Microbes or the fire pit? Fermented foods rather than cooking believed to have supported brain evolution

Recent investigations from the Harvard University suggest that it was fermentation, not the use of fire and cooking, that drove the growth of the human brain. 

Here's a summary of the report published by The Harvard Gazette:

• While it is known that the human brain has significantly expanded from smaller primate brains, the exact reason for this development has remained unclear. Erin Hecht, an assistant professor of human evolutionary biology, suggests that the diet and food consumption may have been the key driver.

• The human brain is most energy-intense organ, consuming around 20% of the glucose reserve. This high metabolic demand of brain tissue necessitated a shift in diet to provide sufficient energy for brain growth. The theory posits that fermented, "pre-digested" foods likely played a crucial role in nourishing our ancestors and supporting this brain expansion. This hypothesis challenges the conventional idea that using fire to cook was the main driver of the increased brain size, as evidence places the use of fire much later than the initial growth of the hominid brain.

• The spontaneous, so-called wild fermentation of food might have provided a more accessible source of nourishment, fueling brain growth and aiding in the survival of our ancestors. The relatively smaller size of the human large intestine compared to other primates suggests an adaptation to food already broken down by fermentation.

• Fermented foods are found across various cultures, indicating their widespread consumption throughout human history.

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