Location: Obesity and Metabolism Research Unit
2012 Annual Report
Substantial results were realized over the 2 years of the project. Capitalizing on the human resources infrastructure of colleagues at the Sanford Research Institute/University of South Dakota, samples were obtained from a number of human omega-3 feeding trials, and novel information was obtained regarding the responses of human subjects to this treatment. First, we determined that omega-3 fatty acids in circulation exhibit a threshold behavior, and that as this threshold is approached, they become harder to change. Therefore, as a persons concentration of omega-3 fatty acids increase, the amount required to produce a change in these levels increases. Moreover, there is a relationship between body mass and this response, such that larger individuals need to consume more to obtain the same benefit. These findings suggest that dietary recommendations for omega-3 fatty acid intake to maintain a beneficial level may be improved by considering the subjects weight. In addition, we have also found that the lipoprotein particles are a rich source of oxygenated lipid mediators, and that each lipoprotein particle displays a unique profile of these mediators. Moreover, omega-3 fatty acid consumption impacts different classes of oxylipins within different lipoproteins to a different degree. Specifically, omega-3 fatty acid consumption decreases pro-inflammatory oxylipins with the very low density lipoprotein particles while increasing the anti-inflammatory lipids in this pool. These findings are consistent with the benefits to vascular inflammation noted for omega-3 fatty acid ingestion, and offer a novel mechanism for cardiovascular risk reduction beyond lowering of low density lipoprotein cholesterol. Together these findings have enhanced our understanding of the impact of omega-3 fatty acids on lipoprotein metabolism and advance the goals of the parent Project 5306-51530-019-00D, Linking Foods, Behavior and Metabolism to Promote a Healthy Body Weight.