September 4, 2013
BBQs Responsible For Evolution
I recently came across the scientific theory that a major reason why humans were able to develop and evolve to far greater an extent than any other species is cooking.
Cooking food is effectively beginning the digestion process outside of the body, which means that once we consume cooked food we are making our stomach’s job easier. The food can be digested more quickly, with less use of energy, and more calories can be consumed from the food.
By contrast, experts say that it takes a long time to digest raw food and that there is an upper limit to the number of calories a creature can ingest per day from raw food alone. That upper limit doesn’t allow enough energy to be gained from food in order for extra, developmental activity beyond the basic requirements of survival. Eating only raw food, our brains can’t grow.
The fact that raw food takes so long for the body to process is the reason why large mammals always seem to be eating. That’s basically all they ever do. For humans to get all the calories they need from raw food only, they would need to eat for 9.3 hours a day. This is slightly more than gorillas at 8.8 hours a day and orangutans at 7.8. That doesn’t leave much time or energy for poetry or computer programming.
These figures were published in the journal Proceedings of the National Academy of Sciences, following a study at Brazil’s Federal University of Rio de Janeiro, by Suzana Herculano-Houzel and her graduate student, Karina Fonseca-Azevedo. It followed work done in the late 1990’s by Harvard University primatologist Richard Wrangham, who made the connection after realizing that the increase in human brain size (or specifically the brain size of our ancestor Homo Erectus) coincided with the time during which they started cooking; 1.6 million to 1.8 million years ago.
Once we started cooking, we gained two advantages over other primates in that we could spend less time on eating and more time developing other skills and ideas, and also that we were better able to gain the nutrition we needed to develop.
Anyone who is interested in healthy eating or dieting will know that there is a very popular belief in the benefits of raw food. That there are benefits is undeniably true; not least because cooking destroys some of the healthiest elements of food, especially certain methods such as boiling. And of course going to other extreme, from raw to highly processed foods, is not advisable either.
But Herculano-Houzel believes that an exclusively raw food diet is not a good idea. Not only because if you stuck with it for 1.8 million years you would be less evolved than your friends, but also because it will take up too much of your body’s energy every day.
The answer is probably that moderation and variation will most likely give the best results, with some raw food being eaten alongside reasonably fresh and natural ingredients, which are cooked using the most suitable cooking methods. That way, we can ensure we stay ahead of our primate cousins.
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