Nutritional modifications in male infertility: a systematic review covering 2 decades

Context: Studies suggest that appropriate nutritional modifications can improve the natural conception rate of infertile couples. Objectives: The purpose of this study was to review the human trials that investigated the relation between nutrition and male infertility. Data Sources: A comprehensive systematic review of published human studies was carried out by searching scientific databases. Article selection was carried out in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The American Dietetic Association Research Design and Implementation Checklist was also used for quality assessment. Data Extraction: A total of 502 articles were identified, of which 23 studies met the inclusion criteria. Data Synthesis: Results indicated that a healthy diet improves at least one measure of semen quality, while diets high in lipophilic foods, soy isoflavones, and sweets lower semen quality. Conclusion: The role of daily nutrient exposure and dietary quality needs to be highlighted in male infertility. Mechanistic studies addressing the responsible underlying mechanisms of action of dietary modifications are highly warranted. Systematic Review Registration: PROSPERO 2013: CRD42013005953. Available at: http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42013005953.