Oh, and about that Paleo diet…
One more thing about that Paleo diet we’ve been discussing with such vigor: it is my distinct impression that the digestive physiology of human beings has changed quite a bit since Paleo times, in ways both known and unknown.
For example—one with which I’m rather intimately familiar, as you will see—take the phenomenon of lactose intolerance. Actually, it would be better to take the phenomenon of lactose tolerance, because that, rather than its opposite, was the anomaly (and still is; the majority of the world’s humans still cannot digest milk).
Lactose intolerance—the inability to digest the milk sugar lactose—was the norm past childhood throughout most of mankind’s prehistory. Young children could digest milk (human and otherwise), but after that, who needed to? However, once people started raising cattle and milking them, it became an advantage to be able to drink their milk past childhood. And so the natural selection process began:
…[I]n dairy consuming areas, a mutation in the gene regulating the ”˜switching off’ of lactase production, situated on chromosome 2, has now become very common. Such a mutation is known to have arisen among an early cattle-raising people, the Funnel Beaker culture, who lived in north-central Europe around 5,000 to 6,000 years ago. This lactase-persistence allele is found in more than 90 per cent of Danes and Swedes, and 50 per cent of Spanish and French ”“ illustrating that the mutation becomes progressively less common in Europeans who live at increasing distances from the ancient Funnel Beaker region. The mutation is rare in non-pastoral communities such as the Chinese (only 1 per cent of the population have it). In pastoral areas in East Africa, there is a very low frequency of this allele, although many adults are lactose tolerant. An international team of researchers has found that lactose tolerance in East African adults is served by three newly discovered variants of the lactase gene, all of which are independent of each other and the European strain. As in the European allele the mutation is present in the control region of the gene. These African variants appear to have arisen several thousand years later than the European allele.
That’s one of the reasons I can’t stand milk: I’m 100% lactose intolerant. How do I know that? For some reason lost in the mists of antiquity and my medical history, I was required to take a test for it when I was about thirty years old. I remember it well: it involved fasting, then drinking a supersized cup of a liquid that consisted mostly of lactose, and then having my blood drawn at regular intervals for the next few hours in order to see whether my blood glucose went up.
It also involved my becoming sick as a dog.
Cruel? You betcha. But when they found that my glucose levels had budged not one whit, the doctors could safely say I had the highest degree possible of lactose intolerance—although the technician was actually able to venture a guess at that even before the results came back, when I told him how I’d been spending my free time in-between blood pricks.
It was a learning experience. And one of the things it taught me was that, although for most of my friends milk was their friend because of recent evolutionary advances, I’d been left behind; it was most definitely not my friend. But of course, I already knew that.
And yes, I fully understand that milk is not included on the Paleo diet, but my point has nothing to do with drinking milk or not drinking milk. My point is that different populations have developed for many thousands of years in response to different diets, and ultimately we are all individuals. For those of you who love the Paleo diet (or the this diet or the that diet), that’s great. I’m happy for you. But diets are very idiosyncratic things.
[NOTE: For a discussion of some of the controversy over the Paleo diet and human evolution, see this.]
[ADDENDUM: Diet wars of another kind.]
Too much thought and consternation over what should come naturally. Eat what you like (in moderation) and as you age eat what likes you back. The end.
Observations about the Paleo diet and health:
1) The diet skips the part where our ancestors encountered other types of hominid and ate them, hence overlooking an obvious source of protein.
2) The diet overlooks the fact that health was partially maintained by hunting or fishing more or less than 8 hours a day. In short, the work day varied.
3) The diet also overlooks that long periods of hunger were the norm, as were periods of gluttony.
4) Also forgotten is the paleo-lifestyle that supported the diet. Such as 8 hours sleep a night is a modern invention. Try it when sleeping out in a cold forest and see how many hours of sleep you get, even without bears nibbling at your toes like they do in Pittsburg Shopping Malls. To get the full benefits of the diet sleep in the afternoon and stay on guard against predators at night.
5) The paleo-diet supported the ADD trait. Hunter gatherers had to be ADD to survive. Attention had to shift quickly to catch prey without becoming prey. Farming weeded out that trait creating a mass of malleable non-ADD slugs that now persecute ADDers with drugs. True Paleo-diets are geared to ADDers and not malleable non-ADD slugs. Paleo-diets are probably good for paleo people, i.e. ADDers.
6) Civilization arose because of nagging wives, and changes in diet represent a change in genome brought about by nagging wives. The paleo-dieters are making subconscious statements that go far beyond the desire for health.
That is interesting. I never thought of lactose intolerance as the norm, but I suspect that one could make an evolutionary case for precisely that.
Pure speculation here, but it seems that in a world where life is tenuous and preservation of the species is high on the evolutionary “to do” list, lactose tolerance in younger children along with lactose intolerance in older children might be mother nature’s way of weaning offspring from the breast to make room for the next cycle of nursing progeny.
Does this mean that you are a throwback, or just genuinely primitive? The mind boggles.
You would think that we would have better scientific data on such a necessary thing as eating a good diet. But we don’t. A couple of possible reasons:
1. For most of human existence food was not always in such abundance as now. Getting something, anything, to eat was more important than knowing if it was creating better health.
