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A pack of walnuts a day will protect you from going to the reproductologist
Last reviewed: 01.07.2025
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Eating 75 grams of walnuts daily improves sperm viability, motility and morphology in healthy men aged 21 to 35, according to a paper published Aug. 15 in Biology of Reproduction's Papers-in-Press.
Approximately 70 million couples worldwide suffer from subfertility or infertility, with the man being at fault in 30-50% of these cases. Some studies have shown that in industrialized countries, the quality of human semen has deteriorated, and that pollution, bad habits, and the Western diet may be to blame.
Dr Wendy Robbins and colleagues at the University of California, Los Angeles, decided to investigate whether semen quality in men who follow a Western diet would improve if they increased the amount of polyunsaturated fatty acids, which are responsible for semen maturation.
If you follow a Western diet, it is important to know that the highest amounts of polyunsaturated fatty acids are found in fish, fish oil supplements, flaxseed and walnuts, the latter of which are rich in linolenic acid, a natural source of omega-3.
Dr. Robbins' team, with support from the California Walnut Commission, recruited 117 healthy men aged 21 to 35 who were eating a Western diet and divided them into two groups: those who would not eat tree nuts (58 men) and those who would eat 75 grams of walnuts a day (59 men). Previous research has shown that 75 grams of walnuts is the dose that will alter blood lipid levels but will not cause healthy young men to gain weight.
Before and 12 weeks after the experiment, the men's semen quality was examined according to generally accepted parameters of male fertility, including sperm concentration, viability, motility, morphology, and chromosomal abnormalities.
After 12 weeks, the team found no significant changes in body mass index or activity levels in either group. However, the men who ate walnuts had significantly higher levels of omega-6 and omega-3 fatty acids and improved sperm viability, motility, and morphology. The men who ate walnuts also had fewer chromosomal abnormalities. On the other hand, there were no changes in the second control group.
Although a study has shown that eating 75 grams of walnuts a day can have a positive effect on the quality of a young man's semen, it is still not known whether this finding will be used to address fertility issues in young men and whether it will help increase fertility.