London, Nov 4 (IANS): Everybody is aware of the fact that exercise is good for your health, but very few know that it can help in preventing breast cancer too, says an expert.

Middle aged women, who regularly partake in some form of exercise each day, are significantly reducing their chances of getting cancer.

And it is said that just 30 minutes of exercise a day, such as a game of squash or a spinning class reduces the risk of cancer by a fifth, reports femalefirst.co.uk.

Scientists have found that obese women are 50 percent more likely to get cancer than those who have a healthy Body Mass Index (BMI). Also those women who did three hours of exercise per week were 21 percent less likely to get breast cancer.

Currently 1 in 8 women get breast cancer, which equates to 50,500 a year, however this new evidence is positive in showing that a healthy lifestyle can reduce the probability of a woman being affected.

Researchers at Oxford University have spent three years monitoring 126,000 women going through menopause and noted if they got the disease or not. They filled in questionnaires about their exercise levels, weight, diet, drinking and smoking.

Scientists believe that being obese increases the risk of cancer, most likely due to the fat cells containing oestrogen which encourage the growth of tumours.

“What’s really interesting about this study is that (reduction in breast cancer risk) does not appear to be solely due to the most active women being slimmer, suggesting that there may be some more direct benefits of exercise for women of all sizes,” said Tim Key, a Cancer Research UK scientist from the cancer epidemiology unit at Oxford University.

“We don’t yet know exactly how physical activity reduces risk ... but some small studies suggest that it could be linked to the impact on hormone levels in the body,” he added.

Tim Key also says that more research is still required to find the link between women’s hormone levels and the prevention of cancer.