Before there were any Paleo diet books there was this book. Practically everyone arguing for eating more animal products online has been influenced by it.
This is the author, Weston Price. He was a highly respected dentist who believed that health, dental and otherwise, was being compromised as the world adopted industrialized foods. To make his case that these foods were harmful, he traveled the world to visit isolated cultures left outside the new food economy. Wherever he went, he drew a contrast between the vigorous health of those consuming their traditional diets, and their ethnic counterparts consuming modern foods, or at least foods that seemed modern in the thirties. It's a very interesting book and he was a very admirable man. He visited hunter gathers and pastoralists, took pictures of them, and described their cultures for posterity, always with great respect and admiration. He was ahead of his time in both his acceptance of the importance of nutrition and in his liberal views of race and culture. Unfortunately, like others who try to use the hunter gatherers as models for nutrition, his premise confined him to people living on marginal lands who had no choice but to eat animal products, thereby skewing his conclusions about diet.
Weston Price's book should be seen now in some historical context. Industrialized food production got off to a rough start. Upton Sinclair's vivid expose of the appalling conditions in the meat-packing industry in The Jungle eventually lead to the Federal Meat Inspection Act of 1906-1907. Read, or try to read, that book and you will see that in the days before regulations and inspectors, quality nutrition was nowhere on the list of priorities for some in the food industry.
The Jungle was set in Chicago. These photos of South Chicago from those days should make clear times were quite different then.
Harvey Wiley, the first head of what is now called the US Food and Drug Administration, brought attention to the use of toxic non-food additives in the food supply around the same time. Bread could contain sawdust, spices could be stretched with clay, and coffee contained ground acorns. His work lead to the Pure Food and Drug Act of 1906. We should not think that pure food laws lead immediately to pure foods in the marketplace. Food toxicology would not be a well-developed science until many decades later. Enforcement of the food laws was lacking. There were few real regulatory standards. We should understand that industrialized food in those days could be far, far worse than ours is today.
It was not until 1938, the year before Price's Nutrition and Physical Degeneration was published, that the United States had even begun regulating poisonous residues in foods. It was not until 1954 that the United States established procedures for determining acceptable thresholds for pesticides in foods. I am only describing the regulatory history of the United States. Can you imagine how much further behind the US these countries Price visited were back then in the area of consumer protection?
So when Weston Price attributes dental and other health problems to modernized foods, he is likely talking about the worst of the worst modernized foods in the diets of predominately poor people. I am not here to categorically defend industrialized food, of course, but the patterns he observed seem to be of somewhat limited value to us today.
These pictures and the neatly binary choices they suggest enable people to oversimplify food issues and feel good about it by calling it "wisdom," one of the most overused weasel words in the primitive nutrition world. Price's work is interesting and we are lucky to have these snapshots of these old traditions, but this is not science. Alternative explanations are not offered. Subject samples are small and non-random. Price clearly selected the people he photographed to support a thesis he had constructed before he collected his data. This is all fine, but it shouldn't be seen as great science today.
I selected a few quotes from this book to give you an idea of his temperament and the times in which he wrote. He was opposed to the idea of the incompatibility of racial bloods, as he put it. He was convinced of the nutritional superiority of whole grains. He was interested in the quality of soil used to grow crops. This was a very thoughtful and progressive man.
Price died in 1948. The organization that bears his name was founded fifty-one years later by Sally Fallon...
along with Mary Enig. They are both cholesterol and saturated fat apologists.
Together they have written a book promoting saturated fats as a weight loss aid and another that seems to argue that contemporary diet recommendations are the products of politically correct organizations that want to control you. Suggesting that the scientists who are actually responsible for improving public health are instead agents of repression is a common ploy among fad diet peddlers. They are not above such cynical techniques to get you to trust them instead of respected scientists and doctors.
Have a look at the way Sally Fallon thinks you should eat. Her example daily menu is 70% fat, and those fats come from high-cholesterol, high-saturated fat sources such as egg yolks, cream, butter, bacon, and cheese. Clearly, this is a very fringe group with a lot of bad information on their web site. I'm not going to try to thoroughly examine all that is there, but let's take a moment to look at just a few examples of their helpful advice.
The wise people at the Weston Price Foundation want you to be scared of soy. They argue that soy phytoestrogens damage your endocrine system.
"Phyto", meaning "plant," estrogens are represented as active hormones-mimickers in the human body. Soy infant formula is said to be similar to birth control pills. We should feel relieved that no such nasty molecules exist in dairy.
It seems to me that their focus on the phyto-estrogens in soy is a case of people living in glass houses throwing stones. Soy does not contain mammalian estrogens. But the raw milk the Weston Price Foundation wants you to drink does.
These estrogens have been shown to be absorbed and active in humans.
These estrogens are suspects in some human cancers.
It is not unreasonable to suspect estrogens in some cancers. Anti-cancer drugs called aromatase inhibitors are effective because they reduce estrogen levels.
Cow's milk has been demonstrated to affect our endocrine systems, lowering testosterone secretion in men. Milk hormones may also contribute to the early sexual maturation of children.
Animal protein in general, which is of course found in milk, has been suspected up accelerating menarche in girls.
Milk is also linked to acne in boys.
These investigators were not surprised that soy milk did not have the mammalian estrogen metabolites that cow's milk does.
Soy phytoestrogens, on the other hand, do not behave like estrogens in the body, even when it would be advantageous if they did.
Soy does not affect the reproductive hormones of men, but it does seem to reduce prostate cancer risk.
Soy also seems to improve blood flow and improve the health of the lining of our arteries.
Soy phytoestrogens may even prevent new body fat from forming.
The Weston Price Foundation is rather irksome to vegetarians and vegans, who are targeted by their site. Chris Masterjohn is one of their contributors. Apparently he failed spectacularly at veganism, which he says caused him a litany of problems, from cavities to anxiety.
Naturally, he is now an anti-vegan ideologue along with the others at the Foundation, who have apparently been chasing after a mysterious indispensable nutrient called the X-factor for a while. This special nutrient can only be found in animal foods, of course.
Their anti-vegan stance explains their hysteria over soy, as soymilk is an obvious alternative to cow's milk. This opposition to veganism has lead them to produce some rather odd nutritional advice.
Here's an example of that from Masterjohn's rundown of alleged vegan deficiencies. Vitamin A is not usually identified as a uniquely difficult nutrient for vegans to obtain from diet. Masterjohn is using the primitive nutrition standard to say otherwise, pointing out the massive intakes of vitamin A by Greenland Inuit. He cites an article for this that I guess he doesn't expect anyone to read. In that reference, these very same Eskimos had very poor status of vitamin C, folate and calcium. The authors themselves describe their intakes of iron, vitamin D, and yes, vitamin A, as borderline toxic. They also had serious heavy metal and environmental toxin burdens. Is this supposed to be an improvement on a vegan diet? Toxic leves of vitamin A? What a strange argument!
