DENVER—Sperm quality may be related to the amount of dietary fat that men consume, according to researchers.
The finding is based on a study of 91 men attending The Massachusetts General Hospital Fertility Center in Boston. Subjects had manual and computer-aided semen analyses and completed a food frequency questionnaire assessing their intake of fats and fatty acids. A subgroup of men also had the fatty acid levels in their sperm and seminal plasma measured.
Compared with men in the lowest tertile of saturated and monounsaturated fat consumption, those in the highest tertile of these fats had 41% and 46% fewer sperm, respectively.
“We did see statistically significant differences between dietary fats and semen quality parameters,” said study investigator Jill Attaman, MD, a reproductive endocrinology and infertility fellow at Massachusetts General. “If a man has marginal sperm concentration, such as 25 million per mL, it could make a difference. I think you could say that males with those parameters may be the most influenced.”
Dr. Attaman, who presented the study findings at the American Society of Reproductive Medicine annual meeting, said fatty acid levels in sperm and seminal plasma were measured using gas chromatography in a subgroup of 21 men. The investigators adjusted for total energy intake, age, abstinence time, body mass index, smoking status, and caffeine and alcohol intake.
Overall, total fat intake was inversely related to sperm concentration and this association was driven by intakes of saturated and monounsaturated fats. Levels of saturated fatty acids in sperm were inversely related to sperm concentration, but saturated fat intake was unrelated to sperm levels in the subgroup. Higher intake of omega-6 polyunsaturated fats was associated with greater sperm motility. Higher intake of omega-3 polyunsaturated fats was related to more favorable sperm morphology.
“There are few modifiable lifestyle factors available for [infertile] males to adopt, and there is an emerging body of literature that does show that specific nutritional parameters can influence semen quality,” Dr. Attaman said. “Our study adds to that.”
Although further study is needed, it is not too soon for urologists to counsel their infertile male patients to try to follow a low-fat diet. “This is the first study to show this association and other investigators will need to reproduce these findings before making firmer recommendations for patient care,” Dr. Attman said. “Our findings are consistent with those for other diseases, such as heart disease. Adapting these lifestyle modifications may not only be beneficial for reproductive health, but for global health as well.”