Bad Health and Agricultural Origins
A few weeks ago on Jason Collins’s Evolving Economics blog there was a discussion of changes in human height assessed from skeletal remains. A well-known finding is that when humans started farming they became shorter, less robust, and exhibited numerous pathologies. The new foods were apparently not so good for us.
This decline in size and indicators of health occurred in the New World, in Europe, and in East Asia. While much of the literature is focussed simply on documenting this remarkable change in our biology, it seems to me that there are very interesting issues that ought to be examined more carefully. The conventional story is that shared nutritional deficiencies are responsible for the health decline, but recent popular nutrition literature seems to emphasize the toxicity of many of the new foods, particularly grasses. For an excellent scholarly summary see the excellent book by the Jaminets [1].
Did we adapt to the new diet over several millenia? If the culprits were simply carbohydrates it might be more difficult that coming up with simple solutions to simple toxins.
One of the go-to guys these days on human paleopathology is Clark Larsen at Ohio State University. I wrote him to ask about the current state of knowledge, and, with his permission, here is his summary:
- All are deficient in one or more essential amino acids (lysine for maize, millet, and wheat);
- None of the common domesticated cereals have adequate bioavailable iron;
- All are deficient in one or more vitamins: e.g., B1 (thiamine), B2 (riboflavin), C (ascorbic acid);
- All have links with malnutrition, immunosuppression, and susceptibility to a variety of pathogens rendering the individual prone to infection where the population derives the majority of calories/energy from plant domesticates;
- All are carbohydrates, creating circumstances that promote a cariogenic oral environment and dental caries, oral infection, and susceptibility to degenerative conditions in later life (e.g., cardiovascular disease, diabetes).
Clark suggested several reviews he has written recently [2,3] as well as the classic volume edited by Cohen and Armelagos[4].
In the Collins blog post cited above there is reported work by Tim Gage showing that there is recovery from the new diet. It is not clear from post who cited this, but at any rate Tim denies having written anything at all about health and the agricultural transition.
If the culprits on the different continents were simply cooked carbohydrates then we do expect roughly the same outcome everywhere, and Larsen suggests that this is so. On the other hand one notices hints of greater complexity in the literature. Caries and gum disease are prominent in North American collections and much less common in Europe. One anomalous European site shows a lot of caries, and the authors suggest that they must have had a lot of honey in their diet.
An easy test for region-specific adaptations comes to mind. New foods, especially cereals, introduced by the Atlantic Exchange after 1492 should have been difficult for the recipients, who were not adapted to plants from the other side of the ocean. I do not recall ever having seen a discussion of this, and it might make an interesting project. Maize spread rapidly in southern Europe and in Africa: did it cause trouble early on? Is it still causing trouble? The staple of the diet in much of southern Africa today is ground maize (“mealie meal”) but no one seems concerned. While maize is associated with iron deficiency in many places, iron overload is a health problem in Africa, perhaps from the widespread use of cast iron pots.
References
[1] P. Jaminet, S.-C. Jaminet, Perfect Health Diet: Four Steps to Renewed Health, Youthful Vitality, and Long Life, YinYang Press, 2010.
[2] C.S. Larsen, Biological changes in human populations with agriculture, Annual Review of Anthropology. (1995) 185–213.
[3] C.S. Larsen, Bioarchaeology: the lives and lifestyles of past people, Journal of Archaeological Research. 10 (2002) 119–166.
[4] M.N. Cohen, G.J. Armelagos, Paleopathology at the Origins of Agriculture, Academic Press Orlando, 1984.
West Hunter 
“New foods, especially cereals, introduced by the Atlantic Exchange after 1492 should have been difficult for the recipients, who were not adapted to plants from the other side of the ocean. I do not recall ever having seen a discussion of this, and it might make an interesting project. Maize spread rapidly in southern Europe and in Africa: did it cause trouble early on?”
Yes, corn (or maize to Queen’s English speakers) caused massive pellagra outbreaks from lack of B3 niacin in southern Europe well through the 19th century. Europeans brought back the corn but not the Mesoamerican cooking techniques, i.e. nixtamalization, which involves soaking it in limewater to break down the barriers locking in the vitamins. Hominy, for example, has been nixtamalized. Europeans already had efficient mills so saw no need for such “primitive” cooking techniques. Oops.
There are good wikipedia articles on this, but I learned this first through a far more entertaining Good Eats episode with Alton Brown.
