Investigating the association between alcohol intake and male reproductive function: A current meta-analysis.

Plain-language summary

This meta-analysis set out to examine how alcohol intake affects male reproductive health by looking at semen quality, antioxidant levels in semen, sperm DNA damage, and sex hormones. It pooled data from 40 studies across five continents, involving over 23,000 men, comparing those who drank no alcohol, moderate amounts (less than 7 units per week), and heavy amounts (more than 7 units per week). Across all drinkers the analysis found lower semen volume and lower antioxidant enzymes in semen, and no relationship with sperm count, movement or DNA fragmentation (breaks in the genetic material inside sperm, where fewer breaks mean a better chance of conception). It also found lower testosterone, lower follicle-stimulating hormone (FSH, a pituitary hormone that drives sperm production, the body raises it when the testicles are underperforming) and lower luteinizing hormone (LH, the pituitary signal that tells the testicles to make testosterone), and no relationship with the other sex hormones measured. Splitting drinkers by amount, no relationship was found between moderate drinking (under 7 units a week) and semen quality, while heavy drinking (over 7 units a week) was tied to worse semen measures and worse hormone levels.

Key findings

• Across all drinkers, alcohol intake was tied to lower semen volume.
• Across all drinkers, alcohol intake was tied to lower antioxidant enzymes in semen.
• Across all drinkers, testosterone, FSH and LH were lower.
• No relationship was found between moderate drinking (under 7 units a week) and semen quality.
• Heavy drinking (over 7 units a week) was tied to worse semen measures and worse hormone levels.
• No relationship was found between alcohol and sperm count, movement or DNA fragmentation.