A Western diet
The study, reported by Inverse, is finding that eating a so-called Western diet results in a lower sperm count (109 to 138 million). Western in this case refers to a diet filled with red meat, fried foods, and sugar-sweetened drinks and desserts.
The research looked at 2,935 young Danish men and found that those who ate "prudently", meaning a diet filled with fruit, vegetables, fish, and chicken, had the highest sperm count (146 to 183 million).
"Dietary factors are necessary for the production of healthy functioning sperm with high fertility potential," co-author Feiby Nassan, a researcher at the Harvard T.H. Chan School of Public Health, told Inverse.
Nassan is the same researcher who last year discovered that marijuana smoking was linked with higher sperm concentrations.
"I believe that it is not only, 'You are what you eat,' but it is also 'Your sperm is what you eat,'" Nassan said.
The research followed 18-year-old healthy Danish men for three months and had them report what they ate. The men were separated into four different dietary patterns: vegetarian-like, Western, prudent, and open-sandwich (a Danish eating style that includes whole grains, cold cuts, and dairy).
The prudent diet was associated with the best semen quality while the open-sandwich diet produced the fastest sperm. In the meantime, the vegetarian-like diet produced the most normally-shaped sperm.
The study has its limitations. For instance, it was conducted on a homogenous population. However, its results could still be useful for those seeking to improve their sperm count.
"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," Nassan concluded.