There are many untruths and myths about the Paleolithic diet and evolutionary nutrition circulating on the internet and among the general public. In today’s article I thought I’d take a look at 10 of the most common misunderstandings people have about evolutionary nutrition, with the purpose of debunking some myths and setting the record straight.
1. Our ancient ancestors consumed a very fatty diet
Some people seem to be under the belief that preagricultural humans derived 60-80% of their calories from fat. As I’ve pointed out many times here on the site (e.g., here, here), that’s simply not correct. We don’t even have to look at the science on this matter to understand that the above assumption is faulty; all we need is a basic understanding of how the different foods that make up the human diet are composed. Butter, GHEE, coconut oil, cream, bacon, and other similar foods with a very high fat density were not a part of preagricultural human diets. Furthermore, game meat tends to be markedly leaner than meat derived from domesticated animals (1, 2). With a few exceptions (e.g., the Inuit), hunter-gatherers don’t consume extremely fatty diets (3, 4, 5). The original human diet differs markedly from the Atkins diet.
2. The Paleo diet concept lacks scientific support
This is one of the most common misunderstandings about evolutionary nutrition. Contrary to what some people seem to think, the scientific foundation upon which the Paleoliithic diet concept is built is very solid. Not only have clinical trials with a variety of different endpoints shown that the Paleo diet is superior to several other prudent diets (e.g., 6, 7, 8, 9), but the basic, foundational premise of the Paleo diet is supported by a wealth of scientific data derived from anthropological research, evolutionary genetics studies, and many other forms of research. This will likely come as a surprise to some people, but the fact is that if we consider the totality of the available evidence, no other diet has a stronger or more rigid scientific backbone than the original human diet.
3. Cereal grains are Paleo
Several archeological studies – many of which have been published over the past couple of years – that have analyzed ancient dental remains and crocks and vessels believed to have been used for the production of food have found evidence which indicates that at least some Paleolithic humans gathered, processed, and consumed grass seeds (10, 11). Some journalists, health “experts”, and nutritionists have put their own spin on these results and jumped to the conclusion that cereal grains were a major part of the diets of our preagricultural forebears. As I pointed out in my recent critique of Peter Ungar’s critique of the Paleo diet, that’s an incorrect assumption. Yes, some Paleolithic humans, in particular those that lived during the late Paleolithic, likely consumed small quantities of cereal grains; however, as I point out in the above critique, a large body of evidence shows that cereal do not make up a large part of the diets of neither ancient nor contemporary hunter-gatherers.
4. X indigenous people are seemingly healthy despite consuming a lot of X nutrient or food; hence, it’s not problematic to consume a lot of that nutrient or food
This is a very common misconception about nutrition in general. It’s well known that the Maasai, the Kitavans, the Inuit, the Okinawans, and many other indigenous people are long-lived and largely free from chronic disease “despite” the fact that they consume unorthodox diets. For example, the traditional Okinawans consume a diet that is very high in carbohydrate, particularly starch, but they are among the longest living people on Earth nonetheless. This has led some people to believe that it’s not problematic to consume a very high carbohydrate diet. Some people even make the case that we all should eat a lot of carbohydrates, seeing as the Okinawans, as well as some other healthy traditional people such as the Kitavans, do so. As any wise nutritional scientist will tell you, this type of thinking is based on a flawed understanding of science. All we get from observational studies are correlations; we don’t get to find causal links. It may be that the traditional Okinawans would have been healthier and more long-lived if they had replaced some of the starch they are eating with another nutrient, such as protein or fiber. Also, perhaps needless to say, a person’s health and longevity are not only determined by the diet he’s eating, but also by a variety of other factors, including his physical activity levels, the quality of his sleep, and genetic/epigenetic factors.
5. We don’t know what our primal ancestors ate
This is another very common misunderstanding about evolutionary nutrition. Yes, it is true that we don’t know exactly what was on the dinner plate of our Paleolithic forebears. With that said, we do have a pretty good idea of what they ate. Not only do contemporary foragers provide us with a window (although somewhat foggy) into the lives of our ancient ancestors, but via fossil research and analyses of genetic material we have been able to create a general picture of what our ancestors ate and how the human diet has changed over the millennia.
