Natural sugars may have helped fuel human brain evolution: study

SYDNEY, Aug. 7 (Xinhua) -- Fruit, honey and other naturally sweet foods may have helped fuel the evolution of the human brain, according to new research suggesting that sugars played a larger role than previously thought.

The study, published in Science, found that natural sugars may have supplied the energy needed to support growing brains before the advent of cooking made starch-rich foods such as tubers and grains easier to digest, according to a statement released Friday by Australia's University of Sydney (USYD).

Researchers modeled the glucose needs of humans and their ancestors from about 4 million years ago until recently. The findings may also provide insight into why humans often crave sweet foods.

"Raw starch does not release glucose, meaning early humans likely relied on naturally sweet foods long before grains became a regular part of the diet," said lead author Professor Jennie Brand-Miller at the USYD.

The findings offer a different perspective on the long-held view that meat consumption was a key driver of human evolution, arguing that the brain's need for glucose has received relatively little attention.

Researchers combined evidence from food composition, metabolism, physiology, fossil isotope studies, dental morphology, archaeology, primate diets and genetics to estimate how humans met their glucose needs as brain size increased from around 300 grams in early hominins to about 1,500 grams in modern humans.

"Glucose is the brain's primary energy source, and for much of human evolution would have come from carbohydrates found in foods such as fruit and honey," Brand-Miller said. Enditem