science

It's easy enough to stop eating crap and start eating a diet closer to what evolution intended. Other evolutionary disconnects are harder to remedy. As a young woman, I can say one of the hardest is childbearing. Most middle-class young women in developed countries cannot afford to have children during our prime childbearing years. Furthermore, having children often means relying on two incomes and leaving the childcare to someone else outside the family. American children start school young (Swedish children start school at 7, American at 4-5) and our schools generally do a terrible job at providing an evolutionarily-appropriate environment. Think about hunter-gatherer children: lots of play, mixed age groups, and spending time and learning from relatives.

What are the consequences of this evolutionary disconnect? I think we are just starting to see them. One alarming trend is that the age of puberty is falling. Some blame diet, others blame pollution, but it's probably all that and more. Here is an interesting study on how social factors might influence puberty. It suggests that poor mother-child bonds might lead to early puberty. The unfortunate thing about these studies is that it's often hard to tease out social issues like that fact that children whose mothers have to work long hours often live in environments that are poor in many other ways.

The evolutionary disconnect goes so much deeper than just eating inappropriate foods for our species like bread....it goes into how we work, move, and raise our children. The problem here is that the disconnect is so deep that it's hard to remedy it unless you want to run off and become Amish. And that the disconnect is psychological and social as well. How many 24-year-old women want to spend their days taking care of children anyway? How many of us have the extended family to help us? 

I've been reading the Continuum Concept lately and that, plus the comments I got, have led me to revise the graphic for the Faileo diet post

Mmm fatty fat flavored fatty fat

The earlier graphic was a pyramid, which many mistook for a dietary recommendation graph like the USDA's' idiotic food pyramid. I feel this graphic illustrates the philosophy behind my thoughts better. Plus it adds on a new concept, which is thinking about diet in terms of the human continuum. Just like the babies in The Continuum Concept biologically expect to be held, our bodies biologically expect certain food. When we consume things like soybean oil our bodies just don't function properly, just like babies that are never held as infants. Of course there is variance based on genetics, gut bacteria, etc, but overall animal fat is the nutrient that the human body seems to be evolved to eat.

Animal fat is the nutrient our bodies can handle most perfectly. We absorb it and utilize it in a way that fuels us without dragging us down. Contrast that with a dinner of just some chicken breast and some spinach. It's a meal that's "paleo", but unlike anything our ancient human would have encountered in a thriving environment. It takes energy to digest all that protein and fiber. Add a chicken thigh with a bunch of skin and things are looking a lot better in terms of actually fueling us.

Not on the human evolutionary continuum: too much omega-6, too much fructose, too many antinutrients, too few nutrients

Butter and ghee might get to jump the continuum...after all, they are very close to being like lard, tallow, and the other animal fats. But they have their detractors.

Another interesting thing about the analogy is that The Continuum Concept maintains that the consequences of not raising children the way humans evolved to be raised aren't just horrifying things like reactive attachment disorder, but annoying behaviors we very as normal in modern children. It's the same for not eating the way humans evolved to eat. Heart disease and diabetes are the tip of the iceberg. Health problems that probably aren't normal for humans include things we view as nuisances like acne, constipation, cold sores, and a whole host of other "small" things.

I would hate for people to think that the paleo diet is about recovering some "paradise lost." Just because peasant agriculture was miserable for most people doesn't mean foraging was a walk in the part. Almost every foraging culture studied has a wide range of remedies for illness and medicine men are revered. Hunter-gatherers suffered from malaria, tuberculosis, parasites, wounds from wild animal bites, and all sorts of horrendous infections. 

The preferred medicine against diarrhea was clay, kaolin-like powders or pulverized bone ash while bee larva, certain tree barks and the fruits of two trees were eaten to relieve constipation.

But many detractors of the paleo diet point to studies of more modern hunter-gatherer cultures to draw out evidence they were ill. We have to remember that what is left on that lifestyle is people who were able to survive on the worst lands not coveted by farmers. The Inuit or the San diet might be healthier than most American diets, but neither is really similar to the diet of paleolithic people.

