Thursday, May 17, 2012

Beyond Ötzi: European Evolutionary History and its Relevance to Diet. Part III

In previous posts, I reviewed some of the evidence suggesting that human evolution has accelerated rapidly since the development of agriculture (and to some degree, before it).  Europeans (and other lineages with a long history of agriculture)  carry known genetic adaptations to the Neolithic diet, and there are probably many adaptations that have not yet been identified.  In my final post in this series, I'll argue that although we've adapted, the adaptation is probably not complete, and we're left in a sort of genetic limbo between the Paleolithic and Neolithic state. 

Recent Genetic Adaptations are Often Crude

It may at first seem strange, but many genes responsible for common genetic disorders show evidence of positive selection.  In other words, the genes that cause these disorders were favored by evolution at some point because they presumably provided a survival advantage.  For example, the sickle cell anemia gene protects against malaria, but if you inherit two copies of it, you end up with a serious and life-threatening disorder (1).  The cystic fibrosis gene may have been selected to protect against one or more infectious diseases, but again if you get two copies of it, quality of life and lifespan are greatly curtailed (2, 3).  Familial Mediterranean fever is a very common disorder in Mediterranean populations, involving painful inflammatory attacks of the digestive tract, and sometimes a deadly condition called amyloidosis.  It shows evidence of positive selection and probably protected against intestinal disease due to the heightened inflammatory state it confers to the digestive tract (4, 5).  Celiac disease, a severe autoimmune reaction to gluten found in some grains, may be a by-product of selection for protection against bacterial infection (6).  Phenylketonuria also shows evidence of positive selection (7), and the list goes on.  It's clear that a lot of our recent evolution was in response to new disease pressures, likely from increased population density, sendentism, and contact with domestic animals.

Why are modern human populations riddled with these common deleterious mutations?  Presumably, these are "genetic shrapnel" that result from rapid changes in the human environment, creating selective pressures that placed strong new demands on the genome.  The modern form of malaria is only a few thousand years old, corresponding roughly to the development of agriculture in Africa and the high population densities that resulted (8).  As soon as malaria evolved into its modern deadly form, there was a massive selective pressure to evolve resistance.  Resistance would be favored at almost any cost, even if it meant that a percentage of offspring would wind up with a serious disorder and probably not reproduce.  So humans evolved this crude stopgap measure, which basically deforms the hemoglobin molecule and makes red blood cells more difficult to infect by malaria parasites.  It also deforms red blood cells into a "sickle" shape if you get two copies, resulting in disease symptoms.

Even the less deleterious mutations like lactase persistence (allows digestion of the milk sugar lactose) are crude.  The mutation that causes lactase persistence basically breaks the genetic "switch" that turns off lactase production after infancy.  In genetics as in life, it's much easier to break something than to build it, so these kinds of mutations are the low-hanging fruit.

Presumably, with time, natural selection would figure out a better way of doing the same thing-- a more sophisticated genetic measure that could fill in for the crude stopgap, which would then fade away.  This is the key principle I'm trying to illustrate with these examples: the crudeness of recent adaptations suggests that we're still in the early phase of genetic adaptation to the Neolithic environment.  Much of the low-hanging fruit has been picked, but I suspect there's a lot of fruit higher up that would also get picked if we had another million years to evolve (assuming our environment remained stable, which it won't).  In other words, I suspect most of us reading this are partially, but not completely, adapted to the Neolithic diet.

Evidence that Adaptation to the Neolithic Diet is Incomplete

Previously, I cited celiac disease as an example of incomplete adaptation.  Affecting just under one percent of US citizens, it's a serious autoimmune disorder that's provoked by gluten from wheat and other gluten grains.  This is a major public health burden coming from a single food type.  On further reflection, I think this isn't a good example of incomplete adaptation, because the gene that confers gluten sensitivity was under recent positive selection.  In other words, the people who first domesticated wheat probably weren't genetically susceptible to celiac disease, but they later acquired it through a twist of genetic irony (9).  Some geneticists suspect the gene confers disease resistance that outweighs its detrimental effects.  Live and learn.  Thanks to Melissa McEwen for pointing this out to me.  I think she heard about it from John Hawks.

