SYDNEY, Jan. 31 (Xinhua) -- Women who breastfeed their babies for at least 12 months have significantly lower risk of ovarian cancer, a study by Australia's Curtin University researchers revealed on Thursday.
Curtin University's study extends what was known about the beneficial effects of breastfeeding on mothers.
The university said a case-control study was undertaken in Guangzhou, China, where information on the number of months of lactation and number of children breastfed was collected from a sample of 493 incident ovarian cancer patients and 472 hospital- based controls.
Curtin's Health Sciences Professor Colin Binns said China was chosen for the study due to its high population size, which provided a higher number of ovarian cancer cases to explore.
"The lower incidence of ovarian cancer in China suggests there are factors operating there to reduce the incidence which we wanted to explore," he said in a statement on Thursday.
"We also knew that Chinese women breastfed for longer than women in the western world so it was an ideal location."
Binns said the study added further knowledge to the relatively limited amount of research from countries with a low incidence of the disease, with more details on the breastfeeding variables associated with a reduced risk of ovarian cancer.
"As breastfeeding often delays ovulation, we were able to effectively demonstrate that breastfeeding for 20 months would decrease the risk of ovarian cancer by 50 percent, and that the 20 months of breastfeeding could be spread over a number of children and still have the same effect," he said.
"The results of our study would recommend that mothers breastfeed for 12 months to gain substantial effect -- and longer if they wish."