"If we could predict which men have an increased risk, we could watch them closely for the development of disease and also use appropriate preventive treatments.

“In short, the widespread use of testing could radically decrease male mortality rates, and even perhaps eliminate the difference in life expectancy between the sexes."

In humans each cell contains 23 pairs of chromosomes, 22 of which look the same and are called autosomes, and a 23rd pair which are the sex chromosomes. Women have two copies of the X chromosome, while males have one X and one Y chromosome.

It has been suggested that women live longer because they do not have a Y chromosome to lose. The average man in Britain lives until 79.5 while women can expect to live to 83.2.

The loss of the Y chromosome - known as LOY- is known to affect up to 20 per cent of men who are aged over 80, and is the most common genetic mutation acquired during a man's lifetime.

The team studied more than 3,200 men with an average age of 73 and found 17 per cent of them showed LOY in blood cells, which increased with age.

Those with an existing diagnosis of Alzheimer's disease (AD) had a higher degree of LOY, and LOY was also a marker for the likelihood of developing the disease during the follow-up period.