Women brains are younger

Female minds seem to be "more youthful" from the beginning than male ones

There are detectable differences between men's and women's brains. © Jake Olimb / thinkstock
Read out

Gender difference: Women appear to have younger brains than men - at least as far as metabolic activity is concerned. Measured by this parameter, the thinking organs of women tend to be more youthful than the brains of men of the same age, as a study shows. This difference, surprisingly, manifests itself at an early age. He could explain why women in old age are less susceptible to cognitive decline.

The brains of men "tick" differently than those of women: for this well-known cliché, scientists have in recent years actually found time and again evidence. For example, women feel more stressed and more prone to depression. Men are more forgetful and suffer from age more often under mild cognitive disorders, as statistics show.

Energy metabolism in view

It is precisely this difference in memory that Manu Goyal of the Washington University School of Medicine in St. Louis and his colleagues have dedicated to. "According to one theory, women have more youthful brains than men, " the researchers write. But what's up to this thesis? In order to track down possible gender differences in brain age, they have focused on one important aspect of our mind: the metabolism.

Because it was already known: In the course of life, the utilization of the energy source glucose changes in the brain. Babies and children use much of this sugar compound for so-called aerobic glycolysis, a pathway essential to brain development and maturation. However, with increasing age, the amount of sugar used for this process becomes smaller and smaller. From the age of 60 years, hardly any sugar flows into the glycolysis.

Differences between man and woman

Based on this parameter can therefore close on the age of a person. The researchers used this fact for their study of 121 women and 84 men between the ages of 20 and 82 years. Specifically, they examined the minds of the subjects using positron emission tomography (PET). This allowed them to detect the amount of sugar added to aerobic glycolysis. display

With the results of the men Goyal and his colleagues finally fed a learning algorithm, which recognized in this way connections between brain metabolism and age. What would happen if the program trained in this way now evaluated the metabolic data of women?

Significantly younger - from the beginning

It turned out that the men-trained algorithm consistently protected the age of female subjects too young. The calculated age was on average 3.8 years below the actual age of the women. A similar effect was also revealed in the reverse approach. If the program was trained with the help of the women's data, the men were on average 2.4 years old.

"The calculated age difference between men and women is significant, " says Goyal. However, according to him, this difference can not be explained by the fact that man's brains age faster. Unfortunately, the metabolic age difference was already evident in the youngest study participants who were only in their 20s. It seems therefore to be a discrepancy that existed from the beginning.

Less prone to mental deterioration?

What does that mean? "We do not know that yet. However, it seems likely that women in old age are less affected by cognitive decline because their brains are effectively younger, "says Goyal. How exactly brain metabolism, aging and memory disturbances are connected and what role the sex plays in this, the scientists will investigate in the future in more detail.

"We're just starting to understand how gender-related factors affect the course of brain aging, " says Goyal. At the same time, however, he stresses that although the difference between men and women is clear, it should not be overstated. "This factor accounts for only a small fraction of the cognitive differences between any two individuals, " concludes the researcher. (PNAS, 2019; doi: 10.1073 / pnas.1815917116)

Source: Washington University School of Medicine / PNAS

- Daniel Albat