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Episode 3 – Blood Type Diet, Anemia, Pcos, Statins & More


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The podcast is back! After a long hiatus, I’ve decided to start it up again and continue on a regular (bi-weekly, for now) basis with my new co-host, Danny Roddy.

It will be a Q&A format, so make sure to send us your burning questions. We’ll also have special guests on occasionally. Stephan Guyenet, Kurt Harris and Paul Jaminet are already lined up. If you’ve got ideas for people you’d like us to have on the show, let us know.

In this episode we cover:

  • The Blood Type Diet
  • Anemia, ferritin & supplemental iron
  • Polycystic ovarian syndrome (PCOS) & pregnancy
  • Statins & cardiovascular disease
  • Vitamin A toxicity (or lack thereof)
  • Side-effects when cutting carbs

Full Text Transcript

Danny Roddy: Hello everyone, and welcome to The Healthy Skeptic podcast. My name is Danny Roddy and with me is Chris Kresser, health detective and creator of TheHealthySkeptic.org, a blog challenging mainstream myths about nutrition and health.

Chris, are you excited for our first episode?

Chris Kresser: I’m definitely excited, been looking forward to it for a long time. Yeah, can’t wait. And why don’t you tell everyone a little bit about who you are, Danny, and how we got together and what you’re interest in all this stuff is.

Danny Roddy: Basically, I got real sick in my early 20’s. Kind of roamed around, tried to figure out things for myself. I’m a self-proclaimed diet experimenter, but I’m going back to school for nutrition and I’m just really passionate about the subject. And I’m really just trying to learn everything I can.

I stumbled upon your blog and I really respect your evidence-based approach. And when you mentioned that you were looking to do a podcast I just jumped at the opportunity because I thought it sounded so fun, so to be a part of this is really an honor. So, yeah, I’m excited.

Chris Kresser: Yeah, and I’m glad you showed up! Because as you know, I started a podcast a while back, I don’t know, maybe several months ago. And I did an interview with Stephan Guyenet, which is great, I really loved that. And I did a podcast on fish oils and essential fatty acids. And then I was graduating, and finishing school, and I was studying for the licensing exam, and things just got really crazy and I couldn’t keep it up myself.

And I had the idea that, Hey, if I had somebody else helping me, and if it was more interactive, then it would be easier to maintain. So that’s the idea now, and I think we’re going to try to shoot for twice a month, to begin with. It seems maybe a little more doable than every week, at least for me, right now. And the idea is to do a Q and A format, pretty similar to Robb Wolf and Andy Deas’ Paleo Solution. I know a lot of listeners listen to that one, as well.

So, questions that people send in to you or me on our various blogs, things that I’m thinking about that I feel might be of interest to listeners—but then I also want to have people come on the show, you know, various folk from the paleo, health-conscious blogosphere. And we’ll probably figure out some other fun stuff to do, too. But there will be a separate category on my blog, TheHealthySkeptic.org. It’s going through a major design overhaul right now, which I’m excited about! It’s going to be ready in a couple of weeks, and there’s going to be a separate category called podcasts, and I’m going to have a special way of submitting questions for the podcast there.

But in the meantime, just go ahead and send them—use the contact form on that blog, or on my professional site, ChrisKresser.com, and we’re keeping track of all your questions, so hopefully we’ll get to them eventually.

Danny Roddy: We have a lot of questions.

Chris Kresser: Yeah, we could do this for a couple years, I think, right now! But the good news is, a lot of the questions—some of them overlap, and many of them are the same, even. So, I’m sure we’re going to get to a lot of it.

Danny Roddy: Cool. Do you want to get to our first question?

Chris Kresser: Yeah, let’s do it!

The Blood Type Diet

Danny Roddy: Okay. Our first question is from David from Australia. Okay. Do you believe in the blood type diet? I’m currently seeing a naturopath and they’ve established that I have type A blood, which means no dairy and no red meat. How does this stack up with the paleo diet, which is loaded with meat? Is there a negative impact for those with type A blood if they eat meat?

Chris Kresser: In a word, no. You know, when I first heard about—the blood type diet’s been around for a while, right? I’m not even sure when the book came out, you know?

Danny Roddy: I’ve been hearing it for years. I think it’s been around.

Chris Kresser: It was around before I even got really, really serious about health and nutrition. But even then, I remember thinking, that doesn’t make any sense! I mean, humans have the same basic physiology, right? Regardless of blood type, or race, or what we’ve been eating, or culture. And scientists have been looking for these real, significant physiological differences across races for a long time.

Think back to World War II and the crazy stuff the Nazi scientists were doing, you know? But they’ve never found them, despite those extremely biased studies that were performed. So the idea that one diet is right for one blood type and another diet’s right for another blood type just never really computed at all.

Danny Roddy: I have to laugh whenever any of my coworkers asks me that question. It seems to me very easily digested for most people, that it seems to ring true for them for some reason, I’m not sure why.

Chris Kresser: I have a little theory about that. I think we all like to feel like we’re special in some way, and that we belong to a group, to a tribe. And I say this kind of tongue-in-cheek, but it’s also, from an evolutionary perspective, true. We’re tribal animals and we want to feel like we belong, it’s part of our evolutionary history. And, I don’t know, this is just my armchair psychology thing going, here. But whatever the reasons for why it’s appealing, let’s take a closer look at why I think there’s no basis to it from a scientific perspective.

And, for a really good written summary—it’s the best I’ve seen debunking the blood type diet—you should check out this article on Don Matesz’s blog. Don writes Primal Wisdom, it’s a fantastic blog.

Danny Roddy: Amazing blog.

Chris Kresser: Yeah, it’s great. For those of you who don’t know about it, it’s DonMatesz.blogspot.com  He’s another Chinese Medicine guy turned paleo, like me, and he just really takes it to the curb better than anybody I’ve ever seen. He lays it out in four sections, and we’ll just follow that template because I think it’s a good, logical way of thinking about it.

So, the first claim that the blood type diet makes is that as we evolve, we adapted to different foods, right? And that this adaptation resulted in the A B O blood groups. The second part of that is that each of these different blood types is adapted to a different type of diet and food. So that makes sense?

Danny Roddy: Okay.

Chris Kresser: So, whether it makes sense or not—but you follow what I’m saying?