Still, I'm drawn to the evidence that early agriculturalists showed signs of nutritional stress.  From Health and the Rise of Civilization, by the anthropologist Dr. Mark Nathan Cohen:
A second common trend is that farmers appear to have been less well-nourished than the hunter-gatherers that preceded them, rarely the reverse.  For example, rates of porotic hyperostosis (suggestive of anemia) are almost universally higher among farmers in a region than in earlier hunter-gatherers in the same region. [he goes on to suggest that this can result from increased parasite load in addition to an iron-poor diet- SG].

Other independent measures of nutrition are less widely reported but most often seem to suggest a decline in the quality of nutrition associated with the adoption and intensification of agriculture.
In the same book, Dr. Cohen comments on the better nutritional state of modern-day hunter-gatherers relative to non-industrial agriculturalists with poor access to animal foods and low diet diversity:
...levels of meat intake reported for most hunter-gatherer groups are comparable to intake by relatively affluent modern Western populations.  They are substantially better than average Third World intake and dramatically better than that of the contemporary third world poor, who may average only a few grams of animal foods per person per day.

A wide range of reports about contemporary hunter-gatherers in various parts of the world suggests that they, like the San, eat eclectic diets of fresh vegetable foods that, along with their meat intake, tend to assure a good balance of vitamins and minerals.  These observations about dietary balance are largely confirmed by reports and observations on hunter-gatherer nutritional health.

Most casual descriptions of hunter-gatherer groups in tropical or temperate latitudes comment on their apparent vitality and the absence of obvious malnutrition...  Reports of acute malnutrition or kwashiorkor are extremely rare [kwashiorkor = protein deficiency- SG].  These descriptions present a striking contrast to descriptions and evaluations of many Third World populations and to descriptions of historic dietary quality for the lower classes in Europe.
It's a great book if you haven't read it.  Anyway, the main point is that hunter-gatherers, living the deep ancestral lifestyle, are generally better nourished than agriculturalists with diets restricted mostly to grains and with poor access to animal foods, and this was particularly true of early adopters of agriculture.  However, the nutritional status of agriculturalists improved over time, presumably because of the introduction of complementary foods (domestic animals, legumes, vegetables, etc.), preparation methods (e.g., fermentation), and genetic adaptations.

If we look for it, there is plenty of evidence to be found that a grain-heavy diet is not optimal, especially in the context of low animal foods.  Children are particularly sensitive, while adults are fairly resistant to the negative effects of extreme diets.  For example, the macrobiotic diet is based around whole grains, legumes, vegetables, and some fruit, and typically contains no animal foods.  It's not a third world diet-- it's a diverse, whole food-based diet that's composed with great care.  It doesn't take much digging to find evidence of deficiency diseases in macrobiotic children, including rickets (10), vitamin B12 deficiency (11), and assorted mineral deficiencies.  Here's a quote from a survey of macrobiotic children conducted in the Netherlands (12):
Ubiquitous deficiencies of energy, protein, vitamin B-12, vitamin D, calcium, and riboflavin were detected in macrobiotic infants, leading to retarded growth, fat and muscle wasting, and slower psychomotor development. Breast milk from macrobiotic mothers contained less vitamin B-12, calcium, and magnesium.
There are a number of nutritional problems with grains, particularly whole grains, that emerge when they make up too large a proportion of the diet.  One of the key problems is that although whole grains contain a sufficient quantity of many minerals, the availability of these minerals is often low because they're bound by phytic acid.  Much of it just ends up in the toilet.  This is why mothers on a macrobiotic diet, eating large amounts of magnesium-rich brown rice, end up with magnesium-deficient milk.

