Thanks to a new study, nursing moms can add another line to the growing list of breastfeeding benefits for moms and babies. A team at Brigham and Women's Hospital in Massachusetts found that women who breastfed for longer periods of time had a much lower risk for endometriosis, a chronic condition that has long been hard to grasp for medical experts.
Endometriosis, when the cells like the ones in the lining of the womb are found elsewhere in the body, affects about 10 percent of women in the U.S. It can lead to painful and heavy periods, debilitating and chronic pelvic pain, pain during and after sex as well as infertility. There's still not a lot known about endometriosis, like what causes it and how it can be cured, but now there's finally some light shed on how woman can reduce their risk for the condition.
The study, published in The BMJ this week, analyzed 72,394 women who had one or more pregnancies for more than 20 years, controlling for factors like body mass index, smoking, oral contraceptive use and age. In that period, 3,296 women were surgically diagnosed with endometriosis after their first pregnancy. Researchers found that for every three additional months that moms breastfed, they had an 8 percent drop in risk of endometriosis compared to women who nursed for less than a month per pregnancy. Women who exclusively breastfed (that is, without the introduction of solid food or formula) saw a 13 percent drop of every three additional months. And those who breastfed exclusively for 18 months or more across their reproductive lifetime? These women were almost 30 percent less likely to be diagnosed with endometriosis.
The exact reasons for this link are still unclear. It has been known that some women can delay the return of symptoms by breastfeeding frequently enough to suppress the menstrual cycle. But researchers say this temporary absence doesn't account for all the cases they've seen, which means there are other mechanisms, including oxytocin, estrogen and gonadotropin-releasing hormones, at work.
Two other caveats are that the study depended on self-reports of breastfeeding, which can be unreliable, and researchers can't differentiate whether breastfeeding moms are less likely to develop the disease itself or whether they're less likely to experience severe enough symptoms for surgical evaluation.
Despite the current limits, the potentials here are huge.
"Our findings lend support to the body of public health and policy literature that advocates for the promotion of breastfeeding," said corresponding author Leslie Farland in a press release. "Our work has important implications for advising women who are looking to lower their risk of endometriosis. We hope that future research will illuminate whether breastfeeding could help lessen the symptoms of endometriosis among women who have already been diagnosed."