Study shows breastfeeding can reduce the risk of developing breast cancer by up to 20%

A study presented at the San Antonio Breast Cancer Symposium in Texas has found that breastfeeding could reduce the risk of developing breast cancer by up to 20%.

Earlier studies had found that breastfeeding reduces the risk of developing certain cancers, but the impact was thought to be relatively small. This research, which drew together and analysed 27 studies (involving over 750,000 women from four continents), found these preventative effects were much larger than previously thought.

This study reported that breastfeeding reduced the risk of developing invasive breast cancers by approximately 10%, while the risk of developing more aggressive forms of the disease were reduced by up to 20%. It did not conclude the optimum length of time to breastfeed for, but did state the risk of developing cancer did appear to reduce the longer women continued.

Whilst the researchers did not know all of the reasons for the preventative effect of breastfeeding, the research seemed to suggest that the high hormone levels required to lactate appeared to affect cell growth, protecting the breast from changes which increase the risk of breast cancer. Women also do not often ovulate while producing breast milk, which is also understood to protect against cancer of the breast and ovaries.

In the UK, the NHS recommends exclusively breastfeeding your child for the first six months. However, rates of breastfeeding in Britain are the lowest in the western world, with only 50% of mothers nursing their child at six weeks, and just 1% following NHS advice and exclusively breastfeeding to six months.

Katherine Woods, Senior Research Communications Manager at Breast Cancer Campaign, said: “This research highlights what we already know; that breastfeeding can lower the risk of breast cancer for mothers. However, more research is needed for us to better understand the connection and to find out which types of breast cancer it affects the most and why.

“The decision of whether to breastfeed is a personal one and it is therefore essential that women are given the information and support they need in order to do what they feel is right for themselves and their baby. Some of the strongest breast cancer risk factors such as gender, genes and age cannot be changed. But risk factors such as lifestyle choices, including cutting down on alcohol and enjoying moderate regular exercise, can be controlled. We therefore encourage all women to make healthy life choices and to stay breast aware.”