Long term Effects of Breastfeeding

Researchers from the University of Oxford, the Chinese Academy of Medical Sciences and Peking University analyzed data from 289,573 Chinese women (average age 51) participating in the China Kadoorie Biobank study who provided detailed information about their reproductive history and other lifestyle factors.

Nearly all were mothers and none had cardiovascular disease when they enrolled in the study. After eight years of follow-up, there were 16,671 cases of coronary heart disease, which includes heart attacks, and 23,983 stroke cases.

The researchers considered a range of risk factors for cardiovascular disease, including smoking, high blood pressure, obesity, diabetes and physical activity that could have biased results.

Study Findings

• Compared to women who had never breastfed, mothers who breastfed their babies had a 9 percent lower risk of heart disease and an 8 percent lower risk of stroke.
• Among mothers who breastfed each of their babies for two years or more, heart disease risk was 18 percent lower and stroke risk was 17 percent lower than among mothers who never breastfed.
• Each additional 6 months of breastfeeding per baby was associated with a 4 percent lower risk of heart disease and a 3 percent lower risk of stroke.

"Although we cannot establish the causal effects, the health benefits to the mother from breastfeeding may be explained by a faster "reset" of the mother's metabolism after pregnancy. Pregnancy changes a woman's metabolism dramatically as she stores fat to provide the energy necessary for her baby's growth and for breastfeeding once the baby is born. Breastfeeding could eliminate the stored fat faster and more completely," said co-author, Sanne Peters, Ph.D., a research fellow at the University of Oxford in the United Kingdom.

The authors noted that women who breastfeed may be more likely to engage in other beneficial health behaviors that lower their risk of cardiovascular disease compared to women who do not breastfeed.

Difference in Breastfeeding Duration

Compared to women in China, breastfeeding duration is typically shorter among women in the United States. Ninety-seven percent of the women in this study breastfed each of their babies for an average of 12 months, compared to 30 percent of U.S. mothers in 2016, according to the World Health Organization.

However, the U.S. Nurses' Health Study found only women with a lifetime duration of breastfeeding of 2 years or more had a significantly lower risk of coronary heart disease than those who never breastfed.

"The findings should encourage more widespread breastfeeding for the benefit of the mother as well as the child," said Zhengming Chen, M.B.B.S., D.Phil., senior study author and professor of epidemiology at the University of Oxford.

"The study provides support for the World Health Organization's recommendation that mothers should breastfeed their babies exclusively for their first six months of life."

Study Limitations

Because this study was observational, relying on information provided by the mothers about their breastfeeding histories, it does not prove cause and effect. Results from observational studies such as this one must be confirmed by a different type of study that can prove that a behavior may result in an outcome.

Reference

1. Zhengming Chen et al., Breastfeeding may reduce a mother's heart attack and stroke risk, Journal of the American Heart Association (2017).

Source: Medindia