VEGETABLES, FRUIT, AND COLON-CANCER IN THE IOWA WOMENS HEALTH STUDY

Previous epidemiologic studies have shown an inverse association betwe en vegetable and fruit consumption and colon cancer risk; few of these studies have been prospective or have focused on women. This report d escribes results from a prospective cohort study of 41,837 women aged 55-69 years who completed a 127-item food frequency questionnaire in 1 986 and were monitored for cancer incidence for 5 years via the State Health Registry of Iowa. After specific exclusion criteria were applie d, 212 colon cancer cases and 167,447 person-years were available for analysis. Intakes of 15 vegetable and fruit groups and dietary fiber w ere the major factors of interest. Consumption of garlic was inversely associated with risk, with an age- and energy-adjusted relative risk of 0.68 (95% confidence interval (Cl) 0.46-1.02) for the uppermost ver sus the lowermost consumption levels. Inverse associations were also o bserved for intakes of all vegetables and dietary fiber; age- and ener gy-adjusted relative risks for the uppermost Versus the lowermost inta ke quartiles were 0.73 (95% Cl 0.47-1.13) and 0.80 (95% Cl 0.49-1.31), respectively. Associations for the other vegetable and fruit groups w ere less remarkable.