The inclusion of nuts in a regular diet significantly improves the quality and function of human sperm, according to results of a randomized trial. The findings, say the investigators, “support a beneficial role for chronic nut consumption in sperm quality.”
The study, presented at the European Society of Human Reproduction and Embryology, was performed against a background of general decline in quantity and quality of human sperm, attributed in industrialized countries to “pollution, smoking and trends toward a western-style diet,” the authors said.
The study was a 14-week trial in which 119 healthy young men aged 18-35 were allocated to either their usual western-style diet supplemented with 60 grams a day of mixed almonds, hazelnuts and walnuts, or their usual western-style diet without nuts. Results found significantly higher levels of sperm count, vitality, motility and morphology in the men in the 60 g/day nut diet than in those following their usual diets free of nuts. Improvements in the former group were by around 16% in sperm count, 4% in sperm vitality, 6% in sperm motility, and 1% in morphology. These four parameters are all associated with male fertility.
Moreover, the subjects in the nut group also showed a significant reduction in their levels of sperm DNA fragmentation, a parameter closely associated with male infertility. Indeed, it was this change in the level of DNA fragmentation in the sperm cells by which the investigators explained, at least in part, the improvement in sperm count, motility and morphology.
These findings were consistent with improvements found in other recent studies with diets rich in omega-3, antioxidants (such as vitamin C and E, selenium and zinc) and folate. Nuts are dense foods containing many of these nutrients and other phytochemicals.