Physical activity may be associated with reduced risk of colorectal cancer.
Dr Chapman and colleagues from England reviewed the available evidence for a link between exercise and large bowel cancer.
The research team performed a Cochrane-type methodology.
The data extracted by the researchers included, type of study, type of physical activity measured and the numerical results.
The risk ratios of the studies were pooled according to the type of study, type of exercise, type of cancer and sex.
|In women only recreational activities are protective against colon cancer|
The team pooled the results using fixed effect meta-analysis and a random effect meta-analysis was used where substantial heterogeneity existed.
Data from 19 cohort studies showed a statistically significant reduction in the risk of colon cancer in physically active males.
The team showed a risk reduction of 0.79 and 0.78 for occupational and recreational activities, respectively.
The researchers noted that in women only recreational activities are protective against colon cancer with a risk reduction of 0.71.
The investigators reported that case-control studies showed significantly reduced risks of colon cancer in both sexes irrespective of the type of activity.
In addition, the team observed no protection against rectal cancer in either sex.
Dr Chapman’s team concludes, “There is considerable evidence that physical activity is associated with reduced risk of colon cancer in both males and females.”