enough is that scientists work at “the borders of ignorance” — what is in front of us is unknown, and we try to find our way forward by making hypotheses based on what is known. This means that we are wrong most of the time, and because of this, scientists have to be very cautious about interpretations that are based on our projected ideas about what is in front of us. What decision-makers, politicians, and the public want is unequivocal guidance, not uncertainty. So this creates a dilemma for scientists. Those who are more prepared to throw caution to the winds and make unequivocal statements are more likely to be heard, whereas a more cautious scientist saying “we’re not sure” will not be taken notice of. The bisphenol A saga has until recently been a story of such contrasts.
So I think it’s a good cautionary tale, and it’s a great reminder to me to keep an open mind like I said before and approach this with a spirit of curiosity. I know I’ve been wrong before. I know that I’m going to be wrong again. It’s really good to remember that and to kind of loosen up around even my most deeply cherished ideas and beliefs, and I think that that makes me a better clinician, it makes me a better author and blogger, and I can serve all of you as listeners and readers better if I embrace that kind of attitude. The only promise I can really make to you is that I’m going to continue to be honest and admit when I am wrong and share and continue to learn and continue to challenge my beliefs so that I can grow and evolve as a clinician and we can continue to get closer to the truth even though we’ll probably never, in our lifetimes, know with certainty the answers to some of these questions. And that’s uncomfortable and messy and disturbing, and dealing with that kind of uncertainty can be really frustrating, but it’s really the best we can do.
Steve Wright: Well, I appreciate all your research, Chris, and I think that I can speak for a lot of people when I say that’s refreshing what you’re saying here and admitting to, and that’s the reason why a lot of people look up to you. And that’s a reason why I try to do the same thing because I feel like with the new media, so like the prevalence of how much access we have to Chris Kresser, for instance, whom we wouldn’t have had much access to back even 50 years ago, I think people that are younger are looking for those to admit that they’ve failed and that they’re wrong because as the media grows more and more, if you’re not admitting that, then I think some people’s ears kind of perk up and getting the bullshit detectors coming through.
Chris Kresser: Yeah, well, the thing is too there’s a public record of you being wrong! All someone has to do is go and, like, take a screenshot or your tweet when you said the wrong thing or your Facebook post or your blog post or whatever. I mean, there are some articles on my site that I’m like: Oh man, I need to update that. I need to change it. My view on that has evolved. And there are 400-plus articles, so it’s really hard to keep up with everything and keep everything up to date. I’ve done all the things that I think are most important and most significant, and I’ll also use the podcast to do updates like this, but it’s really hard. I’m not a scientist. I’m a clinician, and I do my best to keep up with the research because it informs the way that I work with people, but it’s impossible for me — you know, I’m not a reproductive endocrinologist. I’m not a researcher that’s looking at these studies every day, and so I may have become aware of the deficiencies in the early research earlier had I been working in that field, but it’s not my field and I was, like everyone else, somewhat reliant on the organizations that are supposed to be doing this kind of due diligence and vetting the research, and it was an oversight on my part, and I apologize for that because I definitely made claims in the past that BPA is estrogenic, and that was my understanding.
I do want to say, though, before we conclude that the jury is still out, in my opinion, on whether BPA is safe as a chemical to consume in the amounts that people are getting it, because there are other concerns above and beyond its estrogenic effects. Some studies suggest that it may increase intestinal permeability. There are studies that it causes some harmful changes in the brain that can cross the blood-brain barrier, and I think in situations like this where there is uncertainty and we don’t know the answer, you have to do a kind of cost-benefit analysis. And for me, the cost of reducing my exposure to BPA is relatively minor, and it’s something I would do anyway. I don’t like drinking water out of water bottles, and a lot of plastic water bottles don’t even have BPA anymore, but I’ve never liked the taste of water that comes out of a plastic bottle, and environmentally I have a problem with them, so I use a stainless steel water bottle. Not a big deal. I just use stainless steel food containers for storage at home. I don’t have a lot of plastic in my life, and there are a lot of reasons for that, so it’s not that big of a deal for me to avoid BPA. And the upside if it does turn out to be healthy, I think, is a lot greater than the downside of taking steps to reduce your exposure to it. So from a practical perspective, I don’t really think this changes anything in terms of the recommendations I’ve made of minimizing your exposure to BPA, but it appears that BPA may not have estrogenic effects and the effects that are related to that, like reproductive problems and infertility. So I go into a little more detail in the article. It is going to be published on April 12, I just looked it up, and I’ll continue to report on it as I learn more.
Steve Wright: Well, Chris, I don’t know if you intended to do it, but I think today’s show has been a complete overview of kind of what happens as we generate new and trending ideas and then those ideas get more eyes on them and the science evolves, because just as the paleo concept has evolved and the recommendations still basically are the same, the reasons why continue to change, and it sounds like we’re kind of starting to see that with plastics, so I think that’s a great way to wrap it up.
Chris Kresser: Yeah. Thanks, everyone, for listening. I know the update part of the show ended up being a lot longer than I thought it would be, but hopefully some of that information is useful to you. Stay tuned for the Personal Paleo Launch Pad if you’re interested in that. It’ll be available soon. Hope to see some of you at PaleoFX. I’ve heard from quite a few people that are going, and I look forward to meeting you there. And if not, maybe at the Ancestral Health Symposium later in the summer.
Steve Wright: Yes, tickets just went on sale for AHS, so buy your tickets.
Chris Kresser: That’s right. Thanks for reminding me of that. OK, Steve, thanks again, and we’ll see you next time.
Steve Wright: Yeah, thanks, Chris. And if you want to follow more of Chris in between these shows, please head over to Facebook.com/ChrisKresserLAc, and for quick tweets and updates on what’s going on with Chris and the research, head over to Twitter.com/ChrisKresser. We appreciate you listening to the show today. Please keep sending us your questions at ChrisKresser.com. I still have them all. We will get to them. Use the podcast submission link when you’re at the show. And if you enjoyed listening to the show, head over to iTunes and leave us a review. It really helps get the word out. We appreciate you listening. Thanks.
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