Walnuts May Help Fertility Health In Men

by | Oct 29, 2012 | 2012, Men's Health, Nuts and Seeds, Pregnancy and Lactation, Reproductive Health

Written by Greg Arnold, DC, CSCS. From a total of 117 men, those who ate walnuts had a 3.5 % higher increase in blood levels of omega-6 fats and a 4.5 % higher increase in blood levels of omega-3 fats than the control group. The walnut group also had significant increases of 5.5% in sperm vitality and 5.7% in sperm motility compared to control.

While most of the concerns over fertility focus on the 6.7 million women in the United States with reproductive problems (1), an estimated 25% of infertility among couples can be attributed to men in the form of diminished semen quality and other male factors (2). While the exact cause of diminished semen quality is poorly understood, factors affecting quality may include occupation (3), lifestyle (4), age (5) and diet.

Now a new study (6) suggests that walnuts may improve fertility health in men. In the study, 117 healthy men between the ages of 21 and 35 following a Western-style diet were given either 75 grams of whole-shelled walnuts per day (59 patients) or told to avoid eating any kinds of tree nuts in their diet (58 patients) for 12 weeks. The patients recorded past food intake history with a 2007 NCI diet history questionnaire (7) and 3-day food records (8) while random phone call interviews were conducted to assess study compliance twice per month during the 12 weeks. Semen and blood samples were collected before and after the study.

As expected, the walnut group showed a 3.5-fold higher increase in blood levels of omega-6 fats (2.8 vs. 0.78, p = 0.004) and 4.5-fold higher increase in blood levels of omega-3 fats (0.42 vs. 0.09, p = 0.003). This led to the walnut group having a significant increase in the vitality of sperm (defined as the number of live sperm per semen sample) compared to the control group (5.5% vs. 0.51% increase in vitality, p = 0.003) and a significant increase in the motility of sperm (defined as the number of sperm with normal movement) compared to the control group (5.7% vs. 0.53% increase in sperm with normal movement, p = 0.009). Finally, there was a significant increase the number of normally formed sperm per sample compared to the control group (1.1% vs. 0.1% increase, p = 0.03).

The decision to look at Western-style diets is their traditionally low intake of polyunsaturated fats, which have an adverse effect on sperm health (9).  For the researchers, “We found that 75 grams of walnuts per day added to a Western-style diet improved sperm vitality, motility, and morphology (normal forms) in a group of healthy young men when compared to a control group of men consuming usual diet but avoiding tree nuts.”

Source: Robbins, Wendie A., et al. “Walnuts improve semen quality in men consuming a Western-style diet: randomized control dietary intervention trial.” Biology of reproduction 87.4 (2012): 101.

© 2012 by the Society for the Study of Reproduction, Inc. This is an Open Access article, freely available through Biology of Reproduction’s Authors’ Choice option. eISSN: 1529-7268 http://www.biolreprod.org ISSN: 0006-3363

Greg Arnold is a Chiropractic Physician practicing in Hauppauge, NY.  You can contact Dr. Arnold directly by emailing him at PitchingDoc@msn.com or visiting his web site at www.PitchingDoc.com

References:

  1. “Infertility FastStats” from the CDC website.
  2. Templeton A (1995) Infertility—epidemiology, aetiology and effective management. Health Bull (Edinb) 53, 294–298.
  3. Kenkel S, Rolf C and Nieschlag E (2001) Occupational risks for male fertility: an analysis of patients attending a tertiary referral centre. Int J Androl 24, 318–326.
  4. Auger J, Eustache F, Andersen AG, Irvine DS, Jorgensen N, Skakkebaek NE, Suominen J,Toppari J, Vierula M and Jouannet P (2001) Sperm morphological defects related to environment, lifestyle and medical history of 1001 male partners of pregnant women from four European cities. Hum Reprod 16, 2710–2717.
  5. Eskenazi B, Wyrobek AJ, Sloter E, Kidd SA, Moore L, Young S and Moore D (2003) The association of age and semen quality in healthy men. Hum Reprod 18, 447–454.
  6. Robbins WA. Walnuts Improve Semen Quality in Men Consuming a Western-style Diet: Randomized Control Dietary Intervention Trial  . Biol Reprod 2012 Aug 15. [Epub ahead of print].
  7. NCI Diet History Questionnaire, Version 1.0, National Institutes of Health, Applied Research Program, National Cancer Institute, 2007.
  8. Treyzon L, Chen S, Hong K, Yan E, Carpenter CL, Thames G, et al. A controlled trial of protein enrichment of meal replacements for weight reduction with retention of lean body mass. Nutr J 2008;27:23.
  9. Wathes DC, Abayasekara DRE, Aitken RJ. Polyunsaturated fatty acids in male and female reproduction. Biol Reprod 2007;7:190-201.