SHORT COMMUNICATION An inverse relationship between plasma n-3 fatty acids and C-reactive protein in healthy individuals MA Micallef 1 , IA Munro 1 and ML Garg 1,2 1 Nutraceuticals Research Group, School of Biomedical Sciences, The University of Newcastle, Callaghan, New South Wales, Australia and 2 Hunter Medical Research Institute, John Hunter Hospital, New Lambton, New South Wales, Australia High sensitivity C-reactive protein (hs-CRP) is a marker of low-grade sustained inflammation. Omega-3 (n-3) fatty acids have anti-inflammatory properties and are associated with reduced cardiovascular disease (CVD) risk. The aim of this study was to investigate whether plasma n-3 fatty acid concentration is related to hs-CRP concentration. A total of 124 free-living adults, were divided into tertiles of plasma hs-CRP (o1.0, 1.0–3.0 and 43.0 mg/l). Body composition and anthropometric measurements were recorded. Hs-CRP was analysed using immunoassays and fatty acids were measured by gas chromatography. Plasma hs-CRP concentration was negatively correlated with total n-3 fatty acids (P ¼ 0.05), eicosapentaenoic acid (EPA; P ¼ 0.002) and docosapentaenoic acid (DPA; P ¼ 0.01). The highest hs-CRP tertile (43.0 mg/l) had significantly lower concentrations of total n-3 fatty acids, EPA and DPA, when compared with the other tertiles (Po0.05). This study provides evidence that in healthy individuals, plasma n-3 fatty acid concentration is inversely related to hs-CRP concentration, a surrogate marker of CVD risk. European Journal of Clinical Nutrition (2009) 63, 1154–1156; doi:10.1038/ejcn.2009.20; published online 8 April 2009 Keywords: C-reactive protein; omega-3 fatty acids; cardiovascular disease; inflammation Introduction Inflammation plays an important role in all stages of atherosclerosis. High sensitivity C-reactive protein (Hs-CRP) is an acute-phase inflammatory mediator mainly regulated by interleukin (IL)-6 in the liver and has been shown to predict future cardiovascular disease (CVD) events. To date, several large-scale studies confirm circulating levels of hs-CRP to independently predict future CVD events in individuals without known CVD (as reviewed by Clearfield, 2005). The inverse relationship between the consumption of oily fish, fish oil and CVD risk is well established. Conversely, the relationship between omega-3 (n-3) fatty acids and surrogate markers of CVD risk are less clear (Balk et al., 2006). Observational data suggests that n-3 fatty acids are cardio- protective, have anti-inflammatory properties, reduce hypertension, inhibit thrombosis and arrhythmia and improve arterial compliance (Kris-Etherton et al., 2002). In this study, we investigate the relationship between plasma n-3 fatty acids and hs-CRP concentration in healthy individuals. Subjects and methods A total of 127 adults were recruited from the general community of Newcastle, Australia. Individuals with dia- betes mellitus, hepatic/renal disease, chronic inflammatory conditions (that is, arthritis, gout), cancer, and pregnant or lactating women, those using anti-hypertensive/inflam- matory medication, individuals taking fish oil supplements, those on a restricted diet and individuals who smoked tobacco, were excluded from the study. A full medical history was collected from all individuals. Individuals with an hs-CRP concentration X10.0 mg/l (n ¼ 3) were also excluded, given that acute inflammatory conditions are associated with hs-CRP concentrations of 10–50 mg/l. The final study population comprised 124 individuals (46 males and 78 females). All participants gave written informed consent, and the study was approved by the Human Research Ethics Committee of The University of Newcastle, Australia. Received 19 October 2008; revised 13 January 2009; accepted 3 March 2009; published online 8 April 2009 Correspondence: Professor ML Garg, Nutraceuticals Research Group, The University of Newcastle, 305C Medical Sciences Building, Callaghan, NSW 2308, Australia. E-mail: manohar.garg@newcastle.edu.au European Journal of Clinical Nutrition (2009) 63, 1154–1156 & 2009 Macmillan Publishers Limited All rights reserved 0954-3007/09 $32.00 www.nature.com/ejcn