Thursday, August 27, 2015

Paleo diet: Big brains needed carbs: Importance of dietary carbohydrate in human evolution -- ScienceDaily

Paleo diet: Big brains needed carbs: Importance of dietary carbohydrate in human evolution -- ScienceDaily

A new study, entitled "The Importance of Dietary Carbohydrate in Human Evolution," authored by a team led by Dr. Karen Hardy and published in the Quarterly Review of Biology, supports my argument in Powered By Plants:  If, as alleged by modern so-called science, humans came to their current biology by a process of evolution by natural selection, it was undoubtedly a process
powered by plants providing an abundance of starchy carbohydrates.

The abstract states:  "We provide evidence that cooked starch, a source of preformed glucose,
greatly increased energy availability to human tissues with high glucose demands, such as the brain, red blood cells, and the developing fetus."

According to the Science Daily report: 
"Hardy's team highlights the following observations to build a case for dietary carbohydrate being essential for the evolution of modern big-brained humans:

    (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.
Hardy proposes that after cooking became widespread, the co-evolution of cooking and higher copy number of the salivary amylase (and possibly pancreatic amylase) genes increased the availability of pre-formed dietary glucose to the brain and fetus, which in turn, permitted the acceleration in brain size increase which occurred from around 800,000 years ago onwards."
It really is simple.  The idea that a large primate descended from largely frugivorous ancestors evolved a taste preference for sweet foods, a glucose-hungry brain and a large capacity for glycogen storage on a glucose-poor meat-based and fat-rich diet, but then suddenly switched to cultivation of starches 10K years ago, lacks basic credibility.  Occam's Razor cuts away the pretzel logic and low-carbohydrate confusion perpetuated by the "man the hunter" fairy tale.  It is impossible to support the crazed, confused idea that the human brain evolved on a fat-based diet without either failing in scholarship, ignoring evidence or committing fraud outright, as I discussed in this video: 

Pam Popper discusses this latest study, and my book, in this video report:

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