Although the modern diet is primarily made up of processed and refined grains and carbohydrates (an effect of the agricultural revolution which began circa 10,000 BC), this is quite a recent phenomena in human history and runs counter to the way humans ate for millions of years … bursts of animal fat and protein fresh from the hunt and foraged plants/plant roots, followed by periods of deprivation/starvation.
Prior to this, early humans subsisted mostly on plants, fruit, and insects, however, our ancestor’s transition to a diet rich in animal meat ushered in the genus Homo by giving rise to our larger modern brains, the power of speech and the physical stamina to traverse long distances.
READ: Eating meat led to smaller stomachs, bigger brains
So, how did the prehistoric brain fuel itself (and evolve so robustly) if the modern mind currently runs on glucose?
In the absence of sugar, other than what the body can break down from the amino acids in protein (known as gluconeogenesis), the body turns to the liver’s ability to generate BHB (beta-hydroxybutyrate), acetoacetate acid and acetone, which are produced in part from certain amino acids (such as lysine and leucine), but mainly from our body’s fat stores and circulating fatty acids in the blood. These fatty acids undergo oxidation in the liver generating the only substrate other than glucose that can traverse the blood-brain barrier…
Ketones.
Ketone bodies are the superior fuel for human cognition and endurance, a diet rich in fat and minus processed carbohydrates, grains and sugar induce ketosis, a state where the body no longer uses glucose as its principle supply of energy and instead turns to ketones as its primary fuel source.
Samuel Henderson, a well-known doctor of molecular genetics and cell biology who has been researching neurodegenerative disorders for over 15 years says…
“Throughout much of human evolution, ketosis likely served as a valuable survival mechanism to fuel brain metabolism during times of food scarcity. Hence, in some ways, the modern diet can be considered “ketodeficient.”
READ: Ketone Bodies as a Therapeutic for Alzheimer’s Disease
And, an article in Scientific American entitled “The fat-fueled brain” argues…
“Many neurological diseases share one major problem – deficient energy production. During metabolic stress, ketones serve as an alternative energy source to maintain normal brain cell metabolism.”
“In fact, BHB (a major ketone) may be an even more efficient fuel than glucose, providing more energy per unit oxygen used.”
Ketone bodies are also produced during periods of starvation and are highly adept metabolically (the efficient conversion of fuel to run cellular processes being crucial to our ability to survive long periods without food) as they increase a molecule known as Acetyl-CoA which is oxidized in the mitochondria (the power plant of our cells) to produce energy.
Taking out the (Cellular) Trash
Ketones also increase the rate at which the body rids itself of a cell’s dysfunctional, decaying components and helps eliminate the build-up of damaged proteins. As we age, and/or due to environmental exposure, cells begin to experience damage to their DNA and cease to replicate … a condition known as senescence. These impaired cells are unable to divide, rendering them useless in the regeneration and repair of tissue, however, as they remain active metabolically, they wander zombie-like, amassing in our tissues like so much junk, serving to increase inflammation in the body and contribute to many diseases including diabetes and cardiovascular disease.
The process of destruction of the dysfunctional elements of these wasteful cells is known as autophagy, and ketone bodies are exceptional at increasing the run rate of this recycling system, ridding the body of cellular refuse.
Furthermore, the clearing out of senescent neuronal (brain) cells plays a crucial role in long-term cerebral health and the warding off of disorders such as Parkinson’s, Dementia and Alzheimer’s.
It’s no surprise then that ketone bodies are the subject of great interest and experimentation in the treatment of neurodegenerative diseases, as conditions like Alzheimer’s are characterized by the brain’s inability to continue processing glucose as energy.
After year’s of metabolizing refined carbohydrates and sugar to fuel areas of the brain such as the prefrontal cortex, we see a corrosion of the brain’s ability to utilize glucose as an effective energy source primarily because sugar is a pernicious, damage-inducing substance.
According to Samuel Henderson…
“… it has been suggested that high levels of glucose utilization in these areas of the brain may be conducive to the future development of hypometabolism, plaque deposition, and cell atrophy that characterizes Alzheimer’s Disease”
However, as neurons waste away due to their inability to employ glucose for energy, the brain can always harness ketones for fuel. This primal substrate can not only re-energize these suffocating cells, ketone bodies (unlike glucose) are neuroprotective!
