September 6, 2010

Diet and recent evolution

It's common to assume that bread must be good for you because most people in Europe ate a lot of bread over the last few thousand years, so there would have been Darwinian selection for eating bread. No doubt that's true to a sizable extent. 

Still, if you are of European descent, you probably aren't descended on average from the average person in European history. Consider it in the light of Greg Clark's findings in A Farewell to Alms: people of European descent tend to be descended from affluent Europeans, typically from successful farmers and landowners. Your ancestors may well, on average, have eaten more meat (or other expensive foods) than the farm hands they employed.

You may well have ancestors who could afford only bread and other ancestors who ate a lot of the roast beef of merrie old England (or wherever). Which complex of genes for dealing with diet you would end up with is hard to predict. You may differ a lot in which foods are best for you even from a sibling.
I think this may explain a little bit about the famous paradox of how many East Asians stay slender eating a heavily carbohydrate diet, a fact that helped motivate the government's and medical establishment's over-emphasis of grains in your diet in the later 20th Century. According to economic historians such as Clark and David Landes, East Asian cultures tended to maximize population density through early marriage. This in turn meant intensive grain farming to get as many calories out of an acre as possible. Which then means that East Asians tend to be selected for being healthy on a highly grain-based diet.

In contrast, Europeans tended to not have as much of the population boom / famine cycle as East Asians because they delayed marriage and childbearing until they could afford it. Rich girls in England married young, poor girls married later or not at all. This meant that the English could afford a richer diet because they didn't need to squeeze quite as many calories out of each acre, and could devote more land to growing protein and fat (e.g., cows).


chris said...

People don't understand that grain is peasant food. It's what you eat when (nutrient dense) meat and vegetables aren't available.

Steve put down the soy "snacks". If you eat a steak for lunch you won't need a snack genius. Watching your weight like a girlie...

Anonymous said...

Diet talk will bring out all the crazies... everyone thinks they are an expert (and that all the experts are wrong)...

Omnivore said...

How are you so sure that the rich had such a meat-based diet? Read any medieval cookbooks lately? I'm not being snarky.

My understanding is that the medieval diet was heavy in bread and beer. Prosperous people, note:

My understanding of soy products is that they are a pseudo-estrogen. I don't eat them for that reason.

Anonymous said...

Southern European and Mediterranean populations tend to do better with grains than Northern Europeans.

Anonymous said...

My other favorite blog:

Dr. Davis has lots of interesting things to say about wheat.

Harmonious Jim said...

Pursuing Steve's idea here, there seems to be three sets of peoples. First, those with quite a bit of variation in carb adaptation, due to mixed farming, thanks to lowish population density. (Europeans, also African farmers too?) Second, those who had to become more uniformly well adapted to grains, in the dense population zones of Asia. Third, those who are uniformly not at all carb adapted, due to either being hunters or herders.

Makes sense to me.

By the way, I doubt if anyone is well adapted to sugar, since it is a very recent addition to the diet.

Anonymous said...

I'm not sure if East Asians are better adapted to carbohydrates. Traditional East Asian diets tend to consist of small portions of rice, vegetables, and some meat and fish. Rice is really the only refined carbohydrate in it. Sugar, soda, other starches such as potatoes and bread, etc., tend to be pretty rare.

I believe East Asians suffer health problems when they switch to modern Western diets and the many refined carbs they contain.

I think East Asians may actually be more insulin resistant than Western populations.

agnostic said...

Obesity is only one symptom within the larger cluster disease called Metabolic Syndrome or Syndrome X. It also includes type II diabetes, insulin resistance, heart disease, high blood pressure, hypertension, etc.

If East Asians deal well with carbs, then they should have low rates of these symptoms. They do tend to be thinner, but that is only because they don't eat loads of food to begin with.

More glucose causes more insulin causes more storage of fat -- but how much fat gets stored depends on hoe much chow you're eating. If they don't eat many large meals like we do, their higher glucose and insulin levels won't have as much fat to store.

So we need to check whether East Asians or other groups have high / rising rates of diabetes, insulin resistance, hyperglycemia, etc. Those are tell-tale signs of not dealing well with carbs, as they respond directly to how much glucose you're taking in, whereas obesity also requires a high level of food intake to show up.

You can google around, but the other symptoms of Metabolic Syndrome are runaway in East Asia, South Asia, the Gulf states, etc. Here's just one summary of the Japanese from 2005:

"In fact, the prevalence of diabetes, particularly type 2 diabetes, is increasing explosively in Japan, as well as those in the other Asian and African countries. Japan may be one of the most diabetic countries right now. [...] insulin resistance enhanced by change of lifestyle ..."