This explains why cultures that rely too heavily on whole grains (particularly unfermented) can end up with mineral deficiency symptoms despite a seemingly adequate supply of minerals in the diet.  One example is rickets.  Normally associated with vitamin D deficiency, it can also be caused by mineral deficiency, principally calcium, even when vitamin D status is good.  In Dublin in 1942, the incidence of rickets rose sharply, coinciding with a switch from refined wheat flour to whole wheat flour.  Investigators had this to say about it (13):
It therefore appears likely, as Jessop (1950) suggested, that the major change in the
extraction rate of the flour used as a staple item of diet in Ireland was responsible for a marked simultaneous rise in the incidence of rickets, independent of changes in vitamin D intake [or sun exposure- SG]. This hypothesis is supported by the subsequent decline in the incidence of rickets in older children between 1 and 4 years as the extraction rate of flour was reduced. The observation that the incidence of rickets changed little in children under 1 year who consumed little or no bread is consistent with this hypothesis...
The traditional Asian [they mean Indian here- SG] diet contains much unleavened high-extraction cereal as chapatty and a variety of pulses. In Iran Amirhakimi (1973) and Rheinhold (1971) found rural rickets in children whose sunshine exposure appeared normal but whose diets contained large quantities of unleavened wholemeal bread as tanok. In rural Kashmir Wilson (1931) found severe osteomalacia in field workers who spent many hours a day outdoors but whose diets were exclusively vegetarian, consisting almost entirely of rice, lentils (dal) and wholewheat flour (atta). Pettifor et al. (1978) found severe adolescent rickets in rural Bantu children in Natal whose diet consisted almost exclusively of maize and green vegetables; their sunshine exposure was high.
Investigators have shown that a diet high in unleavened whole grain bread causes mineral loss from the body over time, and this cannot be corrected by supplementing vitamin D (14, 15).  These diets lead to zinc deficiency as well, and correcting this deficiency alleviated growth stunting in Iranian children eating a diet rich in unleavened wheat bread (16).

Heavily grain-dependent cultures also often show signs of severe vitamin A and protein deficiencies (17).  Dr Edward Mellanby commented on the high susceptibility to infectious disease in the agricultural Kikuyu tribe compared with their neighbors the milk-drinking Masai, who also physically dominated the Kikuyu and other surrounding agricultural groups.  Based on his studies of vitamin A and infectious disease resistance, he attributed this in part to better vitamin A status among the Masai (Edward and May Mellanby. Nutrition and Disease. 1934):
The high incidence of bronchitis, pneumonia, tropical ulcers and phthisis among the Kikuyu tribe who live on a diet mainly of cereals as compared with the low incidence of these diseases among their neigh­bours the Masai who live on meat, milk and raw blood (Orr and Gilks"), probably has a similar or related nutritional explanation. The differences in distribution of infective disease found by these workers in the two tribes are most impressive. Thus in the cereal-eating tribe, bronchitis and pneumonia accounted for 31 per cent. of all cases of sickness, tropical ulcers for 33 per cent. and phthisis for 6 per cent. The corresponding figures for the meat, milk and raw blood tribe were 4 per cent., 3 per cent. and l per cent.
This is a problem that's more related to a low intake of animal foods and green vegetables than to grains per se.  Animal foods are a more effective source of vitamin A than plant foods, particularly in the subset of the population that converts plant carotenes into vitamin A inefficiently. 

Another issue is that grains are low in potassium compared with tubers.  Potassium is an important nutrient for bone and cardiovascular health, and insufficient intake (i.e. the amount most Westerners eat) may promote osteoporosis and hypertension (18, 19).  All else being equal, a diet based on tubers such as potatoes, sweet potatoes, or taro will be higher in potassium than one based on grains.

The point of all this is to show that we aren't yet well enough adapted to an agricultural diet that we can subsist primarily on a high-grain, very low animal food diet without facing health consequences, particularly if diet diversity is low.  If we had another million years of grain-heavy diets, we would likely be able to subsist on them more effectively, like rodents who are more able to access minerals from whole grains than humans (20).  That being said, this does not suggest that grains, including whole grains, cannot be part of a healthy diet in moderation.  To take that statement out of double negative land, in my opinion well prepared grains can be part of a healthy, diverse, omnivorous diet for most people, particularly if they're "externally digested" by fermentation.  Some people will benefit from avoiding wheat however, particularly flour.