The March of Dimes doesn't mess around with vitamin A. They know the preformed vitamin A in animal foods is not regulated well by the body. On the other hand, plant-based retinoids are converted to vitamin A in the body and are very safe to consume in large amounts. The March of Dimes is concerned about vitamin A because excess preformed vitamin A can cause birth defects. They specifically recommend against eating liver during pregnancy for this reason. Liver is a favorite food for the Weston Price people and the primitive nutrition believers in general.
Pause the video if you'd like to read a good explanation of the issues with vitamin A and diet by Andrew Weil.
Liver is extremely high in copper as well. Copper, like iron, is a trace mineral that can cause problems in excess. Here you see that dietary copper, when accompanied by the saturated fats in animal foods, is associated with with cognitive decline.
I found this interesting study from 1958. Even though the Alaskan Eskimos they studied ate a lot of preformed vitamin A, they were often deficient for it in their blood levels. Go figure.
In any case, vegetarians usually do fine with vitamin A.
It must be said that he Weston Price Foundation is especially interested in promoting raw milk, which has unique safety risks. I won't get into that particular subject here. It is covered very well elsewhere online, especially at the Real Raw Milk Facts web site.
The first of the supposedly wise cultures that the Weston Price foundation and the Paleo people like to talk about are the Eskimos. If you think they were models of health on nothing but meat and fat, think again.
In my first video you saw a picture of Arthur De Vany pulling his luxury SUV down his driveway. Someone who would do something so unusual is surely worth a closer look.
De Vany looks good for his age so he is a big deal in the Paleo world.
I heard him on a podcast and thought he seemed pretty interesting so I bought his book. I intended to spend more time on it but a short sampling had me pining for better things to read.
The cover illustration is promising. It suggests De Vany understands the ancient baggage we carry in our body plans and organ functions going back all the way to our fish days. Unfortunately, the content of the book doesn't live up to the cover.
It isn't important to me how someone uses evolution to rationalize his or her diet as long as that diet is reasonably in line with the best modern science on nutrition. Unfortunately, like Loren Cordain, De Vany has an unreasonable fixation on protein that he justifies through its ability to limit your appetite. Once again, I doubt proto-humans struggling hand to mouth for survival would have found much advantage in appetite control strategies, and I find it hard to believe they would have cared about keeping off the extra inches around their waists.
De Vany says at the bottom of this slide that a diet lacking in protein will lead to obesity, and he provides a reference to support that view. To the reference we go...
The reference is, amazingly, a study of protein consumption in grizzly bears. I'm not kidding. This is why I use pictures in these videos, folks. Sometimes while researching Paleo I didn't know whether to laugh or cry, but laughter definitely feels right on this occasion! Bears fed a low protein diet will keep eating until they get all the protein they need. Now why might this be? Would a bear commonly eat a low-protein diet?
Maybe someone out there would be kind enough to tell the esteemed economist that these godless killing machines
are classified as carnivores, unlike us, although they are functional omnivores. High protein diets are the norm for them.
Grizzlies are actually a great example of the compromises that evolution produces in organisms. They eat plants even though they aren't especially well adapted for that.
For modern bears, the most important protein sources are from plants.
This author went so far as to say they are often almost vegetarian.
Grizzlies do prefer animal meat and fat, but they can't always find it. As a result, even grizzlies in the Arctic depend mostly on plants. They are a more stable food source, which should give us a clue about what the stable food sources might have been for Paleolithic humans during the Last Glacial Maximum.
De Vany might want to check out this middle school level biology textbook to discover that grizzly bears are not known for staying especially lean. If you want to convince your readers that high-protein diets keep you lean, maybe bears aren't the best example for you to use.
Let's see what else he has for us in this reference. He says the same preference for protein is found in humans. It seems he has a study to back that up. Turning the page...
There you see the title at the very top. Let's look at that one.
Here's the abstract. Either Dr De Vany doesn’t understand this or I don‘t. Here's my take. First, it's a study of mice, not humans. Not that I'm complaining but he just said humans show this preference for protein and sent us to this study to support that.
So what does it say? The study is in two parts. Experiment 2 was about an amino acid supplement so I don't think that's what interests him. Experiment 1 is the one we should think about. The short version of my take on this is that it basically shows that rats don’t prefer either very high protein or very low protein diets. The rats were only offered 5% or 35% protein diets. They weren’t offered anything in between. One is too high, the other is too low. It seems DeVany only got half the message here. And I don’t know what this study has to do with feeling full.
I don't think this supports his argument very well. Now I'm not disputing the fact that people have protein needs that must be met, no matter what their diet is. I think De Vany is trying to tell us about the protein-leverage hypothesis, but he has just not chosen good studies to make his point.
The protein-leverage hypothesis states that humans, like other animals, have a requirement for protein intake that must be met. If the foods in our diets are very low in protein, we'll end up eating more calories than we would otherwise in an effort to hit that protein requirement. A better study in animals that De Vany could have used might have been this one, in which the food intake of spider monkeys seemed to be determined mostly by their protein needs. However, they really didn't eat that much protein. These monkeys were not Paleo.
That's the problem with this argument. Studies of the protein-leverage hypothesis in healthy humans do not indicate that we need very high amounts of protein.
Instead, they point to rather moderate protein requirements, even when the diets studied included refined grains, sugars, and unhealthy fats. This study did not make much of an attempt at high nutrient-density, yet it still only indicated protein needs in the 15% range. As any nutritionally aware vegan will tell you, a balanced whole food, plant based diet more or less automatically give you enough protein if you eat sufficient calories.
In the last portion of this end note he references a long technical paper by two low carb promoters saying there is a metabolic advantage to eating protein in terms of weight loss. I'll look at the concept of metabolic advantage in the Better Than Low Carb videos.
This section was naturally of interest to me. From the title you can tell right away that this economist is fully invested in the appeal to nature fallacy.
Getting into specifics, his thoughts on vegetarianism seem to be rather unsophisticated. He says a vegetarian diet forces reliance on high-glycemic foods. "There is no other way to obtain adequate calories," he says.
I don't understand why he would say something so easily refuted. Just look at a glycemic index table. I think I chose some pretty straightforward items to list, and you can tell they are all low to mid GI.