And another from 2002:

"Among Japanese men, these changes have been associated with a steadily increasing body mass index (BMI), a well-known risk factor for the development of insulin resistance, impaired glucose tolerance, and diabetes. Genetic characteristics common to many Japanese may also contribute to their higher prevalence of diabetes. The Japanese have a higher prevalence of polymorphisms for at least three genes that code for proteins thought to play key roles in lipid and glucose metabolism: the beta 3-adrenergic receptor, the peroxisome proliferator-activated receptor γ, and calpain-10. The interaction between changes in lifestyle and the ‘thrifty’ genotype characteristic of many Japanese people may play a significant role in the increasing prevalence of diabetes and associated cardiovascular risk in this population."

Again, just Japan, but it's true for all other thin but carb-scarfing countries. They all point to their inability to thrive on a high-carb diet, but you'd only detect that by looking at diabetes, insulin resistance, glucose metabolism, etc., rather than just obesity.

OneSTDV said...

I suspect it has more to do with preparation. One can avoid the deleterious health affects of carbs if they're prepared in the right manner:

JeremiahJohnbalaya said...

Diet talk will bring out all the crazies... everyone thinks they are an expert (and that all the experts are wrong)...

Honestly, I think I've recent become an expert. I lost enough weight last year for friends and coworkers to notice and ask how I did it. I told them that I tried this really radical new diet called ... "Just Eat A Little Bit Less, You Fat %^&$"

bgc said...

Very good general point here - there are many as-yet-unexplored ramifications to Greg Clark's idea that the modern English (and similar) are mostly descended from the skilled Medieval middle classes, and not from peasants.

Peter A said...

My impression from medieval literature is that the poor ate a lot of porridge and oatmeal, especially in the British Isles. The rich probably ate just as much bread as the poor - and certainly consumed a lot of flour in the form of meat pies and flour dumplings.

Dahinda said...

The fact that Celiac disease is common in people of European descent is a clue that you may be correct. If Europeans ate a primarily bread based diet the gene for celiac disease would have been eliminated by now.

Omnivore said...

"Traditional East Asian diets tend to consist of small portions of rice, vegetables, and some meat and fish. Rice is really the only refined carbohydrate in it. Sugar, soda, other starches such as potatoes and bread, etc., tend to be pretty rare. "

Jeezus, this is an example of the denial I was talking about. THE EAST ASIAN DIET IS TRADITIONALLY 80% CARBOHYDRATE. The carbohydrate is rice, a refined carb.

Don't deny this. It's fact. I'm not going to bother looking up URLs. Look 'em up yourself.

Yet they are thin.


Because they ate hardly any sugar.

What is it about sugar that's different from rice?

They are getting metabolic syndrome now because their sugar consumption is skyrocketing.

The person who answers question, what is different about sugar? gets the prize.

(I have an answer, but I want to hear others chime in on this.)

Charlie said...

I think bread, beer and cheese were the staples of the Medieval diet across the economic spectrum. It seems to me the Occam's Razor explanation here is that Medieval people ate fewer calories per day, and were thus thinner. Why bring in any ideas about evolution? The thinness of East Asians hardly seems to demand an explanation, given that Chinese people also eat fewer calories per day than ourselves, and are thus thinner.

Charlie said...

The obesity of Mexico, now, seems more likely to have a genetic explanation. I don't know if this page has reliable info but it suggests that Americans are indeed at the top in caloric intake, albeit not far below many European countries (which have much higher smoking rates, though, and that may account for the difference in waistlines) but Mexicans are well below Europeans.

Chief Seattle said...

Japanese have a saying "leave the table before you get full". That could be a cultural adaptation to a starch-heavy diet. Cultural adaptations are likely to be more common than genetic adaptations in intelligent populations since they happen much faster. There's lots of European cultural adaptation around alcohol, from prohibition and heavy taxing to when and where it's acceptable to drink. Maybe parts of kosher laws are an old adaptation to milk for a lactose intolerant population.

Has anyone seen stats for the prevalence of Celiac disease? It seems to be increasing. I never heard about it until 10 years ago. Now there's gluten free everything at stores and restaurants. New wheat breeds?

AG said...

Too much generalization here by steve. Mongolians and many Manchurians are pure East Asians. But Mongolians are almost pure carnivores without any carb. Northern Chinese have a lot interbreeding with mogols. So adapted to carb might not be so complete as you thought. Higher diabetes rate among northern Chinese might reflect such nature. At least my own ancestors are land owners who could afford meat and my family have higher diabetes rates. We do well on meat.

CamelCaseRob said...

When I was in China's cities recently, I noticed their drink of choice was Coke and Sprite. They sat down with a 2 liter bottle for lunch and supper. I don't know if this was for my benefit, but they sure swilled it down.

I am Czech/German. I don't know what class my ancestors were, but I could survive on nothing but meat, cheese, and bread. I can't stand milk.

Anonymous said...

