TALKING VOICES Anthropologist Christopher Joyce goes into the ‘meat’ of the debate on energy demands of our body and the brain
Brain versus gut. Are the traditional Tambrahms the exception, who prove the rule? Raising such and similar questions, which turn many existing notions of the right diet on their head, are some of the findings of the ongoing research on human evolution. In a seven minute 46 second talk on the NPR radio, commentator Christopher Joyce asserts that science researchers claim there is something called ‘brain food’, which is not exactly what we think of or know.
Interviewed on the programme was Leslie Aiello, an anthropologist and director of the Wenner-Gren Foundation in New York City, which funds research on evolution. She says, “Digestion was the energy-hog of our primate ancestor’s body. The brain was the poor stepsister who got the leftovers.”
The contention is that our ancestors, the very first ones ate food raw. So their metabolism spent a long time breaking down the foods and giving the necessary energy to the body. And then they learnt to cook.
Even now they had to polish off large quantities of food to meet their energy requirement. So it was more or less, that they ate to be able to eat again…to have the energy to digest their food.
Must have been a blissful state of eating to eat again, but nature, accident or providence intervened and the radio programme says that it was only when they learnt to cook meat that there came about a sea change in the brain and therefore a leap in the evolution history of mankind.
Leslie Aiello is once again heard asserting that a big gut and a big brain cannot co-exist. If all the energy was spent in digestion, where was there any energy left for the poor brain to develop?
Less appetising stuff
“What we think is that this dietary change around 2.3 million years ago was one of the major significant factors in the evolution of our own species,” Aiello says. She goes on to say less appetising things like, “We actually shared saliva with wild dogs and hyenas. The closest relative of human tapeworms are tapeworms that affect African hyenas and wild dogs,” she says.
Tapeworms or canines, the main point is that man began to eat meat. That vegetarianism is a cultivated habit both literally and metaphorically is in no doubt. But this talk attributes our intellectual jump from ‘primitive’ man, say the Neanderthals, to our present day genius to the energy the brain got from the consumption of meat.
Before that it was hungry and so stunted. As we learnt to eat meat, the guts shrunk, so much energy was no longer required to mash, grind and digest the food and so the energy started moving elsewhere, typically the brain.
If you are taking a relook at your menu card, wait there is more. How stylish is it to pick on a salad at lunch…but listen to Joyce who brought anthropologist Richard Wrangham from Harvard University on the show and he said that while raw foods have “…got a tremendous amount of caloric energy in them…The problem is that it’s in the form of starch, which unless you cook it, does not give you very much.” (The talk mentions only turnips, so perhaps the greens can still make good salads!)
Cooking is primarily talked of in the context of meat which is softer and more easily digested if cooked, in addition to being more nutritious.
The Indian dietary concepts claim just the opposite. Ayurveda has always maintained that meat is tamasic food and so dulls the brain and increases animal-like passions.
However, one can see a shadow of the logic of Aiello in our ideas of fasting. Great seers have realised truth only when their process of digestion was inactive; that is they were fasting. So perhaps it is true that the gut and the brain are in competition after all, but in that case will the vegetarians lose out in the race for the next evolutionary jump?