1- Objectives: Previous studies have shown that omega-3 fatty acids may reduce inflammation, oxidative stress, and fat mass in patients with type 2 diabetes, but the results are inconclusive, due, in part, to type of omega-3 fatty acids used. The aim of this study is to compare the effects of pure eicosapentaenoic and docosahexaenoic acids, the two major omega-3 fatty acids, on fat mass, oxidative stress, inflammation and blood sugar in patients with type 2 diabetes.
2- Design: double-blind placebo controlled trial
3- Setting and conduct: Sixty patients with type 2 diabetes will be referred from Institute of Endocrinology and Metabolism, Firouzgar Hospital, Tehran University of Medical Sciences. They will be randomly allocated to receive daily either 1 gram eicosapentaenoic or 1 gram docosahexaenoic acids, or a placebo for 12 weeks. Ten milliliters of fasting blood will be taken at baseline and at the end of the intervention. Serum malondialdehyde, C-reactive protein, fasting blood sugar and fat mass will be measured at baseline and after intervention.
4- Participants: 35-65 year-old patients with type 2 diabetes who are overweight and use oral hypoglycemic agent, Exclusion criteria: treatment with insulin; taking fish oil supplements or NSAIDs during the last 3 months before intervention; taking fish more than once a week; having cardiovascular, liver, kidney disease; smoking; weight changes more than three kilograms during three months before intervention; change in type or dose of oral hypoglycemic agent for at least two weeks prior to entry or during intervention;
5- Intervention: 1 gram eicosapentaenoic or docosahexaenoic acid daily , or placebo (canola oil) for 12 weeks
6- Main outcome measures variables: Serum malondialdehyde, C-reactive protein, fasting blood sugar and fat mass