健康天地
交流防癌、抗癌最新資訊。歡迎廣大熱心於抗癌事業的專家、學者、醫學界的朋友們、對防癌抗癌資訊有興趣的人士來與賀醫生共同探究和交流!
Exercise Has Many Cancer-Related Benefits
American Cancer Society
How many times have you made that New Year's resolution to get in shape? A lot of us put exercise on our list at this time of year, but it's typically one of the first things to fall by the wayside when life gets back to normal after the holidays. If you're looking for some extra motivation to keep you on track, here are 5 good reasons to get active and stay active in 2007.
The evidence linking excess weight to cancer has gotten stronger. Being overweight or obese is known to raise your risk of cancers of the colon, endometrium (uterus), esophagus, kidney, and breast (among women past menopause). It is also thought to be linked to several other types of cancer including ovarian, pancreatic, cervical, and prostate.
How can you tell if you need to lose a few pounds? Most experts use body mass index, or BMI, as a measure. BMI is a ratio of weight to height. A BMI between 18.5 and 24.9 is considered normal. A BMI between 25 and 29.9 is overweight, and a BMI of 30 or over is considered obese.
Watching what you eat is key to keeping your weight at a healthy level, of course. But exercise is equally important. The most recent American Cancer Society recommendations call for adults to get at least 30 minutes of moderate to vigorous physical activity -- over and above usual activities like housework or taking the stairs instead of the elevator -- on 5 or more days a week. Moderate activities include walking, slow biking, gardening, golfing, or yoga. Vigorous activities include jogging or running, fast cycling, soccer, swimming, or jumping rope.
A recent study from Europe found that people who exercised had a lower risk of developing colon cancer than people who didn't get much exercise. Researchers followed more than 413,000 men and women between the ages of 35 and 70 for more than 6 years. Those who got the most physical activity had a 22% lower risk of colon cancer (especially on the right side of the colon) than people who got the least. The benefit of exercise on colon cancer risk was also seen in the overweight participants, a known at-risk group.
People needed to get about 1 hour of vigorous physical activity, or 2 hours of moderate activity, every day to reduce their risk of colon cancer. But it didn't matter whether they got that exercise at home, on the job, or for fun.
"It is important for people to understand that they can take steps in their daily routine to reduce cancer risk," said Lesley Walker, PhD, director of information for Cancer Research UK, which helped fund the study. "You don't need to join a gym to get the benefit of exercise. If regular brisk walking or going for a run doesn't appeal, you can do some strenuous housework. Cleaning windows, vacuuming, and scrubbing floors burn off a lot of calories. So does gardening or cleaning the car."
Numerous studies have linked exercise with a lower risk of breast cancer. Recent research from the Iowa Women's Health Study adds to that evidence. With 18 years of follow-up, the researchers found that women with high physical activity levels had lower BMIs and a 14% lower risk of breast cancer after menopause. Exercise especially reduced the risk of one very aggressive type of tumor described as ER+/PR- (it has estrogen receptors but not progesterone receptors).
In this study, a high activity level was defined as getting vigorous exercise 2 or more times per week, or moderate exercise more than 4 times per week.
Lifting weights can help breast cancer survivors get stronger and feel better about themselves, according to researchers from the University of Minnesota and the University of Pennsylvania. They divided 86 survivors into 2 groups; one group weight trained twice a week for 6 months, while the other did not change their daily activities.
By the end of the study, women in the weight training group reported significant improvements in physical function, as well as in communication, relationship, and psychological issues. The women told the researchers they felt stronger and more confident, with more energy and fewer aches and pains than before. The researchers think the increased strength and sense of control of their bodies resulting from weight training may have been part of the reason for the women's improved attitude.
Cancer isn't the only disease that can be affected by exercise. Regular activity can reduce your risk of heart disease and diabetes, too. Exercise can give you more energy, help you deal with stress, improve your sleep quality, and make you feel better about yourself.
If you're just starting an exercise program, be sure to talk with your doctor first. Discuss how hard you should work out and how often, especially if you have health problems like high blood pressure, heart problems, high cholesterol, diabetes, or if you're a smoker.
Then find an activity you enjoy and get moving in 2007. You'll be glad you did.
Citations: "Physical Activity and Risk of Colon and Rectal Cancers: The European Prospective Investigation into Cancer and Nutrition." Published in the Dec., 2006, Cancer Epidemiology, Biomarkers and Prevention (Vol. 15, No. 12: 2398-2407). First author: Christine Friedenreich, International Agency for Research on Cancer, Lyon, France.
"Recreational Physical Activity and Risk of Postmenopausal Breast Cancer Based on Hormone Receptor Status." Published in the Dec. 11/25, 2006, Archives of Internal Medicine (Vol. 166, No. 22: 2478-2483). First author: Aditya Bardia, MD, Mayo Clinic College of Medicine, Rochester, Minn.
"Effects of Weight Training on Quality of Life in Recent Breast Cancer Survivors: The Weight Training for Breast Cancer Survivors (WTBS) Study." Published in the May 1, 2006, Cancer (Vol. 106, No. 9: 2076-2083). First author: Tetsuya Ohira, MD, University of Minnesota, Minneapolis.
