Trim your cancer risk with exercise
Exercise is one of the most important actions you can take to help guard against many types of cancer. Up to one-third of cancer-related deaths are due to obesity and a sedentary lifestyle, including two of the most common cancers in the United States, breast and colon cancer.
Many people exercise to prevent heart disease, but exercise can also play a key role in preventing cancer. Most cancers are caused by lifestyle factors—not genes.
Reduce your waistline and breast-cancer risk
More than two dozen studies have shown that women who exercise have a 30 percent to 40 percent lower risk of breast cancer than their sedentary peers. The female hormone estrogen seems to play a key role. Women with high estrogen levels in their blood have increased risk for breast cancer. Since exercise lowers blood estrogen, it helps lower a woman’s breast-cancer risk. Exercise also reduces other cancer-growth factors such as insulin.
Even older women need to be concerned about estrogen, because after menopause the hormone is produced by fat cells. Women who exercise have less fat and therefore produce less estrogen. With more than 150,000 new breast-cancer cases reported in the United States each year, preventing cancer through exercise is one of the best ways a woman can take charge of her health.
Win the battle against colon cancer
Exercise plays a dramatic role in preventing cancer of the colon and rectum. Nearly 150,000 Americans are diagnosed with colorectal cancer each year, and nearly 50,000 die from the disease. Encouragingly, more than three dozen studies show exercisers reduce their risk of colon cancer by 20 percent or more compared to sedentary people, and the benefits are seen in both men and women, although the effect is greater in men. Changes in digestive acids and other substances also occur with exercise, and these changes are believed to provide some protection from colon cancer. Decreases in body fat, insulin and other growth factors also may contribute to exercisers’ lower colon-cancer risk. Current research is also uncovering new ways in which physical activity cuts cancer risk—from reducing chronic inflammation to improving DNA repair.
How much exercise is too much?
According to national activity guidelines, a good goal is to exercise at least 30 minutes a day on most days of the week. To get the most benefit, though, aim for about an hour a day. Moderate-intensity activities such as brisk walking may be sufficient, although there is more benefit with increased intensity.
Get up off the couch!
It’s easier than you think! A half hour of physical activity daily such as walking, slow swimming, leisurely bike riding or golfing without a cart will get you started. Here are some other ways to be more active:
- Use stairs rather than an elevator.
- Walk or bike to your destination, and walk around the block after dinner.
- Exercise at lunch with your family or friends.
- Go dancing.
- Wear a pedometer every day and watch your daily steps increase.
- Join a sports team.
- Walk to visit co-workers rather than send an e-mail.
- Use a stationary bike or do sit-ups, leg lifts and push-ups while watching TV.
- Park a little farther from your office, the store or the library for a nice walk.
- When the weather is too poor to be outside, grab a partner and “walk the mall.”
- Vary your type of exercise so you won’t get bored or think it’s a chore.
Often people view exercise narrowly as a way to lose weight or to look better. These incentives can be effective, but exercise is really about a person taking charge of his or her health, preventing chronic diseases like cancer, and living longer.
Women it's never too late to start
Even moderate activity can be critically important in helping menopausal women reduce their risk of cancer, heart disease and other chronic ailments. Exercise reduces fat deep in the abdomen (“intra-abdominal” fat), a hidden risk factor because it can raise insulin levels, which promote the growth of cancer cells as well as cholesterol levels. Most American women gain 1 to 2 pounds on average every year, and that adds up to dangerous levels over a lifetime.
The beauty of exercise as a method to reduce total and intra-abdominal fat—and therefore chronic disease —is that it can be done by most women at low cost and with low risk of side effects. It’s never too late to enjoy the health benefits of exercise!
Want more information?
For more information on this and
other cancer-related topics,
call the National Cancer Institute’s
Cancer Information Service at
or visit www.cancer.gov.