Physical activity in leisure-time and risk of cancer: 14-year follow-up of 28,000 Danish men and women.

AIM

The preventive effect of physical activity on risk of cancer in general remains controversial. This study aimed at assessment of the associations between leisure- time physical activity and incidence of cancer in the general population of adult men and women.

METHODS

13,216 women and 18,718 men aged 20-93 years selected from the general population participated in a health examination including a questionnaire with information on physical activity, smoking, alcohol intake, postmenopausal hormones, and socioeconomic status. Incident cases of cancers where recorded during a follow-up period of 14 years. The six most frequent cancer cases in both sexes were included in this analysis.

RESULTS

A highly significant inverse association was seen between vigorous physical activity in leisure time and cancer of the ovary, adjusted rate ratio being 0.33 (95% CI 0.16-0.67; p = 0.001) for the most physical active women. In men there was a highly significant increase for non-melanoma skin cancer, with adjusted rate ratio of 1.72 (95% CI 1.23-2.40; p = 0.001), for the most active men and vigorous activity was associated with a non-significant lower risk of colon cancer, the adjusted rate ratio being 0.72 (95% CI 0.47-1.11; p = 0.06).

CONCLUSION

Generally, there were no, or only weakly, inverse associations between physical activity in leisure time and incidence of cancer, except for cancer of the ovary.