For men who are diagnosed with infertility, doctors often advise them to make lifestyle changes in order to boost their sperm production.
Men are told to cut smoking, alcohol and recreational drug use, and they are also warned about their weight and wearing tight underwear as limiting their sperm count.
However, new research from the Universities of Manchester and Sheffield in the UK have found that changing these habits and routines have little to no impact on the number of sperm that men produce.
“The issue is that often when male partners are attending fertility treatments, they are given advice on how to increase fertility – stop smoking, drop pounds.” Dr. Andrew Povey, the study’s lead author from the University of Manchester’s School of Community Based Medicine. “We found little evidence that these actually affect a man to be infertile or not. So we need to have a better understanding of those factors that do affect male fertility.”
Published in the journal Human Reproduction, Povey and his colleagues interviewed 2,249 men, 939 of which were classified as having low numbers of swimming sperm. After going analyzing detailed questionnaires, they found that those who had had testicular surgery were 2.5 times more likely to have low sperm counts, and men who wore boxer shorts were 1.3 times more likely to have low counts.
But when it came to the men’s accounts of smoking, drug or alcohol abuse, there was little correlation with their sperm numbers. The men’s body mass indexes (BMIs) also were not found to be linked to the sperm numbers either.
Povey said that even though their research did not establish a link, it’s very hard to show cause and effect when it comes to male fertility.
“It’s actually quite difficult to work out how to definitively prove if a substance did or didn’t cause male infertility,” Povey said. “If you wanted to show that smoking didn’t have an effect, you’d have to do a randomized trial.”
However, Povey hopes to expand on this research to search for other factors that may play a role in sperm production.
“It’s clear that there are some genetic factors that make a man fertile or not,” Povey said. “There are some suggestions that exposures in the room may subsequently effect if a man has lots of good sperm. Are there more generalized environmental exposures – such as using mobile phones or using laptops on your lap. It needs much more research.”
The current guidelines from the National Institute of Clinical Excellence warn men against smoking, drinking and drug use, as well as maintaining a good BMI to promote fertility, but Povey says the guidelines may mean nothing when it comes to boosting sperm. However, because the recommendations are needed for a healthy lifestyle, he doubts the Institute will change its policies.
“In one sense, it won’t make much of a difference,” Povey said. “The clinicians will say – on health grounds – to stop smoking, drinking, etc. But even if you do stop those things, it doesn’t mean it will improve your fertility because the evidence is that it won’t work.”