Relation of Vegetable, Fruit, and Grain Consumption to Colorectal Adenomatous Polyps

Abstract

Previous studies suggest that colorectal cancer risk decreases with higher intake of vegetables, fruits, and grains. Few studies, however, have examined these factors in relation to occurrence of colorectal polyps. The authors used case-control data from 488 matched pairs to evaluate associations of vegetables, fruits, and grains with polyps. Subjects were southern Californians aged 50-74 years who had a sigmoidoscopy in 1991-1993. Diet in the year before sigmoidoscopy was measured with a food frequency questionnaire. Frequent consumption of vegetables, fruits, and grains was associated with decreased polyp prevalence. Specifically, the adjusted odds ratio comparing the highest with the lowest quintile of intake for vegetables was 0.47 (95% confidence interval (CI) 0.29-0.76), for fruits was 0.65 (95% CI 0.40-1.05), and for grains was 0.55 (95% CI 0.33-0.91). The authors also found inverse associations for high carotenoid vegetables, cruciferae, high vitamin C fruits, garlic, and tofu (or soybeans). After further adjusting for potentially anticarcinogenic constituents of these foods, high carotenoid vegetables, cruciferous vegetables, garlic, and tofu (or soybeans) remained inversely associated with polyps. These findings support the hypothesis that high intake of vegetables, fruits, or grains decreases the risk of polyps and suggest that any protective effects might reflect unmeasured constituents in these foods.

Watercress supplementation in diet reduces lymphocyte DNA damage and alters blood antioxidant status in healthy adults

“…Increased vegetable intake, particularly of cruciferous vegetables (CVs) such as cabbage, cauliflower, broccoli, Brussels sprouts, watercress, and mustard greens, is associated with a decreased risk of several cancers in human population studies (1)(2)(3)(4)(5)(6)(7)(8)(9). However, not all associations, which have mostly been obtained from epidemiologic studies, are necessarily causal, and thus, intervention studies with specific dietary factors of interest are crucial.…”

Tissue distribution in mice and metabolism in murine and human liver of apigenin and tricin, flavones with putative cancer chemopreventive properties

“…Epidemiological studies suggest that the consumption of fruits and vegetables is associated with a decreased risk of colorectal cancer [1]. Several naturally occurring flavonoids contained in fruits and vegetables share cancer chemopreventive properties and mechanisms with non-steroidal antiinflammatory drugs, but may lack their unfavorable safety profiles [2].…”

Evaluation of the cancer chemopreventive efficacy of rice bran in genetic mouse models of breast, prostate and intestinal carcinogenesis

“…Safety problems intrinsic to drugs administered over prolonged periods of time strengthen the interest in dietrelated cancer chemoprevention approaches. Epidemiological evidence suggests that human consumption of whole-grain foods may be associated with a low incidence of cancer, especially in the colorectum (Witte et al, 1996;World Cancer Research Fund, 1997). Rice, Oryza sativa, is the staple food of over half the world's population.…”

“…Rice consumed in the Western world is generally white and is obtained from brown rice by removal of the bran. Dietary differences such as this may explain why the incidence of cancers, including those of the colorectum, breast and prostate is much lower in Asia than in the Western world (Witte et al, 1996). Rice bran contains agents believed to possess cancer chemopreventive properties that are absent from the white variety.…”