Three lifestyle strategies that have already been found to lower heart disease and diabetes risk are also proving effective in cutting cancer risk. While smoking is the leading preventable cause of cancer, three lifestyle choices – poor diet, excess weight and inadequate physical activity — have been linked to nearly a third of all cancer cases, according to a joint policy report by the World Cancer Research Fund and American Institute for Cancer Research.

The recently released Women’s Health Initiative Observational Study found that cancer risk could be lowered significantly by following the American Cancer Society’s Guidelines on Nutrition and Physical Activity for Cancer Prevention. In tracking more than 65,000 post-menopausal women over a 12-year period, researchers found that women who closely followed the ACS guidelines were able to lower their overall cancer risk by 17% and even more dramatically decrease their risk of two specific cancers, cutting breast cancer risk by 22% and colorectal cancer risk by 52%. One of the significant discoveries of the study was that cancer risk could be significantly decreased even when healthy lifestyle changes where implemented later in life when cancer risk typically rises.

The “Magic 3” lifestyle choices for lowering cancer risk are:

• Weight. Maintain a healthy weight throughout your life.

• Diet. Eat a diet rich in plant-based and whole-grain foods.

• Exercise. At least 30 minutes of moderate aerobic activity a day is recommended.

The lifestyle changes promoted by the American Cancer Society help your body build and maintain a healthy immune system which is most likely responsible for their success in decreasing cancer risk. The body’s immune system plays a critical role in fighting cancer cells. In the same way that immunotherapy bolsters the body’s innate ability to fight cancer, boosting the body’s immune system may also help prevent cancer.