Regularly eating soya-rich foods cuts a woman's womb cancer risk, say experts.
Researchers looked at how much soya women ate
A study of 1,700 women by the Shanghai Cancer Institute suggested the more soya they ate, the lower their chance of developing the cancer.
Soya contains isoflavones, plant-based chemicals that mimic the effects of oestrogen in the body, the research in the British Medical Journal says.
Having a diet rich in soya has previously been said to reduce the risk of developing breast cancer.
It has also been suggested the chemical's oestrogen effects could be beneficial in fighting heart disease and
This latest research looked at 832 women from Shanghai aged 30 to 69 who had been diagnosed with womb, or endometrial, cancer between 1997 and 2001 and 846 healthy women of the same age group.
The researchers compared the women's soya food intake over five years, and took their measurements.
It was found that women with endometrial cancer ate less soya than healthy women.
The incidence of endometrial cancer in Asian countries is between a fifth and a third of that in Western countries.
The researchers say this could be because the consumption of soya-rich foods is significantly higher than in Western countries.
In this study, women's average intake of isoflavones from soya food was around 25 times that reported in Western countries.
Writing in the BMJ, the researchers, led by Professor Xiao Ou Shu, said: "Dietary factors may play an important role in this international variation.
But they said some of their findings, including an indication that overweight women benefited the most from eating a lot of soya, required further investigation.
'No evidence of harm'
Dr Tim Key, at the Cancer Research UK Epidemiology Unit in Oxford, told BBC News Online said the research added to previous studies suggesting soya lowered endometrial cancer risk.
"The overall picture is that, for this cancer, the data appears to be reasonably consistent that there may be a reduction in risk.
"But there is not sufficient data to suggest there really is an effect.
"For breast cancer, the evidence is considerably less consistent."
He said he would not advise women to increase soya intake in their diet. "There is no evidence of harm, but the evidence of benefit is not conclusive."
Dr Key said the biggest risk factor for womb cancer was being obese.