Conclusion

It's time to wrap up this lengthy series.  I hope a few people followed along to the end.  The evidence suggests that many human populations have been rapidly evolving since the end of the Paleolithic, and that some of this evolving has made us better suited to consuming agricultural foods such as grains and dairy.  We aren't simply hunter-gatherers in a suit and tie-- we're an amalgam of hunter-gatherer and non-industrial agriculturalist adaptations, with a lot of population and individual variability.  The implication is that grains, dairy, and perhaps legumes are part of the European ancestral diet, stamped into our genome, and this applies to many other human lineages as well.  If these foods agree with you, in my opinion they can be part of a healthy diet in moderation.  However, some people are healthier and feel best when eating a stricter "Paleolithic" diet that excludes agricultural foods, and there is currently good evidence from controlled trials to support the health benefits of this dietary pattern in certain people, particularly those with glucose intolerance or diabetes (21, 22).

46 comments:

JohanRSA1985 said...

This was a great series, Stephan. Definitely lots of food for thought! Especially now that I'm moving from a strict low-carb Paleo-style diet to something which is more sensible and practical (at least for me), the timing of this is most fortuitous.

frank r said...

Is standard wheat bread from an American grocery store "fermented"?

frank r said...

Also, what about corn tortillas from an American grocery store (ground yellow or white corn and then treated with lime)? Are these fermented or does the lime treatment have the same effect of allowing for mineral absorption?

Josh said...

Great series, thanks

Kurt G. Harris MD said...

Excellent series, Stephan. I second your recommendation of Mark Nathan Cohen's book. It deserves to be much more popular than it is.

Jiffry said...

Are some lineages more adept to grains than others?

Does this mean that those of purely middle-eastern ancestry are able to tolerate grains better?

The study referring to Indian bread did not give that impression but perhaps that was too extreme of an example.

Shawn said...

Hello Stephan, thanks for the posts. I have a question for you. Since reading your blog I have converted to eating sour dough bread made at home, versus whole grain bread made with yeast. My question for you is, in your opinion what is healthier, whole grain unfermented bread or sour dough made from fermented refined flour? I tried to make sour dough from whole grain but the starter dies and the bread is too sour. I have read that whole grain prevents visceral fat while refined flour causes it. I am wondering if the fermentation process improves the nutrition profile of refined flour or if i am better off with the whole grain? Hope this makes sense and thanks again for you blog.
Shawn

Justin Roberts said...

Great series. Fascinating read. Thank you!

Robert Andrew Brown said...
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Robert Andrew Brown said...

Fascinating content as ever Stephan - Many thanks for all your efforts (-:

Vegetarians tend on average to have Omega 3 long chain fat (DHA mainly) deficiencies too. It is not an inevitable consequence of a vegetarian diet, but many factors in western diet (Vegan or Omnivore) conspire to reduce elongation of the plant based fats to the longer chain fats.

In addition some population groups are less genetically adapt at conversion.

N. Holzapfel said...

A fantastic series. Thank you!

Do you think there's strong evidence that, even for people who experience no discomfort after eating grains, a diet which includes regular unfermented wholewheat, is sub-optimal? Or is that no more than a plausible supposition?

Miki said...

Thank you for an amazing amount of high quality work throughout the series. Just to add - Legumes such as lentils and humus were consumed and later domesticated almost as early as grains in the Levant.(See for example regarding lentils Watkins 2009 "New light on the Neolithic revolution"). Also flour traditionally used for Chapati was and may be still is low gluten (google Monsanto chapati India)

Tuck said...

Great work, as usual.

Are you aware of the work linking corn (and wheat) consumption to high rates of esophogeal cancer?

"Maize meal, non-esterified linoleic acid, and endemic cancer of the esophagus—preliminary findings"

http://www.sciencedirect.com/science/article/pii/S0090698099000064

Pieter said...