2. The modern solution to solving mechanical problems is to come up with a protocol that works in nearly all situations. It turns out that this approach to diet won’t work with humans, we’re too variable.
Now that the scarcity problem has been solved and most of us do not have to work too hard physically to get our daily bread, we are noticing that too much food is not necessarily good for us. The search is on for the proper protocol for all to adhere to. Considering all the differing diets that are claiming to be the best approach, it isn’t working too well. It’s conceivable to me that in fifty years people will know by the time they are teens what types and amounts of food should be eaten to maintain their best state of health. IMO, that would be an excellent preventative healthcare program. (I’ll be long gone by then.) Until then, we can keep trying to learn what works for us and hope we find it. That will make many diet book authors happy.
It sounds like your lactose intolerance problem is genetic. Have you always had this problem, or did it develop over time?
I had no problem with lactose tolerance at all until I reached my thirties. Prior to that point, I regularly ate yogurt, I drank milk (mostly 2% through my teen years, and then mostly skim from my early 20s on) and ate ice cream without any problems. When I first noticed a problem, I started buying lactase enzyme tablets. Those helped, but I still noticed lots of congestion when I had dairy foods, so I mostly avoided it. Instead I substituted soy milk, at first, until I discovered that that bothered me in other ways, and then I went with rice milk for many years.
Over a year and a half ago, though, I read about the health benefits of kefir, so I decided to try it. I also started eating whole milk yogurt regularly. Kefir and yogurt generally have little lactose. Although my complaints about congestion still apply, and although I still don’t drink straight milk, I think that the probiotics in the kefir and yogurt probably have the added benefit of helping me digest more dairy foods with fewer issues than just a few years ago. My theory is that perhaps some of the antibiotics I took at some point negatively impacted the good bacteria in my digestive tract and that contributed to my problems with dairy food. While I still need to be careful with dairy foods, I like to think that the kefir and yogurt I have now have helped to reverse that trend.
Kurt: I’ve disliked milk as far back as I can remember, so I don’t drink it. So I don’t know when I developed the problem, but my guess is very early.
…and I’ve been known to drink a half gallon of milk a day lol. Plus yogurt (I eat yogurt daily if it’s in the house, and it’s almost always in the frig’ …have for years ). Kefir has always been a treat preferred to milkshakes (well, it was in California: the brands in the local Spokane area markets suck, even if they’re loaded with probiotics).
Dairy is a staple for me (that hasn’t changed with my decreased intake of grains, so I’m not really “doing” Paleo per se, just way less grain-based dietary staples …still eating legumes too btw …and yes, I’m still slimming down, since last week even).
…obviously, there must be a Viking or Dane [Funnelbeaker] forebear gene somewhere back there that bred true, too.
Throwback? Maybe.
Primitive? I don’t think you can be primitive and slaver over ballet.
Not that there’s anything wrong with that!
‘that the digestive physiology of human beings has changed quite a bit since Paleo times’
Actually, I suspect that there have been relatively few changes in human digestive physiology in the last 12,000 years. This is a vey short time period in evolutionary terms. We are essentially genetically identical to our late Paleolithic ancestors.
‘Eat what you like (in moderation) and as you age eat what likes you back.’
I agree. I have two additional principles for diet both of which are based on the tremendous variation between individual humans wrt health and diet. 1) Experiment to determine what works best for you and 2) a broad diet is best. The more different ‘types’ of food you eat, the greater the chance you don’t miss anything you need and that way there is also less chance of eating too much of something which is unhealthily (the moderation factor).
‘Civilization arose because of nagging wives,’
Civilization arose around 4000BC, about 6000 years after the Neolithic revolution. That represents a whole lot of nagging. But it wasn’t a genome change per se — as I said in the earlier post, that’s a heartbeat of time in evolutionary terms.
The most supported explanation for how civilization formed is the hydraulic theory. That concentrated authority was necessary for the irrigation of crops in southern Mesopotamia. But by this time over 95% of humans in the world were fed by agriculture and not by hunting, fishing or gathering.
Steve D: that is NOT a relatively short period in evolutionary terms. If you’re talking about new species emerging or something like that, it’s a short time. But modifications based on natural selection can happen quite quickly if the pressures are strong enough.
The changes reflected in the lactose intolerance profile happened rather rapidly in evolutionary terms, for example. Populations of the world have had VERY different diets from each other for thousands of years, more than long enough to effect changes through natural selection.
For an interesting tale of how quickly things can change as a result of natural selection, here’s an interesting story about another species:
The point is that variation exists within populations in individual members’ ability to digest foods and their affinity for different foods. Over time, environmental changes and pressures select one trait over another in the race for survival, and this can be different across different groups and across different times. But it can happen rather quickly, if need be.
I haven’t researched this claim extensively, and it may be folklore, but to back up Neo’s point about 6,000 years being enough time for significant evolution, I have heard that, after correcting for body size, Asian peoples have pancreases that are larger than those of westerners; that is commonly viewed as explaining why the large amount of white rice consumed in Asian cultures doesn’t have the same negative effects as refined carbohydrates do in the west. If it is true, it could be another example of a beneficial adaptation, just like the ability to digest dairy foods beyond childhood is a beneficial adaptation in most of the peoples of northern Europe.
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