Western diet associated with lower sperm quality: Study
New research suggests following a healthy diet pattern is linked to better semen and potentially more favorable fertility. The study points out that semen quality has decreased substantially over the last few decades.
“According to a recent meta-analysis that included more than 185 studies, total sperm count has declined by 50% to 60% from 1973 to 2011 in Western countries, in line with a continued decline since the 1940s. In addition, some investigators have also reported a concomitant secular decline in serum testosterone levels. Although debate is ongoing about the underlying causes for these declines, there is a growing concern and evidence that environmental exposures such as endocrine-disrupting chemicals and air pollution or behavioral factors such as smoking and alcohol consumption could explain this decline.”
The study, published in JAMA Open Network, highlights the possibility of nutrition and eating habits as contributing factors to the decline in semen quality, especially in Western countries. The authors said this is the largest study that they know of that examines the association between diet patterns and markers of testicular function.
While several studies have looked at the association of isolated nutrients such as zinc, folate, antioxidants and saturated and trans-fats, interest has shifted recently to the role of overall diet patterns.
“Although this literature is still expanding, these studies suggest that adherence to generally healthy diet patterns is associated with better semen quality parameters in North America, Europe, the Middle East, and East Asia,” said lead study author Feiby Nassan, a postdoctoral research associate at Harvard T.H. Chan School of Public Health.
To determine whether adherence to specific dietary patterns is associated with testicular function in young men, the researchers examined over 2,900 Danish men who were 19 years old on average and unaware of their fertility status.
For this cross-sectional study, the research team compared sperm counts among men who ate a healthy diet; a Western diet; a Danish diet rich in cold processed meats, whole grains, mayonnaise, cold fish, condiments and dairy; and a vegetarian diet of vegetables, soy milk and eggs, without red meat or chicken.
The results found that those with a diet high in fish, chicken, vegetables, fruit and water had higher sperm counts than those who ate a Western diet rich in pizza, french fries, processed and red meats, snacks, refined grains, sugary beverages and sweets.
Median sperm counts were highest among men who ate a healthy diet with 167 million, followed by the vegetarian diet with 151 million and the Danish diet 146 million. The Western diet fared the worst, with the lowest median sperm count of 122 million. They also had lower levels of some sex hormones that boost fertility, the investigators found.
"Because following a generally healthy diet pattern is a modifiable behavior, our results suggest the possibility of using dietary intervention as a possible approach to improve sperm quality of men in reproductive age," said Nassan. "If we could emphasize diet not only for women, but also for men in regard to fertility success, then we could improve the disease in a similar fashion that diet has improved cardiac health."
Source: JAMA Netw Open
“Association of Dietary Patterns With Testicular Function in Young Danish Men”
Authors: F. Nassan et al.