(NaturalNews) A growing body of research suggests that regular exercise can help prevent cancer, as well as slow its progress, improve recovery and prevent recurrence of the disease.
Researchers believe that regular exercise equivalent to a 30-minute walk five times per week can influence several cancer risk factors. For example, the sugar-regulating hormone insulin is known to lead to faster cell growth and division and to increase women's risk of breast cancer and breast cancer recurrence. Exercise, however, lowers levels of this hormone.
Exercise also lowers blood levels of the sex hormones estrogen and testosterone, both of which have been linked to cancers of the breast, prostate and uterine lining (endometrial cancer). Exercise also helps burn fat, which can store excess quantities of estrogen. By reducing obesity, exercise also reduces the risk of many cancers.
Studies have shown that exercise also improves the outlook for those who are already being treated for cancer. Women treated for breast cancer are less likely to suffer recurrence if they weigh less, for example, while prostate cancer patients who exercise vigorously for three hours per week are more likely to survive the disease.
Exercise is also known to help repair the immune system's T-cells, which can be damaged by chemotherapy. This helps speed recovery from a very taxing form of treatment.
Many doctors are now recommending exercise as a part of cancer therapy.
"Evidence strongly suggests that exercise is not only safe and feasible during cancer treatment, but that it can also improve physical functioning and some aspects of quality of life," the American Cancer Society says.
Some researchers say that as the medical establishment becomes more aware of the benefits of exercise to cancer patients, its use as a treatment will grow.
"We're where cardiac rehab was 20 years ago," said Melinda Irwin of Yale University School of Medicine. Within a few years, Irwin said, exercise will be a "targeted therapy, similar to chemotherapy or hormonal therapy."