Dr. Adam Metherel - March 20

Acute DHA Supplementation Increases Omega-3 PUFA Synthesis – Biomarkers, Mechanisms and Implications of DHA Cycling

Changes in dietary polyunsaturated fatty acids (PUFA) have been shown to affect docosahexaenoic acid (DHA, 22:6n-3) synthesis and accretion rates, and DHA supplementation has long been believed to lower DHA synthesis rates via negative feedback controls. Recently, my research has discovered that acute DHA intake in rats can actually increase the synthesis-secretion kinetics of omega-3 PUFA, including EPA and DHA. This includes an 8.7- to 11.5-fold higher capacity for the synthesis-secretion of eicosapentaenoic acid (EPA, 20:5n-3) and omega-3 docosapentaenoic acid (DPAn-3, 22:5n-3) from plasma unesterified fatty acid sources after 2 weeks of DHA supplementation compared to 8 weeks of DHA. Furthermore, daily synthesis-secretion rates were 11-fold higher after 4 weeks of supplementation compared to a DHA-free control diet. Dietary DHA plus EPA recommendations are frequently stated at 500mg per day, and it is estimated that these recommendations would result in a commercial EPA/DHA production deficit of up to one million metric tons per year. Taking advantage of the aforementioned findings through a dietary DHA cycling protcol (repeated periods of acute DHA intake) in rodents, I have determined that tissue and blood DHA levels matching that of chronic DHA feeding can reduce dietary DHA requirements by at least half. These findings have the potential to significantly narrow the gap between EPA/DHA production and consumption when applied to a human population level. A major focus of my research will build off of these findings with studies assessing alternative dietary strategies for reducing dietary DHA requirements. This will include the optimization of DHA cycling protocols and the application of these dietary strategies to rodent models of pregnancy and lactation, which will be accomplished through DHA accretion and kinetic modeling. Furthermore, applying these novel dietary strategies to human populations is a primary goal of my future research, with a special emphasis on the perinatal and postnatal period of maternal and child health. In summary, my research aims to maximize tissue DHA levels while minimizing dietary DHA requirements focusing on maternal, fetal and child DHA status.

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Biochemistry

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