Newest fertility treatment may be a diet

The newest low-tech fertility treatment may be a diet, researchers said on Wednesday after learning that obese men have more abnormal sperm and make less semen.

Their findings, presented at a meeting of the European Society of Human Reproduction and Embryology in Barcelona, Spain, add to recent research showing that obese women are more likely to be infertile.

"We felt that it was possible that male overweight might contribute to fertility problems, particularly since it is a known risk factor for problems in conceiving among women," said Dr. Ghiyath Shayeb of the University of Aberdeen in Scotland.

Their study of 2,037 men attending Aberdeen Fertility Centre showed that men with a normal body mass index, meaning they were neither overweight nor underweight, produced higher levels of normal sperm and more semen than those in the other groups.

"Other studies have suggested an association between male obesity and increased DNA damage in the sperm, which can be associated with reduced fertility as well," Shayeb said in a statement.

"Our findings were quite independent of any other factors and seem to suggest that men who are trying for a baby with their partners should first try to achieve an ideal body weight," he added.

He said his team will now compare conception rates between obese and normal men to see if the poorer semen quality correlates with reduced fertility.

"The mechanism for the relationship could be a number of things - different hormone levels in obese men, simple overheating of the testicles caused by excessive fat in the area, or that the lifestyle and diet that leads to obesity could also lead to poorer semen quality," Shayeb said.

"We just don't know the answer yet, but this is an important question that needs urgent attention."