Dietary sugars fueled human brain evolution

A study published in Science by researchers from the University of Sydney and the University of Glasgow argues that dietary sugars, not just animal foods, played a decisive role in the expansion of the human brain over the past four million years. The team, led by Professor Jennie Brand-Miller, modeled the glucose needs of humans and their ancestors, calculating the 'obligatory glucose demand' of the brain, red blood cells, kidneys, and reproductive tissues. They found that early hominins likely derived over 65% of their energy from sugars in fruit and honey, and that cooked starches became important later. The findings challenge the traditional focus on meat as the main driver of brain evolution and highlight the importance of carbohydrates during pregnancy and childhood. The study suggests that our instinctive desire for sweetness is rooted in evolution and that modern diets should include high-quality carbohydrate sources.