You’re probably well aware that men have a shorter lifespan than women, and that Black men have a shorter lifespan than men of other races, but do you know why that is? Scientists have unearthed a possible reason why men tend to die at younger ages than women.
The research is the latest to look at the phenomenon of “mosaic loss of Y” — where the Y chromosome disappears from a portion of a man’s blood cells.
Researchers do not know why it happens, but it is associated with aging: It’s detectable in an estimated 40% of 70-year-old men, and more than half of those who live into their 90s.
At one time, researchers thought that losing Y — a small, stumpy chromosome — was just a part of normal aging.
But in recent years, studies have linked Y loss to increased risks of conditions like Alzheimer’s, heart disease and certain cancers, as well as a shortened life span.
Those studies, however, could not show whether the chromosome loss directly contributes to diseases, or is merely a sign that other body processes are going awry.
“The question is, is loss of Y simply a marker of aging, like graying hair?” says study co-author Kenneth Walsh.
His team’s findings suggest the answer is no: In lab mice, loss of Y in blood cells made heart tissue prone to scarring and led to an earlier death.
It’s evidence that the chromosome loss is a direct player, not just a bystander, according to Walsh, who directs the Hematovascular Biology Center at the University of Virginia School of Medicine.
Most people know the Y chromosome as a sex chromosome: Women have two X chromosomes, while men have an X and a Y.
Researchers used to think the Y chromosome did little more than determine male sex characteristics. But studies in recent years have found