In nonsmoking women, breastfeeding for more than six months may protect against breast cancer

To look at the relationship between breast cancer and certain aspects of pregnancy and breastfeeding, Emilio González-Jiménez, PhD, of the University of Granada in Spain, and his colleagues analyzed the medical records of 504 female patients who were 19 to 91 years of age and who had been diagnosed and treated for breast cancer from 2004 to 2009 at the San Cecilio University Hospital in Granada. The team looked at factors including age of diagnosis, how long the women breastfed, family history of cancer, obesity, alcohol consumption, and smoking habits.

Their analysis revealed that women who underwent childbirth and who breastfed were diagnosed with breast cancer at a later age, regardless of the patients' family history of cancer. Nonsmokers who breastfed for periods of longer than six months tended to be diagnosed with breast cancer much later in life-an average of 10 years later than nonsmokers who breastfed for a shorter period. In contrast, female smokers were diagnosed with breast cancer at a younger age and obtained no significant benefit from a longer period of breastfeeding.

"The results suggest that for nonsmokers, breastfeeding for more than six months not only provides children with numerous health benefits, but it also may protect mothers from breast cancer," said Dr. González-Jiménez.