Obesity Can Cause Fertility Problems

There’s been a dramatic increase in obesity in the U.S. over the past 20 years, and a new study from researchers in Scotland suggests obesity might be inhibiting men’s fertility. Past studies have shown that this is the case with women, and this new study, which looked at sperm samples from 5,000 men and divided them into groups based on the Body Mass Index, found that those with a normal BMI (20 to 25) had higher levels of normal sperm than those who were overweight or obese. Underweight men also had fewer normal sperm, “but there were not many underweight men in Scotland,” said Ghiyath Shayeb, the lead researcher. He and his team have a couple ideas about what could cause the issues in overweight men, and they either think fat tissues influence the metabolism of sex hormones, or the increase in fat may cause a rise in body temperature and result in overheating. Sperm is best produced at a temperature two degrees cooler than the normal body temperature — who knew? [CBS News]