Male factor infertility accounts for almost half of infertility cases among couples trying to conceive.1 Various foods have been associated with and traditionally used for boosting fertility both in men and women, but scientific evidence is still lacking at large.
Being incredibly rich in macro- and micronutrients, nuts are an interesting object of scientific research. In fact, another 2019 study conducted in Spain showed that eating nuts can improve men's sexual function in healthy men and reduce the risk of developing erectile dysfunction later in life.2
This study focused on determining if eating walnuts can improve semen parameters and male fertility.
Researchers from the Los Angeles' University of California and the Cedars-Sinai Medical Center conducted this two-arm, single-blinded, randomized clinical trial on men seeking medical help for male factor infertility.
Participants were 75 males aged 27 to 61 with body mass indexes (BMIs) ranging from 19.6 to 46.9 (normal to obese). After being randomly assigned to two groups, half of the men was instructed to complement their diet with 42 grams of walnuts per day, while the other half was given a daily nutritional supplement for male reproductive health.
Tested parameters, including blood samples, sperm concentration, sperm motility, and progressive motility, were measured before the study and after three months. A dietary assessment tool, ASA24, was administered at baseline, after two and three months. A fertility report was done at three months and after a year.
After three months, men consuming walnuts showed increased sperm motility and concentration, with no recorded changes in men taking nutritional supplements.
Improved sperm morphology was observed in both groups. To the publication date of this study, a portion of studied men underwent the 1-year follow-up, showing preliminary improvements in pregnancy rates in the walnut group.
What Does this Mean?
The results of this study show that walnut consumption helps improve sperm parameters, including motility, concentration, and morphology. This can be an important part of natural approaches to boost men's fertility through simple lifestyle changes.
Although some of the participants still await their 1-year follow-up, preliminary findings suggest that eating walnuts helps increase pregnancy chances for infertile men.
- Current Developments in Nutrition, Randomized Clinical Trial: Effect of Walnuts on Semen Parameters and Male Fertility, 2019
- Cleveland Clinic. (n.d.). Male Infertility. Retrieved September 24, 2020 from https://my.clevelandclinic.org/health/diseases/17201-male-infertility
- Nutrients. (2019). Effect of Nut Consumption on Erectile and Sexual Function in Healthy Males. A Secondary Outcomes an Analysis of the FERTINUTS randomized controlled trial. Retrieved September 24, 2020 from https://pubmed.ncbi.nlm.nih.gov/31248067/