Just four pints of lager a week could harm a man’s chances of having a family, research suggests.
A study of healthy young men found that drinking just a little more than three pints a week, or half a pint a day, can reduce sperm quality and male fertility.
The researchers found the effects occurred when more than 7.5 units of alcohol a week – with the average pint of beer containing around 2.3 units.
However, many popular lagers are stronger than this.
For instance, a pint of Stella Artois lager contains 2.7 units – meaning that fewer than three pints a week may be harmful.
The study also found that the more a man drinks, the greater the toll on sperm and male fertility.
The Danish researchers said that given the large amounts of alcohol drunk by young men, their finding is a public health concern.
Around one in seven couples in the UK has trouble starting a family and male infertility is to blame in almost half of cases.
Some will remain childless, despite spending thousands of pounds on IVF.
The study, published in the BMJ Open journal, involved 1,200 military recruits aged between 18 and 28.
They were asked about their drinking habits and gave blood and sperm samples.
They had drunk 16 units on average the previous week and more than half had binged on booze or been drunk more than twice in the past month.
Boozing was linked to changes in reproductive hormones – and to the health of the men’s sperm.
The researchers found that for men who habitually drank heavily there was a clear link between alcohol intake and quality of sperm and male fertility.
The more a man drunk, the less sperm he made and the more abnormal it was in shape and size.
Drinking just a little more than three pints a week, or half a pint a day, can reduce sperm quality
Importantly, the effect was apparent after just 7.5 units a week – although it was particularly strong after 37.5 units a week.
The NHS advises that men don’t regularly consume more than 21 to 28 units of alcohol a week.
The University of Southern Denmark researchers said that they can’t be sure that alcohol is causing the damage.
For instance, it may be simply be that men with poor sperm are more likely to drink.
But they warned that even ‘modest’ amounts of booze may be harmful – and advised against ‘high habitual intake’.
However, going tee-total may not be the answer. The analysis also found that men who didn’t drink at all had poorer sperm than those who had a small amount. More research is needed to explain this.
Chris Barratt, professor of reproductive medicine at the University of Dundee, said: ‘I think the main message of this paper is clear – high levels of alcohol intake do appear to be associated with changes in sperm and semen that may affect fertility.’
Professor Sheena Lewis, of Queen’s University Belfast, described the results as ‘compelling’.
But Dr Allan Pacey, a male fertility expert at the University of Sheffield, said his own study of infertile men had failed to link boozing with sperm quality.
However, he said that binge drinking may be more harmful than consuming the same amount of alcohol over a longer period of time.
Source: Daily Mail