(RxWiki News) According to the old adage, you are what you eat, but for men eating fatty foods, their diets may be affecting their sperm counts too.
A new study reveals that the amount and types of fat consumed by men may be associated with the quality of their semen.
"Limit fatty foods and consume more unsaturated fats than saturated ones."
In a study led by Jill Attaman, of Vincent Obstetrics and Gynecology at Massachusetts General Hospital and Harvard Medical Center, researchers looked at the diets of 99 primarily Caucasian American men who attended a fertility clinic between 2006 and 2010.
About two thirds of the men had never smoked, and 71 percent were overweight or obese. The men were classified according to how much fat they consumed.
The researchers then measured the concentration of the semen and overall sperm counts of 23 of the men. While sperm count is the total number of sperm in one ejaculation, concentration refers to number of sperm per a specified unit amount.
"Normal" sperm count is at least 39 million, and "normal" concentration is at least 15 million per milliliter, according to the World Health Organization.
The researchers found that men who consumed the most fat - those in the upper third of fat intake - had 43 percent lower sperm count and 38 percent lower sperm concentration than men in the lowest third of fat consumption.
Much of the association held true primarily for saturated fats: those consuming the most saturated sats had 35 percent lower sperm counts and 38 percent lower sperm concentrations than men eating the least saturated fats.
"The magnitude of the association is quite dramatic and provides further support for the health efforts to limit consumption of saturated fat given their relation with other health outcomes such as cardiovascular disease," Attaman said.
The men who had higher intakes of omega-3 fatty acids had modestly better (1.9 percent) sperm counts than men in the lowest third of eating omega-3s. Omega-3 fats are those found in fish and plant oils.
Because this study was small, the researchers warned that more research is necessary before determining the impact fat in a man's diet might affect his fertility.
"In the meantime, if men make changes to their diets so as to reduce the amount of saturated fat they eat and increase their omega-3 intake, then this may not only improve their general health, but could improve their reproductive health too," Attaman said.
Past research looking at men's body mass index and semen quality have been inconclusive. While this study is small, it's still the largest known study to look specifically at any connection between dietary fat and male fertility, according to the authors.
Another limitation of the study is that the questionnaires on the men's diet may not accurately reveal how much precise fat intake the men actually have.
The study appears in the journal Human Reproduction and was funded by grants from the National Institute of Environmental Health Sciences and the National Institute of Diabetes and Digestive Kidney Diseases. The authors reported no conflicts of interest.