By TIM HEARDEN
FOLSOM, Calif. - Couples struggling to conceive children might find some help in walnuts, recent research suggests.
A University of California-Los Angeles study found that eating 75 grams, or about 2.5 ounces, of walnuts per day can enhance fertility in men between 18 and 35 years old.
Research published in the recent issue of Biology of Reproduction Papers-in-Press reports that walnuts consumed each day improved the vitality, motily and normal forms of sperm in a group of healthy young men.
The findings may be of interest to the 70 million couples worldwide who experience sub-fertility or infertility, asserts the California Walnut Commission. In fact, as many as half the cases are attributed to the male partner, and in the United States the prevalence of men seeking help for fertility is as many as 4.7 million, according to national survey data.
"We were looking at walnuts and omega-3," said lead researcher Wendie Robbins, a professor at UCLA's schools of nursing and public health. "I read a study that looked at omega-3 in fish oil. They had given men supplements and they saw improved sperm parameters. I thought, what about the plant source of omega-3? Nobody had looked at that yet, and walnuts were the obvious choice."
The study adds a new facet to perceptions of the healthful qualities of walnuts, which in recent years have been found to have a role in preventing or fighting heart disease, cancer and diabetes, noted Dennis Balint, the California Walnut Commission's CEO.
"What it really does is solidifies our position that walnuts ought to be a part of your diet, really whether you're 25 or 75," Balint said. "It's a good, wholesome food."
The study found walnuts are an excellent source of alpha-linolenic acid (ALA), the plant-based omega-3 fatty acid. The study reported higher amounts of ALA correlated with less frequent abnormal cell sperm chromosome numbers which can result in genetic abnormalities such as Down syndrome, according to a news release.
In addition to ALA, walnuts have high antioxidant content as well as numerous micronutrients that may work synergistically, the researchers found. The findings weren't surprising considering the nutritious content of walnuts, asserted co-investigator Catherine Carpenter, an associate professor at UCLA.
For many years, most of the focus has been on the maternal diet with very little attention given to the paternal diet, Robbins said. However, that's changing, she said.
Robbins approached the California Walnut Commission with the idea for the study, she said. The commission provided walnuts and some funding, while UCLA also provided some funding, she said.
"One thing that interested me about walnuts is because I am in California and I know that walnuts are an important crop here in California," she said. "I know there are many family farms that produce walnuts. In that sense, I felt like this was an interesting thing to do."
Biology of Reproduction research paper: http://www.biolreprod.org/content/early/2012/08/07/biolreprod.112.101634.full.pdf+html?sid=fbd66b4a-a368-443f-9431-e379680f8933
California Walnut Commission: http://www.walnuts.org/walnuts/