READ: Neuroprotective and disease-modifying effects of the ketogenic diet
The Faster Brain
Over 2400 years ago, Hippocrates (the father of modern medicine) discovered while treating patients with epilepsy that fasting relieved the dreaded seizures experienced by sufferers of this neurological disorder. As astonishing as this was however, abstaining from food as a successful prescription for sickness was by no means a medical breakthrough. Fasting in ancient times was often used as a treatment for all manner of ailments, as brief periods of starvation seemed to work and provide relief for everything from asthma to arthritis and a host of other inflammation-related illnesses. Especially astounding was its dramatic effect in controlling the violent convulsions associated with epilepsy.
The science behind why fasting can have such a mighty (and positive) impact on our health lies partly in its ability to rewire our metabolism, as the ketone bodies generated during this process transforms the way we process and utilize energy — igniting a metabolic shift from glucose to fatty acid utilization.
With respect to seizures, in a study conducted at Emory University, scientists found that ketones, unlike glucose, create a dense mitochondrial environment within the hippocampus by greatly increasing the number of mitochondria (cellular energy generators) in this area of the brain.
The hippocampus is the center of the autonomic nervous system, which is why increased energy production in this component of the cerebrum may elicit more effective neuronal control and, as such, a corresponding anticonvulsant effect.
In the same study researchers also found that ketones may have a powerful effect on gene expression, in fact “… the most striking finding was the coordinated up-regulation of genes involved in energy metabolism.”
READ: Ketogenic Diet Prevents Seizures By Enhancing Brain Energy Production, Increasing Neuron Stability
Whether it is via changes in gene expression or the production of new/additional mitochondria, the primary fuel used in energy production (glucose vs. ketones), appears to be the key to understanding the brain’s ability to combat metabolic issues such as Epilepsy.
However, given the massive consumption of refined carbohydrates (between 50% -70%) associated with the modern, western diet, and because we now have the luxury to no longer endure periods of deprivation, we do not produce the level of ketones necessary to spark the aforementioned shift in our metabolism, instead we have become reliant, and in most cases addicted to, a cheap, disease-inducing, brain degrading, inferior energy source … glucose.
Not so Fast
The good news is that we do not need to starve in order to get our bodies back to its primal state, we can eat in a way that mimics calorie restriction and induces an abundant supply of ketones, all while achieving a higher level of satiety than we ever could on a diet loaded with carbohydrates!
Read: Ketone bodies mimic the lifespan extending properties of caloric restriction
In the article A Metabolic Paradigm Shift, or Why Fat Is the Preferred Fuel for Human Metabolism, Mark Sisson explains that carbohydrates are not only unnecessary for human survival, they are also completely insignificant with respect to our evolution …
“Civilizations have existed for ages on what is practically a zero carb diet. Think about this: there is actually no requirement for any “essential dietary carbohydrates” in human nutrition. It’s possible to live a very long and healthy life never consuming much – if any – in the way of carbs, provided you get adequate dietary protein and fat.”
“Fat and protein were the dominant macronutrients (when food was even available) over the majority of our two-and-a-half million years as evolving humans. The lack of regular access to food and a scarcity of carbohydrates for much of this time necessitated that we adapt efficient pathways to readily store and access body fat for energy if we were to survive day-to-day and generation-to-generation.”
At the dawn of our ascension as the planet’s alpha species, an ancient biologic fuel (ketones) propelled our transition to a speaking, big-brained, apex predator — and returning to this primal metabolic ideal can release us from a false nutritional paradigm that ultimately renders us weak and sick, a modern dietary trap of equal parts indulgence and convenience, borne of genetically engineered agricultural bounty, insidious marketing, and advances in manufacturing technology for the processing of grain and sugar … the ultra refinement of which has wrought a Medusa’s head of health disorders and debilitating illness.
However, what we once knew instinctively, seeded deep within our ancient biochemistry, the primeval engine of our metabolism, may yet save us.
The steps to unlocking a battery of disease preventing mechanisms, from reducing dangerous levels of inflammation in the body to powering a razor-sharp, peak-state mind (a brain that was once relentlessly primed for the hunt), lies not in the drug, genetic or nutritional breakthroughs of 21st century science, but in an approach to treating obesity and diabetes that stretches as far back as the 1800s.