Thank you! One question is still on my mind after reading this: Evolution by natural selection favors reproduction, and not necesseriliy health. Could these neolithic adaptations benefit reproduction, but with negative health consequences, especially later on in life?

Amy Haines said...

@frank r,

the wheat bread you buy from the grocery store is definitely not fermented, it is leavened with yeast, probably rapid rise, and has added sugar and other yeast nutrients added to it which make the yeast inflate the dough but does little to break down the flour.

Corn tortillas treated with lime are ok to eat. It's not technically fermentation but the treatment with lime breaks down the phytate in the corn and releases the minerals bound in the grain.

@Shawn, I bake a lot of sourdough bread and mostly use white flour or a 60:40 ration of white flour to whole wheat, spelt or rye flour, depending on the recipe. Whole grain sourdoughs can become far too sour too quickly, almost bitter (indicating something other than wild yeasts are eating your flour, like harmful bacteria or mold). There are some excellent sourdough resources out there: sourdoughhome com, breadtopia com, and GNOWFGLINS com are some excellent sites to get info and troubleshoot your sourdough culture.

As far as the claim that whole grains reduce visceral fat, I'm not certain of the context of those studies. Perhaps the fiber from the whole grain controlled appetite and led to reduced overall calorie intake. Perhaps the people in the studies displayed a loss of visceral fat due to other factors: a decision to eat healthier overall, give up sugar and pastries, etc. There are likely many confounding variables in those studies that prohibit identifying the real actor in the phenomenon.

frank r said...

Thanks Amy. So I take it that sourdough refined flour bread from the grocery store is okay.

What about rice? Is white rice okay to eat in large quantities?

Amy Haines said...
This comment has been removed by the author.
Amy Haines said...
This comment has been removed by the author.
Amy Haines said...

@frank r,

some advocate soaking rice for up to 24 hours, or even sprouting it, prior to cooking it. I've never done so, except for wehani (not really rice) simply because it helps it cook more evenly and gives it good texture.

Mark Sisson says that if you put all grains on a spectrum, wheat is very bad and you get less harmful along the way, on to rice and corn at the "least" end. See his site for that info, it's easy to search. Paul Jaminet says rice in moderation is OK in a diet. White rice, like white flour, appears to actually be more easily digestible and contains less phytate than brown rice. If you believe you need tons of whole-grain fiber to stay regular, you might want to google what some have to say about the issue of whole-grain fiber in the diet.

Grains are not a staple food in our house. Bread accompanies a meal, it is not the centerpiece. We have rice once or twice a month with stir fries or soups, or prepared my favorite way, as wild-mushroom risotto with chicken or roast.

I have taken a moderation stance on grains, with a heavy emphasis on veggies and meat as the center of the diet with some grain foods and fermented dairy products, and we (husband and 3 kids) are tolerating it very well from a health and weight loss/maintenance stance. What is likely most important is buying high quality food and preparing it yourself, or sourcing well-prepared foodstuffs. And going non-GMO as far as grains are concerned looks to be the best way to go, though expensive. Eating local might have benefits that are just being explored, like the benefits to gut flora from eating raw foods grown in local soil.

Sorry, I'm going off on tangents here I don't have time to cite research on, nor am I a scientist. Perhaps Dr. Guyenet has some info he can share. Plumb the rabbit holes and see where the search takes you. Good luck.

Chris Kresser said...

Great series, Stephan.

Hemochromatosis is another genetic disease that shows evidence of positive selection. People with hemochromatosis are protected against infection because, although their tissues are iron loaded, they actually have less iron in their macrophages. This would have provided a survival advantage during large outbreaks of disease like plague in Western Europe.

Julian said...

Fantastic stuff Stephan, would read again. I've shown many people not normally interested in nutrition find this series very fascinating. Cheers.

Lauren said...

Best post of the series, I think (despite the crack elsewhere about Oetzi's chromosomes increasing his risk for being killed in the back of beyond :) ). Thanks for the book recommendation; sounds like a perfect addition to the shelf.
I am further edified by Chris's comment that I am unlikely to succomb to bubonic plague.

