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Walnuts 'improve sperm health' in men, say researchers

A study on men consuming a ‘Western-style’ diet showed that eating 75gm of walnuts a day improved sperm vitality.

Image: Hermann J. Knippertz/AP/Press Association Images

WE ALL KNOW that walnuts are good for us – but did you know they could be particularly good for men?

A new study in the journal Biology of Reproduction suggests that men who want to boost their sperm could benefit from eating 75gm of whole-shelled walnuts a day.


The participants in the study were described as ‘healthy young men’ and the hypothesis was that eating the 75gm of walnuts would “beneficially affect semen quality”.

A randomised, parallel two-group tria,l with single-blind masking of outcome assessors, was conducted with 117 healthy men, age 21 – 35 years.

One group ate the walnuts as part of their regular diet for 12 weeks, while the other group avoided tree nuts.


The researchers concluded:

We found that 75gm 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. Improved semen quality was associated with increases in blood serum omega-6 FA and in the plant source of omega-3 (ALA) but not with other omega-3s.

The group consuming walnuts experienced improvement in sperm vitality, motility, and morphology and the group continuing their usual diet but avoiding tree nuts saw no change.

Serum fatty acid profiles also improved in the walnut group with increases in omega-6 and omega-3.

In the study, the added walnuts resulted in a changed serum FA profile for ALA, but not EPA and DHA, “suggesting the beneficial omega-3 effects on sperm from walnuts were related to the plant source of omega-3, ALA”.

The researchers said that whether adding walnuts to the diet will improve fertility outcomes for men will require further research.

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