Instead, new cancer prevention guidelines from the American Cancer Society say at least 30 minutes a day of dedicated exercise above and beyond the usual activities of daily life on five or more days a week is needed to really reduce your cancer risk.
That's a step up from previous guidelines that allowed people to count physical activity from normal activities of daily life toward their recommended 30 minutes a day of physical activity.
In addition, the new guidelines call on communities to take a more active role in encouraging healthy behaviors, by increasing access to healthful foods in schools and workplaces as well as providing safe and enjoyable sidewalks and recreational facilities.
"For years, we've told people what habits to adopt to lower their cancer risk, but it has become increasingly clear we need to create environments that make it easier to make healthy choices," says researcher Colleen Doyle, MS, RD, director of nutrition and physical activity for the American Cancer Society, in a news release.
"Just as excise taxes and smoke-free laws have been critical to reducing tobacco's cancer toll," says Doyle, "community action is essential to create a social environment that promotes healthy food choices and physical activity."
4 Steps to Fight Cancer
Researchers say that for nonsmokers, weight control, physical activity, and dietary factors are the most important modifiable cancer risk factors.
One-third of the more than 500,000 cancer deaths in the U.S. each year are attributable to diet and physical activity habits, such as being overweight or obese. That's about the same number of cancer deaths caused by tobacco.
Given the recent rise in obesity in the U.S., researchers say the new cancer prevention guidelines emphasize maintaining a healthy weight throughout life as the best thing you can do to reduce your risk of cancer.
The guidelines spell out the top four cancer prevention recommendations, along with strategies to achieve them, including:
Maintaining a healthy weight throughout life:
- Balance calories consumed with physical activity levels.
- Avoid excessive weight gain.
- If currently overweight or obese, achieve and maintain a healthy weight.
Adopt a physically active lifestyle:
- Engage in at least 30 minutes of moderate to vigorous physical activity on 5 or more days per week; 45-60 minutes of physical activity is even better.
Follow a healthy diet, with an emphasis on plant-based foods:
- Choose foods and beverages in appropriate portions to achieve and maintain a healthy weight.
- Eat 5 or more servings of a variety of vegetables and fruits each day.
- Choose whole grains over processed or refined grains.
- Limit consumption of processed and red meats.
Limit alcohol intake:
- If you drink alcohol, drink no more than 1 drink per day for women or 2 for men.
The guidelines, which are updated every five years, are based on the most current scientific evidence related to diet and activity and cancer risk. They appear in A Cancer Journal for Clinicians.
SOURCES: Kushi, L. CA: A Cancer Journal for Clinicians, September/October 2006; vol 56: pp 254-281. News Release, American Cancer Society.
By Jennifer Warner
Reviewed by Louise Chang