The daily addition of 75 g of whole-shelled walnuts to a typical Western-style diet appears to have positive effects on the quality of a man’s sperm.

Evidence is particularly limited for men who routinely consume Western-style diets that may lack optimal nutrients and [polyunsaturated fatty acid] profiles needed for healthy sperm and fertility.

A recent study included 120 healthy men between the ages of 21 and 35 years who routinely consumed a Western diet. The men were equally divided into two groups: one receiving no walnut supplementation and the other group received walnut supplementation. After 12 weeks, the investigators found significantly improvement in the semen quality in the walnut group compared with the control group.

In addition, serum omega-3 and omega-6 fatty acid levels were significantly improved in the walnut group after 12 weeks.

The lead investigator, Dolores Lamb, PhD, director of the Center for Reproductive Medicine at Baylor College of Medicine in Houston, Texas, noted that walnut supplementation may represent a useful strategy for some men with fertility problems.  This simple dietary intervention could be easily recommended for men with poor sperm quality.

It is noteworthy that this study was funded through a grant from the California Walnut Commission.

For a full report see Biol Reprod. Published online August 15, 2012