In Innu mythology, Matshishkapeu (literally the "Fart Man") is the most powerful spirit—even more powerful than the Caribou Master, Kanipinikassikueu. He proved himself when the Kanipinikassikueu refused to give the Innu any caribou to eat. Matshishkapeu was so angry that he cursed the Caribou Master with a painful case of constipation.

It's even possible we could do better. For example, both the high and low fiber diets of hunter-gatherers are touted as solutions to digestive problems, but digestive ailments clearly still plagued cultures eating both diets. Personally, I try to eat the vegetables that work for me and I don't worry about counting fiber. I'm pretty such that if I ate the bazillion grams of fiber the San eat, I would feel pretty sick. Maybe that's what anecdotes like this convey: there is lots of learn from hunter-gatherer and ancestral diets, but imitating their fiber consumption with BRAN4LIFE bread is on the same level as imitating snake bite wounds by keeping your own pet PALEOvipers. 

Despite all that hunter-gatherers suffered, the paleo diet is about avoiding diseases of civilization, and it seems they did that well. We should eat like them, but still with an eye to the fact that they ate what they could to survive. 

Postscript: I think many of the stomach problems attributed to hunter-gatherers were probably post-infectious or in the case of the Inuit, because of a lean time...literally...Vilhjalmur Stefansson found that without ample amount of fat, stomach issues ensued. 

This paper explores the diets of gorillas and uses it to recommend a diet for humans low in fat and high in dietary fiber. This is a common mistake. Dozens of vegetarian groups say that because the great apes are vegetarians (which they aren't...but animal food intake is fairly low) that humans are also naturally vegetarians. The most extreme groups say we should eat only fruit because, as primates, we thrive on sugar.

But read the paper carefully. The gorilla diet is very very high in fiber, but that fiber is getting converted into free fatty acids. This conversion is vital for gorillas, providing them with 57% of their calories. That leaves 15.8% of calories from carbohydrate, making the gorilla a defacto low carber! Humans claiming to emulate ape diets by eating lots of fruit aren't able to get the same nutrition. Fruits that are palatable to humans are much higher in sugar and lower in fiber than what the great apes eat. Furthermore, the human colon is tiny in comparison to great ape colons, so even if we did eat high-fiber fruit we wouldn't be able to process very much of it into free fatty acids. 

Here is why a fruity "ape" diet is bird-brained:

• There is some fermentation of fiber into FFAs in humans, but much less since our colon is only 17% of gut volume. In apes it is typically around 50% of gut volume. 
• Since apes are basically converting most of their food into FFAS, they are basically low-carbers. Humans gorging on melons are eating an amount of sugar that no ape in the history of the world has ever eaten. 
• Humans are a fairly unusual species. Contrary to popular misconception, gorillas and chimps are our relatives, not our ancestors. Re the latest fossil evidence "indeed, the new evidence suggests that the study of chimpanzee anatomy and behavior—long used to infer the nature of the earliest human ancestors—is largely irrelevant to understanding our beginnings." It also means that comparing our digestive system to lions and cows is pretty pointless since we are a unique clade. 
• Humans are the longest lived primates. A diet high in sugar cannot support this longevity. Without modern dental-care, humans eating high sugar diets would not live very long because they would lose all their teeth. Our "natural" diet would not be the one that makes our teeth fall out. Apes experience tooth decay in the wild, but it matters less since they don't live as long. 
• Our brains require nutrients like iodine and DHA that simply can't be found on a diet of forest foods. Furthermore, our brains are big and hungry for calories. While modern fruit eaters can survive because of the wealth of sugar-rich fruit at the grocery store, there is no evidence that a homo sapien could survive by foraging for only wild fruit. In fact, there is strong evidence that homo sapiens could not survive in a forest environment at all without access to cultivated foods.