Walnuts Improve Semen Quality in Men Consuming a Western-Style Unhealthy Diet

It is well-documented that maternal food habits and essential nutrient intakes have an important impact on reproductive outcomes.[1, 2] However, there is less information available on the importance of nutrition for paternal reproductive fitness. Evidence is particularly limited for men who habitually

Consume a Western-style unhealthy diet which is lacking in many essential nutrients and omega-3 fatty acids, which are needed for healthy sperm and fertility.[3-13] Omega-3 fatty acids are especially important for proper sperm morphology and function.[5, 6, 8, 9]

 

Raw unprocessed walnuts are a rich source of essential nutrients and provide an array of health promoting phytochemicals, including carotenoids, phenolic acids, phytosterols and polyphenolic compounds such as flavonoids, proanthocyanidins (PAC) and stilbenes.[14-18] Therefore, a study specifically investigated if in young men (age 21-35 yr old) habitually eating unhealthy, adding 75 g of whole-shelled walnuts per day would have an impact on semen quality...[19]

 

The primary endpoint evaluated with respect to efficacy of the walnuts was improvement in conventional semen parameters (sperm concentration, vitality, motility, morphology) and sperm aneuploidy (chromosome abnormalities) from baseline to 12 wk. These semen quality parameters provide clinical markers for male subfertility.

 

Results 

After 12 weeks, it was found that the group consuming walnuts experienced significant improvements in sperm vitality, motility, and morphology. Sperm count, vitality, motility and morphology (form), increased by 3%, 7.2%, 11% and 14.9% respectively. Further, in the walnut group, sperm aneuploidy was significantly decreased. Specifically, decreases were seen in sex chromosome disomy and in sperm missing a sex chromosome. 

 

At week 12, Content of the omega-3 fatty acid ALA (alpha-linolenic acid) in sperm membranes was inversely correlated with the proportion of sperm missing a sex chromosome and percentage of

sperm with any numerical chromosomal abnormality, i.e. the greater the sperm content of ALA the smaller the likelihood of any chromosomal abnormalities.

 

No changes in any parameters were seen in the group continuing their usual unhealthy diet without eating nuts. 

 

Conclusion 

This study demonstrates that walnuts, when added to a typical unhealthy diet, improve sperm vitality, motility, and morphology.[19] The impact of nutrition on reproductive success has mostly been studied in women. However, as shown here, nutrition is of importance for men's reproductive fitness as well.

 

References:

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3.            Young, S.S., et al., The association of folate, zinc and antioxidant intake with sperm aneuploidy in healthy non-smoking men. Hum Reprod, 2008. 23(5): p. 1014-22.

4.            Fraga, C.G., et al., Ascorbic acid protects against endogenous oxidative DNA damage in human sperm. Proc Natl Acad Sci U S A, 1991. 88(24): p. 11003-6.

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19.          Robbins, W.A., et al., Walnuts improve semen quality in men consuming a Western-style diet: randomized control dietary intervention trial. Biol Reprod, 2012. 87(4): p. 101.