The more you nurse, the safer your milk becomes.
Women who were breastfed as infants and have older siblings who were also nursed appear to have a lower risk of breast cancer. When University of Wisconsin researchers compared women with breast cancer to a control group, they found that women who were fourth-born or later had a 42 percent lower risk compared to first-born women.
Researchers believe the reason may be breastfed firstborns are exposed to more toxins leached from their mothers’ fat stores—and that toxin levels diminish as the mother nurses additional babies. Experts still say the benefits of breastfeeding vastly outweigh this risk.