Show me your sperm count and I’ll tell you how old you’ll be.

That, at least is a simplified version of the results of a major 40-year Danish survey published in the Americal Journal of Epidemiology.

“Semen quality may therefore be a fundamental biomarker of overall male health,” says the report titled Good Semen Quality and Life Expectancy prepared by teh Danish researchers Tina Kold Jensen, Rune Jacobsen, Kaare Christensen, Niels Christian Nielsen and Erik Bostofte.

“Men who have good sperm quality have a greater chance of surviving than other men,” says a co-author of the report Rune Jacobsen of the Research Unit for Epidemiology at the University of Southern Denmark.

DOCUMENTATION: See parts of the report here (external link)

Vast
The survey studied 43,277 Danish men who were referred to the Copenhagen sperm laboratory from 1963 to 2001 or until they died.

The conclusion was clear – men with a sperm count of over 40 million per millilitre had a 40 percent lower risk of dying during the survey period than men with under 10 million living sperm per millilitre.

Sperm behaviour is also important – the greater the number of sperm that behave normally, the better the man’s chances of a normal life.

For example - men with 75 percent normal and active sperm had a 54 percent lower risk of dying during the survey period than men who had only 25 percent.

Men without women
One of the first theories to explain the differences was that men with a low sperm quality had fewer children, which could suggest that they had been rejected as partners. Men who live alone are normally less healthy and therefore die earlier.

But the theory did not hold.

“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; therefore, the decrease in mortality could not be attributed solely to lifestyle and/or social factors,” the report says.

“So instead we surmise that there is something biological behind it all. That if you are good at reproducing, you also have greater chances of survival,” says Jacobsen.

The researchers, however, say that those with lesser sperm quality have no reason to panic as the survey cannot prove that they will live shorter lives than other Danish men – only that those with a good sperm quality live longer than the average Danish man.