Location: Food Components and Health Laboratory2009 Annual Report
1a. Objectives (from AD-416)
Objective 1: Investigate macronutrient modulation of biomarkers of chronic disease. Sub-objective 1.A.: Investigate the role of individual fatty acids (such as alphalinolenic, stearic, conjugated linoleic, and/or vaccenic acids) on markers of inflammation and oxidation related to chronic disease. Delineate their metabolic pathways. Sub-objective 1.B.: Determine the differential effects of protein sources and macronutrient profiles on post-prandial oxidation, oxidative stress, insulin signaling,and blood pressure regulation. Objective 2: Improve biomarkers and indicators of nutritional adequacy through investigation of micronutrient metabolism. Sub-objective 2.A.: Investigate the differential in vivo metabolism of various forms of micronutrients (such as tocopherol and/or folate) through mathematical modeling.
1b. Approach (from AD-416)
Appropriate macro- and micronutrient intake is fundamental to a diet that will maintain health and reduce risk of chronic, degenerative diseases. For many nutrients or classes of nutrients, qualitative and quantitative estimates of intake to maintain health are available. However, for other nutrients, where there are a variety of dietary sources, specific sources may offer additional health benefits as compared to others. Many observations of the health effects of specific sources of food are based on epidemiologic data and therefore do not provide an opportunity to show a cause and effect. For example, epidemiologic data suggest that there is no association between consumption of naturally occurring trans fatty acids and risk for coronary heart disease whereas trans fatty acids from partially hydrogenated vegetable sources do increase risk for coronary heart disease and death. Epidemiologic data suggest that a decrease in body weight is associated with low-fat dairy food consumption but identification of the specific component(s) (such as proteins) found in low-fat dairy foods that may be responsible for this effect is needed. This five-year project will investigate the effects of different sources of trans fatty acids and protein on risk factors associated with cardiovascular disease, and diabetes in humans and will assess the relative bioavailability of synthetic and natural sources of vitamin E in humans using mathematical modeling. This research will fill knowledge gaps in macro and micronutrient metabolism and provide a scientific basis for dietary recommendations and nutrition policy.
3. Progress Report
Institutional Review Board approvals were received to study trans fatty acids from different dietary sources. One component of this research is to study the conversion of monomers of trans fatty acids to isomers of conjugated linoleic acids, a fatty acid with purported health benefits. A second aspect of this study is to investigate how different forms of trans fat impact risk factors for cardiovascular disease. The approval permitted recruitment of human subjects. A feeding study with two cohorts of subjects was completed in which dietary fatty acids were varied while the total fat was held constant. Samples collected are in the process of being analyzed.