Danny Roddy: Oh, yeah.

Chris Kresser: So, the claim number two is that people of different blood types have different antibodies in their blood and that because of this, each blood type is susceptible to different diseases. All right?

Danny Roddy: Okay.

Chris Kresser: And then, claim number three and four kind of go together, which is that foods contain lectins that are very close in molecular structure to the various blood group antigens and that, of course, then, eating the wrong lectins would cause agglutination or clumping of blood, and therefore disease.

Danny Roddy: Is he making the claim that all disease is autoimmune?

Chris Kresser: That’s an interesting way of looking at it. I wouldn’t say that, because he’s saying that we’re reacting to the lectins in the food, so food being exogenous. But in the sense that these lectins are, maybe, passing through the gut? I don’t know. I hadn’t thought about it that way.

So let’s take a look at the first claim, that type O—so, D’Adamo—is that how you pronounce his name? I never knew.

Danny Roddy: I’ve heard it pronounced like that.

Chris Kresser: So D’Adamo, he claims that type O is the first blood type, and this is really where the problems start, because molecular biologists had determined that, actually, type A was the first blood type, four or five years before he published his book. So, making an error that basic about the evolution of blood types really, to me, casts some serious doubt on the credibility of a book that bases its entire argument on the importance of blood types, right?

Danny Roddy: I would agree.

Chris Kresser: Yeah. And it should be obvious that type A and type B precede type O because O contains antibodies to both A and B blood types. So this means that type O had to emerge later in an environment where type A and B antigens were already present. That make sense?

Danny Roddy: Yeah.

Chris Kresser: So, that takes care of that. The second part of the first claim is that different blood types evolved as a result of different diets. I think the idea is that A stands for Agriculture, conveniently. Type A’s evolved when humans switched to agriculture, and those people who switched to agriculture evolved a type A blood type. And the type B evolved in response to humans starting to consume dairy.

So, this idea implies that ABO blood types are unique to humans, but they’re not. We actually see ABO blood types in gorillas, orangutans, gibbons, baboons, and a whole bunch of primates. And we see that these blood types actually cross the various species. For example, there are primates with type A, there are primates with type B, type O, etcetera. And we know that primates have not changed their diet significantly in millions of years. I don’t know any monkeys that are practicing agriculture, or cultivating cereal grains, and I’ve never seen any gorillas herding cows and milking them for dairy, for milk.

Danny Roddy: You just haven’t looked hard enough!

Chris Kresser: I guess not! So, it seems clear, then, from that that type A didn’t evolve as an adaptation to agriculture and that type B didn’t evolve as an adaptation to dairy. Otherwise, we wouldn’t see those types in primates that don’t practice agriculture or animal husbandry.

So that’s my response to the first claim. The second claim is that, because each blood type has different antibodies, they’re susceptible to different diseases. So, for example, he claims type O’s get more ulcers than type A’s, and he claims this is because type O’s produce more stomach acid. But apparently he missed the memo that ulcers are caused primarily, not by excess stomach acid, but by a bacterium, H. pylori. The guy who discovered that actually won a Nobel Prize in Medicine for that discovery.

Danny Roddy: Which, by the way, your posts on GERD are just incredible, very good. If our listeners haven’t checked those out, definitely check them out.

Chris Kresser: Yeah, thanks. That was a big—that’s such an interesting story, because everyone thinks that ulcers and GERD are caused by too much stomach acid and, you know, of course, acid-suppressing drugs being the treatment of choice for that. But excess stomach acid’s actually a really rare condition, clinically.

And getting back to how this relates to blood types—type O’s do have a higher risk of gastrointestinal cancer than type A’s, but that’s got nothing to do with stomach acid. Turns out that H. pylori, the bacterium, can more effectively take root in the gut of type O’s because H. pylori has a protein structure that’s so similar to the type O host proteins that it confuses the immune system.

So, basically, H. pylori is somewhat invisible to the type O immune system. And then, H. pylori, of course, being the bacterium that causes ulcers. So that’s why type O’s have more ulcers. It’s got nothing to do with excess stomach acid, and in fact, one of the things that H. pylori does to survive in the human host is to suppress stomach acid. So, you know, I talked about that in the series.

Whereas type A’s, who have lower rates of GI cancer—they more easily recognize H. pylori as a foreign invader, which makes them more resistant to being infected by it, and it makes them have fewer stomach ulcers. So, that’s the second claim. Shall we move on?

Danny Roddy: We shall.

Chris Kresser: Third claim—and I’m just going to put the third and fourth together, because I think they go together. It’s that lectins selectively cause agglutination or clumping of the blood, and disease in different blood types. So the idea there is that people with type B blood should avoid chicken, because it contains lectins that will agglutinate their blood, whereas the lectins in chicken won’t agglutinate the blood of other types.

What I can say about this is that there’s just no evidence for it at all. If you look at the published data, they indicate that any individual lectin will affect all the blood types in essentially the same way. So the burden of proof is on D’Adamo to show that lectins affect different blood types in different ways, and I’ve never seen anything in the scientific literature to suggest that. And some of the studies that he cites in his book that he is claiming proove that, don’t proove that. And Don does a really good job of picking one of those studies apart, so if you want to know more about that, go check out Don’s blog. I think it’s called A Primal Perspective on the Blood Type Diet—the article–or something. It’s great. Hopefully that should be enough to put that one to rest.

Danny Roddy: The blood type diet is bogus.

Chris Kresser: That’s the verdict.

Anemia, Ferritin & Supplemental Iron

Danny Roddy: Okay, so David has a second question that has nothing to do with the blood type diet. So, here we go.

My naturopath performs a hemo review every six weeks to monitor my blood profile. He has noticed that my red blood cells are different sizes, which indicates an iron deficiency. I have been taking iron supplements now for six months, but my red blood cell profile hasn’t changed. I’m aware that it can take three months for the liver to produce new red blood cells. I have taken it on myself to get a serum ferritin test for peace of mind. It came back at 133.

I have read that the high ferritin levels lead to oxidative stress and increased risk of heart attack, so my question is: If my serum ferritin is 133, then I am absorbing iron for it to be stored. But why is my blood profile still showing lack of iron due to different-shaped blood cells? If I’m absorbing through diet supplements, then how, why does my body decide to store it instead of putting it to use? Thanks, and good luck with the podcast. Regards, David

Chris Kresser: Okay—

Danny Roddy: It was a long one.

