The motto "breast is best" has long been a mantra drummed into pregnant women's heads. And heck, it's worked, with more new moms breastfeeding than ever before: At least 75 percent of babies today are breast-fed for some period of time compared to 60 percent 15 years ago—though far less than half of babies are nursed beyond six months, according to the federal Centers for Disease Control and Prevention. That's a shame, since study after study is finding that breast milk beats formula not only for baby's health but for mom's. Research published today in the American Journal of Medicine, for example, found that women who breast-fed for less than a month had nearly twice the risk of developing type 2 diabetes decades later in life compared to those who breast-fed for longer or those who never had children.
And let's not forget the host of benefits that breastfeeding confers on babies such as fewer ear infections, gastrointestinal illnesses, and respiratory infections. "Among formula-fed infants, the incidence of vomiting and diarrhea is nearly 100 percent in the first year of life," while only half of breast-fed infants get such illnesses, according to a report published last year in the journal Breastfeeding Medicine by David Meyers, director of the primary care center at the federal Agency for Healthcare Research and Quality. Breast-fed infants also get perks that extend well past their toddler years; they're less likely to become overweight grade schoolers and have decreased rates of type 2 diabetes, eczema, and leukemia. It appears that the composition of breast milk has beneficial effects on a child's immune system and body fat composition.
The health benefits of breastfeeding for nursing moms are less often discussed, but they are vast, and include protection against a wide array of life-threatening diseases such as:
Reproductive cancers. It's well established that women who have their first baby after age 25 or who have fewer than four children are more likely to get breast cancer than their counterparts who give birth at a young age or have a lot of kids. But research has shown that nursing for six months or more negates these risks. Prolonged nursing also lowers a woman's lifetime risk of ovarian and endometrial cancer , probably because it suppresses ovulation—and the ovulatory hormones that play a role in these cancers—during those first few months that she nurses exclusively.
Heart disease. Last year, researchers found that women who nursed for at least 24 months over the course of their reproductive lifespan had a 23 percent lower risk of developing heart disease. While the reason is still unknown, researchers theorize that it could be due to the beneficial effects that nursing has on the body's metabolism of sugar and fats. Nursing may also decrease visceral fat—the dangerous kind that collects around the abdominal organs—and promote healthier fat storage on the hips and thighs. One thing nursing doesn't appear to do: trigger weight loss. While it takes plenty of calories to produce breast milk, nursing moms usually find that their appetites increase, causing them to eat more.
Rheumatoid arthritis. A number of studies have linked breastfeeding to protection against rheumatoid arthritis. One from Harvard's Brigham and Women's Hospital found that nursing for a total of two years decreased the risk by 50 percent, while nursing for 12 to 23 months lowered risk by 20 percent. Nursing seems to permanently alter levels of female sex hormones, like estrogen and certain androgens, thought to play a role in this debilitating condition.
Diabetes. The latest study adds to evidence that nursing protects against type 2 diabetes. That's likely because lactation makes cells more sensitive to the hormone insulin. (In fact, diabetic mothers who breast-feed usually require less insulin when they nurse.) It could also be due to nursing's effect on where fat is stored: on the hips and thighs rather than on the belly. Excess abdominal fat, often acquired during pregnancy, is a key risk factor in adult diabetes.