Men who lack the Y chromosome in their blood cells are at greater risk of being diagnosed with Alzheimer's disease, cancer and more.
Scientists at Uppsala University found that when men lose their Y chromosome later in life they become hundreds of times more vulnerable to developing the degenerative disease.
The researchers, who have published their findings in the American Journal of Human Genetics, believe that because women do not have a Y chromosome to lose they're less vulnerable to a range of different diseases.
It's believed that the Y chromosome is crucial for a male human's immune system to operate fully and without it the body struggles to fight back against cancerous cells or the amyloid plaques which then lead to Alzheimer's disease.
The breakthrough however has come in the form of a simple blood test which can reveal if a man is at risk from losing the Y chromosome.
If it transpires that they are, preventative measures can be put in place whether that's a lifestyle change or a course of targeted medication to help better protect the body against these new threats.
Prof Lars Forsberg of Uppsala University explains: "If we could predict which men have an increased risk of cancer, we could watch them closely for the development of disease and also use appropriate preventive treatments."
"In short, the widespread use of LOY testing could radically decrease male mortality rates, and even perhaps eliminate the difference in life expectancy between the sexes,"