A large review of existing studies has found that breastfeeding babies for six months after giving birth lowers a woman's risk of developing breast cancer.
The review was carried out in January by the American Institute for Cancer Research.
Researchers found "convincing" evidence that breastfeeding lowered the risk of women developing breast cancer.
The evidence on this is convincing and this is why we recommend that - if they are able to - mothers should aim to breastfeed exclusively for the first six months and then continue with complementary feeding after that," The Telegraph quoted Lucie Galice, from the WCRF, as saying.
"This means that many new mothers are making choices about whether to breastfeed without knowing it can help reduce cancer risk for them and their child."
Based on the review, a survey of 1,998 people was also recently conducted. It showed that three out of four women are unaware of the link between breastfeeding and cancer.
Two thirds are also unaware that breastfeeding lowers a child's risk of being overweight - a major risk factor for cancer.