For decades, smoking has been blamed for being the number one cause of cancer in the United States. What most people don't know, reports the American Cancer Society (ACS), is that current research shows obesity is just as much of a risk factor. The ACS estimates that about one third of the 500,000 cancer deaths a year are related to physical activity and diet and another third are tobacco related. If current trends for smoking and obesity continue, obesity will soon overtake tobacco use as the number one preventable cause of cancer.
Related: 10 Reasons to quit smoking
More than sixty percent of Americans are overweight or obese. The public health implications of the obesity epidemic and its relation to cancer are wide reaching and more challenging to address than smoking. As Colleen Doyle, spokesperson for the ACS points out, "Its easier to target smoking, no one needs to smoke. Every one needs to eat." Tackling obesity involves increasing access to healthy food, town planning that involves safe sidewalks and bike lanes to get people out of their cars, widespread nutrition education, and myriad other public health initiatives.
Future health problems for overweight kids
The obesity-cancer link has potentially tragic implications for today's children. About a third of American kids are overweight or obese-triple the rate than in 1963. "Kids are being bombarded with ads for fast food and junk food," says Doyle. "We are raising an overweight generation." Unless we reverse the trend, Doyle says we could be looking at a public health time bomb.
Seven types of cancer related to obesity
Alice Bender of the American Institute of Cancer Research (AICR) says some scientists believe obesity has already surpassed smoking as the number one avoidable cause of cancer. She estimates that "a 100,000 cases of cancer a year could be prevented if people stayed at a healthy weight." Excess body fat is linked to the following seven cancers: colorectal, post-menopausal breast, esophageal, endometrial, kidney, pancreatic, and gall bladder. And the increased risk is big: studies have shown that obesity raises the risk of post-menopausal breast cancer, for example, by up to fifty percent.
Most cancer is lifestyle related
According to the ACS, the majority of cases of cancer are not due to genetic inheritance or genetic cell mutation, but unhealthy behavior. Doyle puts it this way: "People have a fatalistic view of cancer, but the data is clear: most cancer risk is related to lifestyle. A healthy lifestyle is your best shot of avoiding cancer and chronic disease in general.
7 ways to reduce your cancer risk
The AICR and the ACS have number of recommendations to help you lower your cancer risk:
1. Achieve and maintain a healthy weight. WebMD has a useful tool for calculating your Body Mass Index (BMI) and evaluating how many calories you should consume to reach your optimal weight.
2. Exercise. Not only does physical activity help you lose and maintain a healthy weight, it is directly related to reducing the risk of colon and breast cancer. The ACS recommends a minimum of 30 minutes a day of moderate to vigorous exercise at least five days a week.
3. Eat a healthy diet. Limit consumption of red and processed meats, which have been linked to cancer. Choose two-thirds of your foods from plant-based sources such as fruits, vegetables, legumes, and whole grains.
4. Avoid tobacco. Tobacco exposure causes nearly 450,000 deaths from chronic diseases, including cancer, a year. 80-90% of lung cancer deaths are due to smoking.
5. Limit alcohol consumption. The ACS guidelines are a maximum of one drink a day for women and two drinks a day for men.
6. Limit sun exposure. Use a broad-spectrum sunscreen daily and limit sun exposure between the hours of 10 AM and 4 PM.
7. Schedule regular cancer screenings. Doyle says, "If you remove polyps because of colonoscopy results or remove abnormal cells after a pap smear, you may have prevented cancer from developing."