Including nuts in a man's daily diet can help improve sperm quality and health. [Photo: Bigstock]

Handful of nuts each day could improve men’s fertility

5 July, 2018

Natural Health News — For men, eating nuts regularly could help improve fertility.

The benefits, which were seen after only 14 weeks of regular consumption, “support a beneficial role for chronic nut consumption in sperm quality” may reflect a need to develop dietary recommendations that are more “male specific”.

The results of the study are presented today at the annual meeting of the European Society of Human Reproduction and Embryology.

According to Dr Albert Salas-Huetos from the Human Nutrition Unit of the Universitat Rovira i Virgil in Reus, Spain, who led the study, the research was performed against a background of general decline in quantity and quality of human sperm, attributed in industrialised countries to “pollution, smoking, and trends toward a western-style diet.”

Quick summary

» Spanish researchers have found that men who include 60g of nuts in their daily diet have healthier sperm.

» The benefits of a nut diet extended beyond the usual parameter of sperm count, vitality, motility and morphology (shape) to changes in the integrity of the DNA of the sperm.

» This genetic factor could explain all the other benefits seen from the nut diet.

Significant improvements

The study was a 14-week randomised clinical trial in which 119 healthy young men aged 18-35 were allocated to either their usual western-style diet supplemented with 60 g/day of mixed almonds, hazelnuts and walnuts, or their usual western-style diet without nuts.

Results showed significantly higher levels of sperm count, vitality, motility and morphology (shape) in the men randomised to 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 (shape). These four parameters, explained Salas-Huetos, are all associated with male fertility.

These improvements were consistent with improvements found in other recent studies with diets rich in omega-3, antioxidants (eg, vitamin C and E, selenium and zinc), and folate. Nuts are dense foods containing many of these nutrients and other phytochemicals.

Benefits at the genetic level

The researchers, however also looked deeper into the DNA of the sperm to try and understand why the nuts might trigger these benefits. At the molecular level it has also been proposed that the genetic integrity of each sperm cell is essential for fertility. If DNA strands in the cell become damaged or fragmented, they will be unable or less likely to fertilise an egg and maintain embryonic development.

It is believed that this DNA fragmentation is caused by oxidative stress as a result of environmental and lifestyle factors.

In this study the men in the nut group also showed a significant reduction in their levels of sperm DNA fragmentation, a parameter closely associated with male infertility. The researchers propose that it is this change, at genetic level that is responsible for all the other benefits seen.

More to learn

The men in this study were generally healthy and exhibited no signs of infertility. The researchers say that a next step would be to look at the effects of regular nut eating on men with fertility problems.

Nevertheless Salas-Huetos concludes that “healthy lifestyle changes such as following a healthy dietary pattern might help conception – and of course, nuts are a key component of a Mediterranean healthy diet.”