Two thoughts:

Read the Larousse Gastronomique and you will see that almost all the beef recipes are for the tenderloin and the tenderloin only. Apparently they butchered the cow, cut out the tenderloins and threw the rest of it away as too tough.

The saying "She's no spring chicken" comes from a time not so long ago when you could hardly eat a chicken except in the spring - otherwise it - like beef - was too tough.

Second thought. The only world political figure who was also a world class cook was probably Ho Chi Minh. But he didn't seem to have introduced haute cuisine into revolutionary North Viet Nam.


Anonymous said...

I traveled in India recently and visited many hospitals and clinics. Number one health problem according to physicians is: diabetes. Yet most folks in India are thin and they eat very little sugar.

ricpic said...

The key to keeping your weight under control is what goes on from 6 PM till bedtime. Or between the evening meal and bedtime. If you can refrain from noshing during those 4 or 5 or 6 hours you'll be okay.

Anonymous said...

How many out there are like I am, and literally can't gain weight? When my activity level drops, my appetite is non existent. I weigh what I did when I was 14. I just don't understand how anyone can get hungry sitting on their butt.

B Lode said...

Mongolians and many Manchurians are pure East Asians. But Mongolians are almost pure carnivores without any carb. - AG

Mongolia currently has a population of 2.7 million. China has a population over a billion. That's a pretty serious, and presumably long-standing, population density ratio.

Are you sure Steve overgeneralized? I think he just generalized. The cattle-yak-and-no-rice country in central Asia has been lightly populated for centuries.

coldequation said...

Whites are probably adapted to a grain diet compared to groups like the native Americans who have little history with grains, and who have runaway diabetes on the standard American diet. But that doesn't imply that we are so well adapted to grains that they're better than a paleo diet.

TGGP said...

I remember being told that peasants ate black or brown bread while rich people ate white, causing them to get gout.

Omnivore said...

Re: Indian diabetes.

Facts, please.

Diabetes is "the sugar disease."

Anonymous said...

One effect of the high calories per bite, heavy starch and sugar diet is that it repeatedly exercises the eater's craving synapses so that a craving impulse becomes more pronounced for non-food items. presumably the whole history of civilization (resting on a cravings-inducing agriculture base) has been affected in a thrusting, competitive, consumptive direction by continuous diet-driven arousal of reward circuitry in the brain--circuitry which evolved over 3 or 4 million seed-nibbling human years and 20 million odd ape years in a generally low-crave environment.

Pizza hut ads in football season call to mind the Roman bread and circus, while foodies savor starch, sugar, and fat blends like Roman senators at the baccanal. Ceasar crosses the Rubicon...Coach reaches a billion dollar market cap...

There's kind of a conception that the "fire's been burning since the world's been turning". Paleo tribes were probably more peaceful than their reputation, though, over 2.5 million relatively relaxed, low progress years.

Anonymous said...

Slipping out of the food industry matrix opens your eyes to how convenience and flavor driven the american diet is. I switched to a hunter gatherer type diet, eliminating all starch and milk products and any added sugar. I found the change easy to make and maintain, though with more chewing per day. Chocolate mousse in the dessert display no longer triggers the "mmmm, chocolate mousse" reflex; in fact, people who carry on about food flavor seem foreign to me. People often admire my discipline at dinner parties or the holidays, but there is really no discipline about it. I'm just completely off the cycle of food temptation and gratification which they remain on. While avoiding diabetes is a nice side benefit, my principal motivation was cosmetic. I wanted to avoid that "butter fat tucked under the skin for flavor" look of many naturally muscular american males. If you have the budget for it, there is really no reason why virtually everything in your diet can't be perfectly healthy. while some might view "healthy" as carb-heavy pseudo food in the whole foods packaged foods area, for me it is basically the things I like to eat anyway: fresh produce, gatherables, lean meats and such. I lost about 20 lbs.

Wanderer said...

RE the Clark thesis:

Why was England, specifically, able to spearhead the most significant event on Earth since the invention of agriculture? (i.e., the breaking of the Malthusian Trap via the Industrial Revolution)?

This was the question Clark was endeavoring to answer.

But he was talking about a specific time-window in England's history, not necessarily applicable to all Europeans, or even applicable to the bulk of the genetic ancestors of today's English! (See below, "Post Script"). So Sailer's quip about Europeans being descended mostly from wealthier types with high amounts of meat-intake is a mischaracterization of Clark's work (IMO).

My reading of Clark is this: He proposes that in the centuries running up to the Industrial Revolution, England had a dramatic upswing in average intellectual capacity, because the wealthier [smarter] had a lot more surviving children than the poorer did (which is apparently true -- as he proves from local records). Each generation was sharper than the parent generation: The definition of eugenics. (Was wealth in Elizabethan England times tied closely to quality? It seems reasonable to say yes).