Ah, I was going to mention this, but you got here first. It would seem that in this case, cultural practices (and the lack of their diffusion) “masked” whatever genetic problems maize might have caused Europeans. In other words, Europeans who would have developed problems due to a lack of adaptations to maize died instead of pellagra deficiency that cultural practices could have solved. This would make it harder to see other problems that a maize diet may have caused for them.
Oops, the above post should say “niacin deficiency.” They obviously weren’t deficient in pellagra.
I remember seeing at one time a map of potato growing vs wheat growing regions from a few hundred years ago, with a fair amount of detail. Comparing skeletons and death records between these regions could be the best way to determine if grains of carbohydrates are the problem. Might be possible to make the same comparison in Latin America over a longer period of time (with maize). But I doubt anyone is going to dig up enough skeletons to get a trustworthy answer.
I don’t have anything in direct response to your suspicions, but I would suggest a more explicit focus on gut and mouth flora would probably bear fruit. Also, that different types of carbs have very different impacts on flora. E.g.,
http://humanfoodproject.com/sorry-low-carbers-your-microbiome-is-just-not-that-into-you/
I would caricature this line of thinking as “aside from certain well-known vitamin deficiencies, the major way food is good or bad for us is how it changes the composition of our flora.” This obviously overstates the point, but by less than we generally realize.
Also, this is neither here nor there, but it is interesting:
It hardly seems fair to place too much blame on carbohydrates. Among known warm-climate non-equestrian foragers, hunting and fishing, on average, provide around 45% of caloric intake. (http://www.anth.uconn.edu/faculty/munro/assets/articles/Marlowe2005.pdf) The rest is plant based – lots of carbohydrates and some nuts. The difference is that foragers knew and ate hundreds of different types of plants, but farmers got calories mainly from monocultures. Much easier to develop assorted nutritional deficiencies that way. One could argue that the reduction in protein and fat intake during farming transition, especially among temperate climate people (who ate more fish and meat than warm climate foragers) was one of the culprits, but it is not logical to say that carbohydrates are bad per se.
Also, there was so much wrong with the state of human health and nutrition (especially towards the early modern age, the period when we have the most data – for example, as suggested above, on the proliferation of maize and potatoes in Europe), that it may be difficult to discern effects of specific plants. As one random example, there’s recent evidence that, as late as 1850, upper-class Japanese children frequently suffered and occasionally died from chronic lead poisoning. We only found out about it recently because scientists got around to test some skeletons for lead content. Back in 1850, no one noticed. What’s a few more deaths here and there when infant mortality rate is on the order of 20-30% anyway? In the West, alcoholism was rampant (by modern standards): From the 17th century onwards, British Navy provided its seamen with rum rations equivalent to about 8 standard drinks per day. In the U.S. in 1836, a prominent physician wrote: “…In the western parts of our state [Pennsylvania], where ardent spirit has become almost the substitute for water, whisky is given daily in large quantities, from the youngest to the oldest child; and, so quickly do they become accustomed to this pernicious liquor, that we have seen a child of six or seven years old, drink a wine-glass full at a draught.”
“Also, there was so much wrong with the state of human health and nutrition […] that it may be difficult to discern effects of specific plants.”
Back then, yes, but perhaps now it would be possible. If there are certain adaptations that make it easier to digest e.g. maize, Mesoamericans have still had thousands of years more time to develop them than Europeans and Africans. Maize only became widespread in Europe about 300 years ago, and about 150 of those years have been spent in a post-Malthusian environment. Therefore, Europeans and Africans should still be more poorly adapted to a maize diet than Mesoamericans, in theory.
It seems to me that a series of admixture studies could be used to discover adaptations, and Latin American populations are good for such studies. You could take people who are ~100%, native Mesoamerican, ~50% Mesoamerican/European, and ~100% European, match them up for general health/SES, etc., and put them all on a diet similar to that of the indigenous Mesoamericans before contact (save for the problem of scarcity–they would all get enough calories to maintain their health). Do this for six months or so, and see who has the best health afterwards. Do a similar series of studies with a Mesoamerican/African mix to ensure that your findings are not unique to Europeans (though I’m not sure how many half-Indians/Africans there are left in Mexico).
Furthermore, each person in the study would be genotyped to narrow down which genes might be causing any differences in response to the diet (does a mestizo with a chunk of native genes on (e.g.) chr 5 do better than a mestizo who doesn’t have it?), and so on.
