Breast-feeding doesn't raise your child's risk of developing cancer later in life and may even reduce your daughter's risk of being diagnosed with breast cancer before menopause, a study published in the Journal of the National Cancer Institute shows.
Noting that early studies suggested an increased likelihood among breastfed babies to develop cancer later in life, a team of British researchers looked at data from nearly 4,000 children who were surveyed in the 1930s and tracked until 2003.
At the time of enrollment, participants were all 19 or younger. By the end of the study, they were in their 60s, 70s and 80s.
After analyzing the incidence of a number of types of cancers in relation to which subjects were breastfed, the researchers found that babies who were breastfed faced no increased risk of cancer. After looking at individual types of cancers, the researchers also found that breastfed babies had the same risk for prostate, colorectal and gastric cancers as non-breastfed babies.
The researchers also analyzed data from 10 previously conducted studies on cancer and breastfeeding and again found no association. They did, however, find that women who had been breastfed carried a 12% lower risk of developing premenopausal breast cancer, though the risk of breast cancer after menopause was the same for breastfed and non-breastfed babies.
Studies conducted in the 1930s and 1940s had hypothesized that breastfeeding could increase the risk of cancer through the transmission of cancer-causing viruses from mother to child. And though the hypothesis appears incorrect from the study's results, the researchers behind this latest study hypothesized that breastfeeding could inflate cancer risk because it is believed to increase levels of the growth-related hormone IGF-1, which has been linked to a number of cancers.
Other studies have shown breastfeeding to boost babies' immune system, cutting the risk of ear infections, respiratory and digestive system infections, as well as to reduce the risk of developing allergies, asthma, high blood pressure and obesity later in life.