Darwin’s theory of natural selection could be the explanation behind why men with higher sperm counts live longer lives

A comprehensive 40-year study carried out by five Danish researchers claims to have proven a link between the fecundity of men and their relative lifespans.

In the report ‘Good Semen Quality and Life Expectancy’, published on 27 July in the American Journal of Epidemiology, the team of Tina Kold Jensen, Rune Jacobsen, Kaare Christensen, Niels Christian Nielsen and Erik Bostofte studied 43,277 men who were referred to the Copenhagen Sperm Analysis Laboratory by doctors between 1963 to 2001.

The team’s conclusions were that they greater a man’s sperm count the longer he is likely to live, as mortality rates decreased as sperm concentrations reached a threshold of 40 million per millilitre.

The team was also able to account for cases where a man had a high potency but died relatively young.

‘The decrease in mortality among men with good semen quality was due to a decrease in a wide range of diseases and was found among men both with and without children,’ stated the report.  ‘Therefore, the decrease in mortality could not be attributed solely to lifestyle and/or social factors.’

The report added that ‘semen quality may therefore be a fundamental biomarker of overall male health’.

Rune Jacobsen told Politiken newspaper that the connection could well be primordial in nature.

‘We know for example that reproductive problems can already begin during the foetal stages, if there are problems with development of the precursors to the testicles. So we believe there’s something biological behind the findings. In other words, if you’re good at reproduction you’ve got a greater chance for survival,’ he said.

But even in cases of non-reproductive or foetal problems, the men in the study showing lower sperm counts had a greater predisposition to other illnesses, such as bronchial and intestinal ailments.

According to Jacobsen, however, the study does not prove that those having a low sperm count are headed for an early demise. The study indicates only that men having a strong sperm count generally live longer than the average Danish male.