Skip to main content
ARS Home » Northeast Area » Beltsville, Maryland (BHNRC) » Beltsville Human Nutrition Research Center » Methods and Application of Food Composition Laboratory » Research » Research Project #444902

Research Project: Investigation of Iodine, Purines, Glucosinolate and Nitrates/Nitrites in Foods

Location: Methods and Application of Food Composition Laboratory

Project Number: 8040-10700-004-030-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Aug 30, 2023
End Date: Aug 29, 2025

Analyze iodine in U.S. foods and map against reported foods in NHANES What We Eat in America, 2013-present. Iodine is an essential nutrient in the health of the US population, especially women of reproductive age and consequently, to growing fetuses, particularly for growth and cognitive development. Iodine in foods is highly related to agricultural and fishing practices, processing of commercial foods, and fortification policies of plant (crop) and animal-based foods. Iodine in prenatal vitamins is variable and, in some cases, not true to the label. Therefore, detailed analysis of foods and dietary supplements is crucial in providing guidance before and during pregnancy. Purines (gout and CVD), nitrate and nitrites (NN; cardiovascular benefits and cancer risk), glucosinolates in targeted cruciferous vegetables (cancer preventative properties), and methylxanthines (caffeine, stimulants) are also researched and Special Interest Databases (SIDs) developed. To date, purines (scientific literature data) and iodine data (USDA-FDA analytical and scientific literature data) are released in SIDs; nitrate/nitrite data are being analyzed in collaboration with Univ of OK; new analytical data for purines, in collaboration with the Univ of Florida, are also being determined through USDA sampling frames, foods used in USDA clinical studies, dietary supplements, archived samples from Foundation Food analyses (FoodData Central) and convenience sampling in collaboration with Tx Tech University. From the SIDs, dietary guidance and databases are supported.

Foods likely to contain measurable amounts of iodine will continue to be selected for the expansion of the Iodine Database; selection will be based on the Food and Drug Administration (FDA), 2013-19 Total Diet Study (TDS) and USDA's What We Eat in America Reports. Analyses will include appropriate quality control materials and the most qualified academic, government or commercial labs. Foods for analysis include: dairy foods, seafood/products (especially finfish), seaweed/seaweed extracts, other iodine-containing commercial ingredients/additives, highly consumed commercially processed mixed dishes (especially those containing dairy and/or egg products), other foods determined to have significant amounts of iodine and foods which replace other major contributors of iodine (e.g., alternative plant-based milks). I should be noted that, using current data, four dairy and egg products contribute to two thirds of the national intake of iodine. Variability information is vital to research. These data and data on dietary supplements (primarily MVM and prenatal supplements) are being mapped to NHANES dietary intake data for 2013-present. It is especially important for assessing intake to urinary iodine excretion. From these analyses, iodine intake can be correlated with health outcomes. In addition, sampling and analysis on foods and dietary supplements which contain purines, Nitrates and Nitrites, and glucosinolates are studied, sampled and analyzed for development of Special Interest Databases. Experts in the fields of botanicals, crop plants, meats (processed and raw/cooked), etc. are included in the compound-specific teams.