Dennis Miller is Professor of Food Science and Nutrition in the Department of Food Science at Cornell. He holds a joint appointment in the Division of Nutritional Sciences and is a member of the graduate fields of Food Science and Technology and Nutrition. Miller earned a PhD in nutrition from Cornell, an MS in biochemistry from the University of Washington, and a B.A. in chemistry from Augsburg College in Minnesota. Prior to joining the faculty at Cornell in 1978, he taught chemistry at the University of Minnesota Technical College in Crookston Minnesota.
Current Research
Assess iron and zinc bioavailabilities in staple food crops bred for enhanced levels of iron and zinc; elucidate mechanisms involved in the regulation of iron absorption from NaFeEDTA, a promising food fortificant; evaluate effects of baking on the bioavailaibilities of elemental iron powders used for food fortification; determine effects of prebiotics on iron speciation and absorption in the colon.
Research Interests/Work in Progress
Iron deficiency is the most prevalent nutrient deficiency in the world, affecting as many as 2 billion people worldwide. In the United States, iron deficiency is most common among toddlers, adolescent girls and women of childbearing age with prevalences in these groups ranging from 9% to 11%. Consequences of iron deficiency include decreased work productivity, impaired cognitive development in children, compromised immune function, and adverse pregnancy outcomes.
Many factors contribute to iron deficiency but poor bioavailability of dietary iron is arguably the most important. Bioavailability may be characterized as the proportion of an ingested nutrient that is available for utilization in metabolic processes. In the case of iron, intestinal absorption is the primary limiting factor in bioavailability since virtually all absorbed iron is utilized for hemoglobin synthesis or is shunted into body stores for future use. Iron bioavailability from diets depends to a large extent on the presence of iron absorption enhancers and inhibitors in foods. Meat and ascorbic acid enhance iron absorption while phytate, polyphenolic compounds, calcium, and proteins such as phosvitin in eggs and casein in milk inhibit iron absorption.
One of the most promising approaches for preventing iron deficiency in populations is fortification of staple foods with iron. In the U.S., a systematic program of iron fortification of bread, flour, and other cereal products was begun in the early 1940’s. The program was expanded over the years to include infant formulas and infant cereals. In recent years, there has been increased interest in fortification programs in developing countries where anemia rates in children and women of childbearing age approach 50% or higher. These programs are beginning to show some success but in many poor areas where central food processing is not available, alternative strategies are required. HarvestPlus, an exciting new program, shows considerable promise. It is an international, multidisciplinary program that focuses on using the tools of plant breeding to “biofortify” foods. Plant breeders and nutritionists are working together to develop varieties of staple food crops that are nutritionally enhanced in iron, zinc, and beta-carotene. Seeds of these varieties will then be distributed to farmers throughout the world as a means for increasing the nutrient densities of foods consumed by millions of people in poor countries.
The overall objectives of Miller’s research program are to increase knowledge about factors that influence the nutritional bioavailability of iron in foods and to apply this knowledge toward improving the nutritional quality of people’s diets. A variety of techniques are used including in vitro gastrointestinal digestion, cell culture, and animal models.