Men who grew up in challenging conditions like prevalence of infectious diseases or poor nutrition may have lower levels of testosterone -- male sex hormone -- in later life says a study. The findings suggest that the differences may be linked to energy investment. For instance in environments where people are more exposed to disease or poor nutrition developing males direct their energy towards survival at the cost of testosterone. While high testosterone levels may up the risk of ageing muscle mass prostate enlargement and cancer lower levels may cause lack of energy erectile dysfunction etc. Thus the researchers suggest
