New research published in the journal Andrology has found a connection between nut consumption and sperm quality in men, revealing that those who added a mix of nuts to a Western-style diet for 14 weeks improved their sperm count and function. The dietary change altered sperm DNA methylation through epigenetics, which change what our cells code for (phenotype) without affecting the underlying DNA (genotype).
Lifestyle and environmental factors have long been associated with changes in sperm count and quality. External factors such as these are able to alter our cells through DNA methylation, which adds methyl groups to a DNA molecule, influencing its output for better or worse. Drinking, drug use, and smoking are all associated with negative changes in sperm output, but the effects of diet aren’t so well established.
This new research conducted a randomized clinical trial to investigate if and how the consumption of nuts altered sperm DNA methylation, in a trial named FERTINUTS. They took 72 healthy, non-smoking young men for the study, feeding the nut group of 48 participants a mixture of tree nuts including almonds, hazelnuts, and walnuts.
They then compared the rate of methylation in these participants against the control group of 24 participants who didn’t add nuts to their diet. Their results showed that neither group saw global changes in sperm DNA methylation, but the nut group demonstrated significant changes in 36 genomic regions from the start to the end of the trial, 97.2 percent of which displayed hypermethylation. There were no significant changes seen in the nut-free group.
A previous study in 2018 had found that the supplementation of a Western-style diet with walnuts, hazelnuts, and almonds improves sperm quality in healthy reproductive-aged men, and suggested these beneficial effects could be the result of a reduction in sperm DNA fragmentation or changes in DNA methylation. This new research shows that there are some sensitive regions of the sperm epigenome that respond to the consumption of tree nuts, altering sperm and its ability to fertilize.
Exactly which nutrients in the nuts act on the sperm’s methylation aren’t yet clear but the researchers highlight folic acid and genistein as possibilities. Whether the same effect can be achieved through supplements or if there are other potential health benefits from their consumption are areas they suggest warrant further investigation.
Did you know: Happy, healthy sperm is able to fertilize an egg by corkscrewing like an otter, not wiggling like an eel.