Galina L. said...

@Shawn,
I used to bake a sour dough rue bread from a wholegrain rue flour from Hudson Mills and fermented it with starter in my fridge.It took longer fermenting time than on a counter-top, but the taste and rise were much better. I always kept a back-up starter in my freezer, also I usually have a self-made sauerkraut in my fridge, and sauerkraut brine and sourdough bread starter are interchangeable. I also usually added one tsp of molasses per loaf. It is better to be realistic and realize, that it is impossible to make a beautiful high raised loaf without substantial amount of gluten in your dough and adjust your expectations. It takes time to figure out small details of a bread preparation, first effort would be a failure most of the time. I am not baking bread nowadays, looks like I am better off grains.

I am eating LC for almost 5 years now, tried to add more starches last 6 months, but first time since I started LC diet, my dental hygienist noticed several inflamed areas on my gums. I am from Eastern Europe, and my appearance suggests some of my ancestors came to Russia with Genghis-khan . It looks like I am not among thous who can safely rely on more carbs in their diets. There are individual variations.

Unknown said...

SG - I think you need another post talking about the recent changes in wheat that is currently in the food supply. The parallels between Otzi and grain adaptation, and the current state going on with modern america trying to adapt to a vastly different wheat grain (one that could never exist without human interference). It would complete a nice circle. Just my $0.02. I've enjoyed this series and the timing was perfect with the recent published lit. and Nova.

Jane said...

I think we have to distinguish between evolution of our genome and evolution of our gut bacteria. It's true rodents can deal with phytic acid very well, but that isn't because they have a gene for phytase, it's because their gut bacteria do.

Our own gut bacteria have phytase as well. Until we know how much phytase activity our own gut can produce under optimal conditions - and we may never know because ideally it would have been measured in the Hunza 100 years ago - we can't really say we are not adapted to eating grains because of the phytic acid.

BTW, that study of macrobiotic children may not be all it seems. The parents were sieving their children's porridge. Did this remove the bran and germ?

Porotic hyperostosis is not due to iron deficiency, and kwashiorkor is not due to protein deficiency but to iron overload. See Golden on this. The anthropologists often don't know about the latest research in nutrition. They are stuck in the dark ages where everybody has iron deficiency.

Karen Downie Makley said...

Great series, indeed. Thank you for your intelligent and enthusiastic blog. I'm glad I stumbled upon it, and glad I check in frequently. Terrific work.

294f2868-a1c2-11e1-80e1-000bcdcb2996 said...

Thanks for this series, it's very helpful especially for those of us trying to live out a healthier diet on a low income--hence wanting to include some grains.

One lingering question I'm having is whether untreated phytates in grains only block the absorption of minerals from the grain itself or whether they affect absorption of nutrients from the rest of the meal or the body.

BLUE HACKER said...

i am john fromPrivate Health Care and this was really a great experience :).

Mike said...

Thank you for providing a fair view of the health effects of grains in the diet. I believe humans were meant to eat almost anything, as long as our diet was varied.

Today we develop may illnesses due to eating less-than-optimal foods in large quantities.

psychic24 said...

The negative effects of wholemeal bread, based on the studies you presented, don't seem too convincing. Notable excerpts from the study you cited:

"two young Americans who had not previously consumed fiber, phytate-, and phosphate-rich bread of this type"

"However, all had become positive or nearly so after 50 days"; signifying that there is adaptation taking place, with a timeframe that is still not understood, rather than unable to be overcome.

fluoresentric said...

Great information about archaeology, celiac, diet, evolution, genetics, gluten, Masai, minerals, native diet, paleolithic diet, phytic acid.

PCR Primers

rahul said...

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Jeff Consiglio said...

Regarding "crude genetic adaptations" which can confer BOTH helpful and harmful effects....

In the excellent book "The Rational Optimist" (written my evolution writer Matt Ridley)we learn about how hemochromatosis was natures way of bestowing immunity to the bubonic-plague. Apparently many pathogen thrive in high iron environment, so this mutation results in iron being sequestered into organs rather than blood. Of course that in itself eventually kills you as well,, but would at least keep you alive in an environment chock full of the plague long enough to reproduce and perpetuate your genes into the next generation.

