WASHINGTON, Feb 5, 2019 (BSS/AFP) – Women tend to outlive men and stay
mentally sharp longer, and a new study out Monday could explain why: female
brains appear on average about three years younger.
The study enrolled 121 women and 84 men, who underwent PET scans to measure
brain metabolism, or the flow of oxygen and glucose in their brains.
Like other organs in the body, the brain uses sugar as fuel. But just how
it metabolizes glucose can reveal a lot about the brain’s metabolic age.
Subjects ranged from their 20s to 80s, and across those age spans, women’s
brains appeared metabolically younger than men’s, said the findings in the
Proceedings of the National Academy of Sciences, a peer-reviewed US journal.
A machine-learned algorithm showed that women’s brains were on average
about 3.8 years younger than their chronological ages.
And when compared to men, male brains were about were 2.4 years older than
their true ages.
“It’s not that men’s brains age faster,” said senior author Manu Goyal,
assistant professor of radiology at Washington University School of Medicine,
St. Louis.
“They start adulthood about three years older than women, and that persists
throughout life,” said Goyal.
But why?
One theory is that hormones might begin shaping brain metabolism at a young
age, setting females on a pattern that is more youthful throughout their
lives, compared to men.
Scientists hope to find out if metabolic differences in the brain may play
a protective role for women, who tend to score better than men on cognitive
tests of reason, memory and problem solving in old age.
It “could mean that the reason women don’t experience as much cognitive
decline in later years is because their brains are effectively younger,” said
Goyal.
More work is underway to confirm and better understand the implications of
the research.