Physical activity and colon cancer risk.
The association between low physical activity and colon cancer was examined in a Swedish 14-year follow-up study of 16,477 subjects. The relative risk (RR) of colon cancer in subjects with low physical activity was estimated at 3.6 (1.3-9.8, 95% confidence interval). An association was observed for both men and women, and for low physical activity during occupational hours (RR = 1.6, 0.8-2.9) as well as during recreational hours (RR = 1.6, 1.0-2.7). The relative risk for rectal cancer was not elevated. In the study we controlled for age, gender, domicile and, to some extent, for diet. A possible mechanism is that low physical activity could prolong the transit time of the stool in the colon and thereby the duration of contact between the mucosa and fecal carcinogens.
Gerhardsson
M
M
Department of Epidemiology, Karolinska Institute, Stockholm, Sweden.
Floderus
B
B
Norell
S E
SE
D000230:Adenocarcinoma / Q000453:epidemiology / Q000209:etiology*; D000368:Aged; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000209:etiology*; D015444:Exercise; D005247:Feeding Behavior; D005260:Female; D005500:Follow-Up Studies; D005772:Gastrointestinal Transit; D006801:Humans; D008297:Male; D009790:Occupations; D012307:Risk Factors; D012737:Sex Factors; D013548:Sweden; D013997:Time Factors