Unhealthy lifestyles do not affect the fertility of men and doctors’ advice to patients should be overhauled, claimed a University of Manchester study.
Recreational drug use, smoking, alcohol consumption and being overweight have all been accused of affecting a man’s sperm production but new research is challenging that.
The study, carried out between Manchester and Sheffield scientists, discovered that men who had testicular surgery, were of black ethnicity, worked in manual labour or wore tight-fitting underwear ejaculated low numbers of swimming sperm.
Dr Andrew Povey, from the University of Manchester’s School of Community Based Medicine, said: “This potentially overturns much of the current advice given to men about how they might improve their fertility and suggests that many common lifestyle risks may not be as important as we previously thought.
“Delaying fertility treatment then for these couples so that they can make changes to their lifestyles, for which there is little evidence of effectiveness, is unlikely to improve their chances of a conception and, indeed, might be prejudicial for couples with little time left to lose.”
The study was published in medical journal Human Reproduction, and used 2,249 men from 14 fertility clinics around the UK.
Researchers asked them to provide detailed answers about their lifestyles and this information was then compared between 939 men who ejaculated low numbers of swimming sperm and a control group of 1,310 men who produced higher numbers.
In assessing male fertility, the team chose to use the number of swimming sperm men ejaculated because this broadly correlates with how fertile a man is likely to be and also often determines the type of fertility treatment that may be used if required.
Dr Allan Pacey, Senior Lecturer in Andrology at the University of Sheffield and part of the study team, said: “In spite of our results, it’s important that men continue to follow sensible health advice and watch their weight, stop smoking and drink alcohol within sensible limits.
"But there is no need for them to become monks just because they want to be a dad. Although if they are a fan of tight Y-fronts, then switching underpants to something a bit looser for a few months might be a good idea!”