Here’s how starch-rich foods helped in the human brain’s evolution
The human brain is unique — no other animal possesses such a large brain relative to the size of its body. It has been argued that an increase in meat consumption could have triggered the increase in size, but now scientists believe that we may have another food to thank: The humble potato, reports the DailyMail.co.uk.
Researchers suggest carbohydrate consumption, particularly in the form of starch, was critical for the extraordinary development of the brain over the past million years. They say starches would have been readily available to ancestral human populations in the form of potatoes as well as in seeds, some fruits and nuts.
Carbs not proteins: The new study combines archaeological, anthropological, genetic, physiological and anatomical data to argue that carbohydrate consumption was key in the human brain’s evolution. There has been a heavy focus on the role of animal protein and cooking in the development of the human brain and the importance of starch rich foods has been overlooked. Dr Karen Hardy and her team at the Autonomous University of Barcelona say that there are five reasons why a starch-rich diet was critical in human development.
Easy energy: Firstly, the human brain uses up to 25 per cent of the body’s energy and up to 60 per cent of the body’s blood glucose. While synthesis of glucose from other sources is possible it is not efficient and such high glucose demands would not have been met on a low carbohydrate diet. This need for carbohydrates would have been satisfied in part by the development of cooking. While raw starches are often poorly digested in humans, when cooked they lose their crystalline structure. The ability to use fire for cooking would have unlocked nutrients and enabled our ancestors to eat a far broader diet. Pregnancy and breastfeeding also place additional demands on the body’s glucose budget. Low maternal blood glucose levels compromise the health of both the mother and her offspring, which suggest that a level of carbohydrates is essential.
The starchy gene: The researchers also point out that humans possess six salivary amylase genes, while other primates just have two, increasing the ability to digest starch. Dr Hardy explained that after cooking became widespread and the salivary amylase genes multiplied, it increased the availability of dietary glucose to the brain, which, in turn, allowed the acceleration in brain size.
— Source: www.dailymail.co.uk
