I do find Robb Wolf‘s arguments interesting, that handling gluten is like handling another stressor, albeit a big one. Maybe gluten is innately problematic, but some people simply have better defenses against it? Or some people have fewer stressors, so will not notice the problems caused by it?
But that would probably be the case with most foods, in the sense that most foods probably contain compounds that the body has to detoxify or otherwise deal with in some way. What makes gluten special, then? Why should it be especially difficult for the human body to deal with?
The evolutionary argument is made, to explain why it is especially difficult for humans to deal with gluten: gluten is a plant defense. The argument is that all grains have poisonous compounds that protect them, because these poisons are a way for mama plant to protect baby plant: since mama plant doesn’t have claws or teeth or legs, it uses toxins to coat baby plant so that it can survive. That’s why grains are bad.
But how does this make sense? Domestication across a variety of species tends to reduce the number of toxins. The wild almond is deadly. The domesticated almond may be merely problematic, and maybe not problematic for most people at all. Inasmuch as something is domesticated, damaging characteristics get bred out.
This happens for three reasons. First, humans notice such toxins through the wisdom of the body; and humans would thereby innately prefer less toxic grain strains to more toxic strains. This alone would tend to select for lower level of toxins. How this might occur–check out Mark Schatzker’s work. In a nutshell: animals, including sheep and goats but also presumably including humans, can *sense* when foods are not nutritious, or are toxic to them, and learn instinctively to avoid such foods, and to eat others.
Second argument. Even if the first argument were not correct, and there was no wisdom of the body, as postulated in a modified form by Schatzker, nonetheless coevolution would occur by virtue of one simple fact: the grains that killed their domesticators, or prevented them from thriving, would be the grains that would not last evolutionarily. The strains, on the other hand, that had thriving domesticators would continue on. The survival of the domesticators themselves would select for lower toxin loads of grains! This is because grains without surviving domesticators would themselves die. Grains, therefore, would co-evolve with human groups to be increasingly nutritious and decreasingly toxic.
Three, organisms that do not need characteristics will, over time, in the absence of evolutionary pressure, tend not to express them. Take the example of muscles in human beings. Now compare them to our cousins, the chimpanzee–or even the not-so-distant neanderthal, not to mention the australopithecus. Humans are weak nerds–that’s because, once muscles became less important, we stopped expressing copious amounts of them like our ancestors!
In the case of domesticated grains, it is not necessary for such plants to continue to express toxins, because their domesticators will breed them *regardless*, no, *because*, their babies (seeds/grains) are being eaten. And if it is not necessary, and if the expression of such toxins is energetically costly, such toxins will be selected against due to such costliness. Later generations will not have such toxins–in the same way that modern homo sapiens no longer have big muscles or robust skeletons.
I find the second argument most compelling. But don’t take my word for it. Look up domestication processes on plants. Fact is, in the process of domestication, you lose LOTS of toxins. That’s an empirical fact.
So why would grains be different? The only thing I can think here: the selective (mis-)breeding resulting in the multiplication of the quantity of protein in each grain kernel caused by Borlaug and the Green Revolution. As the argument goes: yes, the toxins are gone because of domestication, but the selective breeding in the 1960s, in intentionally increasing the amount of protein in each grain by as much as three-fold, and without a slow co-evolutionary process that occurred as humans resampled and reselected different strains, “reawakened” the dormant toxic capacity of grains, without humans being able to intervene co-evolutionarily. Remember, this selective breeding was done purely scientifically, in a top-down way, and purely to increase yield; it was assumed that such a process was safe. But if the co-evolutionary story above is true, then the co-evolutionary stop-gap that ensures a less toxic and more nutritious plant is taken out, because entirely new strains of grains are introduced without the feedback of human health to exert selective pressures back on the grains. This is how a scientific approach of industrial agriculture may yield qualitatively different results from the piece-meal approach of traditional agriculture; and how, scientific agriculture is not merely an intensification of degree, but rather, the introduction of an entirely new relationship between man and nature.
In any case, if this is the explanation, the problem with grains would not start in the neolithic, but in the very recent past–the 1960s. Such an interpretation would also jive with Loren Cordain’s statements–Cordain admitted in one academic paper that the recent industrialization of food probably had a more negative impact than the transition from the paleolithic to the neolithic. Notably, in my opinion, this really problematizes the Paleo diet “story”, but that’s a matter for another post. But the point is, even if the anti-grain mythos of Paleo is true, it may not be true for the reasons Paleo says it is.
[I wrote the above post cursorily and as a matter of stress relief between study sessions. If you want the citations and quotations, please let me know at email@example.com. If someone is interested enough to ask, I will be delighted to provide, and I will add them to this main page.]