Is The Paleo Diet a Fantasy Diet?
Well, according to one evolutionary biologist, yes…
Four years ago, biology professor Marlene Zuk was attending a conference on evolution and diseases of modern environments. She sat in on a presentation by Loren Cordain, author of “The Paleo Diet” and a leading guru of the current craze for emulating the lifestyles of our Stone-Age ancestors. Cordain pronounced several foods (bread, rice, potatoes) to be the cause of a fatal condition in people carrying certain genes. Intrigued, Zuk stood up and asked Cordain why this genetic inability to digest so many common foods had persisted. “Surely it would have been selected out of the population,” she suggested.
Cordain, who has a Ph.D in exercise physiology, assured Zuk that human beings had not had time to adapt to foods that only became staples with the advent of agriculture. “It’s only been ten thousand years,” he explained. Zuk’s response: “Plenty of time.” He looked at her blankly, and she repeated: “Plenty of time.” Zuk goes on to write, “we never resolved our disagreement.” ‘snip’
It is striking how fixated on the alleged behavior of our hunting-and-foraging forbearers some educated inhabitants of the developed world have become. Among the most obsessed are those who insist, as Zuk summarizes, that “our bodies and minds evolved under a particular set of circumstances, and in changing those circumstances without allowing our bodies time to evolve in response, we have wreaked the havoc that is modern life.” Not only would we be happier and healthier if we lived like “cavemen,” this philosophy dictates, but “we are good at things we had to do back in the Pleistocene … and bad at things we didn’t.”
The most persuasive argument Zuk marshals against such views has to do with the potential for relatively rapid evolution, major changes that can appear over a time as short as, or even shorter than, the 10,000 years Cordain scoffed at. There are plenty of examples of this in humans and other species. In one astonishing case, a type of cricket Zuk studied, when transplanted from its original habitat to Hawaii, became almost entirely silent in the course of a mere five years. (A parasitical fly used the insects’ sounds to locate hosts.) This was all the more remarkable because audible leg-rubbing was the crickets’ main way of attracting mates, literally the raison d’etre of male crickets. The Hawaiian crickets constitute “one of the fastest cases of evolution in the wild, taking not hundreds or thousands of generations, but a mere handful,” Zuk writes. Adjusted to human years, that amounts to “only a few centuries.”
Let me begin with my personal disclaimer that I find evolution a rather silly idea and the science typically shoddy. That being said let me ask the question that this article raises in my mind: what if we’re just not designed to eat carbs?
What is the human body simply cannot deal with them? It seems the good doctor’s argument is that if we decided to start eating arsenic we would simply “evolve” (a process which, to this lay person, is apparently indistinguishable from magic) and next Tuesday we would find arsenic not merely tasty but delicious to boot.
Pretty good deal, huh?
Here’s a fun exit question: how long will it take a cat to evolve to eat a predominantly carb based diet? Or a ruminant to eat a predator’s diet?