Study: Breastfeeding May Reduce Risk of Breast Cancer

Breastfeeding may reduce the risk of breast cancer, according to researchers at the Icelandic Cancer Society in Reykjavik, who say their research is the first cohort study to indicate a negative association between breastfeeding and breast cancer.

Dr. Laufey Tryggvadottir and her colleagues studied the link between breastfeeding and breast cancer by analyzing data on 993 women, ages 29 to 90, who had given birth and later developed breast cancer and comparing them with more than 9,700 matched control subjects who did not have breast cancer.

Researchers were able to find a correlation between breastfeeding duration and the risk of developing breast cancer in women diagnosed with the disease before age 40. For women diagnosed after age 40, the link was less notable.

The risk of developing breast cancer at all ages appeared to be smaller for women who had breastfed compared with those who had not, according to the study published in the American Journal of Epidemiology.

"The present results, in the context of results from previous studies, indicate that breastfeeding reduces the risk of breast cancer diagnosed under the age of 40, and it may offer some protection for older cases also," said the study.

Researchers plan more studies to determine whether the lessened risk of developing breast cancer in women who have breastfed applies to those with a genetic risk for the disease.

Other sources: American Journal of Epidemiology