MINERAL UTILIZATION AND BIOAVAILABILITY IN THE 21ST CENTURY, WITH CHANGING DIETS AND AGRICULTURAL PRACTICES

The general objective is to determine how current and proposed changes to the American diet that may adversely affect intake and/or how bioavailability of the essential mineral nutrients can be modified to enhance trace element nutrition, with emphasis on selenium (Se), iron (Fe), zinc (Zn), and copper (Cu). Specific objectives are: Objective 1: Determine how shifts in agricultural and dietary practices, such as the availability of functional/genetically modified foods and emphasis on plant-based diets with reductions in meat consumption will impact the intake, bioavailability, and dietary requirements of minerals. This objective will address the production of foods with enhanced bioactive Se compounds, and assess their ability to enhance health, especially by controlling oxidative stress and reducing cancer risk. The impact of organic farming methods will also be assessed (Finley). It will also address the practical impact of dietary changes that emphasize plant-based diets on meeting nutritional needs for Fe and Zn (Hunt). Objective 2: Determine the effectiveness of current and proposed mineral fortification/supplementation practices for improving mineral nutrition while avoiding excessive or imbalanced mineral intakes. This objective will evaluate the bioavailability of Fe fortificants such as elemental Fe and micronized, encapsulated Fe compounds in human studies (Hunt). Objective 3: Determine the mechanisms of uptake, transport, and retention of food minerals and how mineral nutritional status influences these mechanisms to impact the bioavailability of essential minerals, non-nutritive metals, and other food components. Cell and whole animal models will be employed to elucidate how the modifications of mineral content of foods can influence the biochemical regulation of specific transporters, cellular trafficking, and interactions of minerals such as Zn, Fe, Cu, Cd, Se, and Mn. (Reeves). Problem to be addressed with increased funds: Elucidate the roles and diets in support of optimal health and prevention of obesity and related illnesses, cardiovascular disease, osteoporosis and cancer. Problem to be addressed with increased funds (FY05): Under Performance Measure 4.1.1 of the ARS Strategic Plan and the NP107 Action Plan, this project will develop an enhancement to the food supply by increasing the nutritional value of beef. Objective modification FY05: Increase the amount of omega-3 fatty acids in beef to a nutritionally significant level by feeding flax. Demonstrate that the increase in omega-3 fatty acids in the meat are sufficient to have a physiological effect. Study feasibility of increasing selenium in beef to levels that will have an impact on human health when the meat is consumed at recommended levels. This may include studies of organic form of selenium in beef, stability with varying cooking methods, sensory issues, bioavailability and health effects in both steers and consumers.