As for eating frequency, you can eat bigger meals, or simply be ok with snacking if that's a problem. He says you can't be very active as a vegetarian unless you eat high-GI foods because you have to eat so often. I think he doesn’t know the difference between glycemic index and calories. Otherwise, this sentence makes no sense.
De Vany doesn't even try to present himself as a critical thinker here. He complains about the few vegetarian students he knows who think a potato chip is a vegetable. Kids these days, right, Art! Tell me about it! The old man has a point.
There is no question college students are often poor examples of proper nutriton, much less responsible alcohol intake or healthy sleeping patterns. If you were considering a diet based on stressed and out of control kids away from home for the first time, Art has made a convincing case just for you.
He goes on. Children who don't eat animal protein will have underdeveloped nervous systems and brains? He then just goes on to say many, I guess not all, vegetarians he knows have terrible body composition? They're "skinny-fat"? Wait, what about the children not developing their brains? Isn't he sort of burying the lede here? Why skip that to make a catty remark about vegetarians being skinny-fat when you have that bombshell? Would someone please give a non-bear reference for that one? I can only guess he is talking about vitamin B12 deficiency. Unfortunately, there are still lots of vegans who are ignorant about supplementing B12. Otherwise, there are some really good books out there on vegan nutrition for pregnancy and childhood if you want to learn about that. As for the "skinny-fat" comment, many of the omnivores I know have terrible body composition, too, so I'm not sure where that gets us here. Vegans have a lower BMI on average so at least they are less likely to have metabolic diseases.
De Vany then gets into some specious reasoning. He says diabetes is increasing in places vegetarianism is practiced like India. Do you think this economist knows what a trend line might look like? Does he think vegetarianism is new in India? Does he think it is vegetarianism that is increasing there? De Vany acknowledges obliquely that the people who have studied this trend toward diabetes are blaming Western foods, but he has a different belief. It's the rice.
Rice GI values vary a lot by region. Unless he can say the GI values of rice have been rising in these places I'm not sure he has much of an argument about this.
It's not quite right to call India vegetarian for these purposes. Indians consume a lot of dairy and a lot of fat now.
This explains why vegetarian Indians have more body fat than non-vegetarians. By the way, is De Vany saying that in a country where they consume high levels of dairy fat their children are not getting B12?
Dairy has plenty of B12. Are we having a logical consistency problem here?
Amazingly, vegetarians in India are singled out here to have particularly low intakes of fiber. This should tell you everything you need to know about the quality of their diets.
In any case, vegetarians are a minority of the Indian population, so blaming that for a rise in diabetes is chronologically and statistically a tough argument.
The grizzly bear citation is funny, but De Vany outdoes himself at the end of this section. These three excerpts are from the same paragraph. He starts out pretending to offer vegetarians diet advice, as though he has demonstrated mastery of the topic by this point. He then turns full Rain Man. "I eat a lot of meat. Carnivores can love the environment, too." How’s that for a non sequitur? Carnivores can love the environment? Who said they couldn't love the environment? Would their emotions change their actual effect on the environment, though? He finishes by recommending a restaurant in Utah for its boar sausage. This in a paragraph that started as helpful advice for vegetarians. I am amazed that a college professor wrote this. I wonder if he graded anyone’s papers.
I'd like to address De Vany's statements on another topic as well. Calorie restriction is a strategy under investigation for its potential to extend lifespan. De Vany claims that his diet accomplishes what calorie restriction does because it restricts glucose. Remember, his diet is very high in protein and I have already shown you that excess protein appears to shorten lifespan, not lengthen it, so he is misguided before he ever brings up glucose. He is making his argument about glucose in humans based on experiments in bacteria. Really.
Slow down, Doctor. Let's check it out in mice first. In this study, we see De Vany's hypothesis is tested. It turns out his idea is a bust. The researchers reject glucose restriction.
De Vany bases this idea on a just-so story he seems to have made up himself. According to him, a lot of glucose in the diet signals abundance to the brain, so the brain decides it is time to store fat. So is the corollary that in cold weather the body will not try to store fat? Why would that be good? And why wouldn't any surplus energy be stored as fat, regardless of its source? Does that make sense to you? It doesn't to me.
Mammals generally develop fat storage patterns to assist in temperature regulation. I don't see why early humans in cold climates would have benefited from low body fat stores.
Here's an alternative just-so story. Think summertime. An abundance of fruit and starch signals an abundant food supply. Therefore, no fat storage is needed. A diet with restricted carbs signals food scarcity. Think winter. Calories consumed as fat should be stored as fat until carbs are found. I think my story makes more sense than DeVany's. How would DeVany explain the natural tendencies of the Eskimos, who had about as little carbohydrate as any population yet were often described as overweight. This author observes that people in hot places weigh less than those in cold places.
As you can tell, I'm not impressed with the thinking De Vany put into his book. I sincerely hope he is better with economics than nutrition.
The Eskimos are one of the model cultures for the Paleo belief system. I'll look at some of those cultures in the Primitive Nutrition series. But first, let's meet the man who brought our attention to these cultures, Weston Price.
Is there anything about Paleo that is more random and peculiar than its prohibition of legumes? Legumes are an incredibly nutritious, inexpensive and environmentally responsible food. When it comes to legumes, the Paleo people don't know beans.
If you are going to be pro-meat and anti-vegetarian, I guess then it’s just necessary to be anti-bean. Beans are nutritional equivalents to meat, so they appear threatening to the modern caveman.
Beans look pretty great in comparison to meat, even as a source of protein.
When you factor in cost, legumes look even better. Here you can see that 12 pounds of lentils costs only $33, and that's dry weight. That's a lot of lentils.
12 pounds of grass fed beef, however, is $103. I think I'll take the lentils and pocket the $70.
If we look at grass fed as dry weight, it really starts to get ugly. This is the price for only a quarter of a pound.
Really nice dry beans are about one twentieth the price. If you like to save money like me, this is too big a price difference to ignore. Legumes give me great nutrition and save me a lot of money. Thank you, beans.
As I've shown you already, we've been eating legumes for a long time so I am not impressed by the usual Paleo arguments against them.
This has not been a mistake. Humans have relied on beans because they are an incredibly valuable food that is under-appreciated by too many today.
Beans improve cardiovascular health, make weight control easier, and improve bone density.
They improve all aspects of diabetic control. I imagine the Paleo dieters would be posting a study like this everywhere if it were about meat instead of beans. But you will never see the fad diet promoters mention this one.
Just imagine a study like this where "bean" is replaced by "meat". Do you think they'd like it?
Beans are incredibly high in natural antioxidants.
The longest lived people in the world have eaten diets high in legumes.
And unlike with meat, eating beans is good for the planet.
