Why Women May Live Longer Than Men
Meanwhile, a team of scientists at the University of California San Francisco (UCSF) may have found a genetic reason why women tend to outlive men. Their research suggests that the X chromosome—of which women have two—plays a crucial role in brain aging.
Traditionally, scientists believed that only one X chromosome in women was active, while the other remained dormant. However, studies on lab mice suggest that this “silent” X chromosome actually reawakens later in life, potentially providing cognitive benefits.

Dr. Dena Dubal, senior author of the study, explained: “In typical aging, women have a brain that looks younger, with fewer cognitive deficits compared to men. These results show that the silent X in females actually reawakens late in life, probably helping to slow cognitive decline.”
Scientists found that around 20 genes from the silent X became active in older female mice, including one called PLP1, which supports myelin production—essential for brain cell communication. When researchers boosted PLP1 in both male and female mice, they saw improvements in memory and learning abilities.
This discovery could explain why women’s brains show more resilience against aging. Lead researcher Margaret Gadek noted: “We immediately thought this might explain how women’s brains remain resilient in typical aging because men wouldn’t have this extra X.”
Dr. Dubal further emphasized the significance of these findings, suggesting that studying the X chromosome could lead to new treatments to slow cognitive decline for both men and women.

Looking Ahead
With groundbreaking insights into longevity and brain health, scientists are hopeful that genetic and lifestyle factors could one day be used to extend lifespan and improve cognitive function in old age. Could this research pave the way for future interventions that slow the effects of aging?