1) Objectives: Studying the effect of Docosahexaenoic acid on effective factors of vascular thickness and function in diabetic patients. 2) Design: 72 T2DM patients will be evaluated for inclusion criteria and submitters will be divided in 2 age, sex, BMI matched groups (n=36) and will be randomized for intervention. 3) Setting and conduct: blood samples will be collected in starting and end of study and biochemical and anthropometric measurements will be conducted. Weight, height, waist circumference, hip circumference will be measured according to standard methods and obesity and central obesity indices will be calculated. Lipid profile, Fasting Blood Sugar, fasting insulin will be measured according to standard methods and serum LDL cholesterol level and insulin resistance will calculate using equations. We will measure telomerase activity by using PCR- ELISA, ADMA and sCD163 by ELISA kits and expression of interleukin 6 and TNF-alpha genes with real-time PCR. Questionnaires will be filled up and 3 day food record forms will be delivered to patients to fill them in first and last week of intervention. 4) Participants: 72 T2DM patients (males and females); Age from 30 to 70 years old and Body Mass Index from 18.5 to 30 kg/m2 Main exclusion criteria: Insulin therapy; any type of Cancer; Liver, Kidney, Coagulation, Thyroid, Cardiovascular disorders; consumption of Anticoagulants, ant-inflammatory drugs; Fibrates; Thiazolidinedione’s; Supplementation with omega-3, vitamin A,D and B6 5) Intervention: Participants will receive 2 gram per day DHA or placebo (Sunflower oil) capsules, for 8 weeks. 6) Main outcome variables: Interleukin 6 gene expression, TNF-α gene expression, ADMA, sCD163, Telomerase activity, Total cholesterol, Triglyceride, HDL- cholesterol, LDL-cholesterol, Fasting Blood Sugar, Fasting insulin, Insulin resistance, Glycated hemoglobin