Men who consume nuts may be helping the health of their nuts, according to a new study. The research out of Spain has found having a healthy mixture of tree nuts in the diet - including almonds, hazelnuts and walnuts - can help sperm quality and fertility.
The study was led by researchers from the Human Nutrition Unit at Rovira I Virgili University and compared the sperm quality of men who were fed a mixture of tree nuts over 14 weeks as a supplement to their standard Western diet, with those who weren't.
Those who ate the nut mix had significantly improved the sperm count, viability, motility (its ability to move independently) and morphology (length of the head and tail), they found.
Thanks to omega-3 fatty acids and B vitamins, nuts have previously been associated with fewer sperm abnormalities, but the study published in Andrology journal this week is the first hard evidence of its kind.
"This work demonstrates that there are some sensitive regions of the sperm epigenome that respond to diet, and which can result in changes in sperm and in its ability to fertilise," said study author Albert Salas-Huetos, who is now based at Harvard University.
"Adding nuts to a regular Western-style diet subtly impacts sperm DNA methylation in specific regions, demonstrating that there are some sperm epigenome regions that could respond to diet."
Drinking, drug use, and smoking are all associated with negative changes in sperm output, but the effects of diet have previously not been established.
The new revelations come after a study last year that found there was a significant general decline in men's sperm counts - about 1.6 percent a year - in North America, Europe, Australia and New Zealand between 1973 and 2011.