The overall goal of this project is to improve the understanding of the role of carotenoids in the etiology and prevention of cancer by applying the USDA-NCI carotenoid database to epidemiologic studies. The following are the specific objectives of each analysis: 1) The objective of the National Health Interview Survey analysis is to compare dietary carotenoid intake among U.S. adults by demographic and lifestyle characteristics in order to identify high risk groups for chronic disease prevention efforts. 2) The objectives of the Nurses Health Study analyses are to estimate the relative risks of breast cancer incidence by level of carotenoid intake alone and in relation to recognized risk factors for breast cancer. The USDA-NCI Carotenoid Food Composition Database contains values for five carotenoids in over 2,300 foods in the typical U.S. diet. The fiv carotenoids are: alpha-carotene, beta-carotene, cryptoxanthin, lutein/zeaxanthin, and lycopene. Total carotenoid intake can be calculated by summing all five. The 1987 and 1992 National Health Interview Surveys: The intramural component of these efforts focus on linkage of the USDA-NCI Carotenoid food composition data base to the food frequency questionnaires in the 1987 and 1992 surveys and subsequent data analysis. The Nurses Health Study: The intramural effort on this study involved the linkage of the carotenoid data base to the original and followup dietary food frequency questionnaires and the identification of specific hypotheses relating dietary carotenoid intake and breast cancer risk. Additional methodologic activities will include defining a woman's carotenoid intake and fruit and vegetable intake over time.