Assessment of Sources and Dietary Intake of Isoflavone in the U.S. Diet

Soy products are a major source of dietary isoflavones, with weak estrogenic, and other biological properties that may contribute to the reduction of the risk of some chronic diseases, such as certain cancers, i.e. prostate and melanoma. This presentation will examine sources of isoflavones in the diet for different age and gender groups. Data for isoflavones taken from the USDA Database for the Isoflavone Content of Selected Foods, Release 2.0 were combined with food consumption data from NHANES. Using the information in the Food and Nutrient Database for Dietary Studies and the corresponding consumption data, weighted grams consumed for each food item reported consumed was calculated. By multiplying total isoflavone content by the grams consumed of the respective food items, the dietary intake of total isoflavones contributed by individual food items was determined. Soymilk was the leading source of total isoflavones, followed by meatless bacon bits and tofu. Many people do not consume soy foods directly, but soy‐based ingredients are commonly used in food manufacturing. Non‐soy products, such as frankfurters and various baked products which may contain soy‐based ingredients, such as soy flour or soy isolates, provide isoflavones to the diet. Knowing the quantities of isoflavones consumed and their relative contributions to dietary intake will assist in a range of studies relating to various diseases.