Study shows breastfeeding can reduce cancer risk up to 20 percent

Information presented at San Antonio Breast Cancer Symposium


SAN ANTONIO – A new study that suggests breastfeeding could reduce a woman's risk of breast cancer by 10 to 20 percent is making international news.

That research, which looked at 27 reputable studies from more than 30 years, is being presented in San Antonio at the Breast Cancer Symposium.

Scientists believe breastfeeding cuts the risk by reducing estrogen levels, which can trigger cancer. Some even believe the process of making milk stops cancer cells from forming.

"Although we always thought that really breastfeeding did reduce the risk, it was always a question about how much that risk reduction really was," said Dr. Anees Chagpar, director of the Breast Cancer Center at Smilow Cancer Hospital at Yale-New Haven.

This new research suggests a bigger impact than previously suggested. In general, women are about 12 percent less likely to develop breast cancer if they breastfeed. The study found the protective benefit could be even higher.

"This was a meta analysis, so a level of evidence that is really quite robust in a sense that it puts together all of the data that we have so far. And when you continue to see that effect, it really tells you that this is real," Chagpar said.

The studies included in the new research included more than 36,000 women from four continents.

The researchers said the results were significant enough to give new moms something to consider when deciding how to feed their newborns.