Along with smoking, stress, and obesity, another factor might be affecting the quality of your semen: Pesticide residue in your produce. According to a new study from Harvard’s School of Public Health, men who eat fruits and vegetables that contain higher levels of pesticide just might be linked with a lower sperm count — and fewer sperm cells that appear normal in shape or size — than those eating produce that’s chemical-free.
Research already shows that workers exposed to pesticides on the job are associated with lower sperm production, but the new study is the first to link any residue we actually put into our mouths as consumers and it’s potential effects on fertility. It adds to a growing body of evidence that suggests eating healthy could help protect your potency: Another study found men with diets packed with saturated fat had a lower sperm count compared to those who consume less, while men who load up on healthy fat like omega-3 fatty acids found in fish had stronger sperm. But lower semen quality isn’t just about fertility — researchers have also found that it can be a solid marker of overall good health and a long life too.
For the current study, the researchers analyzed semen samples from 155 men registered at a fertility clinic, and asked them what sorts of fruits and vegetables they ate. Using data from the U.S. Department of Agriculture, they divided the produce into those tending to have high pesticide residue (like strawberries, apples, pears, spinach) and moderate or low (like peas, grapefruit, onions). Men who ate produce with high levels had about a 49 percent lower total sperm count than those eating food with fewer residues. These men also had about a 32 percent lower proportion of "morphologically normal" sperm — which just means they had fewer sperm that looked normal in shape and size (sperm morphology is one factor that might be checked during a fertility analysis).
But before stressing too much about your last produce purchase, study author Jorge Chavarro says it’s important to remember this is still a new finding, and thus has its limitations. "This is the first time that pesticide residues in food have been linked to an adverse reproductive health outcome in men and it will be necessary for other studies to replicate our findings before the dust settles on this question." He adds that a lower semen quality doesn’t always translate to reduced fertility — so more research on that will have to continue as well.
Still, you can take precautions to eat clean while more research is underway. "For men who would rather be safe than sorry, what our findings suggest is that consuming fruits and vegetables known to have no or few pesticide residues may be the way to go," says Chavarro. "This includes buying organic produce if the wallet allows and choosing produce known to have low pesticide levels in the US food supply such as the Clean Fifteen list advocated by the Environmental Working Group." The list, and others, is available online