Sperm Quality Linked to Dietary Fat

Published: March 13, 2012

Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco.

Action Points

• Explain that men who consumed large quantities of dietary fat had significantly lower sperm production and concentration compared with men who had lower fat intake.
• Point out that higher intake of omega-3 fatty acids was associated with better sperm morphology.

Men who consumed large quantities of dietary fat had significantly lower sperm production and concentration than men who had lower fat intake, results of a clinical study showed.

Sperm count and concentration were about 40% lower in men whose diet derived 37% or more of calories as fat or 13% or more of calories as saturated fat, as compared with men who had less fat intake. The strength of the association increased after controlling for body mass index (BMI) and other lifestyle factors.

Higher intake of omega-3 fatty acids was associated with better sperm morphology, investigators reported online in Human Reproduction.

"Given the limitations of the current study, in particular, the fact that it is a cross-sectional analysis and that it is the first report of a relation between dietary fat and semen quality, it is essential that these findings be reproduced in future work," stressed Jill A. Attaman, MD, of Dartmouth-Hitch**** Medical Center in Lebanon, N.H., and co-authors.

Several lifestyle factors have been associated with male infertility, including smoking, heavy marijuana use, alcohol intake, cocaine use, and exposure of the testes to heat. Few studies have examined the impact of diet on men's reproductive potential, the authors wrote.

Some evidence has suggested that specific nutrients might affect semen quality, and studies in animals have indicated that dietary fat may influence male fertility, they continued.

Extending the animal research to humans, Attaman and colleagues studied 99 men participating in an ongoing study of environmental factors and fertility. All of the men had complete data on dietary and semen quality.

In a subgroup of 23 men, the investigators used gas chromatography to examine fatty acid levels in sperm and seminal plasma. Diet was assessed using a food frequency questionnaire (FFQ).

The study population had a mean age of 36, and 89% of the men were Caucasian. Additionally, 71% of the men were overweight (BMI 25 to 29.9) or obese (BMI ≥30), and two-thirds had never smoked.

Stratification of the men by tertiles of fat intake resulted in median cutoff values of 26%, 32%, and 37% of total daily caloric intake. Corresponding figures for saturated fat were 8%, 10%, and 13%.

The authors found that 41 of the men had normal semen parameters, whereas 12 had low sperm count (