6. We don’t have access to the same foods as our preagricultural ancestors; hence, it makes no sense for us to try to replicate their diet
The foods that we find at the supermarket today differ in several respects from the foods that our ancient ancestors ate. There’s no doubt about that. Some people have taken that to mean that the whole Paleo diet concept is invalid and should be dismissed. As any sane person will understand, that makes absolutely no sense. Nobody in their right minds has ever suggested that it’s possible for the modern forager, who derives his food from the aisles of grocery stores, to eat a diet that is identical to that of the ancient forager. The goal of the modern Paleo dieter is not to replicate the ancient human diet down to the letter, but rather to eat foods that are similar to the types of foods that our ancient ancestors ate with respects to their nutritional composition, given that it’s those types of foods we’re best adapted to eat.
7. The fact that certain diet-related genetic adaptations (e.g., lactase persistence) have taken root in some human populations post agriculture suggests that many humans can consume milk and grains without experiencing any adverse health effects
The thing that eludes the people who hold the above belief is that natural selection acts on traits that affect organismal fitness, not traits that affect organismal health and/or longevity, unless those latter traits affect organismal fitness in addition to organismal health and/or longevity. A trait that is detrimental in terms of its impact on health and/or longevity will spread within a population if it’s beneficial in terms of the impact it has on Darwinian fitness. The fact that some contemporary people carry lactase persistence alleles and are able to drink milk and consume other lactose-containing dairy foods without experiencing gastrointestinal distress doesn’t necessarily mean that it’s healthy for these people to consume dairy. The same is true in the context of other recent diet-related genetic adaptations (e.g., increased AMY1 copy number).
8. Nutritional needs vary widely from person to person
No two people are completely identical or have an identical lifestyle and medical history. Hence, it could be argued that no two people are completely identical with respects to their nutritional requirements. With that said, we humans are a fairly homologous bunch with respects to our genetic make-up. We all belong to the same species, and we all likely descend from a small group of people who lived in Africa not so long ago. As I pointed out in a recent article here on the site, the personalized nutrition concept is based on a faulty premise. There’s no doubt that diets should be customized according to individual needs and goals; however, I’m very skeptical of the idea that we humans vary widely with respects to our nutritional needs. As I see it, the main reason some people do better on a specific diet than others likely has to do with inter-individual variability in microbiota composition.
9. It’s perfectly safe to consume a lot of salt
Some Paleo bloggers have made the case that it’s perfectly safe to consume a lot of salt. As I see it, this idea is not supported by the best available science. Actually, I would go as far as to say that there’s a wealth of scientific data that refute that idea (12, 13, 14, 15). The fact is that it wasn’t until quite recently that significant quantities of salt were infused into the human diet. Our primal ancestors didn’t eat processed and canned foods, cured meats, potato chips, crackers, or other modern, salty foods. Rather, they ate primarily fresh fruits, vegetables, nuts, roots, and meats; all of which contain little or no sodium. Some preagricultural humans consumed various types of seafoods; however, even these people wouldn’t have consumed anywhere near as much salt as the typical modern man.
10. Our Paleolithic ancestors ate almost exclusively plant foods
I wasn’t sure whether I was going to give this statement, which is so scientifically flawed that it should be discarded as bullocks right away, a place on the list. The reason I ended up including it is that it’s actually a fairly common misunderstanding about Paleolithic nutrition. Furthermore, I wanted to get the list up to the round number 10 and couldn’t think of any other misunderstandings that I felt were more deserving of a spot. Some vegans and vegetarians actually do seem to think that preagricultural humans were herbivorous, just like them. One doesn’t have to have a special insight into the human mind or a PhD in Evolutionary Nutrition to understand that this is a stance they’ve taken because it fits with their ideas about healthy eating and sustainable food production, not because they’ve actually come across strong evidence supporting the notion that Stone Age humans ate almost exclusively fruits and veggies. As anyone who’s read a paper or book that cover topics related to evolutionary nutrition will tell you, our preagricultural ancestors did eat meat (3, 4, 17, 18). They didn’t just eat meat, but they definitely did eat some animal source foods.