Chris Kresser: Yeah, and I was hesitant to take it on, as you know. We talked about whether I was going to try to tackle this. The thing about oxygen deliverability and anemia issues is they’re so complex, it’s so tricky sometimes to figure them out. Because there are so many factors that can affect all of the markers that are involved in oxygen deliverability—’cause that’s what we’re talking about here. Excuse me.

There are two ways that we produce energy in the cell. We get—glucose and oxygen are required for energy production in the cell, so we’ve got to have a steady supply of oxygen, we’ve got to have a steady supply of glucose. That’s why looking at these markers can be pretty important in terms of determining overall health.

I’m unclear on a lot of things in David’s question. I’m not exactly sure what hemo review is. I’m just going to kind of interpret his question, the way I think he means it, and hopefully that answers his question. If it doesn’t, well have an interesting discussion about what I want to talk about, in terms of anemia and oxygen deliverability.

I think what he’s referring to is a marker called RDW, red blood cell distribution width. If our red blood cells develop properly, they should be relatively uniform in size, and that helps them function better in the body, if they’re all roughly the same size. If they don’t develop properly, because of iron deficiency or other causes, then they’ll vary a lot in size. And that variation is the red blood cell distribution width or RDW. So if we see RDW high on a lab panel, iron deficiency is one of the first things we’d think about. He didn’t mention what his iron level is, or total iron-binding capacity, which are two other markers I’d want to look at. He didn’t mention what his hemoglobin hematocrit or red blood cell levels were, which I’d also want to look at, just to complete the whole picture.

Danny Roddy: Those other markers have a lot to do with B vitamins, correct?

Chris Kresser: Yeah, B vitamins are involved. But essentially, what all of those markers are measuring is how much oxygen is being delivered to the cells. And the pathology that we’re talking about is anemia. So if hemoglobin, hematocrit and red blood cells are low, and iron is low, you’ve got an iron-deficiency anemia. And there are lots of different kinds of anemias, and we could have five podcasts talking about ’em, but I don’t want to do that because it gets confusing.

David is confused because he tested his ferritin and it was higher than normal, instead of low. And ferritin’s the storage form of iron, so he was expecting it, I’m sure, to be low, because he had what he said was iron deficiency. The problem is that ferritin is something that’s called an acute phase reactant. This is a protein that’s involved in the inflammatory response. C-reactive protein or CRP, which I’m sure a lot of people have heard of, is another acute-phase reactant. And elevated ferritin, like CRP, can be a result of systemic inflammation—independently of iron status.

So it’s possible that what’s happening is that his iron is still low, as indicated by the RDW, but ferritin is high, not because there’s too much iron being stored, but because there’s some inflammatory process in the body. Another possibility is maybe something called the anemia of chronic disease or the anemia of inflammation, and that presents with low iron levels and normal or high ferritin. And that can happen in chronic infection or chronic immune activation, or chronic inflammatory conditions like autoimmune disease, for example. What happens there is that, in response to the inflammatory cytokines that are being produced, the liver produces increased amounts of something called hepcidin, which is a peptide hormone. And then hepcidin, in turn, stops ferritin from releasing iron stores. So this reduces serum iron levels, but the ferritin, or the storage form of iron, will still be high. But if he doesn’t have any other symptoms, I wouldn’t necessarily suspect that. Again, it’s just really hard to know without those other markers, what’s happening here.

Danny Roddy: Dr. Kharrazian, if I remember correctly, says that anemia is a deal-breaker, which was pretty interesting. He never—in his book, Why Do I Still Have Thyroid Symptoms?—he never really explains what to do about it, perhaps because it’s so complex.

Chris Kresser: Yeah, it is a deal breaker. The first two things I look at on a lab panel are oxygen deliverability and blood sugar, because if those aren’t—we just said, glucose and oxygen, required for cellular energy production, ATP. That’s the fundamental, the fuel that we run on. If you’re not getting a steady supply of oxygen and glucose into your cells, nothing else is going to work right. So those are definitely the two deal-breakers, and I wish there was some way to say, this is how you resolve anemia.

The thing that a lot of people don’t fully understand is that anemia is such a broad—it’s like saying inflammation or maybe even more general than that! You have to find out what the cause of the anemia is. You’ve got iron-defiency anemia, you’ve got also folate and B12-deficient anemia. If you don’t know what the cause is, then you don’t really have a good hope of treating it properly.

So David might want to get CRP tested if he is having other symptoms, inflammatory symptoms, just to see what’s happening there. He also might want to try a different type of iron, the ionic forms that are in most supplements are not well-absorbed, and they’re made from some pretty dodgy materials. And then there’s another form called heme iron polypeptide which is a lot better absorbed and tolerated. The brand in the US is called proferrin, I think. I’m not sure what it would be in Australia.

I would expect iron levels to come up after several months. It sounds like he’s been at it for a while. But the other issue is that he’s not eating any red meat, because of this blood type diet. It says he’s type A. Eating red meat is also a good way to increase your iron levels.

Danny Roddy: I didn’t even put that together.

Chris Kresser: Yeah. So, get off the blood type diet, David.

Polycystic Ovarian Syndrome (PCOS) & Pregnancy

Danny Roddy: Okay, good advice. So let’s go to our second question. This one is from Elena, I’m not sure where she is. People, please send your location in with your question.

Dear Chris, I have PCOS, polycystic ovarian syndrome, and from last year I’m trying to eat healthy with The Zone because I’ve read that the origin of PCOS is insulin resistance. I’m trying to conceive and have added to my regimen R-lipoic acid or alpha-lipoic acid, as I’ve read it is good to control blood sugar. Do you know if alpha-lipoic acid is bad for the fetus once I get pregnant? Thank you so much and sorry for my bad English. I would love to find information about PCOS on your blog. Best regards, Elena.

Chris Kresser: That’s definitely a good topic for a series at some point, or maybe a podcast devoted to that or, you know, something! I think a lot of people wonder about it.

