Dr Rachel Thompson of the World Cancer Research Fund has said that women who breastfeed for a year in total across their lives are 4.8 per cent less likely to develop breast cancer.
"We recommend that women should breastfeed exclusively for six months and then continue with complementary feeding after that," the Daily Express quoted her, as saying.
There is evidence that breastfeeding lowers the levels of cancer hormones in the mother's body and helps to expel breast cells with DNA damage.
"Reducing your risk by about five per cent may not sound like a big difference but the longer you breastfeed, the more you reduce your risk," Thompson said.
"So if a woman breastfeeds two or more children for at least six months each over her lifetime, she can make a significant impact on her risk, not to mention all the other benefits of breastfeeding," she added.
It can also reduce mothers' risks of osteoporosis and ovarian cancer.