The Importance of Dietary Carbohydrate in Human Evolution

Archaeological Starch

“…According to a hypothesis proposed by Hardy et al [2], the regular consumption of starchy plant foods offers a coherent explanation for the provision of energy to the evolving brain during the late Pliocene and Early Pleistocene. The development of cooking and concomitant increases in salivary amylase expression, could explain how the rapid increases in brain size from the Middle Pleistocene onward were energetically affordable.…”

“…The development of cooking and concomitant increases in salivary amylase expression, could explain how the rapid increases in brain size from the Middle Pleistocene onward were energetically affordable. Several key features in human evolution are considered directly linked to alterations in dietary composition [2]. These include: changes in tooth morphology [92]; a reduction in the size of the digestive tract, achieved by 1.8 million years ago [93]; an accelerated increase in brain size from around 800,000 years ago [94]; increased aerobic capacity by around 2 million years ago [95].…”

“…Salivary amylases are largely ineffective on raw starch but cooking substantially increases their energy-yielding potential [17]. Copy number variation in the salivary amylase genes would have become advantageous and may have further enhanced the role of starch in human evolution when cooking became widespread among early hominins [2].…”

“…This article will consider how starch granules associated with archaeological artefacts and in dental calculus can provide an insight into plant usage by our ancestors. We consider how starch granules could survive for hundreds of thousands of years as part of the archaeological record and review a hypothesis, based on a combination of archaeological, physiological and genetic evidence, that plant foods containing high quantities of digestible starch were essential for the evolution of the modern human phenotype [2].…”

The Metabolic Plant Feedback Hypothesis: How Plant Secondary Metabolites Nonspecifically Impact Human Health

“…Retrospectively, dietary carbohydrates were essential for the evolution of the human brain, which uses up to 25 % of the bodyʼs energy and up to 60 % of blood glucose. Accordingly, salivary amylase (AMY1) genes, which are usually present in several copies in humans, correlate positively with salivary amylase protein levels (individuals from populations with high-starch diets have, on average, more AMY1 copies than those with traditionally low-starch diets) [4], but AMY1 exists only in two copies in other primates. High copy numbers of AMY1 increases the amount of salivary amylase produced and so increases the ability to digest starch [5].…”