Do antioxidants improve a woman's fertility?

A new review from New Zealand suggests that there is little to no evidence that supplementation with antioxidants, such as vitamins E and C, improves women's chances becoming pregnant.

The review analyzed data from 28 trials involving a total of 3,548 women many of whom underwent fertility treatment, including taking antioxidant supplements (e.g., vitamins, amino acids and/or omega-3 fatty acids) to try to increase their chances of becoming pregnant (1). The analysis showed that women taking anti-oxidants did not significantly increase their chances of conceiving or having a baby, compared to those taking placebos or being given standard treatment, including folic acid. Women taking antioxidants exper-ienced no more adverse effects compared to those who received placebos or standard treatment.

Overall, the researchers considered the quality of the analyzed trials to be of a low standard. They pointed out that the number of different antioxidants tested made it difficult to compare efficacies of each substance. Future trials may provide another result, the scientists noted. Oxidative stress has been identified as playing a key role in the development of subfertility in both males and females (2). While adverse effects of oxi-dative stress on sperm quality and functions have been well documented, in females its impact on oocytes and reproductive functions remains unclear. This imbalance between pro-oxidants and antioxidants can lead to a number of reproductive diseases such as endometriosis, polycystic ovary syndrome (PCOS), and unex-plained infertility. Antioxidant supplementation may be effective in controlling oxidative stress and continues to be explored as a potential strategy to overcome reproductive disorders associated with infertility.

1. Showell M. G. et al. Antioxidants for female subfertility. The Cochrane Library.
   Published online August 2013.
   
   2. Agarwal A. et al. The effects of oxidative stress on female reproduction: a review.
   Reprod Biol Endocrinol. 2012; 10:49.