Breastfeeding and breast cancer risk

Breastfeeding your children can slightly lower your chances of breast cancer.

The longer you breastfeed, the more your risk is lowered.

Why does breastfeeding reduce risk?

It’s not fully understood why this happens, but breastfeeding might alter the balance of hormones in your body. 

It could also change the cells in your breast by making them less prone to changes that could lead to cancer.

Other benefits of breastfeeding

There are lots of other benefits of breastfeeding for both you and your child. 

Breastfeeding can lower your baby’s risk of infections, childhood leukaemia, type 2 diabetes and obesity. 

As well as breast cancer, breastfeeding may also lower your risk of ovarian cancer, osteoporosis (weak bones), heart disease, stroke and obesity.

However, it’s important that you make the right decision for you. Whether or not you choose to breastfeed is a personal decision. Some women choose not to, and others find it difficult or are unable to for a number of reasons.

Being breast aware while breastfeeding

Be aware of any unusual changes to your breasts when you’re breastfeeding. 

It’s normal to find lumps in your breasts at this time. This is sometimes caused by a milk gland in your breast becoming blocked. 

However, if you notice any unusual changes, get them checked by your doctor. 

Find out more about the signs and symptoms of breast cancer.

Pregnancy and breast cancer risk

Overall, having children means your risk of breast cancer is lowered in the long term. Your risk becomes lower the more children you have and the earlier you begin your family.

This is because hormone changes that occur during pregnancy leave lasting changes to breast cells. 

Having children could also be linked to lifestyle choices you might make when you’re pregnant that lead to a decrease in risk, such as reducing your alcohol intake or changing your diet.

Research also suggests that temporarily your risk of breast cancer slightly increases after you give birth, regardless of your age. It’s not known why this is. It might be due to hormone changes in your body after you give birth. But this is only a very small increase in risk that goes away after a number of years.

Last reviewed: September 2019
Next planned review begins underway

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