Stefan Mileschin

The finding suggests that changes in how the brain uses energy over a person's lifetime proceed more gradually in women than they do in men. While researchers are unsure of the medical consequences, it may help explain why women tend to stay mentally sharp for longer. "Brain metabolism changes with age but what we noticed is that a good deal of the variation we see is down to sex differences," said Marcus Raichle, a neurobiologist at Washington University school of medicine in St Louis. "If you look at how brain metabolism predicts a person's age, women come out looking about four years younger than they are."

The scientists used a brain scanning technique called positron emission tomography to measure the flow of oxygen and glucose in the brains of 121 women and 84 men aged 20 to 82. The scans revealed how sugar was being turned into energy in different parts of the volunteers' brains. To see how brain metabolism differed between the sexes, the researchers used a computer algorithm to predict people's ages based on brain metabolism as measured by the scans. First, the scientists taught it to predict men's ages from metabolism data gleaned from the male brain scans. The striking result came when the scientists fed metabolism data from the women into the same program. While the program estimated male ages accurately, it judged the women's brains to be, on average, 3.8 years younger than their real ages.

https://www.theguardian.com/science/...ns-study-finds