Male Obesity and Infertility
Obese men need to lose weight if they want to have children states Dr. A Ghiyath Shayeb, from the University of Aberdeen, Aberdeen, UK, at the 24th annual conference of the European Society of Human Reproduction and Embryology July 9, 2008. Dr. Shayeb's research shows that men with higher body mass indexes (BMI) have lowered volumes of seminal fluid and higher numbers of defective sperm.
Shayeb and his colleagues reviewed the results of seminal fluid analyses of over 5000 men attending the Aberdeen Fertility Centre for infertility treatment. It was found that 2037 male patients at the center had complete data on their BMIs. This led the researchers to wonder if male obesity might be a contributory factor in infertility since obesity is already a known risk factor for female infertility.
Better and More Sperm
The scientists created four groups of men according to their BMIs, from those very underweight, to those with significant obesity. The researchers attempted to look for a relationship between obesity and semen quality while taking into account other factors such as alcohol intake, age, smoking, length of time between sexual encounters, and social deprivation. The men with optimal BMIs of between 20-25 percent had higher sperm counts, quality, and volume than those of the other groups. However, there was little difference between the four groups in terms of sperm concentration and motility.
Researchers did not investigate DNA damage to sperm, preferring to stick to the parameters of routine semen analysis, though Dr. Shayeb notes that other studies suggest an association between male obesity and DNA damage to the sperm and believes this may be another factor in reduced fertility.
"Our findings were quite independent of any other factors," said Dr. Shayeb, "and seem to suggest that men who are trying for a baby with their partners should first try to achieve an ideal body weight. This is in addition to the benefit of a healthy BMI for their general well being."
In most cases, leading a healthy lifestyle by eating a balanced diet and engaging in regular exercise, leads to a normal BMI. This new study proves that optimal body weight can lead to an improvement in sperm quality.
Researchers have seen a significant rise in the number of men with poor quality sperm but have not yet shown a link to male infertility statistics. Shayeb's team intends a follow-up study to compare the male BMI of both fertile and infertile couples to check for a correlation between poor semen quality and infertility.
Dr. Shayeb believes that research is needed on how obesity affects semen production. Possible theories are that obesity affects hormone levels, causes an overheating of the testicles, or just suggests an overall poor lifestyle leading to inferior sperm as well as obesity.