Summary A cohort of 11,580 residents of a retirement community initially free from cancer were followed from 1981 to 1989. A total of 1,335 incident cancer cases were diagnosed during the period. Relative risks of cancer were calculated for baseline consumption of vegetables, fruits, beta-carotene, dietary vitamin C, and vitamin supplements. After adjustment for age and smoking, no evidence of a protective effect was found for any of the dietary variables in men. However, an inverse association was observed between vitamin C supplement use and bladder cancer risk. In women, reduced cancer risks of all sites combined and of the colon were noted for combined intake of all vegetables and fruits, fruit intake alone, and dietary vitamin C. Supplemental use of vitamins A and C showed a protective effect on colon cancer risk in women. There was some suggestion that beta-carotene intake and supplemental use of vitamins A, C, and E were associated with reduced risk of lung cancer in women, but none of these results were statistically significant. These inverse associations observed in women seem to warrant further investigation, although there was inconsistency in results between the sexes. Diet appears to play an important role in human carcinogenesis (Ames, 1983; (Buring & Hennekens, 1989;Fontham, 1990; Willett, 1990a). The quality of the epidemiologic studies evaluating these hypotheses, especially in terms of statistical power and the rigor with which the dietary data were collected, has varied considerably.We report here the results of a prospective cohort study of an elderly population in which we examined the relationship between dietary intake of vegetables, fruits, beta-carotene, and vitamin C and the incidence of cancer. The effects of vitamin supplements on cancer risk was also assessed. Responses to each food item was assigned numerical values indicating approximate daily intake frequency (i.e., 0 for 'rarely or never', 0.01 for 'a few times per year', 0.03 for 'about monthly', 0.1 for 'a few times per month', 0.5 for 'a few times per week', and 1.0 for 'daily or almost daily'; if 'in season only' was marked, the figure was multiplied by 0.25) and these figures were summed over a group of food items to obtain scores for the following five food categories: (1) all vegetables and fruits (44 items), (2) all vegetables (21 items), (3) all fruits (23 items), (4) dark green vegeatables (other leafy greens, broccoli, and brussel sprouts), and (5) yellow vegetables (sweet potatoes, carrots, summer squash, red peppers, and chili peppers) (see Appendix). Therefore, the potential range of scores for each of these categories was from zero to the number of items in each food group (for a subject who ate all items in the group every day).Average daily intake of beta-carotene was estimated for each subject by summing the products of the respective betacarotene content in the common measure (serving size) of each food item (converted from Vitamin A values in the US Department of Agriculture tables of food composition (US Dep...

Risk factors for pancreatic cancer were examined in a cohort study of 13,979 residents of a retirement community. After 9 years of follow-up, 65 incident cases of pancreatic cancer were identified. An increased risk of pancreatic cancer was associated with a history of diabetes and cholecystectomy. Higher intake of vegetables, fruits, dietary beta-carotene, and vitamin C were each associated with a reduced risk of pancreatic cancer, although none of these associations was statistically significant. Risk of pancreatic cancer decreased with increasing tea consumption but was unrelated to coffee consumption. No strong or consistent association was seen between either smoking or alcohol consumption and risk of pancreatic cancer, but a consistent and significant increase in risk followed cholecystectomy.

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We examined trends of colorectal cancer incidence rates among Japanese (Miyagi Prefecture) and United States (US) whites (State of Connecticut) between 1959 and 1992. Agestandardized rates in Japan have increased dramatically and are now similar to US white rates. For both colon and rectum, age-specific rates in Japanese men born after 1930 exceed those in US whites, and the Japanese excess increases with year of birth. Similar patterns are evident for women. The current trends suggest that colorectal cancer will become a major source of morbidity and mortality in Japan, as these young Japanese age and their risks increase.