Our Evolving Brains Needed A Carb-Rich 'Paleo' Diet, Study

What exactly did our ancestors eat? It isn't really clear---so scientists need to do a lot of guesswork apart from research.

As businessinsider put it, paleo diets permit you to eat just "meat, nuts, eggs, fruits, vegetables and healthy oils like olive and coconut," mirroring what our ancient ancestors ate. However, now researchers feel that our ancestors ate a carbohydrate-rich diet that gave "energy to evolve bigger brains."

However, while meat brought about a big transformation in their diets, so did carbohydrates---though today's paleo diet nuts don't like it.

As our ancestors introduced "cooked starches into their diet", they helped to "fuel the evolution of our oversized brains", says Mark G. Thomas, an evolutionary geneticist at University College London, and his colleagues., according to nytimes.

While cooked meat began to help the human body to grow and evolve, something else did it too. Cooked starches.

When we eat starch, we convert it into glucose, which is our fuel. It starts when we start chewing with saliva, which contains an enzyme called amylase that breaks down starchy foods.

Interestingly, amylase works better on cooked foods that become more digestible, rather than raw food.

Cooking helps tubers to become more nutritious, "which is not to be sniffed at, especially if you're a very hungry Pleistocene hunter-gatherer," he said.

As humans have many extra copies of the amylase in their DNA, we are able to extract more nutrients from starches, says Dr. Thomas.

Human production of amylase seemed to have evolved with the use of wheat and other starchy crops, according to the scientists. However, recent studies of the DNA of pre-agricultural hunters from Europe show that people had extra copies of amylase genes even before they began to farm. With fire and cooking, even more amylase could be released, and with more glucose, they got more fuel for bigger brains.

Hence, the fossils show "a drastic acceleration in the size of hominin brains" beginning 800,000 years ago. And today, our brains use a quarter of our calories.

However, not all experts agree. "They may be right, but it's not a slam-dunk," said Greg Wray, an evolutionary biologist at Duke University. "The timing is not well resolved enough."

Even Dr Thomas isn't completely clear. "I think evolutionary biology can have a lot to say about food and health," he said. "But nutrition is so incredibly complex, and we've only scratched the surface."