Environmental causes of testicular dysfunction

Abstract

Male reproductive disorders are remarkably common, and there is growing, if inconclusive, evidence that these may be caused by altered diet, lifestyle (smoking, alcohol, sedentation, recreational drugs, pharmaceutical drugs) or chemical exposures (e.g., pesticides and other endocrine-disrupting compounds). Such factors may cause their impact via effects during fetal development (i.e., maternal pregnancy effects) or in adulthood, or via a combination of the two. There is now strong evidence that a proportion of male reproductive disorders originate as a consequence of ‘testicular dysgenesis syndrome (TDS)’ which is thought to involve subtle deficiencies in fetal androgen production/action. However, what may cause TDS remains unclear. Although there is a widely held perception that environmental chemical exposures are an important cause of male reproductive disorders, evidence to this effect is equivocal, and it is argued that dietary and lifestyle changes are more likely to be important. There are considerable difficulties in studying how environmental effects can impact male reproductive health, especially where fetal origins are suspected, but readers are reminded to remain open to accepting such effects, bearing in mind that our reproductive processes have evolved so as to be in tune with (i.e., to reflect) our environment.