Men who eat fatty foods may be harming their chances for fatherhood, researchers say.
Sperm samples from almost 100 men on a range of diets showed those with the highest total of saturated fat intake had lower semen counts and concentrations, according to the study published Wednesday by the journal Human Reproduction. Men who ate more omega-3 fatty acids, found in some fish and flax, had a larger amount of normal-shaped sperm, scientists said.
Infertility affects about 15 percent of couples, with men’s health linked to the issue 40 percent to 60 percent of the time, researchers said. While an earlier study showed an association between obesity and fewer healthier sperm, the new analysis looked at types of fats consumed among overweight individuals, said Jill Attaman, lead author.
“This is the first study to demonstrate such an association,” Attaman, an assistant professor of obstetrics and gynecology at Dartmouth Medical School in Hanover, N.H., said in an interview.
The study examined sperm samples and food surveys from 99 men, 71 percent of whom were obese or overweight, taken from 2006 to 2010 at Massachusetts General Hospital Fertility Center in Boston. Participants were asked how often in the past year they ate specific foods. Men in the top third of fat consumption had 43 percent fewer sperm and 38 percent lower sperm concentration than those in the lowest fat intake group.
A reduced sperm count and concentration can decrease the odds of fertilizing an egg, according to the Mayo Clinic. Having normal-shaped sperm, or morphology, is also important.
“There are a few clearly identifiable lifestyle modifications that can be made to optimize natural fertility, especially for males,” Attaman said.
Omega-3 fatty acids, a polyunsaturated fat, have been shown to benefit heart health, according to the American Heart Association. U.S. sales of fish and animal oil supplements containing omega-3 increased 11 percent to $1.1 billion in 2010 from the previous year, according to the Nutrition Business Journal.
Attaman said the study may be limited because participants self-reported their food consumption and the results must be matched in further research before a definitive association can be made between diets with fatty foods and sperm quality.
The study was funded by the National Institutes of Health. Preliminary results were presented at the American Society for Reproductive Medicine Annual Conference in 2010, Attaman said. She conducted the research while a clinical and research fellow at Massachusetts General and an instructor at Harvard Medical School.