OK … so this has nothing to do with prostate cancer … but we couldn’t resist it … A paper just published on line in Biology of Reproduction suggests that eating walnuts actually does improve sperm quality in young males otherwise eating a pretty standard western diet!
Naturally the research has (once again) been funded through a grant from the California Walnut Commission, so it has to be looked at with a degree of skepticism. However, this study by Roberts et al. (the full text of which is available on line), based on a real, randomized, controlled study in more than 100 young males, does actually seem to demonstrate that — over a study period of 12 weeks — the 59 young men who were eating a daily “dose” of 75 grams of whole-shelled English walnuts had
- Better sperm vitality
- Better sperm motility
- Improvements in sperm morphology and
- Higher levels of ω3 and ω6 fatty acids
than the 58 young men men who continued their usual diet but were asked to avoid eating any type of tree-grown nut.
Now whether eating walnuts can be expected to have similar effects in men over 50 years of age is untested … but for those readers who are hoping to become grandparents (or great-grandparents) in the near future, the implications for the diets of your sons, grandsons, sons in law, and grandsons in law may be important!
Of course it is perfectly possible that eating almost any type of tree-grown nut may have a similar effect: almonds, cashews, brazil nuts, peanuts, beech nuts, filberts (a.k.a. hazelnuts), chestnuts, macadamia nuts, pistachios, you name it. (We suggest leaving the acorns and the horse chestnuts to the squirrels.)
We feel obliged to point out that (as yet) there is no specific evidence that the eating of nuts by young males is associated with an increased probability of healthy live births among their female partners. Perhaps the California Walnut Commission will be investing further in such research.