Development of nutrient databases for epidemiological studies in Taiwan.

The nutrient and related databases are essential for calculating intake values in epidemiological studies. To suit our research needs, we have developed an integrated management system not only for processing individual dietary questionnaires including 24-hour recalls, food records and Chinese food frequency questionnaires (CFFQ), but also for maintaining and tracking updated food composition databases. The recall and record calculation system (Normal University Food and Nutrient Calculation System: NUCAL system) considers date of recall/record, number of days and meal separations. The CFFQ editing system (CFFQES system) contains the management of food list, and frequency and portion size selections to facilitate processing the various versions of CFFQ. Since the extension of many bioactive compounds including polyphenols, pollutants and carcinogens in foods and water is considered by epidemiological hypotheses, limitation of current food composition tables needs to be noticed and improved. Laboratory analyses are the foundation of food databases, more resources and efforts are urgently needed for analysing the local food items. In practical uses of efficient data processing procedures, the multiple grouping and nomenclature systems need further attention in the future. Nutrient databases need multidisciplinary efforts and play the key role for the success of epidemiological studies.