(NaturalNews) Eating a couple of handfuls of walnuts a day can improve the health of sperm, according to new research just published in the medical journal Biology of Reproduction.
According to the study, sperm shape, movement and overall vitality improved in men who added walnuts to their diets over the course of 12 weeks, the BBC said in detailing the study's findings.
Fatty acids found in walnuts are believed to have aided in sperm development, the study said, though it wasn't clear if they contributed to improving male fertility. About one in six couples are infertile, according to separate research, with 40 percent of those due to a male deficiency.
"It would be relatively easy to poke fun at studies like this, but there is increasing evidence to show that aspects of a man's diet can affect the number and quality of sperm produced by his testicles," said Dr. Allan Pacey, senior lecturer in andrology at the University of Sheffield in England, told the BBC.
Scientists said the next step in researching the findings would be to work with couples who are currently attending fertility clinics, to see if placing men with fertility issues or those with poor semen qualities, into a walnut-enriched diet would result in high conception rates.
No fooling - Walnuts
The study by UCLA's Fielding School of Public Heath involved 117 men between the ages of 21 and 35 who were divided into two groups. One of the groups added 2.6 ounces of whole-shelled walnuts to their daily diets, while members of the second group continued their same diet but avoided tree nuts.
Both groups ate typical Western-style fare.
"We found a significant improvement in sperm parameters in the group that consumed the walnuts," said Prof. Wendie Robbins, lead author on the study. "The men who ate no tree nuts saw no change."
Robbins added that sperm quality improved overall, in terms of concentration, shape, vitality and chromosome abnormalities.
"The study has been well executed and my only criticism would be that the men in the walnut-eating arm of the trial could have altered other aspects of their behavior to give the results shown in the paper," Pacey said.
"A better trial would be to produce tablets of walnut extract that looked identical to a placebo so that the study was completely blind," he continued. "In spite of this, the results of the study show a small but statistically significant improvement in sperm health."
Researchers believe the fatty acids in the nuts were largely responsible for the positive results.
"Walnuts provide a particularly rich source of a-linolenic acid, a natural plant source of omega-3, which we suspect may have been responsible for the improvements we observed," said co-author Catherine Carpenter, from the UCLA Center for Human Nutrition.
The study was funded by the UCLA Fielding School of Public Health's Center for Occupational Environmental Health, and it utilized walnuts from the California Walnut Commission, the BBC noted.
Earlier studies contain similar results
Earlier studies have noted that diet can affect sperm count.
For instance, one study of 99 men who were patients at a fertility clinic in the U.S. found that higher consumption of so-called "junk food" can lower sperm quality, while increased consumption of Omega-3 fatty acids improved quality.
"The magnitude of the association is quite dramatic and provides further support for the health efforts to limit consumption of saturated fat given their relation with other health outcomes such as cardiovascular disease," said Prof. Jill Attaman from Harvard Medical School in Boston, who led the study, the results of which were published the journal Human Reproduction.
Men who had higher fat intakes had a 43 percent lower sperm count and 38 percent lower sperm concentration, compared to men who ate the least junk-food fat, the study found.