Starting menstrual periods at a young age is linked to a small increase in adult breast cancer risk [43,152-154]. Women who began their periods before age 12 have about a 20 percent higher risk compared to those who began their periods after age 14 [153]. This likely relates, at least in part, to the amount of estrogen a woman is exposed to throughout her life. The earlier a woman starts having periods, the longer her breast tissue is exposed to estrogens released during the menstrual cycle and the greater her exposure to estrogen. Higher levels of estrogen are linked to an increased risk of breast cancer (learn more about estrogen and breast cancer risk).
An adult woman cannot change the age at which she started her periods. However, the age a girl starts getting her period can be impacted by certain lifestyle factors. For example, girls who are lean and get more physical activity tend to start periods at a later age than other girls. It is a good health recommendation for all young girls to be physically active and not be overweight. It is not recommended that girls do anything to try and change their natural age at menstruation.
Updated 11/10/09
