Why Men Have a Shorter Lifespan than Women: Loss of Y Chromosome Increases Cancer Risk

It's well known that men have shorter life expectancies than women--but why is that the case? A recent study has found that there's a correlation between a loss of the Y chromosome in blood cells and both a shorter life span and higher mortality from cancer in other organs.

In order to discover why men are more prone to developing cancer and living shorter lives, the researchers analyzed the DNA in blood samples from a group of more than 1,600 elderly men. They found that the most common genetic alteration was a loss of the Y chromosome in a proportion of the white blood cells.

"Men who had lost the Y chromosome in a large proportion of their blood cells had a low survival, irrespective of cause of death," said Lars Forsberg, one of the researchers, in a news release. "We could also detect a correlation between loss of the Y chromosome and risk of cancer mortality."

The Y chromosome itself is only present in men. Much smaller than the X chromosome, the Y chromosome contains genes that are mostly associated with sex determination and sperm production. Now, though, it looks as if the Y chromosome also holds other information that's crucial to a man's health.

"You have probably heard before that the Y chromosome is small, insignificant and contains very little genetic information," said Jan Dumanski, one of the researchers, in a news release. "This is not true. Our results indicate that the Y chromosome has a role in tumor suppression and they might explain why men get cancer more often than women. We believe that analyses of the Y chromosome could in the future become a useful general marker to predict the risk for men to develop cancer."

The findings are important for better understanding how to potentially help men at risk for developing cancer.

The findings are published in the journal Nature Genetics.