These are the findings of a new study that shows healthy American men in their 20s and 30s who ate a 75g (2.5 ozs) packet of walnuts a day were able to increase the vitality, motility and structure of their sperm compared to counterparts who did not eat walnuts.
A report on the study appeared online on 15 August in the Biology of Reproduction journal’s papers-in-press section.
Infertility and subfertility is a common problem that affects about 70 million couples worldwide. Between a third and a half of cases are due to poor semen quality in the male partner, with scientists giving a number of reasons for this in industrialized societies: pollution, unhealthy lifestyles and the Western-style diet cited amongst them.
First author Wendie Robbins, of the University of California, Los Angeles (UCLA) and colleagues focused on the last of these, as they explained in their background information to the study:
“We tested the hypothesis that 75 gm of whole-shelled walnuts/day added to a Western-style diet of healthy young men would beneficially affect semen quality.”
75 g is about 2.5 ozs, equivalent to one of those small snack-style packs you can get in the supermarket.
Walnuts are rich in polyunsaturated fatty acids (PUFAs), which play an important role in maturing sperm and preserving the integrity of the membrane around the cell which in turn affects its ability to fertilize an egg.
In the Western-style diet, PUFAs are usually found in fish, fish oil supplements, flax seed and walnuts. Walnuts also offer an important source of linolenic acid (ALA), a natural plant source of omega-3.
For their study, which was partially funded by the California Walnut Commission, Robbins and colleagues enrolled 117 healthy men aged 21 to 35 who followed a Western-style diet.
The participants were randomly assigned to one of two groups: 58 were asked to avoid eating tree nuts, and 59 were asked to eat 75 g of walnuts a day.
The researchers picked 75 g because other studies have suggested this is enough to change lipid levels in the blood but not enough to make healthy young men put on weight…
Read more:Catharine Paddock Ph.D, Medical News Today