Dietary factors in cancer of the lower urinary tract.

This dietary study was based on 195 male and 66 female cases of lower urinary tract cancer, identified in Hawaii between 1977 and 1986. Each case was matched for sex, age, and ethnic group (Caucasian or Japanese) to 2 population-based controls. There was a decrease in risk with increasing levels of consumption of vitamin C in women (p = 0.03) and dark green vegetables in men (p = 0.02). When examined by quartile, the odds ratios for the highest quartile of intake compared to the lowest quartile were 0.4 for women and 0.6 for men, respectively. Although dark green vegetables are a source of carotenoids, the intake of total carotenoids, retinol and total vitamin A was weakly and inconsistently related to risk in both sexes. Among women only, there was also an inverse association with the consumption of regular ground coffee (p = 0.02) but not with other types of coffee. Finally, there were no statistically significant or consistent differences between cases and controls in the intake of artificial sweeteners and tea.