While not all types of cancer are preventable, you can greatly reduce the risk of developing the disease by avoiding risk factors and practicing healthy living. Physical activity is beneficial to your health for several reasons—one major perk is that it can lower your chances of getting certain types of cancer.
Studies suggest have found an association between regular exercise and a reduced risk of colon, prostate, lung, endometrial (uterine) and breast cancers. People who exercise regularly have been found to have a 40 to 50 percent lower risk of colon cancer. According to BreastCancer.org, about 1 in 8 women in the United States (about 12 percent) will develop invasive breast cancer at some point in her life, but research has shown that exercise can lower the risk for women by 30 to 40 percent. Men and women can reduce the risk of developing colon cancer by 12 to 14 percent compared to those who are sedentary.
How Exercise Reduces Risk of Cancer
The way that exercise reduces the risk of cancer is multifaceted. First, it helps you reach and maintain a healthy body fat percentage. With exercise, you increase the number of calories you burn and boost your metabolic rate. Managing a healthy weight has been shown to lower the risk of cancer, especially the risk of breast cancer following menopause.
Evidence also suggests that exercise helps kill or slow the growth of cancer cells by strengthening the body's immune system. Most recently, researchers found that exercise's anti-cancer effects were linked to the release of adrenaline, or epinephrine. Its release stimulated by exercise, adrenaline helps mobilize immune cells, including one called the Natural Killer (NK) cell. NK cells patrol the body and are able to infiltrate tumors to slow or prevent their growth. Being active also helps manage inflammation, especially in cancer-susceptible areas like the colon. While inflammation is an important immune response, at times it can do more damage and cause cells to multiply more frequently than normal, which increases the risk of cancer.
Exercise also reduces the amount of insulin in your bloodstream. Insulin is involved in how your body uses and store fuel from the food we eat and is responsible for keeping your blood sugar level at an appropriate level. However, research indicates that insulin can stimulate the multiplication of cells that lead to cancer.
Physical activity has also been shown to lower estrogen levels in women, which is associated with a lower breast cancer risk. Breast cancer cells have receptors that attach to estrogen, encouraging their growth. Additionally, estrogen is produced by fat cells. Women who are more physically active generally have less fat and will produce less estrogen. By reducing estrogen levels post-menopause, the ability of breast cancer cells to grow lessens.
How Much Exercise is Needed to Reduce Cancer Risk
You don't need to jump into an overly aggressive, rigorous workout routine to lower the risk of cancer. One study actually found that walking at 2 miles per hour for four hours per week or running at 6 miles per hour for 1 hour per week was enough to reduce the risk of cancer. That's equal to walking 30 minutes everyday.
Getting in more exercise, however, has proven to lower the risk of cancer even more. Researchers in that same study found that those who vigorously exercised (example: running) for 2 hours per week saw an increased reduction in their cancer risk.
The American Cancer Society recommends getting in 150 minutes (2.5 hours) of exercise every week to lower the risk of developing cancer. Physical activity recommendations from the Center for Disease Control and Prevention (CDC) are similar. The organization recommends that adults participate in moderate-intensity exercise for at least 30 minutes on five or more days of the week, or participate in vigorous-intensity exercise for at least 20 minutes on three or more days of the week.
How Exercise Can Increase Chances of Surviving Cancer
Even after a cancer diagnosis, exercise has been shown to help patients manage their illness. According to the National Cancer Institute, physical activity in women with breast cancer was shown to improve the women's quality of life, reduce fatigue and support energy balance. Additionally, One study found an association between regular moderate exercise and an improved survival rate in breast cancer patients. In another, regular vigorous exercise was shown to slow the progression of prostate cancer in men 65 or older.
Incorporating regular moderate to vigorous exercise into your lifestyle does lower your risk of cancer, and studies show that the higher the activity level, the lower the cancer risk. Incorporate exercises that challenge your cardiovascular system, like walking, running, swimming and cycling.