Paleo Diet Debunked?
“…carbohydrate consumption, particularly in the form of starch, was critical for the accelerated expansion of the human brain over the last million years. Eating meat may have kick-started the evolution of bigger brains, but cooked starchy foods together with more salivary amylase genes made us smarter still.”
Proponents of the popular Paleolithic diet (or “Paleo”) encourage fairly high levels of meat consumption paired with low carbohydrate intake. In fact, there’s even an ongoing community debate on which vegetables are suitable for the Paleo diet with somewhat contradictory information. For example, the tuberous root vegetable known as the sweet potato ‘is Paleo’ while white potatoes (tuber and nightshade vegetables) are not…sometimes. It’s confusing and comes off as a bit silly to outsiders.
This new study points out that the Paleo diet may be operating on a few false assumptions. Most importantly, they tackle the likelihood that our ancestors didn’t eat nearly as much meat as we originally thought, which would certainly put a dent the primary structure of the Paleo diet, which claims to be a diet “…based on the food humans’ ancient ancestors might likely have eaten…”
- (1) The human brain uses up to 25% of the body’s energy budget and up to 60% of blood glucose. While synthesis of glucose from other sources is possible, it is not the most efficient way, and these high glucose demands are unlikely to have been met on a low carbohydrate diet;
- (2) Human pregnancy and lactation place additional demands on the body’s glucose budget and low maternal blood glucose levels compromise the health of both the mother and her offspring;
- (3) Starches would have been readily available to ancestral human populations in the form of tubers, as well as in seeds and some fruits and nuts;
- (4) While raw starches are often only poorly digested in humans, when cooked they lose their crystalline structure and become far more easily digested;
- (5) Salivary amylase genes are usually present in many copies (average ~6) in humans, but in only 2 copies in other primates. This increases the amount of salivary amylase produced and so increases the ability to digest starch. The exact date when salivary amylase genes multiplied remains uncertain, but genetic evidence suggests it was at some point in the last 1 million years.
Only further research can reveal the comprehensive nature of the Paleolithic tendencies of mankind (in its entirety) and it’ll be very interesting to see what else Dr. Karen Hardy and her team discover down the line.
Image source: https://upload.wikimedia.org/wikipedia/commons/a/ae/Diorama,_cavemen_-_National_Museum_of_Mongolian_History.jpg