Evidence of Physical Activity for Disease Control and Health Promotion

Using the database of PubMed, a literature search concerning meta-analysis of the relationships between physical activity and stroke, cardiovascular disease (CVD), or cancer has been conducted. Three meta-analysis studies of physical activity and stroke, four studies of CVD, and seven studies of cancer were retrieved. The results showed that the relative risk of stroke in highly active person was 0.75 (95% confidence interval [CI]: 0.67-0.84) for ischemic, 0.67 (95% CI: 0.52-0.86) for hemorrhage, and 0.71 (95% CI: 0.64-0.80) for unspecified type. Meta-analysis of prospective cohort studies showed a strong dose response relationship between walking level and risk reduction for coronary heart disease (CHD) in both sexes. The minimum level of physical activity that showed a significant suppressive effect for the onset of CHD is estimated to be three hours walking per 1 week. For the relationship between physical activity and cancer risk, greater physical activity reduced the risk of colon cancer by 20%, pancreatic cancer by 25%, and lung cancer by 30% in both men and women, and ovarian cancer by 25% in women. In conclusion, maintaining moderate to high levels of physical activity in daily life might reduce the risk of stroke, CHD, and some types of cancer.