A lot of people are not aware of the fact that the keto diet does wonder for the brain. While most people follow keto diet to lose or maintain their weight, a keto diet affects the body in a variety of ways. While it may seem too good to be true. After all, this diet plan asks people to consume a lot of fat.
All sorts of opinions floating on the internet such as keto benefit us because it reduces insulin levels by freeing fat from fat cells, keto puts us in the best metabolic state so that we burn the most calories and many others.
Putting aside all of these opinions, we will now turn to the facts, and see what are the documented benefits that a keto diet gives us towards the healthy functioning of our brain. Also, we will understand the relation between ketones and brain function.
What is ketosis?
For the most part, our bodies run on sugar. The food that we eat, gets converted into glucose, which is then burned to create energy. When we don’t consume enough carbohydrates, our body starts to produce ketones.
The liver produces these ketones, and they get released into the bloodstream so that the brain and the other organs can use them. There are three types of ketones as Beta-hydroxybutyrate (BHB), acetoacetate and acetone.
Excess acetone is usually breathed out as a way of getting rid of it, while excess BHB and acetoacetate are disposed of through urine.
The main reason there exists an alternative fuel source for fat is because the body cannot burn them to be used by the brain cells. The brain, as opposed to other organs of the body, needs fast acting energy sources.
Fat becomes metabolized very slowly and, thus, does not meet the brain’s requirements. Due to this, the liver can convert fatty acids into a source of energy for the brain, in the form of ketones.
While all of this happens within the body, the blood glucose level is maintained due to the glucose which is derived from certain amino acids as well as the breakdown of fatty acids. Thus, there is no risk of low blood sugar if a keto diet is properly followed.
How ketosis helps the brain?
The answer to the question “How does ketosis protect the brain against many brain diseases?” is a long one. Ketones do so by either affecting processes in the brain or by affecting the neurons directly. Let’s see what happens in both cases.
Affecting processes in the brain
One possible answer is that ketones, being a more efficient source of fuel, can correct energy deficiencies in the brain. Ketones can maintain normal brain cell metabolism even during periods of metabolic stress.
In fact, Beta-hydroxybutyrate (BHB) is a more efficient than glucose as a source of fuel and provides more energy per unit of oxygen used.
A study conducted on rats following a keto diet found enhanced levels of genes encoding for mitochondrial enzymes higher energy metabolism in the hippocampus of the brain, the part of the brain responsible from memory and learning (1).
Cells of the hippocampus can degenerate in brain diseases related to aging, thus causing memory loss as well as cognitive dysfunction. But utilizing ketones as a more efficient energy source can lead to neurons having a greater capacity to ward off stressors which may kill these cells.
Ketones also inhibit the production of reactive oxygen (also called free radicals), produced naturally as a byproduct of the body burning glucose for fuel.
These free radicals cause a variety of harmful effects as they damage DNA and mitochondria, the basic building blocks of all tissues. Free radicals lead to neurodegeneration, aging and increased risk for heart diseases.
Ketones also help out by enhancing the breakdown of free radicals through increasing the activity of our innate antioxidant system. A study, using a non-metabolized glucose analog, also found that neurons activate stress proteins to stabilize mitochondria and lower oxidant levels (2).
A keto diet, due to its high-fat nature, also leads to an increase of polyunsaturated fatty acids (PUFAs, such as DHA and EPA). This, in turn, reduces inflammation as well as oxidant production. PUFAs target inflammatory stress by inhibiting the expression of genes encoding for all pro-inflammatory factors.
Affecting the neurons
There are two main neurotransmitters which control the brain. The one called glutamate excites while the one called GABA inhibits neuronal function. When our neurons get over-excited, they lose their functioning and die.
This is evidenced by the fact that too much glutamate leads to excitotoxicity and can cause stroke, neurodegeneration, as well as seizures. Hyperactivity, therefore, is toxic.
A study of hippocampal neurons of individuals on a keto revealed that ketones decrease excitatory transmission (3). Ketones decrease the incidence of excitation being transmitted by inhibiting a neuron’s ability to absorb glutamate, thus limiting any chance of it being transferred from one neuron to another.
Another study, which followed a similar model of epilepsy that used a chemical identical to glutamate to induce damage, revealed concurrent findings (4).
The research concluded that the keto diet protected mice against cell death. Cells in the mice’s hippocampus were protected by inhibiting molecules which signaled death.
While ketones undoubtedly affect the excitation end of the spectrum, their effect on the inhibition pole is just as significant. A study concluded that, in rats, ketones increase GABA in the synapses, where all neurotransmitters are released (5).
Another study confirmed the same findings In the brains of some epileptic humans subjects as well (6). With the increase in inhibition that occurs as a result of following a ketogenic diet, it results in both neuroprotection as well as anti-seizure effects.
There are other hypotheses as well, surround the mechanisms through which a keto diet can help neural activity. A study concluded that the overall acidity of ketones might decrease the pH of some brain microdomains, and this may be the reason why a keto diet has a positive effect on Type II Bipolar disorder (7).
The reasoning for such a conclusion is that the overall change in the body that a keto diet causes also inevitably affects brain functioning as well.
Which disorders can keto help?
Various trials have been conducted recently to give concrete evidence regarding which mental disorders can be assisted through a keto diet. One of these mental disorders is Parkinson’s, in which a study showed that 5 out of 7 patients followed the keto diet and it leads to marked reduction in their symptoms. (8)
Two studies have been conducted with regard to Alzheimer’s. One study concluded that those who took a ketogenic agent, over a period of 90 days, showed remarkable cognitive improvement over those who took a placebo drug.
This was also correlated with the level of ketones in their blood. (9) The other study conducted on Alzheimer’s patients showed that 23 elderly patients with mild cognitive impairment had improved verbal memory after six weeks in comparison with a standard high-carb diet. (10)
In a trial on mice who had Amyotrophic Lateral Sclerosis (ALS), a ketogenic diet showed delayed motor neuron death. Although a keto diet did not lead to an increased lifespan, it led to functional and histological improvements. (11)
Over to you on ketones and brain function
While still in its infancy, recent research on how keto diets affect the brain has opened up new pathways to explore. Because a keto diet acclimatizes the body to using fat as a source of energy rather than glucose, it leads to various benefits.
These benefits also reach the brain, and the keto diet has conclusively been shown to help certain mental disorders such as Epilepsy, Alzheimer’s, ALS, and Parkinson’s are some mental disorders.
Also, all these neurological diseases are currently being studied in-depth to find out more about the specific mechanisms through which a keto diet results in benefitting these conditions.