It’s already fairly well known that among western women, a mother who breastfeeds for 24 months (duration for all her children) has a 25% lower chance of developing pre-menopausal breast cancer than a woman who formula feeds her children. Because so few women nurse beyond 12 months, no western studies have been able to identify the benefits of extended nursing.
A new study in China looks at their breast cancer cases (over 400 cases). The study found that for women who breastfed each child for 24 months or longer, their chances of breast cancer were cut in 1/2 compared to women who breastfed 1-6 months. For those moms who could claim a breastfeeding duration of 109 months or more (that’s 9 years!), their chances of breast cancer were reduced by 75%. You can read the study abstract.