Estrogens and phytoestrogens in male infertility

Purpose of review A time-related negative trend in male reproductive function has been suggested. It has been hypothesized that this is due to exposure to chemicals interfering with the action of sex hormones. Also a negative effect of phytoestrogens on male fertility has been postulated. This review aimed to review the epidemiological evidence of deteriorating male reproductive function and summarize the most recent literature on exposure to endocrine disrupters and phytoestrogens in relation to male fertility and/or semen quality. Recent findings There is no doubt that the incidence of testicular cancer has increased through the past 50 years, a decline in sperm counts, if any, may have leveled off during the past decade. There are some reports indicating negative association between exposure to certain chemicals and sperm parameters such evidence has not been found for phytoestrogens. The majority of these studies have been limited to assessing postnatal exposure. Summary Although possible negative impact of industrial chemicals and male fertility is an important issue on the research agenda, so far, it has no clinical implications. The future research should focus on looking at the impact of low dose exposure to a mixture of chemicals, two generation studies and gene-environment interaction.