United Nations Framework Convention on Climate Change
One of the worst greenhouse gases is nitrous oxide.
According to this study...
A vegetarian diet results in far less loss of nitrogen into the environment.
Legumes are a big reason why. They are nitrogen-fixers, pulling nitrogen from the air and fixing it to the soil where it is needed to grow food. Beans are an important part of the answer to our need for sustainable food production. No one should stigmatize them without a very great reason.
The reasons offered by the Paleo crowd to avoid beans are weak. Enzyme inhibitors and lectins have little effect after cooking. Once again, be a behaviorally modern human and employ some basic technology. Even cavemen knew how to cook. What’s more, the same factors that are put forth as antinutrients in beans can have important health-promoting benefits.
On page 91 of The Paleo Diet, Loren Cordain tries to blame beans for rheumatoid arthritis because of their lectins.
Here is the paper he published to make the same point.
Now if you are really concerned about lectins, you can read this helpful blog post on the subject. The blogger gives us a particularly nice little quote I included here.
If Cordain is right that beans cause rheumatoid arthritis, you might expect it would be easy to find epidemiological evidence of this since some countries eat so many beans. These would be poor countries. Unfortunately for Cordain, the parts of the world where bean consumption is highest have the lowest rates of rheumatoid arthritis.
According to draft report The CGIAR Standing Panel on Impact Assessment
The Consultative Group on International Agricultural ResearchFeb 2011
Look at per capita consumption of pulses and Niger really stands out. Shouldn't they be devastated with lectin-induced rheumatoid arthritis?
Well they aren't. In fact, the first documented cases ever of rheumatoid arthritis in Niger were reported in 2010.
Meat consumption, however, has the highest statistical relationship in the diet with rheumatoid arthritis. Cordain must be attempting some misdirection on this subject. Don’t fall for it.
Legumes have a counterpart to celiac disease. There is a condition called favism that causes fava beans to be dangerous to individuals with a genetic defect. Somewhat like celiac, the explanation for this genetic trait was a selective advantage in resisting malaria once upon a time.
Pythagorus was likely the most famous sufferer of favism. Beans eventually did kill him, but indirectly. Rather than cross a field of beans, he took his chances with pursuing soldiers, who proved to be even worse for his health.
Leaky gut is one of the dire health problems Paleo is supposed to help you avoid. Beans cause leaky gut, Cordain says.
Which in turn cause autoimmune diseases. He mentions type 1 diabetes, which really caught my attention. Can you guess where I’m going with this?
This study looked at the worldwide epidemiology of type 1 diabetes.
I'm zooming in here on on the top and bottom ends of their graph. Notice which countries have the most type 1 diabetes and which have the least. Which end of the graph do you think eats more beans and which less? This is just too easy.
I pulled out the data for some countries from a table in that paper. The top two have very low rates of type 1. The bottom two have much higher incidence rates. I'll show you a bit more on Okinawans in my Ancient and Out of Fashion video. I'll just say for now that they eat a lot of beans. Algeria also has low rates of type1.
Algerians love their chickpeas and lentils.
And they don't eat much meat.
At the high end for type 1 incidence are Germany and Australia.
The Germans don't eat very many legumes.
Australians eat hardly any at all.
But both eat a lot of meat. The Germans are the biggest meat consumers in the EU.
And the Australians are some of the biggest meat eaters in the world.
The strongest dietary associations with type 1 diabetes are foods of animal origin. So I must ask, does Cordain really care about type 1 diabetes? Or is he just trying to push a fad diet?
Here’s an extra comment about leaky gut. The vaunted omega-3 fatty acids, a favorite nutrient of the Paleo dieters, actually promote the dreaded intestinal permeability. This permeability seems to provoke an immune response in babies, which is a good thing. Their immune systems develop faster as a result. It seems once again that the Paleo people have oversimplified diet and human health.
There is one other perceived problem with beans I shouldn’t let pass. Some think if they eat beans it will cause their social grace to escape them. Well, that objection just doesn’t cut it. I hate to break it to them, but with this study, it looks like that excuse has just run out of gas. Either way, I think an occasional loss of dignity is a small price to pay for better health. After all, if you wind up with colon cancer, you won’t be able to blame it on the dog!
Enough of the abstract arguments. It's almost time to look at some of the fabled hunter gatherer role models for the Paleos. But first, an interlude.
Primitive Nutrition 22: Thin Gruel on Grains, Part I
The Paleo dieters really have a problem with grains. They seem to have blown out of proportion every possible conjecture, every bad experience, and every legitimate food intolerance to make you feel they are dangerous. I'm not here to say you should or shouldn't eat grains. My purpose in this video is just to restore some balance to this recently much maligned pillar of civilization.
Even though I want to, I will not sidetrack here into the essential role played by grains in feeding the impoverished, evening out commodity prices, promoting political stability, or enabling human culture to advance. Paleo is not about the big picture. It's about the small stuff. The very, very small stuff. I just want to point out now that a food that is inexpensive, easy to cultivate, and doesn't spoil quickly is a food that can do a lot of good for humanity.
In an effort to scare you off of grains Cordain takes us to some strange places. When was the last you heard a public service announcement about rickets, or its counterpart in the elderly, osteomalacia? Cordain's concerns with grains seem drawn from a bygone era.
It has been known since 1923 that rickets is caused by vitamin D deficiency, not by grains.
It is only a problem today in poor populations with imbalanced diets and where peoples’ skin does not receive adequate exposure to the sun. If you don't know anyone living in conditions like these or eating diets like you see described here, you probably don't need to give rickets a second thought.
Cordain digs up a couple other golden oldies to scare you with beri beri and pellagra.
You see in my copy of his book I circled the use of the word "invariably." Once again, Cordain is a rare scientist in that he leaves himself so vulnerable to falsification due to his absolutist language and binary world view.
You might pause the video to read that second paragraph on the left. He doesn't quite say it, but he wants you to think corn causes pellagra. Yet the deaths due to pellagra he references in the preceding paragraph are from seventy years ago. Aren't we still eating corn? What gives?
All the way back in 1915 it was suspected that pellagra could not happen in the context of a reasonably normal and balanced diet.
In 1912 it was recognized that Mexicans ate corn as a major staple food yet pellagra was unknown to them.
That's because they had been demonstrating the eminently human adaptation of using technology to process their grain for around 3000 years, in this case through a process called nixtamalization. In nixtamalization, corn is soaked in an alkaline solution to liberate its nutrients.
Cordain has known about this for a long time but he didn't want to use his fad diet book to inform you about it, maybe because that might undermine his efforts to get you to fear the deadly pellagra.
