Exercise powerful for stroke and colon cancer prevention

2009-11-14 12:18

Two important studies show that exercise is a powerful intervention for disease prevention, and is underutilized for health maintenance. According to the study from Dutch researchers, exercise can cut risk of hemorrhagic and ischemic stroke significantly. In a second study, the scientists point to findings that exercise as an intervention that can prevent colon cancer.

Stroke prevention and exercise

Primary causes of stroke include heart disease, high blood pressure, smoking, diabetes, high cholesterol, obesity, and excessive alcohol consumption, blood clotting disorders, use of contraceptives, heart rhythm disturbance (atrial fibrillation), smoking, diabetes, and carotid stenosis.

Stroke causes death in one out of three individuals and is the third leading cause of death in industrialized countries according to background information from the study authors. Researchers found that exercise can reduce risk of fatal and non-fatal stroke by twenty to thirty percent.

Stroke caused by lack of blood flow to the brain (ischemic stroke) was found to be lowered by 24 percent in women and by 27 percent in men as the result of regular exercise. More intense physical activity was found in the analysis to be even more effective for preventing stroke.

Exercise reduced the risk of stroke from bleeding (hemorrhagic) in men to a greater degree than in women – for men, exercise lowers the chances of having a hemorrhagic stroke by forty percent, but for women the risk reduction was eight percent. The researchers say the difference may be because fewer women were included in studies. When they looked at case controlled studies, exercising reduced risk of hemorrhagic stroke by sixty eight percent for both men and women.

Aerobic exercise was most likely to be associated with preventing stroke, as well as heart disease. Men who exercise in their free time were found to have a twenty-four percent lower risk of coronary artery disease, and for women the risk was twenty three percent less.

The findings show that walking at a moderate to fast pace, jogging, swimming, bicycling and similar aerobic exercise, thirty minutes a day can prevent disease.

Regular exercise reduces disease risk. The effect of exercise curbs obesity, keeps blood vessels healthy and promotes blood flow that can prevent stroke. Regular moderate to intense physical activity boosts glucose metabolism, keeping diabetes under control and at bay. One recent study shows that walking slowly can actually increase risk of heart disease.

Exercise is a powerful way to prevent disease, and now is shown to substantially reduce stroke risk. The findings are important. The authors say that though stroke treatment has evolved, fifteen to thirty percent of stroke patients require care in a nursing home and have lasting disabilities.

Exercise reduces risk of colon cancer and improves survival during treatment

In a second study, the researchers provide information that colon cancer is repeatedly shown to stem from lack of exercise and poor diet that leads to obesity. The authors looked at colon cancer risk in 150,000 people over a period of six years. They found that exercise reduces risk of colon cancer by forty percent in individuals who exercised more than seven hours per week.

The findings also show that the effects of exercise for preventing colon cancer are direct. Previous levels of physical activity were taken into account. Exercise was not found to prevent polyps of the colon, but was protective for the development of colon cancer.

The authors write, “The recurrence of colonic polyps seems not to be prevented, however, suggesting that the protective effect of exercise and sport is exerted only after the development of adenoma [a type of colon polyp] in the adenoma-carcinoma sequence.”

The study also suggests a vicious cycle that occurs during cancer treatment that leads to physical inactivity following surgery and during cancer treatment. Fatigue makes exercise seemingly impossible. The authors write, “Physical training can counteract these symptoms. Exercise is therefore an essential component of treatment for CRF” (cancer related fatigue).

Many patients who develop colon cancer were not found to modify lifestyle to follow exercise guidelines and other healthy lifestyle guidelines. Just twenty-three percent of patients exercised, twelve percent continued to smoke, and sixteen percent drank moderate to large amounts of alcohol.

Study participants recruited between 1990 and 1994 from the Melbourne Collaborative Cohort Study, (MCSS) were questioned about vigorous and less intensive exercise levels, then classified into “no activity” and “activity once or more per week” - 41 528 study participants were examined for exercise levels and incidence and survival of colon cancer and observed for ten to fourteen years.

Among the group, 526 developed colon cancer - 229 who actively exercised, and 297 classified as “no activity”. Both groups received the same treatment, but patients who exercised regularly had higher survival rates after five and a half years. For stage II and stage III colon cancer, mortality decreased overall rates of death by 39 percent and disease-specific mortality by fifty one percent.

Additional findings revealed that death from colon cancer was associated with a 45 percent mortality decline among those who exercised for at least three times 45 minutes weekly.

The power of exercise for disease prevention deserves attention and promotion by clinicians. The authors recommend careful screening for heart disease and a standardized exercise test for patients prior to beginning a physical activity program. The goal is to improve aerobic capacity that declines drastically with age.

Through clinical collaboration, watchfulness for wound complications, blood counts, patient and by gauging patient motivation and preference, the researchers say exercise during treatment for colon cancer is possible.

The authors write…"exercise training during treatment for colorectal carcinoma necessitates close cooperation among all medical disciplines involved, e.g., primary care physician, gastroenterologist, oncologist, sports medicine and exercise specialist, and psychologist. Following surgery the wound-healing process must be taken into consideration: premature and unplanned exercise favor complications and scar instability."

Colon and rectal cancer is the most common type of tumor in Western countries. The study results show that exercise can prevent colon polyps from progressing to cancer and reduce deaths from colon cancer among patient undergoing treatment.

Colon cancer is less prevalent in individuals who exercise regularly. Improving aerobic capacity through physical activity can improve colon cancer treatment outcomes and may be underutilized for disease prevention and cure.

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