What are the memory benefits?

Normally, the body transforms carbohydrates, lipids and proteins into energy which will supply vital organs, including the brain. The digestive and nervous systems are the two systems that require the most energy. “When you deprive yourself of food, the digestive system needs less energy. Thus, there is more energy available for the brain“, explains Mickael Dieleman, dietitian. In order not to run out of energy, the body will develop mechanisms allowing it to tap into these internal resources. During a fast, the production of a protein called BDNF (brain-derived neurotrophic factor) is favored in the same way as when playing sports. “This protein allows the cell generation of the brain.“BNDF acts on neurons in the hippocampus, cortex, and forebrain, which are the parts of the brain that control memory.”It is then assumed that fasting can improve memory.”

What are the benefits on dopamine?

“Dopamine is a neurotransmitter that secretes a feeling of pleasure. It often occurs during a sweet food intake for example. But the downside is that the effect is short-lived and addictive. A priori, after a few days of fasting, the dopamine and serotonin produced in the blood would generate a pleasant sensation, allowing the body to feel better“, explains the dietitian.

What benefits on stress?

Fasting is a practice that requires taking a step back, refocusing, detoxifying and starting from scratch. Whether for religious reasons or to stop addictive habits such as excessive sugar, alcohol or coffee, “when you start a fast, there is a real desire to put oneself on the side of the active and stressful life of everyday life. In fact, fasting can indeed have benefits on stress“. Moreover, “a well-functioning brain influences the digestive system – which is considered to be a second brain – and vice versa”. A reassuring message is then sent to the nervous system. But according to Mickael Dieleman, if this process is interesting, it is however not necessarily viable in the long term because it is impossible to fast for too long.

Does fasting prevent Alzheimer’s disease?

More and more articles explain that fasting could prevent Alzheimer’s disease. This would be due to the BDNF protein secretion (see paragraph on memory above) which would help reduce the risk of dementia or memory loss. According to Mark Mattson, a neuroscientist at Hopkins University, a low level of BDNF could accentuate the onset of Alzheimer’s disease and depression. This other study scientist explains that “glucose is the main energy substrate of the brain. In Alzheimer’s disease, there appears to be a pathological decrease in the brain’s ability to use glucose. Neurobiological evidence suggests that ketone bodies are an effective alternative energy substrate for the brain in Alzheimer’s disease. (…) Iketone bodies are normally produced from fat stores as an alternative to glucose during periods of hypoglycemia prolonged, such as during a fast or when very few carbohydrates are consumed” A test carried out on twenty elderly people with Alzheimer’s disease then highlighted the fact that hyperketonemia would improve the cognitive functioning of people with memory disorders. And Mickael Dieleman to develop: “During a prolonged fast, the body needs glucose. It draws first on the glucose reserves present in the liver then uses fatty acids to convert them into ketone bodies and make energy.” The dietician remains very cautious, however: “Be careful not to generalize from one experience.“

Does fasting prevent Parkinson’s disease?

It has been very difficult to find studies on the effects of fasting on Parkinson’s disease. Especially since taking heavy treatments in the case of diseases such as Parkinson’s seem hardly compatible with certain types of fasting. However, in an article by The lifeProfessor Andreas Michalsen of the Berlin public hospital explains that “for patients with Parkinson’s disease, Alzheimer’s (…) the improvement is slight. But, overall, fasting proves to be a relevant therapeutic tool that strengthens immune defenses and brings both physical and emotional well-being“.

What are the dangers of fasting for the brain?

“Everyone is more or less sensitive to food and/or water deprivation. For some, prolonged fasting is unsustainable. If in the short term, the sensations are mainly fatigue, hypoglycemia, a decrease in concentration and a drop in blood pressure, on more long term, these phenomena can be aggravated. Loss of consciousness, muscle wasting as well as damage to certain vital organs are then possible..”

Thanks to Mickael Dieleman, dietitian.

Sources:
– Scientific studies “Effects of β-hydroxybutyrate on cognition in adults with memory impairment“, March 2004, ScienceDirect.
– “Fasting has good therapeutic results“, article published on July 3, 2019, La Vie.