RSS feedThe mere mention of the word ‘cancer’ sends shivers down most spines. Therefore, most people would try to do anything which may reduce one’s chances of getting cancer or improve one’s chances of survival after cancer treatment. Does physical activity influence the development of cancer?
A Norwegian University study on 59,369 men and women looked at the incidence of colon cancer in these people in relation to their recreational physical activity (Cancer Epidemiol Biomarkers Prev 2008; 17: 183 – 188). During 17 years follow-up, the study found an inverse relationship between recreational physical activity and colon cancer risk. They also found that the risk of developing cancer in certain parts of the colon was associated with physical activity. The risk of developing transverse colon cancer was 56% less in those who reported high physical activity compared to those with no physical activity. Similarly, for sigmoid colon cancer, the risk was 52% less.
In the United States, researchers from the National Cancer Institute looked at the number of colon cancers in 488,720 participants of the NIH-AARP Diet and Health Study who were aged 50-71 years at baseline in 1995 – 1996 (Cancer Causes Control; 2008 Apr 25, epub). In comparing men who engaged in exercise / sports five or more times per week to those who never or rarely exercised, the risk of colon cancer was 21% less in these active men. In men, sedentary behaviour (such as time spent watching television / videos) was associated with a 61% increased risk of colon cancer. A similar but less pronounced relationship was observed in women.
A Swedish study from the Karolinska Institutet investigated the association of occupational physical activity with subsite- specific colorectal cancer risk (Eur J Cancer Prev 2008; 17: 201 – 208). The study found that the risk for colon cancer increased with decreasing occupational physical activity. For men, the risks for proximal (right sided) and distal (left sided) colon cancer increased by 20% and 40%, respectively. Inactivity seemed to be particularly associated with descending colon cancer (140% increased risk). In sedentary women, decreased activity was associated with a 40% increased risk of developing proximal (right sided) colon cancer and a 100% increased risk of developing transverse colon cancer. Rectal cancer was not associated with activity in either sex.
Why certain subsite colon cancers are more common in men but not women is not fully known. What is quite clear is the association of physical activity and reduced risk of developing colon cancer. In addition to keeping the flab at bay, there is now an added incentive for you to do regular exercise. Indeed, regular exercise also helps to stave off the development of metabolic syndrome, another dreaded 21st century health issue.