On a side note, pellagra is another historical example of the abuse of the theory of evolution. This slide is a cautionary tale.
What about beri beri? Well, that is explained in the paragraph to the right. Cordain uses another sarcastic pair of quotation marks for the word "enriched." He is trying to sublimate the message that if you have to add a vitamin to a food to prevent it from hurting you, you shouldn't eat it. But he says a few lines earlier that this doesn't happen with brown rice. So shouldn't he say instead that we shouldn't strip the naturally occurring nutrients from our rice?
This has been understood for 100 years, yet Cordain thinks you should be concerned about this old problem, too.
Couldn't he instead say that brown rice cures beri beri, which is how they put it in 1918?
Here's another weird one. Cordain actually published an article called "Whole Wheat Heart Attack." Haven't you heard that whole wheat causes heart disease?
Probably not. His idea is based on the hypothesis that lectins in grains hurt your arteries, but only fellow Paleo promoter Staffan Lindeberg will join him out on this limb.
Search "whole wheat atherosclerosis" and with the exception of Cordain's article, it looks like it's a rather positive story for whole wheat. That last one found no relationship between whole grains and inflammation. Notice it appears no one has cited Cordain's article. Why won't anyone buy into his hypothesis?
Probably because there is a consistent inverse association between whole grains and heart disease, as stated in this study of studies.
Actually, whole grains seem to lower your LDL cholesterol.
Regrettably, most of us don't eat a lot of whole grains.
We should all recognize the differing health effects of whole and refined grains. There are very few health professionals, if any, advising the consumption of latter, yet most recommend the former, and there are good reasons for that.
This abstract offers a nice rundown the health benefits of whole grains.
Eating more fiber will help you live longer, and whole grains are a great source for that, yet there is a lot more to them than fiber.
Their phytochemicals promote health in a way that isolated fiber supplements cannot. They work together in the matrix of the whole food to fight disease. Refine the grain and you lose most of these benefits.
These phytochemicals may have been under-appreciated in the past.
Whole grains also improve the composition of gut microflora far more than wheat bran just by itself.=
Of course, some people have an entirely appropriate reason for avoiding grains. They have celiac disease. The Paleo world sees celiac as some sort of proof for their diet. In Part II, I'll show you why they are mistaken about that.
Primitive Nutrition 23: Thin Gruel on Grains, Part II
Paleo gurus don't talk for long before they bring up celiac disease and gluten intolerance. For those who legitimately suffer from those issues, avoiding gluten is not optional.
However, for the rest of us, to argue against eating gluten because of the problems these people have seems to me to be an example of an exception fallacy.
After all, celiac disease is known to be a genetic disorder. The usual idea you’ll hear to explain its origin is the timing of the introduction of grains within past populations, so that the descendants of those who adopted grains more recently are more prone to celiac.
However, celiac seems instead to be the result of positive selection based on the immune system.
As we have seen, as cultures adopted agriculture and came to eat grains, they lived closer together, and their immune responses adapted.
The study of our ancestors has revealed that genes related to celiac disease may have provided an advantage in resisting epidemics that would have struck dense populations.
The genetic traits for celiac may have persisted as a balancing polymorphism due to a heterozygote advantage ...
with the homozygote much more likely to develop celiac disease.
A classic example of a balancing polymorphism like this is sickle cell anemia, which also has immune advantages in its heterozygote form in protecting against malaria.
The case that celiac has been positively selected for immunity continues to build. On the other hand, the imagined evolutionary novelty of grains causing celiac as hypothesized by Cordain doesn't seem to have gained much traction.
The Paleo people also blame grains for schizophrenia.
Loren Cordain, The Paleo Diet
That includes Loren Cordain.
However, this recent review of environmental factors in schizophrenia finds a lot of better candidates to consider than grains.
There does seem to be a link between schizophrenia and celiac disease.
But don't forget, celiac is a genetic disorder.
And this disorder is associated with a variety of neurological symptoms. 35% of the celiac sufferers in this study had a history of psychiatric illness.
So we shouldn't be surprised that celiac and schizophrenia share genetic variants. To ignore this and instead imply that grains can cause schizophrenia in anyone is highly irresponsible in my view.
What about gluten intolerance? Gliadin is a glycoprotein that is increasingly getting the attention of Paleo promoters. However, I noticed that the references offered to support this concern here were all in vitro, meaning in isolated lab tests and not in patients' bodies.
In this test of subjects without celiac disease, no anti-gliadin anitibodies were detected. Certainly, gluten intolerance in non-celiac individuals seems to exist.
However, it isn't clear how many people it affects. It certainly seems to be a minority.
Alessio Fasano is a celiac researcher Loren Cordain cites to support his fad diet.
Let's see what Dr Fasano himself says about diet without Cordain filtering his ideas. He describes the past human race as only eating meats occasionally.
In response to claims that gluten sensitivity is widespread, Dr Fasano says, "I have a really hard time believing that we are plagued by this." He characterizes gluten avoidance in the general population as only a reflection of a current fashion trend.
For most people, a gluten-free diet is a fad diet.
Experts on celiac disease say that adopting a gluten-free diet unnecessarily is always a bad idea.
A gluten-free diet may reduce the beneficial bacteria in your digestive tract.
Even if you do have celiac disease, you don't need to give up on all whole grains.
Before I leave grains, let me state the obvious. There is a huge difference between refined and whole grains. Cordain knows the difference but he wants to condemn all grain products.
Most people who think carbs are fattening seen to only understand the term "carb" to equal a refined grain product. You will get no argument from me that refined carbs are bad for you. Not only does the milling of grains remove its health-promoting nutrients, it reduces the them to tiny particles that cause a greater glycemic response. Consume grains in their whole form with less or no milling and you may find them to be more helpful in achieving your goals.
Responsible researchers who are concerned about the effects of junky carbs also encourage you to eat good carbs, like oatmeal and legumes. That brings us to the humble bean, next in the Primitive Nutrition series.
I have no problem with any macronutrient. We need them all, including protein. People may want a little more or less depending on their individual needs so I am not claiming there is an exact right amount. However, protein seems to be a point of fixation for the new cavemen so it must be discussed in the Primitive Nutrition series.
Here is the macronutrient composition of a hypothetical woman's daily intake according to Loren Cordain's The Paleo Diet. Note the saturated fat content, although I won't go into that here. Saturated fat is unhealthy and saturated fat and meat are inseparable but this video is focused on the issue of protein. Notice the amount of dietary cholesterol is not listed by Cordain, which is a rather important consideration to leave out. Do the math and you'll see this is a 2300 rather than a 2200 calorie day.
