Michael Harper for redOrbit.com — Your Universe Online
There are some wild diets out there. As many of us attempt to either lose weight or simply eat healthier, we´ll try our hands at diets of all kinds: All meat, no meat; All vegetables, only specific vegetables; foods in a specific order, foods in a specific season.
There´s a diet for any kind of person and personality, no matter how odd or strange. One such diet, the raw food diet, has come under plenty of scrutiny for it´s strict regulations. While there are different varieties of the raw food diet (such as veganism, vegetarianism, and even animal-based diets) the basic rule is the same: Food is not to be cooked to a temperature more than 115 degrees Fahrenheit. Not only does this diet sound like a giant bummer to many cheeseburger and taco-loving humans, a new study this week suggests it could potentially starve a dieter´s brain. What´s more, the study has also found that homo erectus began to develop more rapidly whenever we finally got that whole cooking thing mastered. According to Suzana Herculano-Houzel, a neuroscientist at the Federal University of Rio de Janeiro in Brazil and co-author of this report, a human eating the raw diet would have to eat for 9 hours straight just to consume enough energy to feed their brains.
“If you eat only raw food, there are not enough hours in the day to get enough calories to build such a large brain,” said Herculano-Houzel, speaking to Science Magazine.
“We can afford more neurons, thanks to cooking.”
One of the many ways in which we are different from our primate cousins is the number of neurons found in our brains. According to the study, humans have nearly 86 billion neurons, on average, in their brain. Gorillas, on the other hand, have roughly 33 billion neurons, with chimps falling slightly behind at 28 billion. As the saying goes, there´s no such thing as a free lunch, and while humans have larger brains packed with more neurons, our brains consume 20% of our body´s energy just by sitting still.
In order to test this theory about raw food diets, Herculano-Houzel and her graduate student, Karina Fonseca-Azevedo, who is now a neuroscientist at the National Institute of Translational Neuroscience in SÃ£o Paulo, Brazil, began by measuring the number of neurons in 13 species of primates and more than 30 species of other mammals. To begin with, the team discovered that brain size is directly linked to the number of neurons, a fitting observation.
The team also discovered that a brain with more neurons needed more calories to sustain itself than a brain with fewer neurons.
Setting to work, Herculano-Houzel and Fonseca-Azevedo began to crunch some numbers to determine how long a mammal would need to eat a diet of raw foods in order to feed their brain. Gorillas would have to eat the uncooked food for 8.8 hours to sustain their brains, while orangutans would need to eat for 7.8 hours at a time, and chimps would have to eat for nearly 7.3 hours consistently.
While humans on the raw food diet often add supplements, such as proteins and other nutrients in order to live a healthier lifestyle, primates don´t have the same luxury. Therefore, unless primates eat raw food for hours at a time or begin to cook their own food, they´ll never be able to grow their brains to our size.
“The reason we have more neurons than any other animal alive is that cooking allowed this qualitative change–this step increase in brain size,” concludes Herculano-Houzel.
“By cooking, we managed to circumvent the limitation of how much we can eat in a day.”
This study can be seen as good news for anyone worried about a primate take over or looking for a new point to argue against anyone pushing a raw food diet.