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Exercise cuts cancer risk and helps patients feel less weary

August 3, 2008 12:16 am

MOVE MORE, live longer. It sounds simple, but complex research shows folks who are more physically active have far lower rates of cancer. Even folks who already have cancer can benefit--people who exercise during cancer treatment feel better faster, studies prove.

You may think you already know everything there is to know about exercise and why it's good for you. And if you're a cancer patient, you may be exhausted and wonder how you can muster the energy for a workout.

I hope the research I'll share with you today will serve as a source of motivation and remind you of the many benefits you can reap from even modest amounts of movement.

COUNT THE WAYS

Folks who are more active in their leisure time have a 13 percent to 16 percent lower risk of all types of cancer, according to a Japanese study of 80,000 adults. American studies show even stronger results.

It's never to late to start exercising, according to the American Cancer Society. The group recommends exercising for at least 30 minutes, five times a week, to help prevent cancer from developing. It also recommends exercise to the more than 10 million Americans who have survived cancer--exercise can reduce the risk of cancer's returning.

Any exercise is good for overall health and reducing cancer risks, and up to 60 minutes of moderate to vigorous activity a day is best, according to another research group, the American Institute for Cancer Research.

LOTS OF EVIDENCE

In one big study, women who exercised the most had a 23 percent lower chance of developing breast cancer before men-opause compared with nonexercisers.

Researchers looked at metabolic equivalents and found that exercise equal to running about about 3.25 hours a week, or walking 13 hours a week, offered the most protection.

Smaller doses of exercise are still helpful but have smaller effects.

The research provides strong evidence for the benefits of exercise because it comes from the gigantic Nurses' Health Study, involving nearly 65,000 women.

A similar 23 percent drop in the risk of kidney cancer was found in another national study on people who exercise compared with couch potatoes.

Breast, prostate, colon, ovarian and endometrial cancers, particularly, seem to be reduced by exercise.

Scientists aren't sure why, but they have theories. We know exercise improves the function of white blood cells, the vanguard of the immune system, equivalent to our body's security guards.

We also know that exercise reduces excess insulin, which may be especially important for people with colon cancer. Also, exercise can modulate estrogen and testosterone, which may play a part in protecting against breast, uterine, ovarian and prostate cancers.

QUALITY OF LIFE

Of course, exercise is one of several good habits that reduce cancer risks, such as eating less saturated fat and more fruits and vegetables, as well as limiting alcohol and avoiding smoking or chewing tobacco.

But here's more on the power of exercise:

Walking or bicycling actually help people feel more energetic and less fatigued during cancer treatments, according to British research published this spring.

Dutch researchers recommended a 12-week exercise program, finding that participants reported feeling more "vitality" and improved physical function. Similar results were found in a study of Canadians who exercised while being treated for colon cancer.

A lot of research has been done about exercise during breast cancer treatment.

Tai chi chuan, a gentle Chinese martial art, proved helpful for American women undergoing breast cancer treatments. That's according to researchers at the University of Rochester School of Medicine and Dentistry, in upstate New York.

Women who were instructed to take walks at home during breast cancer treatment felt better. They reported less fatigue, depression and insomnia than women who didn't walk, according to a study at Duke University in North Carolina.

And Korean women receiving radiation therapy for breast cancer reported a better quality of life, better range of motion and less pain when they were enrolled in a special exercise class.

Results are equally hopeful for men. Men with the strongest muscles are the least likely to die of cancer, according to a Swedish study.

Exercise, eating a vegetarian diet, and stress-management classes enabled some men with early-stage prostate cancer to delay surgery and other treatments by two years. That's according to research at the University of California-Irvine, which showed that changing lifestyle reduced levels of PSA, a chemical marker linked to prostate cancer.

GETTING STARTED

New exercisers should check with their doctors and start slowly.

You don't have to run marathons, cycle the Tour de France or win soccer championships to get benefits--gentler activities such as dancing, tai chi, gardening and walking can be helpful, too.

The main thing is to schedule physical activity into your day and to find both indoor and outdoor activities that you enjoy so you can be active no matter what the weather.

Remember, the first few weeks of any new activity can be a little awkward or uncomfortable. But once you get into the habit, it's really fun.

Jennifer Motl welcomes reader questions via her Web site, brighteating.com, or mailed to Nutrition, The Free Lance-Star, 616 Amelia St., Fredericksburg, Va. 22401.