Western Dietary Pattern Reduced Male Fertility: A Systematic review and Meta-analysis of Observational Studies

Background: Previous studies have investigated the associations between dietary patterns and male infertility, but found contradictory results. So, this meta-analysis was conducted to examine the association between dietary patterns and male infertility. Methods: An electronic search was conducted to identify the studies over association between dietary patterns and male infertility. The western and healthy dietary patterns were selected in this regard. The random-effect model was used to compute the summary risk estimates. Results: We found eight articles, of which five (n = 7679 participants) were included in our meta-analysis. This meta-analysis determined that the western dietary patterns containing high levels of processed, meat, high-fat dairy, and low levels of vegetables, fruit, and whole grains could significantly reduce the sperm concentration (MD = -0.07, P = 0.01). However, no significant relationship was observed between this dietary pattern and the sperm motility and morphology (MD = 0.01, P = 0.71, MD = 0.2, P = 0.39, respectively). Moreover, regarding the healthy dietary pattern, which contains high level of fruit, vegetables, whole grain, low-fat dairy, as well as low level of red meat and processed food, no significant relationship was observed (sperm concentration: MD = 0.11, P = 0.11, morphology: MD = -0.02, P = 0.42 and motility: MD = 0.35, P = 0.09). Conclusions: Findings of our meta-analysis suggested that the western dietary patterns could decrease the sperm concentration and reduce male fertility.  Further prospective studies are required to confirm this result