It’s true that PCOS is definitely connected to insulin resistance. And insulin resistance, in women in particular, tends to lead to higher testosterone levels. It upregulates an enzyme that converts estrogen into testosterone. And high testosterone, in particular, is what causes PCOS. So that’s the link, there. I’m pretty reluctant to use much of anything during pregnancy, in terms of supplementation. I don’t think there’s a lot—you know, a lot of things haven’t really been studied, there’s a lot we still don’t understand about how pregnancy works and the changes in the body that occur.

So I would be way more likely to suggest a fairly high-fat, low-carb diet to control the blood sugar and improve insulin sensitivity. And I would probably couple that with some high-intensity strength training, which has a really big effect on insulin sensitivity and improving glucose tolerance. And I would have her measure her blood sugar with a glucometer to determine what her carbohydrate tolerance is. So that’s a device that a lot of diabetics use. You just prick your finger and put a drop of little blood on a strip, goes in a machine and it tells you what your blood sugar is.

And the way that you use that to test your carbohydrate tolerance is you eat a meal, you take your blood sugar right before you eat the meal, and then you wait an hour and you take it an hour later, and then you take it two hours later. The deal is, you don’t want your blood sugar going above 140 after one hour and you don’t want it above 120 after two hours. And if it’s going above that, then you’re eating more carbohydrate than you can tolerate, in general.

So, the lipoic acid can be helpful now, but during pregnancy, I wouldn’t do it. I would try to get a better handle on it before pregnancy, with the glucometer and strength training, and the high-fat, paleo type of diet, and then let the body do the rest.

Danny Roddy: Agreed. Food seems to be a better medicine.

Chris Kresser: Especially during pregnancy. I don’t think there’s any time when that’s more true than during pregnancy.

Danny Roddy: Agreed.

Statins & Cardiovascular Disease

Danny Roddy: Okay, let’s get to our third question, from Peter. Hi Chris, I love both of your blogs and I have undertaking reading through everything you’ve written, with special attention to your posts on statins and cardiovascular disease, in order to help my dad, who has CVD. He had a heart attack about four years ago, after which he underwent a bipass surgery and was put on a number of meds, including statins. After doing a lot of research, I’m quite certain that the statins are completely unnecessary, if not detrimental, considering that I don’t believe high cholesterol is a factor in his illness.

Besides the immense difficulty in convincing him to go against the advice of his doctor, I also face another challenge in getting him off of them. About a year ago, he received a stent to open up one of his arteries. I’ve seen a number of studies that seem to show that statins confer special benefits to CVD patients with stents. The benefits seem to come, not from cholesterol lowering, but from the anti-inflammatory effects.

So my question is, would it still be wise to try to get him off statins, given the fact that he falls into an apparently special class of CVD patients? My hunch is that the same anti-inflammatory effects could be achieved through exercise and diet, but if I can’t be sure he’ll pursue those things, are the statins better than nothing? Thanks so much for the work you’re doing.

Chris Kresser: This is a good question and it’s one that comes up quite a bit. In general, I think I’d start by saying I never tell anybody to stop taking a drug. I mean, there’s a legal issue there, for me, because I’m not a medical doctor, it’s not within my scope of practice to do that. There’s another, more general issue, which is that I think it’s really important for people to make decisions for themselves and understand why they’re making those decisions.

And this is where it gets difficult with things like statins and other drugs that can have pretty serious side effects. The whole cultural paradigm is set up to make people believe that these drugs are almost miraculous in their ability to protect against heart disease. Very few people in the conventional wisdom—or lack of wisdom—even question that, from primary care doctors, to cardiologists, to the media, to Joe Shmoe on the street. So, anyways, that’s just a little caveat.

I think the challenge we all face with our family and friends is one of education, primarily. How do we help them to make decisions that are in their best interests without trying to make those decisions for them ourselves. And that’s tricky! So I empathize with anybody who’s in that position. I’ve been there myself, many times.

It is true that statins have been shown to reduce the risk of cardiovascular events and mortality in people with stents. There’s a very small percentage of people that statins are demostrated to benefit, and this is one of them. It’s basically men with preexisting heart disease. The other 95% of the population, not so much, but that 5%, they do have some benefit. But of course—go ahead.

Danny Roddy: Is that because of the anti-inflammatory effects on CRP?

Chris Kresser: CRP—that’s controversial. What you see in studies is that as CRP goes down, you don’t necessarily see a reduction in CVD events. I think it’s almost certain that the effects of statins in those cases are anti-inflammatory. They also increase endothelial nitric oxide, which is a really important antioxidant in the epithelium of the arteries. It has pretty profound effects on improving blood flow—so, we don’t really know, frankly, why they’re working. Just like we don’t fully understand all of their side effects, which are pretty serious.

Danny Roddy: Like Alzheimer’s, memory loss–

Chris Kresser: Right. Stuff that you really don’t want happening to you as you get older. I mean, the number one is muscle pain and fatigue. And there’s a doctor named Beatrice Golomb–I’d love to meet her. She’s at Berkeley, she’s not far away, she’s in my neighbourhood somewhere—but she’s done amazing research on statin side effects, and she’s just an independent observer. She’s got no agenda to figure out what these drugs are doing.

And she’s found that irreversible muscle pain and fatigue is the main side effect of statins. That’s scary! I know tons of people who have muscle aches and pains when they take statins. And unfortunately, sometimes, that’s actually irreversible. Cognitive impairment. You mentioned Alzheimer’s—a lot of studies in the literature lately linking statins to Alzheimer’s. Decreased libido and sexual dysfunction, depression, mood instability. Why would they do that?

Well, cholesterol plays a really important role in the brain, and if you just arbitrarily lower cholesterol across the board, you’re going to have these systemic effects. I’ve said this before on my blog: Drugs don’t have side effects. They just have effects. They’re affecting the whole system globally.

So even though one of the effects might be something desirable, there’s bound to be several other effects that are not desirable, and there’s no way to stop that with a drug unless it’s ultra, ultra, ultra specific, which we’re just not really capable of doing yet, and that’s not how the body works anyways, because there are proteins and genes that are related to several functions, just for the one protein. So if you screw with that one protein, you’re going to screw with all of the functions it’s associated with. We’re not able to just turn off one aspect of its function.

