Antioxidants for male infertility: a review of the evidence

This review looked at antioxidants for men with infertility. They found that antioxidants can improve semen quality, including for men with varicoceles (VCs).

Male infertility, such as low sperm count, contributes to half of all cases of infertility. Sperm require specific conditions to develop normally. Sperm are particularly vulnerable to oxidation. These chemical changes can affect all bodily tissues. However, sperm have less protection due to their small size. Instead, the seminal fluid contains antioxidants that can prevent this type of damage. The man’s diet is a major source of the antioxidants in semen.

Men with infertility have lower amounts of antioxidants than other men. Because of this, many doctors recommend antioxidant supplements for men with infertility. However, the evidence is mixed on whether antioxidants improve male fertility. The dose used can also affect whether a supplement is effective.

This review included 97 studies of antioxidants and male fertility. 34% of studies randomly assigned participants to a supplement or an inactive pill. The quality of each study was determined using the Cochrane guidelines and other standards. Out of 90 studies that looked at semen parameters, 20 studies were of high quality.

Of the low-quality studies, 85.7% found an improvement in semen quality following supplements. 65% of high-quality studies found an improvement from antioxidants on semen quality. 

VCs are enlarged veins that can reduce fertility. 11 low-quality studies looked at antioxidants for this condition. 75% of studies found semen quality improved for men with VCs after taking antioxidants.

This review found that antioxidant supplements can improve semen quality.

This review treated each study as a unit. This approach is unusual and does not account for how many participants were in each study. However, it also allowed for a comparison of studies with different designs.

Consult with your doctor about antioxidant supplements.