AICR’s report updating the global scientific evidence on breast cancer identified and reviewed the 18 studies on lactation. Thirteen of these studies focused on length of time, showing a 2 percent decreased risk per 5-month increase in breastfeeding duration.
There are several possible ways by which breastfeeding may influence breast cancer risk. Lactation may delay a new mother’s menstrual periods, reducing lifetime exposure to hormones like estrogen, which is linked to breast cancer risk. The shedding of breast tissue after lactation may also help rid cells with DNA damage.
Diet, Nutrition, Physical Activity and Breast Cancer found many other lifestyle factors linked to breast cancer risk. Staying a healthy weight, avoiding alcohol and being physically active were also found to lower risk of this cancer.
“With the many benefits of breastfeeding it’s important that new moms get support to successfully breastfeed for longer than a few days or weeks,” says Bender. “It’s also critical to know there are steps all women can take to lower the risk of this cancer.”