So, the decision about whether to take drugs—there’s always two important things for me, as a practitioner and as a patient-consumer. It’s a cost-benefit analysis first, like: Do the potential benefits I’m going to get from this drug outweigh the potential costs? Or is it the other way around? And then the second question is: Even if the benefits outweigh the cost, could I achieve the same result in another way? I think that’s the main question, here, and he alluded to it in his question.

It would be great if we had a study comparing statin use with an anti-inflammatory paleo diet, but I don’t think that’s going to happen any time soon. I don’t think we should wait around for that! I suspect if we did, the dietary approach would be equal to or greater than the statin effects, without any of the side effects except people feeling better, and sleeping better, and having more energy. But the reason I feel that way is because it’s addressing the problem at the source.

Heart disease is an inflammatory condition. It’s caused by inflammation and oxidative damage, not high cholesterol. And so, it obviously makes sense in the treatment of heart disease to focus on reducing inflammation. Of course, you can take a drug that does that, but why not just stop eating the things that are causing the inflammation in the first place? What am I talking about? It’s the same old things I’m always talking about: not eating industrial seed oils, which are really high in omega-6; balancing the omega-6 to -3 ratio—if I had a stent and I had heart disease, I’d be avoiding those to the fullest extent possible. I’d try to get my omega-6 down to 2% of calories, which is really, really hard. I mean, even if you’re hardcore with this kind of diet, it’s hard to get it down to that, but if I had a stent, I would do that.

Danny Roddy: We’re talking about cooking pretty much every single meal yourself.

Chris Kresser: We’re talking about very little restaurant food. I know this is going to sound so, so, what?

Danny Roddy: Militant?

Chris Kresser: Militant, overzealous, dogmatic, fundamentalist—

Chris Kresser: But let me just say, yeah, it means eating at home a lot. And it means when you do go out, and you eat out, you’re eating things that aren’t liable to be cooked in oil, because you can bet they’re not using butter or coconut oil to cook, to stir fry your veggies in the restaurant.

Sorry, my phone’s ringing over there. I don’t know how to turn that one off, so you’re just going to have to listen to that.

So, it also means that the handful of walnuts every day—that’s out. Walnuts are really high in omega-6. Just a hundred grams a day—

Danny Roddy: Would you agree, nuts are overrated in general?

Chris Kresser: Nuts are totally overrated. I mean, they’re convenient snacks, they’re tasty, but the whole nut fetish in the paleo community has got to go. That’s causing a lot of problems. You know, getting back to the walnut example, if you eat just 100 grams a day—which is not that much, that’s like a big 3 ounces—in a week, you’re getting 270 grams of omega-6. You’re supposed to be getting less than 4.5—if you have a 2000 calorie diet you want to keep it to 4.5 grams a day, which is very little.

So, just to give you an idea: In order to have the equal amount of omega-3 and omega-6, which is what we should have for optimal health, you’d have to eat 34 pounds of salmon in a week just to balance out that ratio. Just with a handful of walnuts! And then you’ve got chicken skin, particularly a thigh or a leg with chicken skin, very high in omega-6, unfortunately.

I’m just pointing out the less obvious things. Of course, we have all the packaged and processed foods, and things that are loaded with industrial seed oils—that’s obviously out. But also, you’ve got to reduce the nuts, you’ve got to reduce the poultry, because poultry is high in omega-6 often, at least the skin and the darker meat, and then you’ve got to be eating salmon or cold-water fatty fish like mackerel or herring or sardines—probably 6 ounces, two or three times a week.

Then we want to be reducing carbohydrates and replacing those with saturated fats. That would give you three beneficial effects: It’ll increase the HDL, it’ll decrease the triglycerides, and it’ll decrease levels of small, dense LDL, which is the type of LDL that’s associated with heart disease.

Let me get a sip of water, here. Go ahead and—

Danny Roddy: It sounds like Peter is—arguing with family about this stuff is a non-winning situation. No matter any health ailment my family has, they’re very reluctant to take any information from me. Not that I’m a doctor or anything, but if I’m suggesting anything that they look into, it’s—and Robb has talked about this on his show—it’s just a non-win scenario.

I don’t know what it is about family, but—have you experienced that at all, Chris?

Chris Kresser: Well, didn’t Jesus say, No man’s a prophet in his own town? He had it right. It’s true.

I have to say, I’m pretty fortunate, because my parents are totally down with all this stuff now. It took a while, but—my dad had a scare, you know. He went in, he had one of those scans of his carotid artery and the doctor read him the riot act and told him he’d better start eating lots of brown rice and broccoli with no fat and, you know, Weight Watchers meals and things like that.

And he obviously knew what I was up to and had read several of my articles, and he called me up, and we switched him over to—he’s not on a hardcore paleo diet, but he’s pretty close. He doesn’t eat any grains, it’s a high fat, moderate protein, pretty low-carb diet. And his numbers have gone completely normal, even according to the conventional view. And his doctor is just flabbergasted, she doesn’t know what to make of him. Like, she asks him what he’s eating and she just slaps her forehead and says, I don’t understand, but—

Danny Roddy: He’s obviously an anomaly.

Chris Kresser: Right, exactly. But, yeah, it’s really hard to work with family on this stuff in general. I think the best you can do is just give them information, and just sort of let it go after you pass it on. We can’t control people. Anyone who’s tried to knows how that turns out. One of the fastest ways you can increase your suffering is to try to control somebody else, especially a family member or a partner.

Getting back to a few things to do, if there’s interest there. In addition to what we’ve already talked about, eliminating the seed oils, getting enough omega-3, reducing carbs and replacing with saturated fat. Also want to make sure fat-soluble vitamins are there, vitamin D and particularly K2, which a lot of people outside of nerds like us, that read health books all the time, don’t have a clue about! K2 is a really important fat-soluble vitamin. It regulates calcium metabolism, so that means it makes sure that calcium gets into the hard tissues—the bones and the teeth, where it belongs—and stays out of the soft tissues, like the arteries, where it doesn’t belong.

