Environmental impacts on the immune system: why sex and gender matter

Increasingly, it has been recognized that sex and gender can have a significant influence on the functioning of the immune system. Most often, when mechanisms for these differences are explored, they are tied to biologically-based sex differences, especially sex hormones, which can undoubtedly have profound effects on immune function. However, the differing environmental experiences of men and women may also be important, particularly in terms of socially-based differences in exposure to acute provocateurs of relevance to the immune system, such as stress and toxin exposure. Such differences may account, at least in part, for the observed differences in baseline immune function between men and women, as well as the incidence of clinically-relevant immunological disorders.