Women who breastfeed for two years of their lives are significantly less likely to develop ovarian cancer, according to groundbreaking public health research.
Almost a decade ago Curtin University public health professor and medical doctor Colin Binns led a research study looking at the relationship between ovarian cancer and prolonged lactation.
The results were promising, but the research was not quite there yet.
It appeared that woman who breastfed did have a lower incidence of ovarian cancer.
In recent years Dr Binns undertook the study again, this time with a larger study group and a more narrowed focus.
A handful of Curtin University and Chinese researchers studied about 1000 woman in China's Guangdon Province for a year.
Processing the results took "longer than that", Dr Binns said.
They discovered women who had breastfed for at least 20 months of their lives were 60 per cent less likely to develop ovarian cancer.
The period of breast feeding can be spread out across multiple children with the same result, according to the study.
"The longer you breastfeed the more the effect is," Dr Binns said.
"But in order to do our scientific calculations you've got to pick a time so that you can work out how effective it is."
Dr Binns suspects the results were linked to lower periods of ovulation.
"It's to do with a suppression of ovulation by breast feeding and that's what we think is the explanation," he said.
Dr Binns was hopeful the research could now be expanded to look at other cancers that might be related to the reproductive tract.
"It's really fascinating to see that breast feeding is a primary benefit to mothers like this," he said.
"There are lots of reasons why mothers should breastfeed for the health of their infants and here's another reason to add to that for their health as well."
Dr Binns said there were also a lot of reasons mothers have to cut their breast feeding short but he hoped the results of his study would encourage mothers.
"There are a lot of mothers who are in situation where they have to return to work or where there are other social pressures where it's not possible," he said.
"Breast feeding must be encouraged and supported where possible."