Also, very interesting what you mentioned about potassium being much higher in tubers than grains. Since it is a mineral which has much to do with insulin sensitivity and controlling blood pressure, that may explain why the kitavans seem to do well on a higher carb diet, as compared to those who get lots of their carb intake from grains.

Paige Gerson said...

Having a dietitian background (Tulane U. and BS from KSU) from a standard american diet point of view; I find your article educational and informative. I was in school when the 1st version of the Food Pyramid was published by the USDA. And I am one of those few people out there who lost a great amount of weight and have maintained it for over 20 years. I teach consumer nutrition classes at businesses throughout a large US city in the manner that you describe. My audience is not the "paleo" community. My audience is middle class, moderately overweight and believes that MyPlate and the Food Pyramid are correct. Your article is the first common sense, yet scientific article that I have read that I would pass on to my students. Your article makes sense and yet is not fanatical!!! Thank you!

Ned Kock said...

Stephan, what you are describing falls under the general classification of "costly traits".

They are fascinating, and their existence is sobering. Evolution may look simple at first glance, but may lead to counter-intuitive outcomes.

A couple of posts further illustrating this comment:

http://bit.ly/qiXjwZ

http://bit.ly/bW0jCR

LeonRover said...

The application of the adaptation paradigm to species history AKA Evolution has resulted in two outcomes:

a) The Darwinian narrative which provides one explanation for the Fossil record - Food Source change providing an impulse to utilising chance changes in genes. (Bones)

b) The Red Queen narrative which has led to an explanation of how costly secondary traits have resulted from their use as health indicators promoting sexual selection. (Covering and decoration.)

I am not clear which narrative (or even another one) is the basis for promoting those changes involved in any Expensive Tissue hypothesis. (Internal soft tissue organs.)

Eva said...

I would think that, both logically and from my observation, those genetics that come from people who were very recently huntergathers, like native americans, would be more likely to be more maladapted to high grain intake. Using an even more rough mental hueristic, you can look at those populations that statistically are more overweight with more health problems. Now look at how their recent ancestors lived and you will find that their recent ancestors were less agricultural. A scant few generations of grain evolution puts some people at more of a disadvantage in adaptation to current food sources than others. One might be advised to look to one's ancestors for clues on what might work better for each individual, but considering how few if any races are unmixed and considering high levels of diversity even within groups, there will still be much that has to be figured out on an individual basis.

jpatti said...

I have similar concerns as Pieter... in that I'm a postmenopausal woman, so evolution has little use for me. But *I* still have use for me even though I will never reproduce again.

Thus I'm never sure how much credence to give evolutionary arguments since they apply to me less than to a young Creationist.

Nevertheless, I've found this series interesting; particularly like the even-handed discussion as opposed to the normal cherry-picking most blogs seem to do to bolster their preconceived notions.

As far as the yeah or nay to grains, my own take on it is this...

Buckwheat and barley generally have more micronutrients, especially flavanols, than other grains, so are preferred. I buy both whole - hulled barley and buckwheat groats and soak before cooking. BTW, barley makes a decent risotto.

Wheat is OK if not gluten-intolerant. Bought bread is OK if it's sprouted or REAL sourdough (not just sour flavor added).

I do a homemade bread using regular yeast, but it sits from 18-24 hours before baking, so I consider it well-soaked, if not fully fermented.

Non-wheat pastas are sad and not very edible, IMO. I do like pure buckwheat soba noodles. But they work better in Asian cuisine than in Italian. Having spent over 2 decades as a low-carber, I'm familair with doing zucchini noodles or cabbage strips, etc. IMO, nothing replaces wheat pasta!

White rice has less phytic acid than brown, so I figure it's preferred.

I soak scottish or steelcut oats overnight before cooking them... with a TB of wheat flour as oats don't have much phytase.

