Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/17/2008
Publication Date: 3/1/2009
Citation: Kelley, D.S., Siegel, D., Fedor, D.M., Adkins, Y.C., Mackey, B.E. 2009. Docosahexaenoic Acid Supplementation Decreases Serum C - Reactive Protein and Other Markers of Inflammation in Hypertriglyceridemic Men1-3. Journal of Nutrition. 138: 30-35, 2008.
Interpretive Summary: Cardiovascular disease (CVD) and stroke are the leading cause of all deaths in United States, accounting for 38% of all deaths. Increased inflammation is an important factor causing the development and progression of both these chronic diseases. Circulating concentrations of number of inflammatory markers are used to evaluate the inflammatory status, but the most extensively studied biomarker of inflammation in CVD is C-reactive protein (CRP). Serum CRP is now accepted as an independent risk factor of a first myocardial infarction, ischemic stroke, peripheral vascular disease, and all-cause mortality. Fish oils that contain two fatty acids (eicosapentaenoic acid or EPA, and docosahexaenoic acid or DHA) have been reported to reduce the circulating concentration of inflammatory markers, however, the individual effects of these two fatty acids are not known. We studied the effects of DHA supplementation on the circulating concentration of inflammatory markers including CRP. Men with elevated triglycerides (17/group) supplemented their diets with either DHA oil (DHA 3 g/d) or olive oil for 90 days; 12-h fasting blood samples were drawn at the start, middle and end of the intervention. DHA supplementation for 45 and 90 d decreased the number of circulating neutrophils by 11.7 and 10.5 % respectively. Within 45 d of supplementation, DHA did not alter the circulating concentration of a number of other inflammatory markers, but within 90 d, it significantly reduced the concentrations of CRP (15%), Interleukin-6 (23%), and granulocyte monocyte-colony stimulating factor (21%) and increased that of anti-inflammatory matrix metalloproteinase-2 (7%). Our results suggest that DHA supplementation may improve cardiovascular health by attenuating the inflammatory response, in addition to the many other benefits (decreased triglycerides, and number of total and small dense LDL particles, remnant like cholesterol particles and increased HDL) we previously reported from this study. Increased intake of DHA may be used in the prevention and management of CVD and stroke.
Technical Abstract: Inflammation is an independent risk factor for the development of cardiovascular disease (CVD). N-3 polyunsaturated fatty acids (PUFA) reduce inflammation but the anti-inflammatory effect of docosahexenoic acid (DHA) in hypertriglyceridemic men has not been reported. We determined its effects on circulating concentrations of inflammatory markers and their associations with RBC fatty acids and plasma lipids and lipoproteins. Hypertriglyceridemic men (n=17/group) aged 39-66 y, participated in a double-blind, randomized, placebo controlled, parallel study. They received no supplements for the first 8 days then received either 7.5 g/d DHA oil (3 g DHA/d) or olive oil (placebo) for the last 90 d. Fasting blood samples were collected on -7, 0, 45, 84, and 91d. DHA supplementation for 45 and 91 d decreased the number of circulating neutrophils by 11.7 and 10.5 % respectively (P<0.05). Within 45 d of supplementation, DHA did not alter the circulating concentration of a number of other inflammatory markers, but within 91 d, it significantly (P<0.05) reduced the concentrations of CRP (15%), IL-6 (23%), granulocyte monocyte-colony stimulating factor (21%) and increased that of anti-inflammatory matrix metalloproteinase-2 (7%). RBC concentrations of SFA and (n-6) PUFA were positively connected and those of 18:1 (n-9) and (n-3) PUFA were negatively associated with plasma concentrations of several inflammatory markers. Mean size of VLDL particles was positively associated with plasma concentrations of neutrophils and CRP. In addition to other mechanisms, DHA supplementation may improve cardiovascular health by attenuating the inflammatory response.