There are many reasons why a man can have reproductive problems—from hormonal imbalances, use of certain medications and genetics to exposure to toxins in the environment or workplace, high heat (as in hot tub use), radiation, excess alcohol and smoking, all of which can impair sperm quality and/or production. But as the following recent studies found, a healthy diet and exercise may have reproductive benefits.
Walnuts may improve sperm quality in younger men, according to a study from UCLA funded by the California Walnut Commission. Men, ages 21 to 35, who ate about 2.5 ounces of walnuts a day for 12 weeks had improvements in sperm motility and appearance, along with a greater percentage of live sperm and fewer sperm cell chromosome abnormalities, while a control group who ate no nuts showed no changes. The benefits may be due to alpha-linolenic acid, an omega-3 fat in walnuts; it’s possible that other sources of this fat, such as canola oil and flaxseeds, would have similar benefits.
Meanwhile, an antioxidant-rich diet may help preserve sperm quality in middle-aged and older men, suggests a study by researchers from the UC Berkeley School of Public Health and other institutions. Men over 44 who had higher intakes of vitamins C and E and zinc produced sperm with less DNA damage, compared to those with lower intakes—similar to sperm of younger men. As antioxidants, vitamins C and E may help counter the oxidative damage to sperm that occurs with aging and that’s associated with increased risk of genetic defects in the offspring of older men, while insufficient zinc may compromise antioxidant defenses.
Physical activity may also be good for sperm. In a Spanish study published in the European Journal of Applied Physiology, physically active men had better-formed and faster-swimming sperm, as well as hormone values more favorable for sperm production, compared to sedentary men. Another study, in the British Journal of Sports Medicine, found that young men who were most active had significantly higher sperm concentration than men who were least active. Conversely, men who watched the most TV (more than 20 hours a week) had lower sperm concentration than men who watched none. Moderate-intensity exercise may be key to the benefits, since light exercise had no effect, while previous research has found that extreme endurance exercisers—such as triathletes—have reduced sperm quality.
Bottom line: None of these studies looked at whether improvements in sperm actually increased fertility or resulted in healthier babies. And because most were observational studies (not controlled clinical trials), they don’t prove cause and effect. Rather, men who eat a healthy diet and/or are physically active may be doing other things (the “healthy user effect”) or have other traits that help keep their sperm healthy. Still, if you are a man having problems conceiving, it can’t hurt—and may help—to add some nuts and more antioxidant-rich fruits and vegetables to your diet and step up the activity.