I buy organic masa harina to use as "cornmeal". I also buy frozen, canned or fresh corn only if organic, so as to avoid GMO corn.

Dry beans or peas, I just soak overnight in water, same as all your regular recipes say to.

Main thing is grains are never a main component of our diet.

We eat gobs of veggies (half the diet by volume) and lots of low-sugar fruit. No shortage of fiber here! My grocery cart ALWAYS has mostly produce in it, even if I just went to the Farmer's Market beforehand.

I get raw milk, pastured dairy, eggs and meat delivered from two local farms.

When we're too broke for as much grass-fed meat as I'd like, we buy more eggs and cook more legume-based meals.

Generally, I don't prefer we eat a lot of starch, but as far as starches go, I prefer potatoes.

When we do eat grain, it's almost always cooked in a bone broth with a few drops of Concentrace added. For me, reducing phytic acid is only half my nutritional strategy, I add lots of minerals too.

allison said...

Postmenopausal women do serve an evolutionary purpose: providing extended familiar care for grandchildren. This fact is also probably why women live longer than men.

I'm still curious about evolutionary adaptations that may predispose an individual to heart disease. I've read about adaptations to the immune system as a result of plague and other historical pandemics. Could some of these changes in the immune system be a tradeoff: resistance to disease but susceptibility to dietary causes of heart disease?

Jonathan A said...

Awesome post. It shows that one diet does not fit all, thanks.

BB said...

One adaptation that is counter intuitive, is the selection for small heads. Loren pointed this out years ago perhaps in not quite the same words.
The Neolithic diet/lifestyle leads to a smaller pelvis, hence difficulty in birth. Hence increased maternal and infant mortality. This is very expensive to the tribe, and is one of the most powerful inflexion points for natural selection.
Infants with smaller heads will have a safer passage through the birth canal.
Natural selection can favour that even if it means reduced intelligence. Better small head than dead. I've attached a long post on this issue with more details.
The mathematics of selection alluded to by Stephan basically fit in with classical evolution/population theory as espoused in the Logistic Function which is quite different to logistic regression.

Wanna Be Mother said...

I like this series. This was the issue I had with the paleo diet for years before I decided to just try it even if it sounds crazy. Of course we've evolved since agriculture and it makes sense that we would have evolved faster since it was a huge environmental change.

The other issue I have with the whole evolution argument for paleo is that evolution only favors those who pass on their genes to as many kids as possible. This is not always going to coincide with my definition of health, which would involve longevity past childbearing. I have yet into see a good article taking on this issue. I have a feeling menopause is part of this, since isn't it the case that only humans have that?

My current working theory is that a traditional diet in the WAPF idea is probably great for most people if they do it from birth or are pretty healthy. I think paleo is better for those who have been too damaged by SAD (or vegan/vegetarian diets, like me) so even traditional agricultural diets don't work well for them. I also really wonder about modern wheat's role in all this.

LeonRover said...

BP,

"as espoused in the Logistic Function which is quite different to logistic regression"

I'm curious, please explain.

Slainte

Go Meat! said...

What do you think of sourdough bread made with eikhorn wheat (the ancestral variety)? This procedure was inspired by Ramiel Nagel, but I would soak the grain for 24 hours, dry it, grind it into flour, sift the flour two times to remove all the bran and germ, and then ferment for several days. I believe this would result in a bread with little to none phytic acid and hopefully very little gluten; there is an Italian paper online that was able to reduce gluten in sourdough bread to a level safe for celiac patients to eat with only 1 day of fermentation (however they used three strains of bacteria that were very good at breaking down gluten)! Would you consider this a healthy food?

BB said...

Logistic function for growth of a population of a species in a habitat. It was worked out in the early 1800's to graph the ideas of populations limits explressed by Malthus and is still used today.
Logistic function is quite different from logistic regression of data points, which many people might accidentally get it confused with.
There is a discussion of logistic function on Wikipedia and 366 movies if you search Youtube for logistic function and 36 movies if you search for logistic function evolution.
HTH
Ben

Chris J said...

Great Series, thank you for your perspective.