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

Abstract

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.

Keywords: diet; food compounds; male infertility; nutrition; sperm quality.

Figure 1

PRISMA flow diagram of the literature search and selection process

Figure 2

Common nutrition-related factors that may result in male factor infertility. Abbreviation: PUFA, polyunsaturated fatty acids.

Figure 3

Overall effect of diet and nutrition on spermatogenesis. Increased intake of unhealthy diet may lead to impaired spermatogenesis due to elevated cholesterol, leptin, reactive oxygen species, and fat-soluble toxicants. Abbreviations: FSH, follicle-stimulating hormone; GnRH, gonadotropin-releasing hormone; LC, Leydig cells; LH, luteinizing hormone; ROS, reactive oxygen species; SC, Sertoli cells.