New Study Finds Walnuts Improve Sperm Quality In Men

::Research published in the recent issue of Biology of Reproduction Papers-in-Press reports that 75 grams
(approximately 2.5 ounces) of walnuts consumed per day improved sperm vitality, motility, and
morphology (normal forms) in a group of healthy young men between 21-35 years of age. These
findings are of particular interest to the 70 million couples worldwide who experience sub-fertility or
infertility. In fact, 30 – 50% of these cases are attributed to the male partner, and in the United States
the prevalence of men seeking help for fertility is estimated at ~3.3 – 4.7 million[1].
This research suggests that walnuts provide key nutrients that may be essential in male reproductive
health. According to Professor Wendie Robbins, Ph.D., R.N., F.A.A.N., who led the research at the
University of California, Los Angeles, School of Nursing, “the positive finding of walnuts on sperm may
be a result of their unique nutrient profile.” Walnuts are the only nut that are an excellent source of
alpha-linolenic acid[2] (ALA) – the plant-based omega-3 fatty acid, and this study reported higher
amounts of ALA provided by walnuts correlated with less frequent aneuploidy or abnormal cell sperm
chromosome numbers which can result in genetic abnormalities such as Down syndrome.
In addition to ALA, walnuts have high antioxidant content, along with numerous micronutrients that Dr.
Robbins thinks may work together synergistically. Co-investigator and UCLA Associate Professor of
Medicine and Nursing Dr. Catherine Carpenter believes that “these findings are not surprising when you
look at the nutritious content of walnuts, however the results are amazing considering the impact they might have on men of all ages, including older men,
and men with impaired fertility.”
Throughout history, food has been linked with human reproductive success; however most of the emphasis has been on the maternal diet and very little
focus has been given to the paternal diet. According to Dr. Robbins, science is suggesting that a father’s diet not only impacts fertility, but can also influence
the health of the child and future generations. Citing a review of the science in this area, Dr. Robbins commented that, “diet is not just maternal territory
anymore.”[3] It appears the nutrition status of fathers can be passed down transgenerationally and affect the health of generations to come. “Healthy diet
and nutrition are essential for reproductive health,” commented registered dietitian and father Milton Stokes. Based on this research, he would advise his
male clients trying to have children to include walnuts in their diet on a daily basis to promote healthy offspring.
Improvements in cardiovascular risk factors and endothelial function from walnuts are well documented. The young men eating walnuts in the study
conducted by Dr. Robbins experienced improved blood lipid profiles which reinforces these previous studies and provides one more reason to include walnuts
in the daily diet.
This randomized, parallel two-group dietary intervention trial evaluated the effect of 75 grams of walnuts/day on semen quality. The study included 117
healthy young men who routinely eat a Western-style diet. Approximately half consumed the 75 grams of walnuts per day for 12 weeks, while the remaining
half served as the control group. After 12 weeks, compared to the control group, the walnut group experienced improvement in sperm vitality, motility, and
morphology – key components in male fertility.
For more industry information, health research and recipe ideas, visit www.walnuts.org.
California Walnut Commission
The California Walnut Commission, established in 1987, is funded by mandatory assessments of the growers. The Commission is an agency of the State of
California that works in concurrence with the Secretary of the California Department of Food and Agriculture (CDFA). The CWC is mainly involved in health
research and export market development activities.
Non-Discrimination Statement
The California Walnut Commission (CWC) prohibits discrimination in all programs and activities on the basis of race, color, national origin, age, disability,
sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an
individual’s income is derived from any public assistance programs. Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the CWC offices at (916) 922-5888. To file a complaint of discrimination, write to USDA,
Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). CWC
is an equal opportunity employer and provider.
The California Walnut Commission offices are located at 101 Parkshore Dr., Ste. #250, Folsom, CA 95630
[1] Anderson JE, Farr SL, Jamieson DJ, Warner L, Machaluso M. Infertility services reported by men in the United States: national survey data. Fertil Steril.
2009;91:2466-2470.
[2] Please note: One ounce of walnuts provides 18g of total fat, 2.5g of monounsaturated fat, 13 g of polyunsaturated fat, including 2.5 grams of alpha
linolenic acid – the plant based omega-3; 2g of fiber; 4g of protein, 3.68 mmol/28 g of antioxidants. (http://www.nal.usda.gov/fnic/foodcomp/cgi-bin/
list_nut_edit.pl)
[3] Nair KS, Irving BA, Lanza IR. Can dietary nitrates enhance the efficiency of mitochondria? Cell Metab. 2011 Feb 2;13(2):117-8.:::