Scientists from Stony Brook University conducted a large-scale study involving 19,300 people and found that the first signs of brain aging become noticeable on average at 44 years of age.
It is at this age that the availability of energy for neurons begins to decrease, which subsequently leads to a deterioration in cognitive functions. The fastest rate of age-related changes is recorded at 67 years, and by 90 the aging process stabilizes.
The researchers named insulin resistance of neurons as the main reason for this phenomenon. During the experiments, it turned out that with age, brain cells respond worse to insulin, which is why they receive less glucose, the main source of energy. This leads to a deterioration in their work and disruption of signals between neurons. Also, an analysis of genetic data showed that brain aging is associated with GLUT4 and APOE proteins: the first is responsible for the absorption of glucose, and the second for the transportation of lipids. The latter has long been known as one of the risk factors for Alzheimer’s disease.
Scientists checked whether it is possible to slow down this process using alternative energy sources. To do this, a group of 101 people aged 40 to 80 years were given ketone supplements, which can compensate for the lack of glucose. The results showed that the subjects, especially in the 40-59 age category, had stabilized neurometabolic parameters. This means that timely intervention can indeed stop the destruction of neural connections and potentially reduce the risk of developing neurodegenerative diseases. The authors of the study note that their discovery may lead to a change in the strategy for preventing age-related cognitive decline. Instead of waiting for symptoms to appear, people at risk of accelerated brain aging can be identified in advance using metabolic markers and treatment can be started in time.