INFLUENCE OF DIETARY FATTY ACIDS ON HUMAN HEALTH WITH EMPHASIS ON IMMUNE AND INFLAMMATORY RESPONSES
Location: Immunity and Disease Prevention Research Unit
Title: Docosahexaenoic acid supplementation improves fasting and postprandial plasma lipid profiles in hypertriglyceridemic men.
Submitted to: American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 5, 2007
Publication Date: April 5, 2007
Citation: Kelley, D.S., Siegel, D., Vemuri, M., Mackey, B.E. 2007. Docosahexaenoic acid supplementation improves fasting and postprandial plasma lipid profiles in hypertriglyceridemic men. American Journal of Clinical Nutrition. 86:324-333, 2007.
Interpretive Summary: Cardiovascular disease is the number one killer in United States. Individuals with elevated triglycerides, LDL cholesterol (C), small dense LDL particles and low HDL cholesterol are considered to have an atherogenic phenotype. Fish oils that contain long chain omega-3 fatty acids (eicosapentaenoic acid or EPA and docosahexaenoic acid or DHA) lower triglycerides, and increase LDL and HDL cholesterol. While the reduction in triglycerides and increase in HDL cholesterol will reduce the risk for cardiovascular disease (CVD), but the elevated LDL may actually increase the risk for CVD. The small dense LDL particles are atherogenic, while large LDL particles improve cardiovascular health. Effects of fish oils, EPA or DHA on the concentration of the various subclasses of the LDL and the mean size of the LDL particles (LDLp) have not been studied. Men with elevated triglycerides (17/group) supplemented their diets with either DHA oil (DHA 3 g/d) or olive oil for 90 days; fasting and postprandial blood samples were drawn at the start, middle and end of intervention. DHA supplementation reduced concentrations of triglycerides (24%), small LDLp (25%), total LDLp (11%). It increased concentrations of LDL-C (12.6%) and HDL- C (7.5%), large LDLp (120%), large HDLp (63%), and mean size of LDLp (0.6 nm), in fasting plasma. Similar changes were observed for area under the curve for postprandial samples (0-6 h). DHA supplementation may reduce risk for CVD by reducing concentrations of triglycerides and total and small dense LDLp and by increasing concentrations of HDL-C. These finding are important in the prevention and management of CVD.
Background: The effects of docosahexaenoic acid (DHA) on the concentrations of different subclasses of VLDL, LDL and HDL particles, and their mean diameters in fasting and postprandial plasma has not been studied.
Objective: To determine the effects of DHA supplementation on the concentrations of apoproteins, and large, medium, and small subclasses of VLDL, LDL, and HDL particles, and their mean particle sizes in fasting and postprandial plasma.
Design: Hypertriglyceridemic men aged 39-66 y participated in a double-blind, randomized, placebo controlled, parallel study. They received no supplements for the first 8 days and received either 7.5 g/d DHA oil (3 g DHA/d) or olive oil (placebo) for the last 90 d (n=17/group). Lipoprotein subclasses and particle sizes were measured by NMR spectroscopy.
Results: DHA supplementation for 45 d significantly (p<0.05) reduced concentrations of fasting apo CIII (13.5%), triacylglycerol (24%), large VLDL (92%), IDL (53%), small LDL (25%), total LDL (11%), and the mean diameter of VLDL particles (11.1 nm). It increased concentrations of LDL- (12.6%) and HDL- C (7.5%), small VLDL (133%), total VLDL (10%), large LDL particles (120%), large HDL (63%), and mean size of LDL particles (0.6 nm), in fasting plasma. Similar changes were observed for area under the curve for postprandial samples (0-6 h). Continued supplementation with DHA beyond d 45 did not cause any further significant changes; placebo treatment altered none of the responses tested.
Conclusions: DHA supplementation may reduce risk for CVD by reducing concentrations of triacylglycerols and total and small dense LDL particles, and by increasing concentrations of HDL-C.