Scientists have identified a new way of spotting men most at risk of ill health - by testing their semen.
The team found young men with the lowest sperm counts had higher rates of heart disease, diabetes and cancer later in life.
Researchers at Frederiksberg Hospital in Denmark tracked 4700 men for 30 years. Those with sperm counts lower than 15 million per millilitre of fluid were 40% more likely to get heart disease than those registering more than 40 million per millilitre.
They needed hospital care, on average, seven years earlier than men with healthy sperm counts, the results of the study, published in the American Journal of Epidemiology, showed. Low sperm count can reflect poor diet and lifestyle, which increases the risk of serious illness.