The media love sexy studies, and what could be sexier than nuts? According to a new study, walnuts help boost quality output from your own huevos. So should guys run to the store and start stuffing nuts in their mouths?
As many of those affected will tell you, infertility is no laughing matter. The work up and treatment for male and female infertility is expensive, difficult, and often frustrating. Finding ways to boost fertility could help many people fulfill their desire to have children. What causes infertility? Is it insufficient nut consumption?
Definitions of infertility are problematic. The most common definition is the inability of a married woman to conceive after a year of trying. Some agencies differentiate fertility from fecundity, which is the inability of any woman to get pregnant or to carry a baby to term. This leaves out a host of people who choose to conceive in other ways, but since this paper is about semen, we’ll stick to “fertility” for now.
Infertility in married couples is a “couples” problem. While we often read about women who are infertile, it is actually the couple who is having trouble conceiving (and to be more accurate, conception is an egg from one person fertilized by a sperm from another and successfully implanted in a woman; a problem can occur anywhere in the process.) About 40% of the time, the health of the male is a causal factor male-female couple infertility. While semen quality (however measured) affects fertility it’s not entirely clear how or to what extent.
With this knowledge we can start to tease apart the semen-nut study. It’s good, but not perfect (not placebo-controlled). It’s an interesting study looking at a difficult medical problem. It’s grounded in scientific plausibility. And it’s relevance is unknown. The best thing about this study, something often absent from sensationalist headlines is in the final paragraph:
Whether adding walnuts to the diet will go beyond the shifts in sperm parameters as seen in this study to improving birth outcomes for men within fertility clinic
populations or in the general population is not yet known and will require further research.
The authors explicitly acknowledged that their study does not show improved fertility. And while almost all studies conclude “further research is required,” in this case, maybe it truly is. Now if we could only implement better definitions of fertility.