Adding carotenoids to the NCI Diet History Questionnaire Database

Food frequency questionnaires (FFQ), like the Diet History Questionnaire (DHQ) developed by researchers at the National Cancer Institute (NCI), are commonly used to estimate long-term total daily energy and nutrient intake. However, the methodology used to create the database to determine dietary intake varies by FFQ and is often a “black box” to researchers. This brief communication discusses how we added values for carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin, lycopene) to the NCI DHQ database. The NCI DHQ database is based on intake of 4220 foods from 24-h dietary recalls of adult participants in the 1994–96 Continuing Survey of Food Intakes by Individuals (CSFII). These 4220 foods are categorized into 255 food groups consistent with line items on the NCI DHQ. Given the extensive number of foods from CSFII used to create the NCI DHQ database, we used the University of Minnesota Nutrition Data System for Research (NDS-R) that has values for the carotenoids in μg/100 g units for approximately 18,000 foods, 8000 brand name products, and many ethnic foods. We matched foods in the NDS-R database to the 4220 CSFII foods according to the detailed description of the foods and their energy and nutrient content. We re-evaluated the matches of certain foods that had estimates of energy, fat, and other nutrients from the NDS-R that differed from the respective CSFII values. Data files with the latest NCI DHQ database that contains the carotenoids are now available at http://riskfactor.cancer.gov/DHQ.