The effect of EPA and DHA on metabolic syndrome patients: a systematic review of randomised controlled trials

Abstract

Metabolic syndrome (MS) is characterised by accumulation of CVD risk factors. The use of very long chainn-3 polyunsaturated fatty acids (VLCn3 PUFA) could potentially benefit MS by reducing risk factors. To better understand the possible VLCn3 PUFA benefits, the literature was systematically reviewed for randomised controlled trials (RCT) that published effects of VLCn3 PUFA on MS patients. 17 RCT fulfilled the inclusion criteria and were analysed for relevance to the research question. The available RCT convincingly show that the administration of VLCn3 PUFA doses > 1 g for at least 3 months produces a significant reduction of triglycerides ranging from 7 % to 25 %. These results confirm the hypotriglyceridemic effect of VLCn3 PUFA in MS patients. The triglyceride lowering may produce further benefits by reducing the % of pro-atherogenic small dense LDL particles (sdLDL) and also perhaps by ameliorating the inflammatory process associated with MS. High doses of VLCn3 PUFA ( ≥ 3 g/day) may produce further TAG reductions but could raise other risk factors such as LDL-C. No clear effects were found on other MS markers. The combination of VLCn3 PUFA plus a statin may be useful to prevent the occurrence of coronary events. More studies are needed using different amounts of VLCn3 PUFA, time lengths, dietary backgrounds and different profiles of MS patients before clear recommendations can be made.