Cordain did calculate the ratios correctly. Clearly we are dealing with a low carb diet here, but low carb is also a separate topic for other videos. What Cordain has imagined here is a woman eating 33% of her calories in the form of protein. That's a lot.
A diet made up of 35% protein has been shown to damage the kidneys of rats.
33% translates into an amazing 190 grams of protein for a woman. How does this primitive advice compare to the recommendations of modern health institutions?
The Centers for Disease Control and Prevention arrived at a much lower figure. They recommend only 46 grams of protein.
What about the World Health Organization and the Food and Agriculture Organization of the United Nations? Well, if we assume the average woman is 5 foot 6 inches and her healthy body weight is 130 lbs or 59 kg, they recommend only 49 grams of protein per day. Exercise physiologist Loren Cordain is recommending almost four times the protein intake as this.
There is also the question of where you get your protein. Government scientists in the UK advise only a pound of red meat per week.
This is similar to recommendations by the European Food Information Council.
Clearly Cordain's meat-centered diet is far out of the mainstream.
Of course, you need adequate protein. This is an interesting study that reinforces that point. In an experiment on mice, the offspring of male mice fed low protein diets were made more likely to have high cholesterol. That is certainly not desirable.
At the other end of the spectrum, the collective world of broscience dictates that you need high levels of protein for strength, but this is not clear from the scientific literature.
For example, in this study of older and younger subjects, high protein diets did increase nitrogen balance, but this seemed to be counterbalanced by a more catabolic state after the protein is absorbed.
High protein diets may also impair performance in endurance exercise.
It's important to get the right amount and mix of amino acids, but it is not clear there is an advantage to animal protein.
As long as you consume the amino acids you need, vegetable sources of protein may provide added benefits, such as preventing chronic diseases.
They also might lower blood pressure, which would be a big plus.
If meat were so healthy by itself, why would researchers bother adding plant nutrients to it to make it healthier?
To put my discussion of protein in the right context, you might pause this video and read Loren Cordain's thoughts on our ability to digest starches. He is asked how he rationalizes not eating important starches when it is clear we have adapted to them over thousands of years.
Don't worry if you don't understand what he is saying. Just notice how hard he is working to get around the basic point that we have clearly been eating starches long enough to have made important adaptations. Also notice that he is relying entirely on old experiments on animals. Imagine how many papers he had to comb through to find these. He did this because most observations about the consumption of unrefined starches by humans are overwhelmingly positive.
As I go through this material about proteins, if you think I'm being somehow unfair, my answer to you is that I am presenting research that is at least as mainstream as what Cordain will reference to turn you off of starches. By failing to address the issues I will raise even as he scavenges every possible demerit for grains and legumes, Cordain reveals his fad-diet-promoting bias. That is true of him and most of the primitive nutrition advocates, and that is my basic point in this video. These guys don't apply their skepticism consistently.
Here is a basic fact. Your body can store excess carbohydrate as glycogen or fat, and we all know it can store excess fat and excess calories in general as fat, but protein cannot be stored as amino acids, and amino acids are the reason we need protein in the first place. Excess protein beyond our needs is instead converted into glucose for energy or triglycerides for fat. It's not used to build or repair tissue.
There is such a thing as reserve protein, but it is used for conversion to glucose for energy, not for protein synthesis.
The process your liver uses to turn protein into glucose is called gluconeogenesis. With enough carbs, this is not necessary and your protein can be used for your body's needs that really require protein.
It seems a lot of the rationale for eating protein in excess is to just burn calories sitting still. Leaving aside whether or not this really works, realize this epitomizes the slouching low carb approach to health. It is not about maximum nutrition. It is not about better performance. It is not about feeling your best. It is about suppressing your appetite and burning calories without having to exercise as much.
The claim that protein speeds up your metabolism implies your body wastes energy trying to process the protein. Much of the extra energy your body expends on a high-protein diet is wasted in gluconeogenesis. This is hardly an efficient use of food calories.
When fed a low-carb, high-protein diet, it is clear that the body tries to compensate for the lack of carbs by producing more glucose from protein.
Over time your body gets better at gluconeogenesis on a high-protein diet. This suggests to me our bodies prefer adequate carbohydrates over excess protein. We adapt to better manufacture carbohydrate when we don't get enough from the diet.
The American Heart Association decided to respond in 2001 to the trend toward high-protein diets for weight loss. They pointed out the obvious. Such an imbalanced diet in favor of one macronutrient means less of another. If all that protein winds up as glucose anyway, why not just eat healthy carbohydrates that bring more nutrients to the table instead? This is one of the most common criticisms of low carb diets. They are nutritionally inadequate.
Let's look at the opposite extreme. Here you see that people following a raw vegan diet, and therefore eating extremely high levels of fresh fruits and vegetables, have significantly higher antioxidant status than omnivores. Additionally, you can be sure they are benefiting from high fiber intake and superior hydration through their foods. The Paleo approach tries to compensate for the comparative nutritional lack in typical low carb diets by making its few calories from carbs come in the form of fruits and vegetables, but this only helps Paleo look good in comparison to nutrient-poor diets. It also limits all the beneficial phytochemicals in plant foods that fight disease. Vegans like these can eat safe and extremely nutrient dense diets so they don't need to accept this trade-off. Every single calorie can deliver health-preserving phytochemicals while the diet as a whole can provide the necessary gross macronutrients we all need.
In one of the journals published by the American Heart Association, these researchers connected the imbalanced high-protein approach to high blood pressure in the children of mothers who ate high animal protein diets. A diet that gives your children high blood pressure sounds less than optimal to me. Claiming cavemen ate like this doesn't make the problem go away.
Another problem with such high meat consumption is gout, a painful condition which is unfortunately making a comeback these days.
Increased meat and seafood consumption explain the increase. Total protein and vegetable protein do not relate to gout risk. This is one reason high protein vegan diets seem to be relatively safe for athletes who want to pursue that strategy.
Gout is just another part of a pattern, in which high animal protein diets can be shown to detract from health. For example, here is a rat study suggesting that high protein diets might lead to diabetes.
Subsequent to that study, protein from red meat was found to be associated with diabetes while vegetable protein was not.
High protein diets are also likely to be detrimental to colon health.
There appears to be a relationship between red meat intake and colon cancer.
High animal protein diets may also damage heart health in ways that are not apparent in the usual blood tests. I'll look soon at some of the reasons why this may be true.
But first, one more basic issue with excess protein. The digestion of protein produces urea, an apparent toxin in elevated amounts that your body works hard to remove. Water is wasted in the effort to eliminate this urea.
