Cooking: Brainfood, Tasty Downfall

by Natasha Chart

categories: Eats, Health, How Things Work

Published April 22, 2009 @ 06:30AM PT

Anthropologist Richard Wrangham was interviewed in the New York Times recently talking about how cooking made us human. Which is to say that it makes a lot more energy available to our digestive tracts than raw foods, allowing us to get away with smaller digestive systems and energy-hogging, glucose-chugging brains.

Consider this:

... The brain, which accounts for 2 percent of our body weight, sucks down roughly 20 percent of our daily calories. A picky eater, it demands a constant supply of glucose ...

In part, cooking achieves this by softening food. Wrangham spoke to The Economist a while ago about the digestive effects of eating softer food:

... Another telling experiment, conducted on rats, did not rely on cooking. Rather the experimenters ground up food pellets and then recompacted them to make them softer. Rats fed on the softer pellets weighed 30% more after 26 weeks than those fed the same weight of standard pellets. The difference was because of the lower cost of digestion.

Indeed, Dr Wrangham suspects the main cause of the modern epidemic of obesity is not overeating (which the evidence suggests—in America, at least—is a myth) but the rise of processed foods. These are softer, because that is what people prefer. Indeed, the nerves from the taste buds meet in a part of the brain called the amygdala with nerves that convey information on the softness of food. It is only after these two qualities have been compared that the brain assesses how pleasant a mouthful actually is. ...

Our ability to process food in ways that make it easier to digest seems to represent a leap akin to the development of mitochondria in single-celled organisms. The development of mitochondria in cells allowed 13 times the net energy production from sugars as could be gotten by processing sugars without a mitochondrion.

Cells that had mitochondria went on to be the parents of all multicellular lifeforms. There just doesn't seem to be enough get-up-and-go in the other kind to produce cooperative organisms like sponges, plants, fish, cockroaches or apes.

Where I'm going with this is that the amount of energy that can be gathered from food has big consequences. While we thrive on a higher energy diet than most of our mammalian kin, we can't properly handle the overabundance we're presented with today.

So next time you're in the store and you're tempted by the bread or pasta made with refined flour, the soda, the sweet cereal in wholly unnatural shapes, the russet potato, consider an option a little lower on the glycemic index. Get the whole grain option, get more of the food that's still obviously from a plant.

Because a better evolution of the species doesn't seem to be in the offing. Unless by 'better', you mean more diabetes ridden, or by 'evolution', you mean prematurely keeled over.

(Photo credit: Uwe Hermann on Flickr.)