Following a Mediterranean diet rich in fruits, vegetables, fish and low-fat dairy products, and low in processed meat may help improve sperm quality in men, suggests new research.

The researchers from Rovira i Virgili University and the Pere i Virgili Health Research Institute in Spain conducted a systematic review of observational studies on sperm quality and male fecundability and their relationship with diet, food and nutrient consumption.

The results, published in the journal Human Reproduction Update, showed that healthy diets rich in certain nutrients such as omega-3 fatty acids, certain antioxidants, other vitamins (vitamin D and folate) and low saturated fatty acids and trans-fatty acids are associated with high sperm quality parametres. "Male adherence to a healthy diet could improve semen quality and fecundability rates," the study said.

Fish, shellfish, seafood, poultry, cereals, vegetables and fruits, low-fat dairy products and skimmed milk were positively associated with several sperm quality parameters, the study said. In contrast, diets rich in processed meat, soy foods, potatoes, full-fat dairy and total dairy products, cheese, coffee, alcohol, sugar-sweetened beverages and sweets were associated with lower-quality sperm. 

"As far as fecundability is concerned, a high intake of alcohol, caffeine and red meat and processed meat by males has a negative influence on the chance of pregnancy or fertilisation rates in their partners," the researchers said.