In a four-year study to learn how diet affects sperm, researchers at Southern California’s Loma Linda Medical School found that men who did not eat meat had a significantly reduced sperm count, reports The Telegraph.
The area in which the study took place has a large population of Seventh-Day Adventist Christians, who practice a strict vegetarian lifestyle because they believe that meat is impure. Overall, this group has a 10-year advantage in life expectancy beyond the American average of 79-years-old. But in their study, researchers discovered that vegetarians and vegans had much lower sperm counts than meat eaters — 50 million sperm per mil compared to 70 million per mil — and a much lower number of active sperm. Only one-third of the vegetarian/vegan’s sperm were active, compared to 60 percent of the sperm studied in meat eaters. The researchers concluded that vitamin deficiencies play a big part, but replacing meat with soy could also be a factor.
Soy contains phyto-oestrogens which have similar properties to the female hormone oestrogen. Eliza Orzylowska, MD, an obstetrician at Loma Linda Medical School, says that replacing meat with soy “could be affecting fertility.” For children who have “grown up on this kind of diet, sperm quality may be impacted as early as puberty,” she adds. While she says she understands it’s difficult to tell people not to be vegetarians if they are trying to conceive, she would caution against using soy for at least 74 days beforehand, as that is the amount of time it takes for sperm to be replaced. This dietary change could help couples who are trying to conceive naturally.
Similar research from Harvard University found that a diet high in fruits and veggies might impact fertility because of the high quantities of pesticides men are consuming. Study author Jorge Chavarro says that there is evidence that occupational and environmental pesticide exposure may have an adverse impact on male fertility. The positive effects of fruits high in antioxidants could be neutralized by the opposing effects of pesticides. In the Harvard study, the researchers found that men who had the largest intake of fruits and vegetables high in pesticide residue had lower sperm quality, both in sperm count and mobile count.
Both new studies will be presented at the annual meeting of the American Society of Reproductive Medicine.