Ketogenic diet may protect the aging brain

The proposed benefits are based on a change in energy metabolism. Normally, brain cells obtain energy from glucose, but in neurodegenerative disorders, the ability of neurons to absorb glucose is often impaired. A ketogenic diet shifts the body to a fat-based metabolism, causing the liver to produce ketone bodies (acetone, beta-hydroxybutyrate, and acetoacetate). These compounds can cross the blood-brain barrier and serve as alternative fuel for the brain, helping to maintain ATP levels and reducing the risk of neuronal damage and death.

In addition to providing energy to the brain, the ketogenic diet also affects other key processes. It can activate autophagy, a mechanism that helps cells eliminate damaged structures and toxic protein aggregates that accumulate during neurodegeneration. Additionally, the ketogenic diet reduces oxidative stress by producing fewer free radicals compared to glucose metabolism. Another important aspect of the ketogenic diet is its impact on the gut microbiome. Diet can change the ratio of bacteria, for example, by increasing the proportion of certain beneficial microorganisms, such as lactobacilli, and reducing the number of those associated with inflammation. Since there is a close biochemical connection between the gut and the brain, these changes can help to reduce neuroinflammation.

Clinical observations have shown some positive effects. Patients with Alzheimer’s disease have experienced improvements in memory, daily activities, and quality of life without any serious adverse reactions. In Parkinson’s disease, people have reported increased energy levels, reduced fatigue, and improved motor function. However, data on the ketogenic diet in multiple sclerosis is limited, and it is too early to draw definitive conclusions.

The history of the ketogenic diet dates back to 1921, when American physician Russell Morse Wilder proposed it as a treatment for drug-resistant epilepsy in children. Over time, interest in the diet expanded, and it began to be studied in the context of neurodegenerative disorders. However, a significant amount of evidence still relies on preclinical models and small clinical studies, and the long-term effects remain poorly understood.

Following a ketogenic diet comes with a number of challenges. Many people find it difficult to maintain this type of diet for an extended period due to its strict focus. Headaches, fatigue, nausea, and dizziness are common early on, known as the “keto flu.” Long-term effects may include deficiencies in B vitamins, magnesium, and fiber, as well as risks to the cardiovascular, renal, and skeletal systems. There are also direct contraindications: the diet is not recommended for people with type 1 diabetes, liver and kidney failure, cardiovascular diseases, pregnancy, lactation, and a number of other conditions. In addition, the effect of the diet on the microbiome is not always clear-cut — some studies have described potentially adverse shifts in the composition of intestinal bacteria.

However, large-scale and long-term studies are needed to make confident conclusions. It remains to be seen what the long-term safety and efficacy of the diet are, what the optimal dietary regimens are, how individual responses vary, and how significant the contribution of microbiome changes to the neuroprotective effect is.

Therefore, the ketogenic diet is of scientific interest as a way to support brain energy metabolism and reduce risk factors for neurodegeneration, but its use requires careful evaluation and mandatory medical supervision.