This is why people seem to lose weight on high protein diets. Water is lost, and dehydration becomes more likely.
This is one reason why high protein diets are not recommended for athletes. Performance could suffer in a dehydrated state.
This is also why Eskimos were often observed to consume unusually high quantities of water. This doesn't seem like an efficient use of the body's limited resources to me.
With the basics out of the way, let's look at a few of the evolution-based rationalizations for high meat consumption Paleo propagandists have tossed out in the next part of Protein Choices.
Primitive Nutrition 20: Protein Choices, Part II
Given the basic nutritional arguments one can make against consuming excess protein, what reasons can Paleo promoters find to follow high-protein diets anyway? Well if it's Paleo, there are evolution stories that makes it feel right. But that doesn't mean those stories are right.
It seems irrelevant what dietary patterns enabled our bigger brains thousands of years ago, but for what it's worth, cooking seems like a better explanation than meat. You've seen this already in my Primal Primates presentation.
Here's a more interesting rationale put forth by Cordain for high animal protein consumption in The Protein Debate. I want to repeat that I find most diet advice based on speculation about evolution to be suspect as this approach requires an appeal to nature. Humans, he thinks, have a special high-meat history that makes us super meat-eaters. He says humans have a special adaptation that prevents the overproduction of uric acid, enabling the gorging of meat. His evidence for this is an enzyme called xanthine oxidase.
It turns out this xanthine oxidase adaptation did not take place first in humans. We know this mutation took place before we split off from our primate ancestors, as we share it with the great apes. Cordain has his evolutionary history wrong. This is significant. It proves
Cordain's argument is only a just-so story. It is not hard science.
Just-so stories are a type of ad hoc fallacy.
If you doubt my science on this point, here is another reference for this.
And another.
Our closest relatives - chimps, gorillas and orangutans - eat very little meat, yet they share this mutation.
This adaptation was most likely in response to blood pressure regulation in low salt environments, not high meat intake.
Here's another folly of meaty Paleo-logic. Cordain is aware of a condition called rabbit starvation which occurs when too much protein is eaten. Serious illness results because of the high metabolic demands of eating meat. He knows there is a maximum amount of protein the kidneys can process. He also says there is only one case in the medical literature of a person eating enough protein to experience this so-called rabbit starvation. He seems to prefer to think of the rarity of this condition as evidence of how hard it is to induce, rather than as evidence that hardly anyone has been crazy enough to try to induce it. By contrast, there are no similar problems with digesting carbohydrates. You can easily eat 80% healthy carbs for years on end and have no adverse health consequences. Moreover, through the last several millenia the vast majority of humans have eaten high-carb diets, and they were just doing what came naturally. I would think all this would help him realize that humans shouldn't eat high quantities of meat, but somehow he concludes the opposite. He wants us to eat so much meat we are near the body's limits for metabolizing it safely. By definition, his nutrition beliefs are therefore extreme.
We can look at protein and evolution another way. Primitive hunter gatherers have been said to under-utilize lean meats in favor of fat and carbohydrate. This author suggested this may be because high protein can be a problem during pregnancy.
You'll see in my Masai video that they restrict animal protein during pregnancy, but they aren't alone. This practice is commonplace among hunter gatherers.
An alternate hypothesis for this is that meat would have raised the chances of exposure to parasites and other pathogens, so women developed an aversion to meat to prevent infections during pregnancy. It's an interesting idea.
Cordain's last line of this paragraph from The Protein Debate is odd. He references a study showing an apparent improvement in gout symptoms due to high protein consumption. This was a pilot study of only twelve people on calorie restricted diets. He says this study was somehow the proof in the pudding that eating lots of meat is good. Proof in the pudding? He must think this is pretty compelling. As we have seen, gout is strongly linked to high meat intake for obvious metabolic reasons. So what's the explanation for this one? Well, I’ve already hinted at it.
To preface this, look again at this study. This was a widely referenced article. This is strong epidemiological evidence against high-meat diets. By contrast, I haven't seen low protein or vegan diets linked to higher gout risk anywhere.
The study he mentions is usually seen as a reflection of the benefits of calorie restriction and weight loss in obese men with gout. Obesity is strongly associated with gout, so once again, we see that calorie restriction can improve some chronic diseases. Protein intake was not the only diet variable that changed, either. Their whole diet was new. And as I said, this was only twelve people. This study doesn’t prove anything, except that this was the best study Cordain could find to confuse you about the link between meat and gout.
Discussing protein in the context of evolution brings up the interesting case of a nonhuman sialic acid called N-glycolylneuraminic acid, or Neu5Gc. I’ll bet you Paleo guys saw this coming. Humans are unique among mammals in that we cannot produce Neu5Gc.
Agit Varki has examined this curious issue. He believes it has implications for human health.
He has observed that cancer patients accumulate Neu5Gc in their tumors. Since they can't make it themselves, it must come from dietary sources, and those are red meat and dairy. This nonhuman sialic acid seems to contribute to an inflammatory process in cancer.
The inflammation occurs because the immune system recognizes this molecule as foreign. This reminds me a bit of the Paleo fears of lectins, but I've never seen that dietary lectins accumulate in cancer tumors, for crying out loud.
There are numerous toxins associated with meat. Again, imagine the harsh scrutiny being applied to grains and legumes by the Paleo peole being equally applied to animal protein and you'll understand why I mention these. First, the National Cancer Institute says exposure to heterocyclic amines and polycyclic aromatic hydrocarbons constitutes a risk. These are recognized potential carcinogens produced in well-done meat and meat cooked at high temperatures.
Meats also are high in advanced glycation end products, or AGEs, much moreso than carbohydrates.
AGEs are very bad for you and this is not in doubt.
They might contribute to type 2 diabetes.
Here's an in depth examination of the AGEs in different foods. Animal foods did not fare so well.
N-nitroso compounds are also well-known to be present in processed meats, and they are likely carcinogens. What is less well known is that meats cause these chemicals to be produced inside your body. High meat diets are here compared to smoking tobacco.
A typical response to these cooking-related toxins would be to say that meat simply shouldn't be cooked long or at high temperatures, but there is an interesting angle on this for the natural-is-better Paleo belief system. Humans like the taste of these toxic compounds, and we aren't alone. Primates like these flavors, too, and they don’t cook anything. A Paleo dieter may wish to eat like his ancestors, but this isn't the same as eating for health. In trying to reconcile our attraction to these toxic flavors, it has been suggested that their tastes are reminiscent of some plant foods, and that is why they are preferred by primates like us.
Of course, trans fats are naturally found in animal products as well. We all know to avoid trans fats.
Animals also bioaccumulate environmental toxins.
