More benefits of cooking our food

Further to a mention in this column of the role of cooking in human evolution (PJ, 14  May 2011, p571), Hourglass was interested to read of a new study in which a Harvard researcher, Rachel Carmody, found that cooked meat provides more energy than raw meat.

Although Richard Wrangham (author of the book mentioned by Hourglass) came up with this as a theory several years ago, Carmody’s work is believed to provide the first evidence to support it. The study involved feeding two groups of mice a series of diets consisting of either meat or sweet potatoes prepared in four ways — raw and whole, raw and pounded, cooked and whole, and cooked and pounded. Changes in each mouse’s body mass and their use of the exercise wheel were tracked during the course of each diet.

The outcome was that cooked meat delivered more energy to the mice than raw meat. According to Carmody, this suggests that humans are biologically adapted to take advantage of the benefits of the cooking, and that cooking played a key role in driving the evolution of humans from an ape-like creature into one more resembling modern humans.

Humans once ate meat raw — before they had the ability to control fire — but approximately 1.9 million years ago the bodies of early humans grew larger and their brains grew in size and complexity. Although these changes were thought to be the product of increased meat in the diet, Carmody says that her research points to the possibility that it was cooking that provided early humans with more energy.