And there’s a lot of research now suggesting that K2 deficiency is pretty widespread and is probably a really significant factor in heart disease. That K2 is really only found in the MK4 form—which is the form that has been shown to have all these benefits—in grass-fed dairy and goose liver. I don’t know about you, but I think a lot of people aren’t eating goose liver. Grass-fed dairy is more common, but still not that common, so it kind of explains why a lot of people aren’t getting enough of it. There is a form of K2 called MK7 that’s in natto and other fermented plant foods, but we don’t really know if it has the same effects as MK4 that’s in grass-fed dairy and goose liver, and some studies have suggested it doesn’t.

Then there’s, of course, stress management and high intensity strength training, bit of exercise every day, all that kind of basic stuff. Honestly if you won’t, if somebody won’t do that, it’s possible that a statin does make sense, even if it’s just a few percent absolute reduction in risk for mortality. I don’t know. It’s a really hard question.

Danny Roddy: Unless Peter was cooking for his dad all the time, and going to—I think Trader Joe’s carries grass-fed cheese and raw dairy, and you’d probably have to search around if he was going for raw milk or anything, but—I guess we’d have to ask more questions about the involvement of Peter’s treatment with his dad, or if he’s just giving him info or not. But all great answers.

Chris Kresser: Yeah, definitely. And of course, I have a whole special report on heart disease. I’m sure Peter knows this, ’cause this sounds like he’s read a lot of it, but there are some videos there. There’s one set of videos called, I Have High Cholesterol and I Don’t Care.

Danny Roddy: That one was good. I like that one.

Chris Kresser: That kind of debunks the whole idea that eating saturated fat causes heart disease, so that’s a good one to start with for the general philosophy. But I also have a set of videos called The Truth About Statins. So that could be—I find that videos are pretty accessible for most people. A lot of people won’t read a special report with nine articles, with 422 scientific references, their eyes just start to glaze over, but a lot of people will watch a 10-minute video, so that’s—

Danny Roddy: And you break it down really well, especially the high cholesterol one, I really dug that one.

Chris Kresser: I try to make it easy to understand for people, because I think it’s important.

So good luck, Peter! Let us know how it turns out. Let us know if we can help in any other way.

Danny Roddy: Ditto.

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Vitamin A toxicity (or lack thereof)

Danny Roddy: Okay, let’s go to Marlee. She has a question about beef liver.

Hi Chris, I’m a big fan of lamb and beef liver, and I’ve been eating it regularly for a while. I read something online about getting vitamin A toxicity from eating too much. Any idea what a safe amount of consume per week would be? And any benefits from eating it raw compared to cooked? Thanks for all the good info, Marlee.

Chris Kresser: Mmm, raw beef liver! First of all, I’m totally jealous of Marlee that she loves beef and lamb liver. I mean, there’s no better superfood on the planet than liver, but to be—here’s my really frank admission, that I cannot stand liver. I would—

Danny Roddy: Have you ever put marjoram on it?

Chris Kresser: Marjoram?

Danny Roddy: I got this from—yeah, marjoram.

Chris Kresser: Like, margarine. Mmm, margarine and beef liver—

Danny Roddy: Margarine and beef liver!

Chris Kresser: I’ve put everything you can possibly imagine on it, I’ve cooked it in 15 different ways, I’ve resorted to cutting it up, raw, into tiny little pill-sized chunks and freezing those, and then swallowing those chunks. I mean, it’s a character deficiency, what can I say? I can’t stand it. It makes me literally want to barf when I eat it.
I think it has a lot to do with not eating it growing up, too. I know a lot of people who love liver, they ate it growing up and it still seems to be an acquired taste. But, anyways, that’s my little thing that you can know about me, now, even though I go around telling everyone to eat liver. And I still will, because it’s amazing. Anyhow this is a good question, too, and I’m glad it came up. It was inevitable it came up, because it comes up all the time. Let’s tackle it.

It’s true that very high doses of vitamin A can be toxic. One of the primary concerns is that it increases the risk of osteoporosis, and this has been shown to happen at not even super-high doses, at just moderately high doses. But here’s the really important thing about that, that rarely comes up in the discussion. High doses of A are only harmful in the presence of vitamin D deficiency. This is huge! It’s not an excess of A that causes problems, but an imbalance between A and D. Kind of like the omega-6 and -3 ratio, right?

What we know is that we have to have an equal amount, or roughly equal amount of those. It’s not that omega-6 is necessarily bad in any amount, it’s just that if it exceeds the amount of omega-3 by a significant margin, then we’ve got problems. So all of the fat-soluble vitamins, A, D, K and E, exist in a synergistic relationship. And there are a lot of studies that show that vitamin D reduces the toxicity of A, and vice versa. And that even the other fat-soluble vitamins, K and E, also play a role in the toxicity of both A and D.

One study that comes to mind showed that supplementing with vitamin D pretty dramatically increases the amount of A that’s needed to cause toxicity. So, for a hypothetical 150-, 160-pound person, supplementing with vitamin D raised the toxicity threshold to above 200,000 units of vitamin A a day. Which basically means you’d have to eat more than 200,000 IU of A to experience toxicity.

Danny Roddy: And that’s a ton!

Chris Kresser: Put that in perspective, yeah. 3 ounces of beef liver is 27,000 IU. So if you can choke down 30 ounces of beef liver in a day, more power to you, but probably shouldn’t do that. 3 ounces a couple times a week might be a better target.

There was another study, an animal study on turkeys, I think—and I haven’t read that many studies on turkeys—but these poor turkeys were split into three groups. One group was fed high vitamin A only. Another group was fed high vitamin D only, and then the third group was fed high amounts of both vitamin A and D.

And in the vitamin A only and the vitamin D only groups, they both developed pretty serious diseases, all the diseases you would expect from toxicity of each of those vitamins. But guess what? The turkeys that were fed high doses of both A and D did not develop any of the toxicity symptoms of A and D. So what this suggests is that vitamin A can only have toxic effects against the backdrop of vitamin D deficiency.

So I think this is really important and that people should know about this. Have you come across this idea that vitamin A is toxic?

Danny Roddy: Yeah. In my own personal experience with all my experimenting, I know megadosing anything usually led to more problems, so I guess in a food context, if you’re eating tons of liver, the potential for vitamin D deficiency seems pretty high.

