Breastfeeding has health benefit for moms: Study
Reported July 21, 2009
Breast isn’t just best for baby: mothers who don’t breastfeed their babies may increase their risk of heart attacks and strokes decades later, new research suggests.
The evidence comes from the massive Women’s Health Initiative trial and involved nearly 140,000 women.
Researchers found that women who breastfed were less likely when they were older to have developed high blood pressure, diabetes, high cholesterol and cardiovascular disease the leading cause of death in Canadian women.
“The longer a woman breastfed her baby, the better it was for both of them,” says lead author Dr. Eleanor Bimla Schwarz, of the University of Pittsburgh.
“We know that women who don’t breastfeed their babies are at a higher risk of getting breast cancer and ovarian cancer,” Schwarz says. Recent studies show women who don’t breastfeed also have higher risks of diabetes and high blood pressure.
“Ours is the first study that shows that there really is a strong effect in terms of preventing heart attacks and stroke for women who nursed for more than six months,” says Schwarz, an assistant professor of medicine, epidemiology and obstetrics, gynecology and reproductive sciences.
The study appears in the latest issue of Obstetrics and Gynecology.
Health Canada recommends breast milk should be the only food or drink for the first six months of life, and that breastfeeding continue, along with the gradual introduction of solid food, for two years or more. But a national survey released last month found only 14 per cent of new moms in Canada were exclusively feeding their newborns breast milk by age six months.
Breastfeeding helps protect babies against infections and disease, benefits that are thought to last a lifetime.
“We now know that it’s important for mothers’ health as well,” Schwarz says.
Her team analyzed data from 139,681 post-menopausal women, average age 63, enrolled in the Women’s Health Initiative study, known best for its research on hormone replacement therapy. Researchers looked at the women’s lifetime history of breastfeeding, meaning how many months in total they had breastfed their babies.
Women who had breastfed for one to six months had less diabetes, less high blood pressure and less high cholesterol, all known risk factors for heart disease.
Those who breastfed for seven months or more were significantly less likely to have actually developed cardiovascular disease compared to women who had never breastfed. Women who breastfed for a lifetime total of at least 12 months were 10 per cent less likely to have had a heart attack or stroke or developed heart disease when they were older.
The finding held after researchers took age, income, body mass index, diet, physical activity, family history of heart disease and other factors into account.
For Schwarz, the study was personal. “As a new mom who went back to work, I found pumping a bit challenging,” Schwarz says. “Everybody kept telling me it was good for my baby. I wondered what effect it had on my own health.”
Fat stores accumulate during pregnancy, and other studies have shown that, in populations where breastfeeding is rare, pregnancy might increase the risk of heart disease.
One theory is that breastfeeding lowers that risk by mobilizing fat stores.
“Breastfeeding has an important role in the way women’s bodies recover from pregnancy,”Schwarz says. “I think what we’re seeing is that when this process is interrupted by women feeding their babies things other than human milk, women are more likely to have a number of health problems.”
When milk isn’t expressed, she said, women don’t unload all the body fat stored up during pregnancy.
Prolactin and oxytocin, hormones involved in producing milk and releasing it from the body, may also have effects on a woman’s heart.
The study doesn’t prove cause and effect, just an association, and there may be other issues at play, cautions Dr. Beth Abramson, a Toronto cardiologist and spokeswoman for the Heart and Stroke Foundation. For example, women who choose or are able to breastfeed may have less stressful lives.
“They may be in a different economic bracket because they may not at that time have had to go back to work. You sometimes can’t correct for everything.
“If a woman is considering breastfeeding, this may be another potential benefit,” Abramson says, “but if a woman has, for various reasons, chosen not to, or can’t breastfeed, not all hope is lost. There are a lot of healthy behaviours we can engage in to reduce our risk of heart disease and stroke,” such as not smoking or quitting, keeping physically active and managing weight.
Source : Canwest News Service
