What this means is that men's brains do not age faster, they simply have a bit older brains, to begin with.
"Ultimately, many studies keep showing that the differences between any two people tend to be negligible, and that the power of this type of study is in looking at large numbers of brain scans". But she cautions that even though women'sbrain metabolism is higher overall, some women's brains experience a dramatic metabolic decline around menopause, leaving them vulnerable to Alzheimer's.
"We're just starting to understand how various sex-related factors might affect the trajectory of brain aging and how that might influence the vulnerability of the brain to neurodegenerative diseases", lead scientist Manu Goyal told the Independent.
The team trained an AI algorithm to guess people's ages based on the amount of oxygen and glucose flowing through their brain. But as people age, their brain undergoes a reduction in aerobic glycolysis, which reaches very low levels by the time they are in their 60s.
In the study published in the journal Proceedings of the National Academy of Sciences, researchers studied 205 people to figure out how their brains use sugar. "For each person, we determined the fraction of sugar committed to aerobic glycolysis in various regions of the brain", Goyal said. One explanation could be that the genes involved in energy use could be less impacted by age in women, or that women don't experience the same loss of blood flow in the brain after puberty than men.
Then, the researchers added women's brain metabolism data into the algorithm and directed the program to calculate each woman's brain age from its metabolism. They used the women's data as a baseline, and estimated the men's ages based exclusively on their metabolism data. The findings are that the men's brains were 2.4 years older than their true ages.
Still, Goyal noted that the difference between men and women's brain ages was relatively small compared with other well-known sex differences, such as height.
Interestingly, the gap between men and women's brain ages was detectable even in young adults in their 20s.
"What we don't know is what it means".
"It's not that men's brains age faster - they start adulthood about three years older than women, and that persists throughout life", Goyal said. I think this could mean that the reason women don't experience as much cognitive decline in later years is because their brains are effectively younger, and we're now working on a study to confirm that'.
Goyal said that the researchers are now working on another study to test whether the findings play a role in why women don't experience as much cognitive decline as men.
To explore this next question, Goyal and his team are now expanding their research to evaluating the likelihood of adults' developing cognitive problems over time.
Exploding e-cigarette kills man by slicing artery
A United States government report says there have been 195 documented cases of exploding e-cigarettes between 2009 and 2016. Smoke and Vape DZ told CBS Dallas that Brown didn't buy anything, but wanted help using a Mechanical Mod style vape pen.
Sea lion video found on USB in frozen leopard seal poo
For more than a year a frozen slab of leopard seal poo, which is scientifically known as "scat", has sat in a Niwa freezer. The video shows the curious sea lions swimming about and approaching the kayak before darting off.