Packaged meats also are a main route of exposure for xenoestrogens called phthalates. Anti-soy Weston Price fans take note.
Another potential area of concern with high animal protein diets is our endocrine function. This study found that whereas some fruits and vegetables appear to improve semen quality, meat and milk might adversely affect it.
Amazingly, this has been observed in the male children of mothers who ate a lot of beef.
Fish is also suspect in similar ways. It may be the environmental toxins that concentrate in fish that explain its association with poor semen quality
Opposing effects of plant and animal foods have been observed regarding women's fertility as well. Plant protein was better here.
Vegetables and meat, including fish, also had opposing effects on stress hormone concentrations during pregnancy. Vegetables were better again.
These stress hormone levels apparently remain elevated into the child's adulthood. Those hunter gatherer women seem to have been on to something.
Environmental pollutants are actually more reliable biomarkers of fish consumption than omega-3 fatty acids.
This analysis found that the children of mothers who ate more fish had better test scores in spite of the confounding effects of the mercury in the fish. The authors’ advice was to eat fish lower in mercury to obtain the beneficial nutrients in the fish, like omega-3s. It seems to me it would be better still to find sources for these fatty acids that have no mercury.
One of the supposed advantages of red meat is its high content of heme iron. I'll look at that issue in Part III.
Primitive Nutrition 21: Protein Choices, Part III
Red meat has been associated with some cancers. How might this be explained?
Let’s consider the iron in red meat. Certainly, we need iron in our diets. However, too much likely increases the chances of the free radical damage that is associated with many degenerative illnesses.
In excess iron becomes toxic…
and promotes heart disease.
The iron in meat comes in the form of heme iron. There is no heme iron in plant foods. Heme iron is what makes red meat look red.
It is the heme form of iron that is considered a suspect in contributing to colon cancer.
The high levels of sulphur created from the digestion of meat can harm the good bacteria in our digestive system. Maybe this adds to the heme iron problem.
Exess heme iron from red meat appears to be the cause of the production of those carcinogenic n-nitroso compounds inside the body I mentioned in the last video.
It also seems to increase the risk of heart disease.
Remember how in the Truthiness Paleo-style video we learned that Loren Cordain is ok with atherosclerotic plaque, just so it isn't unstable? Well it's not glucose or some other agent associated with carbs that’s found in unstable plaque.
It's iron. Normal arteries don't have it. Unstable, dangerous plaques do. Is there a connection to dietary heme iron here?
I don't know, but red meat is associated with heart disease enough that I would rather get my protein elsewhere. You don't see concerns like this expressed about beans.
Richard Fleming has shown us very clearly the differing effects on blood flow of low fat diets, as you see on the top, and high-protein diets, on the bottom, with the bottom right scan being made after a high-protein diet. Which blood flow would you rather have? Was this due to the cholesterol? What about the heme iron? Or was it something else? All that I need to know is that a diet high in animal protein was responsible for that bottom right scan.
Here are a few studies linking heme iron to cancer. This meta-analysis focused onthe link between meat and colon cancer.
The authors offered hypotheses blaming heme iron for this.
Here an association was found between heme iron and gastric cancer.
This one found a connection between iron overload and breast cancer.
Here red meat was associated with a variety of cancers while whole grains were not.
Studies like these had this meat scientist asking in the journal Meat Science if we should all just become vegetarians. It seems the best they can hope for is to find additives to put in meat to neutralize the toxicity of the heme iron.
I find it interesting that the Paleo promoters are so focused on celiac disease yet they ignore hemochromatosis, which affects 1 out of 200 people as opposed to 1 out of 133 with celiac. Hemochromatosis is a debilitating condition caused by the buildup of excess iron from the diet. You'd think it would be worth a mention every now and then.
People with this serious genetic disorder are advised to avoid red meat and animal fats.
There is one minor issue related to protein I'd like to comment on here, and that is the amino acid taurine. Paleologic includes a fallacious premise. There is a single ideal diet for all possible human goals and values, which of course is the Paleo diet. There can be no nutrient that is better supplied by a supplement because that just feels too modern. You want taurine, and meat is the Paleo way to get it.
The problem with this logic is that almost all the research I've seen supporting taurine’s benefits has come from studies using supplemented taurine, not taurine in food. Here is an article about the possible benefits of taurine for heart health. This used a supplement, not meat. If you haven't heard, animal foods hardly have a good reputation in relation to heart disease, yet the Paleos have decided this validates their fad diet. The subjects described here had bypass surgery. I wonder if their meaty diets got them into that situation in the first place.
These are some confounders in studies of taurine. Interpret with caution.
It's possible the benefits of taurine supplementation are only seen in individuals consuming unhealthy diets.
There is no evidence of humans becoming deficient in taurine under normal conditions. Infants with vegan mothers seem to be healthy despite lower taurine exposure in utero.
There is considerable overlap in the amounts of taurine in the milk of vegan and omnivorous mothers.
If you are interested in a dietary source of taurine that is vegan, nori has just a little. Otherwise, if you want extra taurine, you can certainly supplement it. Then you can really say you are following the example set by most of these taurine studies.
You may remember in my "Define 'Healthful'" videos that Loren Cordain cares about the IGF-1/IGFBP-3 ratio. Protein has an interesting effect on that.
You may know that calorie restriction has been shown in animal experimentation to extend lifespan. One of the ways it seems to work is by decreasing IGF-1. This is not exactly what happens in humans, as revealed in this study. In this research, protein drove up IGF-1. What lowered IGF-1 was protein restriction. I am surprised Cordain even mentions this subject.
Maybe this why excess protein is believed to lower lifespan, in addition to the other issues I have mentioned so far.
One of the dietary mediators in lifespan appears to be the amino acid methionine. It's impact has been demonstrated in mice.
There have been a lot of recent studies on methionine restriction. I present this just one as an example. Here, obese adults with metabolic syndrome improved fat burning and insulin sensitivity beyond what one would expect just from their weight loss through the restriction of methionine.
Here are the highest foods in methionine. Eggs and fish top the list, followed by other meats. If you find the methionine research on lifespan convincing and you want to live longer yourself, you might lose interest in these foods.
I'll close by reminding you that dietary fiber has been shown to reduce all-cause mortality. Why not get your glucose from carbs instead of extra protein and enjoy the benefits that come with a natural high-fiber diet?
Do you think I’ve been too rough on meat in these videos? Do your own research on all these issues and try to stick to mainstream sources. I think you’ll find I’m on firmer ground with all I’ve presented here than the Paleo dieters are when they malign grains. I’ll lend some support to the staff of life just ahead.
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