Chris Kresser: Yeah, and Vitamin D, a lot of people are deficient in. I think 50% of Americans is the last statistic that I saw.I can tell you just in my own private practice, that number is at least 50%. And my patient base is more health-conscious than average, way more than average, so I think that number’s probably higher. But if people were eating all of the foods that were part of our evolutionary template, which contained vitamin D, and if people were getting exercise and getting outside and getting exposed to sunlight, the question wouldn’t really come up so much, because it wouldn’t be as easy to get out of balance with the A and D ratio.

So let’s get back to her question of how much vitamin A can you eat, or take, or how much liver can you eat. Considering that, I think, a quarter of Americans consume less than half the RDA of vitamin A, I think vitamin A deficiency is probably a bigger problem for most people than excess. And considering its important role in pretty much every system of the body, and considering that A isn’t toxic with adequate levels of D, I think aiming for a dose of somewhere between 10,000 and 20,000 IU per day, or extending that over a week, is a good idea.

6 ounces of beef liver would get you about 50,000 IU, so if you did that twice a week, and if you’re taking maybe some cod liver oil in small doses every day throughout the week, that would probably be a good amount. Or maybe 3 ounces of beef liver twice a week, plus cod liver oil. Just make sure that your D levels are sufficient. They should be at somewhere between 35 and 40, and you’ll benefit tremendously from the liver. So don’t let that idea that it’s toxic scare you away.

Danny Roddy: Agreed. Superfood.

Side-effects When Cutting Carbs

Danny Roddy: Okay, let’s get to our last question. This one’s going to be from Peter.

I have tried cutting back on carbs several times, but when I do I get insomnia and feel uptight, in general. I have not read about this in any low-carb book or blog and was wondering if you had any explanation for it, and any ideas as to what steps I could take to prevent this from happening?

Chris Kresser: Ah, yeah. So this is an interesting question. I think this has come up once or twice before. I’m going to try to answer it, but I’m just speculating here. I really would need more information to make better sense of it.

The first question I would have is, is he cutting back from the standard American diet amount of carbs? Most people eat about 200 to 300 grams a day of carbohydrate in Western societies like the US, or is he cutting back from a moderate carb intake to very low carb? Is he trying to get down to 50 grams a day or 25 grams a day? Because my answer would be really different for each of those scenarios.

But let’s assume for the sake of argument that it’s somewhere in the middle, that maybe he has a normal, sort of average carb intake, 200 grams a day or something, and he’s trying to get down to something like 100 or 125.

Insomnia also, of course, is a really nonspecific symptom. I mean, it can be caused by so many different things—all kinds of different physiological problems, emotional problems, emotional shifts, psychological issues, stress, etcetera.

Danny Roddy: Symptoms of life.

Chris Kresser: Life, exactly. Insomnia caused by life. In my experience, though, the way that symptoms of life play out is causing blood sugar imbalances and trashing our adrenals. From what I see, those are the two major causes of insomnia from a physiological perspective.

Adrenal stress can be both the cause of, and caused by, blood sugar imbalances, and vice versa. So there’s a really tight relationship between blood sugar and adrenal function. I’ve mentioned before that our cells require a steady supply of glucose to function properly, and if blood sugar drops through the night, then cortisol will kick in, the stress hormone, and raise blood sugar back up to appropriate levels. But what can happen here is that it will overshoot the target, and blood sugar will go a little bit higher than it needs to and can actually wake you up!

Or, if cortisol’s low because of chronic stress, and there isn’t enough cortisol to kick the blood sugar back up, then adrenalin, norepinephrin and epinephrin, will kick in to raise the blood sugar back up. And you can bet that if adrenalin’s kicking in in the middle of the night to get your blood sugar up, you’re gonna—that’s when you wake up going, Oh my god! My business! Or, my taxes! Or, whatever it is you wake up in the middle of the night being terrified of. And your heart’s beating out of your chest. That can be an adrenalin surge.

Another potential issue here is serotonin, which, of course, is one of the neurotransmitters involved with regulating mood and producing feelings of well-being, and of course it has a big impact on our sleep. How does what we eat affect serotonin? Tryptophan, which is an amino acid found in proteins, is the precursor to serotonin.

Excuse me, I just need another drink of water here.

Danny Roddy: No problem. I’ve personally noted that any time I dropped carbs way too low, it usually gave me sleep disturbance. But I like the idea of the perfect health diet, I like having a good amount of safe starches in the diet. I’ve noticed that personally helps me get to bed all the time.

When I was on the standard American diet, I never got to sleep. I was up ’til all hours of the night.

Chris Kresser: Yeah. I agree. I definitely think—I’m not a big fan of zero-carb or very low-carb diets. We’ll take that on, maybe in the next show.

But getting back to serotonin: Tryptophan gets converted to serotonin, but tryptophan requires the help of a transport molecule to cross the blood-brain barrier and there are several other amino acids from food that compete for those same transport molecules.

Normally, if you eat carbohydrates or certain proteins, insulin gets released, and then insulin helps to clear out the amino acids that compete with tryptophan for transport molecules into the brain. But here’s the catch. If somebody is insulin-resistant, insulin won’t be able to clear those other amino acids out as effectively, and then not as much serotonin gets made from the tryptophan that they eat in foods.

So if somebody’s been eating a standard American diet, high in processed and refined carbs, there’s a pretty good chance they have some sort of insulin resistance, or they’re hypoglycemic or reactive glypoglycemia. And then when they switch over to a high-carb diet, which would certainly benefit them over time and stabilize their blood sugar, the transition can be really rocky. And it can cause symptoms like insomnia or agitation related to blood sugar fluctuations and serotonin imbalance.

So, basically, when the body’s used to burning carbs for energy, it takes a while to switch the machinery over to burning fat. Things like L-carnitine can help. L-carnitine is responsible for transporting fat into the mitochondria, where’s it burned for energy. B6 and magnesium are needed for converting tryptophan into serotonin. A lot of people are magnesium deficient, I’d say more than vitamin D.

Beyond that, I’d need more information to know what to recommend. But I agree with you, Danny, and of course with Paul and Shou-Ching from the perfect health diet about their recommendation for keeping glucose intake at around 400 calories a day or 100 grams a day, from safe starch. I think that actually benefits people.

Danny Roddy: It seems like that’s kind of coming around in the paleo circle. It seems like starches, and potatoes in particular, are coming back in a big way ever since Don—I’m sorry, what’s his—Matesz?

