Breastfeeding has benefits for mom, too

Most women know breastfeeding is good for their babies’ health. But doctors and midwives rarely tell moms-to-be that it’s also good for nursing mothers. Nursing mothers reduce their relative risk of breast cancer by 4.3 per cent for every 12 months they breastfeed, in addition to a relative decrease of 7 per cent for each birth. Breastfeeding is particularly protective against some of the most aggressive tumours, called hormone receptor-negative or triple-negative tumours, which are more common among African-American women, studies show. It also lowers the risk by one-third for women who are prone to cancer because of an inherited BRCA1 mutation. Women who breastfeed are also less likely to develop ovarian cancer, Type 2 diabetes and rheumatoid arthritis and may have improved cardiovascular health. Yet only 16 per cent — or fewer than 1 in 5 women surveyed — said their doctors had told them that breastfeeding is good for mother as well as baby, according to a new study published in Breastfeeding Medicine. “We have an ounce of prevention that could save lives,” said Dr. Bhuvaneswari Ramaswamy, the paper’s senior author and associate professor of medical oncology at Ohio State University in Columbus. “But are we fully educating the mothers when they make this difficult choice? Because it is not an easy choice.” The study surveyed 724 women aged 18-50 who had given birth to at least one child. The vast majority of them had breastfed. Just more than half knew before they gave birth that breastfeeding reduced the risk of breast cancer, and more than a third of those said the information influenced their decision to breastfeed. But only 120 of the women said that their health care providers had informed them about the implications for their own long-term health. Most of those who knew about the health advantages to nursing moms had gleaned the information from popular media or the internet. And these women tended to breastfeed for much longer — 13 months on average — than women who did not know about the health implications, who breastfed for only nine months on average. Scientists do not entirely understand why lactation helps prevent breast cancer but say the breasts undergo changes during pregnancy as they develop more milk ducts in preparation for breastfeeding. The breasts eventually go through a process called involution that returns them to their pre-pregnancy state and involves massive cell death and tissue remodelling. That transition can occur slowly through gradual weaning, or abruptly if there is no breastfeeding or only brief breastfeeding. When it happens abruptly, it creates an inflammatory condition that is conducive to cancer, Ramaswamy said. Breastfeeding also appears to reset the body’s metabolism after pregnancy, improving glucose metabolism and insulin sensitivity, burning calories and mobilizing stores of fat that have accumulated during pregnancy, which may explain why women who breastfed have lower rates of diabetes and other problems.