Of our cave ancestors we know two things for sure. The first is that they did not have refrigerators or fast food restaurants. The second certainty is that, despite these shortcomings, they survived, and that is why we are here. What this implies is that early humans did not eat three times a day, every day. They had to search, gather, or hunt for their food before they could eat. In winter or during periods of drought, they went hungry.
What happens when you cut carbs? Benefits of the ketogenic diet
If our species survived it is because we are adapted to be able to function in a fasted state. But, in addition, it would make sense that in those moments of deprivation, when we most need to sharpen our wits to search for food, we are not only functional, but better than normal. And indeed, that is what research has begun to find in recent years.
fat as fuel
Our body can run on two types of fuel: sugar (glucose) and fat. Glucose is obtained from sugars and starch (bread, potatoes, pasta). But unless it was summer and they found ripe fruit or honey, our ancestors didn’t have many sources of glucose. In those moments, the body uses fat to feed the cells, both the one we can eat, and the one we carry in the belly and hips.
However, the neurons, which make up the nervous system, including the brain, are not capable of using fat for fuel directly. This is when ketosis kicks in. Ketosis is not a diseasebut a natural mechanism. The liver breaks down fatty acids and converts them into ketone bodies. These molecules serve as alternative fuel for neurons, and apparently make them work better than with glucose.
The brain that runs on ketones
The ketogenic diet, a diet that restricts carbohydrates to a minimum (below 50 grams per day), and therefore provides very little glucose, is a way to induce ketosis and get the body to use ketones as an energy source . In ketosis, the brain receives up to 70% of its energy needs from the hundreds.
The ketogenic diet has been used successfully for more than 90 years to treat epilepsy in children. In addition, it has been found that this diet also improves symptoms and protects against neurodegenerative diseases such as Alzheimer’s or Parkinson’s. ketosis protects against amyloid protein deposition and tau, which cause Alzheimer’s. It may also protect against epilepsy, malignant glioma, migraines and other neurological disorders. As if that were not enough, ketones also speed recovery in cases of brain injury.
Although the mechanisms are not yet well defined, it is considered that the protective effect of ketones is due to an increase in the energy reserves of neurons, which protects them against metabolic alterations, in addition to antioxidant and anti-inflammatory effects.
In people with Alzheimer’s, several studies have shown that your cognitive abilities improve on a ketogenic diet. In healthy people, the combination of a ketogenic diet and supplementation of medium chain fatty acids (MCT oil derived from coconut) is able to induce ketosis more quickly. In an experiment with young people measures of mental performance improved within two weeks of increasing your ketones. In another experiment with healthy older people, a single ketogenic (very low-carb) meal supplemented with MCT was enough to improve their cognitive abilities.
The ketogenic diet is not recommended for people who have liver disease or thyroid problems, and it can be difficult for others to manage. However, there is another way to get your brain going on ketones: fasting.
Do I fast to think better?
Controlled fasting, like intermittent fasting, has been shown to have a host of health benefits, from weight loss to anti-aging to improved immunity. But is fasting capable of increasing cognitive abilities?
Studies to date have found very positive effects of intermittent fasting on cognition and symptoms in people with neurodegenerative diseases. Animal studies have shown that intermittent fasting, with periods of between 12 and 48 hours without eating, protect against Parkinson’s disease, ischemic stroke, autism spectrum disorder, and mood and anxiety disorders.
One of the explanations for these positive effects is its effect on the intestinal microbiota. intermittent fasting promotes the diversity of intestinal bacteriawhich protects against inflammation that causes metabolic diseases, mental disorders and neurodegenerative diseases.
But can intermittent fasting improve the mental capacity of healthy people? The results of the studies are not so clear. In a recent review it was found that there were experiments in which they did improve and others in which there were no changes.
The key seems to be, interestingly enough, in ketosis. Intermittent fasting 16:8, where you can eat for 8 hours each day and fast the rest of the time, including sleeping, may not be enough to increase ketone levels sufficiently.
Some of these experiments were done with people who abruptly went from eating every day to fasting. Because they weren’t used to it, they were more likely to feel hungry, and feeling hungry interferes with cognitive abilities. Instead, when the body enters ketosis, the feeling of hunger is suppressed.
The feeling of hunger disappears when intermittent fasting is practiced for a longer time, which indicates that the body has become accustomed to using ketone bodies and enters ketosis more easily. Physical exercise also helps. In experiments it has been seen that people who did intermittent fasting on alternate days and added regular exercise found it easier to control their diet.
Current research is focusing on the prevention of neurodegenerative diseases. Combining fasting with a ketogenic diet and ketone supplements, such as MCT oil, appears to increase memory and cognitive abilities in people with mild cognitive impairmenta disorder that often precedes dementia.
What is all this based on?