Chris Kresser: Matesz, I think, yeah.

Danny Roddy: —Matesz, he wrote that awesome primal potatoes article. I think that got everybody kind of out of the super-low-carb that everybody was kind of into.

Chris Kresser: Yeah. There are times when low-carb diets can be beneficial, and ketogenic diets can be beneficial, but for the average person I don’t think they’re a great idea. I’ve seen a lot of people, patients of mine, who come into my practice doing zero-carb diets and intermittent fasting and they’re actually plateaued on weight loss or they’re even gaining weight. I’ve stopped the intermittent fasting, which I believe is beneficial for most people, but not for everybody—we’ll talk about that later—and then I have them start eating more carbohydrate, which they think is crazy, because they’re trying to lose weight, and in their mind, carbohydrate equals getting fat. But as soon as they do that, almost all of them start to lose weight again, and they feel better, too.

I think that’s it! Did we make it through? That’s amazing!

Danny Roddy: We stumbled through our first episode.

Chris Kresser: Wow. Impressive.

Danny Roddy: Cool. So that’s going to bring us obviously to the end of this week’s episode. Chris, why don’t you tell us everything you’re doing this week and how we can find your work on the internet.

Chris Kresser: Please don’t make me tell you everything! I think we’d be here for another hour.

Let’s see. I’m really excited about a seminar I’ve got coming up called Growing a Health Baby: Nutrition for Conception, Pregnancy and Breast-Feeding. We’re going to talk about what we know from looking at anthropological evidence and evolutionary medicine, and combining that with what the modern, clinical research suggests is a healthy diet for fertility and pregnancy. I’m offering that as a live seminar in Berkeley the first time, on the 13th, it’s nearly sold out, which is pretty exciting!

Danny Roddy: Awesome.

Chris Kresser: Then, I’m going to package that content into a six-week online class, I think, so it can be accessible to people around the world. And I’m also considering turning it into a DVD so that people who even can’t manage to attend the class can get the information, because I think it’s super important.

Couple of other things: Big website redesign, I mentioned that at the beginning of the show. So look out for a brand new, polished up, Health Skeptic site. There’s going to be some good, new functionality on there, too.

And, man, what else?

Danny Roddy: What’s your Twitter, Chris?

Chris Kresser: Twitter’s @ChrisKresser. Come check us out on Facebook, if you haven’t already. We’re getting close to 3000 fans, which is awesome. It’s Facebook.TheHealthySkeptic.com Is that right?

Danny Roddy: How do they do their URLs? I think it’s Facebook.com/TheHealthSkeptic?

Chris Kresser: I have this tricky redirect thing. The Healthy Skeptic—I really should have had this all together before we talked. Yeah. Just go to Facebook.com/TheHealthySkeptic

Danny Roddy: If you type in The Healthy Skeptic in the search bar, it’s the first thing.

Chris Kresser: Anyways, the Facebook page is fun because I take pictures of my food and put it up there, I do a lot of links to studies that never make it to my blogs, there’s a big community of really engaged, smart—I learned a lot from all the people who post there, and it’s really cool. I was a social media skeptic for a long time, and I still don’t use it much personally, but I really am enjoying the Facebook page. So check us out, come join us if you’re not there already!

That’s all that comes to mind. I’m sure there’s a lot more, but I’ve been so busy lately, my brain is a little bit scattered. So, we’ll pick it up next week, next time.

Danny Roddy: Cool. Okay, you can find me at Twitter.com/DannyRoddy and my website is TheHealthyHairDiet.com Keep sending us your questions at both of Chris’s sites, TheHealthySkeptic.org and ChrisKresser.com and his Facebook page, and thanks for listening, guys! We’re super excited, and take care.

Chris Kresser: Thanks, everybody! Good me talking, you listening. See you next time!

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Join the conversation

  1. From my perspective your 2013 review of D’Adamo’s work is unfair and based on a few mute points and the 2010 opinions of another clearly ‘Politically Paleo’ blogger. Not fair to laugh at others lifetime work after over two decades. I think The Blood Type Diet Theories that are older than your ‘interest in heath’ still have a substantial message. And they still have a following. Health seekers spending any time being volleyed back and forth like a tennis ball in a tennis match between Vegan and Paleo might welcome some reasoning for both of those being best for the two largest blood type groups. Both groups are holding on to their own turf and I think the Blood Type Diet is the Net true and applicable for both sides. I would like to hear anecdotal evidence testimonies from Blood Type Diet followers. Not science but yet practical to consider what works for folks.

  2. If, “Turns out that H. pylori, the bacterium, can more effectively take root in the gut of type O’s because H. pylori has a protein structure that’s so similar to the type O host proteins that it confuses the immune system.” is true, are there not other things (foods, for example) with this same characteristic?

    In other words, if H.pylori can hide from type O, but type A treats it as the invader it is, are there foods that type O will treat as an invader and, if there are, how does the body respond to those foods?

  3. Hi,

    I wonder whether anybody could help me. I started running four months ago and had a dip in thyroid function. So far, so standard (or so I gather). I got tested, upped my meds and went back to the top of the normal range for free T4.

    I recently had some private blood work done and they indicated a ferritin level of 4 (!), red blood cell 3.95 (3.8-5.0), haematocrit 37% (37-47), haemoglobin 11.9 (12.0-15.0), mcv 94 (84-100); vitamin B12 was 400. Apart from the ferritin level my GP wasn’t very concerned, and she basically said that every premenopausal woman in the UK was anaemic to some degree. I was prescribed ferrous fumarate ten days ago and started taking it, together with 1000 mg vitamin C, at bedtime (well away from my thyroxine). The trouble is that I now feel worse than ever, very tired and confused. Is it possible that the increase in iron necessitates an increase or decrease in thyroxine?

    By the way, I noticed that when I was undiagnosed and running my fingertips would often go blue. At first I thought it might have been Raynaud’s (from which I also suffer) but there was no white finger first and it only happened when running. I concluded after diagnosis that maybe it was because I wasn’t getting enough oxygen because I was anaemic. After I started the ff ten days ago the fingertip blueness while running disappeared but it started coming back last night. I know you can only speculate, but what the hell is going on?