Contrary to popular belief, everything does not cause cancer.

"The public have been led to believe that everything causes cancer," says Cancer Council Australia CEO, Professor Sanchia Aranda, "but one-third of cancers are preventable by lifestyle factors."

Exercise is a vital contributor to good health. Credit:Getty

A new study shows this figure may be a conservative estimate and as much as 40 per cent of cancer diagnoses and half of all cancer related deaths can be prevented through changes to lifestyle.

These changes involve: not smoking; no or moderate drinking of alcohol (one drink a day for women or less; two drinks a day for men or less); maintaining a healthy body weight (a BMI of at least 18.5 but lower than 27.5) and moderate aerobic exercise for 30 minutes, five days a week, or high intensity exercise for 15 minutes, five days a week.