“In the West, alcoholism was rampant”
It seems to me that alcohol is a much ignored factor in demographic history. I’ve got to believe that pervasive drinking, especially among young mothers, was a major contributor to the historical underperformance of certain groups – such as in the U.S. the Irish, Polish and the Scotch-Irish as compared to say Italians and Jews.
Today, the heaviest-drinking country is France, and they don’t exactly seem to be underperforming. And did the Irish a d Poles actually underperform the Italians? That’s news to me…
In America very much so. Read Moynihan’s “Beyond the Melting Pot” – Italian-Americans were already caught up to American whites generally by the 60’s. The Irish, who came over here generally much earlier than the Italians, had still not caught up by then,but were still mired in nepotistic public-service occupations.
“the heaviest-drinking country is France”
What’s your scource? France is after Ireland in this list.
http://en.wikipedia.org/wiki/List_of_countries_by_alcohol_consumption
Both France and Ireland are somewhere between 2 and 2.5 drinks per day per person. Maybe 3 drinks per day if you exclude children. Historically speaking, that’s nothing. If everyone (except pregnant and breastfeeding mothers) drinks at the same rate, 3 drinks/day is still within reasonably healthy limits. If there are some heavy drinkers, everyone else drinks even less.
Russia is close to 3 drinks/day/person with strong male bias, that’s borderline dangerous territory.
Even that is low by the standards of early modern Europe. The French were consuming about 3 drinks/day/person worth of wine alone from 1870 to 1940. (SInce the population was still fairly young, that could have worked out to close to a bottle per adult per day.) During the “gin craze” of the early 18th century, London distilleries were producing ~15 gallons of gin per year for every resident of London (4 drinks/day/person), and that’s not including beer, which was essentially a dietary staple.
If alcohol was a factor might there not be a difference between beer, wine and spirits?
Yes, the same from me. In essence, the daily amount of ethanol counts, doesn’t it?
Maybe some populations exhibited/exhibit functional alcoholism (drunkenness does not have much of a effect or some kind of controlled binge drinking). What about the (Middle eastern) Muslims? They should have a high resistance against alcoholism, still there is the cultural ban of alcohol? (More or less strict depending on the country, pretty low in Turkey afaik)
Zuk gives the following reference for Gage’s work:
Gage, T. B. “Are Modern Environments Really Bad for Us?: Revisiting the Demographic and Epidemiologic Transitions.” Yearbook of Physical Anthropology 48 (2005): 96–117
You can find that paper here: http://onlinelibrary.wiley.com/doi/10.1002/ajpa.20353/abstract
Tim suspected that this is the paper cited. It is about the last few centuries and not about the issues we are discussing: I suspect it was a careless citation by Zuk.
It occurs to me that my post title is sloppy in using the word “health”. This is particularly bad in the context of skeletal populations with a limited number of indicators of pathology. Children of Bushmen in Botswana who were foraging were active, outgoing, healthy to the eye. Children of Bushmen employed on ranches around the town of Ghanzi were startlingly different: they were dull-eyed often, lots of mucus from the nose and pussy eyes, often swollen mastoid processes. What apparently was going on was that kids in the bush did not have enough fat reserves to sustain illness and they either recovered or died very fast. Around Ghanzi the kids had enough food to survive illness.
If we were to examine skeletal collections from these two groups we would conclude that the setlled Ghanzi population was unhealthy and that the Bush population was healthy, and in one sense of the word “health” that would be true. On the other hand the kids around Ghanzi survived when kids in the Bush did not: mortality rates were something like a third to a half less among the settled Ghanzi children.
We discussed these issues years ago in
J. W. Wood, G. R. Milner, H. C. Harpending, K. M. Weiss, M. N. Cohen, L. E. Eisenberg, D. L. Hutchinson, R. Jankauskas, G. Cesnys, M. A. Katzenberg, et al. The osteological paradox: problems of inferring prehistoric health from skeletal samples [and comments and reply]. Current Anthropology, 33(4):343–370, 1992.
I am surprised at the assumptions that early farmers only ate their harvests. In Europe you’d have wild berries, nuts, mushrooms, fishing, and occasional hunting all supplementing the diet. As such, assuming that their diets were nutritionally deficient is questionable.
Our knowledge of early agricultural civilizations indicates that would usually be the case. There wasn’t a whole lot to eat in Ancient Egypt other than harvested goods – if you were poor, which almost everyone was.
