Can breastfeeding lower breast cancer risk?

The research on breastfeeding and breast cancer risk, it is clear that this has been a difficult area to study. If breastfeeding does lower risk, the level of protection is small and depends on women breastfeeding for a long time. In countries such as the U.S., most women who breastfeed their babies stop after several months, or they breastfeed less frequently as they start to supplement with formula and baby food. Women who have many children and breastfeed each baby for a long time seem to be at somewhat lower risk of breast cancer than women who have smaller families and breastfeed for a shorter time. Studies that have found that breastfeeding does lower breast cancer risk have also found that protection builds up over time (that is, duration of breastfeeding) and number of children that are breastfed.