So, by the late 1700s, England had a population more "able" to handle such a thing as the Industrial Revolution than anywhere else. (Europe's lower density was the other crucial factor as Sailer does mention).

In other words, Clark's was not a theory to explain all of European history or all of Europe, at all. If it were, the Industrial Revolution would have started everywhere about equally. It didn't. Why did it begin with England so starkly? He presents a decently-supported theory of England's uniqueness to explain this.

England in the several centuries before 1800 was something unique and special. After all, as we all inherently know: all else being equal, the natural tendency of any population (today no exception) is for the bottom-50% to have a majority of the children. Prehistoric eugenic die-offs of various sorts helped prevent human extinction by the Idiocracy-esque specter of inescapable freefall in quality. Such "selective pressures" even impelled quality upwards in many cases. More recently, social and religious custom tried its own hand at quasi-eugenics (social penalties for unwed-pregnancy and bastardism being a prime example).

In sum:
England's brilliance in the 1700s and 1800s came from centuries of eugenic breeding, allowing it to soar ahead. As regards the meat-eating question, England truly is "the exception that proves the rule"! (The rule being that Europeans of today -- Even the English of the 2010s [see below] descend more from grain-heavy eaters than meat-heavy eaters).

Post Script:
Sadly, England's glory is all behind her now. Many generations of dysgenic breeding (the huge poor families of the post-1800 Oliver-Twist era), Anglo-Saxon emigration, and immigration/assimilation of foreign laborers (I've read that the average white-Englander today has more than 2.0/16 ethnic-Irish-Catholic great-great-grandparents). These combined factors, over the past 200 years, seem to have given back England's gains made in the first 8 centuries of the second millennium after Christ. "White-trash" behavior among the urban British seems to have increased rapidly.

A 2009 I-Steve thread on British Intellectual Decline:

Ortu Kan said...

Mongolians and many Manchurians are pure East Asians. -- AG

Genetic studies of Mongolians, at least, have registered a low but pretty consistently detectable European-like component, which is in concord with the predominance of Caucasoids in Bronze and Iron Age South Siberia (substantiated by ancient DNA as well as cranial traits as far east as Lake Baikal) as well as subsequent population movements during the heyday of steppe empires.

Are you sure Steve overgeneralized? I think he just generalized. The cattle-yak-and-no-rice country in central Asia has been lightly populated for centuries. -- B Lode

The modal East Eurasian individual is a rice-eating Han Chinese, no doubt, but the extremes of variation in dietary practice between ethnie in the region are so dramatically greater than the equivalent European range that I'd speak of singular "diet" only with debilitating qualification.

Subsisting on nomadic stock-rearing is equivalent in many ways to life as an apex grassland predator (with the notable deviation of dairy use), so it's no surprise that people like Mongols comprise only a drop in the ocean of sedentary agriculturalists (dense monocultures of what were often essentially forced vegetarians). But, as AG said, the metabolic peculiarities selected for under this kind of regime probably have broader relevance than you think because sedentary recipients of significant gene flow from Inner Asian pastoralists are vastly more numerous than the pastoralists themselves.

Worth considering is the fact that not all of East Asia was amenable to wet-rice agriculture -- look to the prominence of millet in northern China, parts of Korea, etc. For near-carnivory of a more maritime orientation, look to the Eskimos and some other boreal peoples.

Matt said...

TGGP: "I remember being told that peasants ate black or brown bread while rich people ate white, causing them to get gout."

Yeah, but at least they didn't get ergotism.


One thought on this would be that China at least may have more upward mobility than the premodern West due to success on the civil service exam, which may be a confound.

On a related note, it's really hard to find out anything to about how much social mobility there was in China in the pre-modern period. I mean, sure they don't have an important nobility and in theory anyone who gets educated can take power, but how much did this shake out in practice?

Allison said...

But syndrome X may simply be a genetic adaptation that isn't working in the modern world for people who've left their genetic homeland.

Ever thought about why vitamin D matters? Apparently, vitamin D deficiency is related to breast cancer, diabetes, autism, and a host of things. In Minnesota, the Somalia immigrant population has a terribly high rate of autism--much higher than the "native" minnesotans have. And curiously, the same high rate is seen by Somalis in Sweden (in Somalia, autism is un heard of, but it's hard to know what that means...)

So, here's a reasonable hypothesis: moving above the 45th parallel is bad for someone with extremely dark skin.

But more, even the people of Scandinavian descent in MN have vitamind D deficiency. Why? Well, what is it that Scandinavians eat at home but not in MN? Oily fish, the kind high in vitamin D.

So maybe very small ethnic differences account for very large differences in the body's ability to handle food and vitamins. Maybe similarly, maybe the mediterranean diet is good if you're ethnically mediterranean, but isn't good if you are from North Asia. And maybe what's called diabetes in some isn't a problem the way it is in others, because some ethnic groups dont' get the heart disease from it the way others do.