Other ancient societies had such rapid population growth that they eventually had to turn over every bit of ground to production, so again there would have been nothing to eat except the products of agriculture. Consider especially the Maya.
Societies that didn’t fall into this Malthusian trap had some other means of keeping their populations down.
What about all the wussy hunter-gatherers? The pencil-necks who’d normally be dedcapitated by proto-Conan as he heads off to strangle Cthulhu? Agriculture gave us a shot at survival. Sure, we die of pellagra after having kids. Beats getting squished in passing by Miocene proto-mammoths before we get jiggy with hominim beta chicks.
The Dutch height spurt of the later 20th Century might have something to do with changing diets.
In what way? I have the impression that the whole thing is a mystery; I would be inclined to attribute it to having a breakfast of bread, butter, cheese, ham, and chocolate sprinkles, but perhaps the Dutch have eaten breakfasts like that for a century or three.
In addition to deficiencies, what about protein allergies? Celiac disease is a well known example involving wheat and other gluten-containing Old World grasses. Is there any analogous condition involving the proteins in maize?
The origin of agriculture has bothered me for years – what was the benefit of the early stages of farming given obvious physical hits that early farmers sustained compared to neighboring hunter-gatherers (Mississippian culture, Anasazis, Catalhoyukians, etc.). There must have been a huge benefit for so many in so many different places and times and crops to invent agriculture despite the impact on their stature, lifespan, functionality, etc. This is not like ants growing fungus in their nests where the benefit is clear and the costs are not. Perhaps higher density living permitted by agriculture gave more protection but it seems that the negatives of richer targets for raiders and the special diseases of higher density living outweigh these benefits. Perhaps it was driven by culture – people’s groups got bigger and they wanted to live together in one place – how else can you do that except via agriculture? Apparently the earliest residents of Catalhoyuk were hunter-gatherers who settled near natural rich grain fields. They figured out planting and tending later. Currently, I think of early agriculture like the evolution of the ear – beneficial in the end state, but I’m not so sure about the early phases (unlike the eye, which is beneficial in it’s simplest form). BWDIK – I’m sure this crowd will instruct me.
You didn’t read the parable of the Rat King?
“what was the benefit of the early stages of farming given obvious physical hits that early farmers sustained compared to neighboring hunter-gatherers”
It doesn’t have to happen in one go. If h-gs had a higher survivability threshold then you end up with a h-g population who are either very fit or very dead. If they switch to farming and survival is easier then people can survive with more defects so the first generation start off very fit but subsequent flawed individuals who might have dies as H-Gs survive as farmers so the average fitness drops to a new lower mean survivability level.
Good points GW and Z. I had missed the Rat King post – a classic! So the early farmers survived and bred, leaving warped skeletons. The plowing (flaming hoops) and threshing (mazes) came later. Soon they had the brains to design tractors. Got it.
Also weaker selection on physical traits doesn’t necessarily mean weaker selection on cognitive traits. It’s possible the farmers became a little smarter at the same time as they became more flawed physically.
The switch h-g to (first-time) ac should be regarded as gradual. In rich environments h-g were already sedentary e.g..
Not sure if this is to the point, but I’ve always assumed that people took to agriculture by necessity, not choice — that population pressure and the competition for good hunting and gathering grounds forced the weakest tribes to the margins, where feeding on wild grasses began out of semi-desperation to supplement an otherwise inadequate diet of game, fruit, nuts, roots, berries, etc. Just think how much work it is to change wheat seeds to bread. This might help account for nutritional deficiencies in early horticultural societies, if indeed that is what the evidence shows.
Raymond Crotty in “When Histories Collide” argued the opposite, and only a group with a sizable surplus would be willing to plant rather than eat their seed-corn.
There would have been no seed corn in the beginning, just wild grasses that they gradually learned to cultivate.
The major beneficiary of the introduction of farming and urbanization/civilization of the human kind that followed were the infectious diseases and several species of microorganisms, that found an optimal environment for growth and propagation in the farming centers. Not the first farmers themselves. Could the civilization has been caused by bunch of viruses?
I think you and Dr. Cochran would be interested in this. Peter Turchin has a post up talking about a recent simulation about the rise of states that has been making the rounds. Within, Turchin talks about multi-level selection, and I know Dr. Cochran has been rather unforgiving to discussion of selection over the level of the individual. Any thoughts?
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