Diabetes is a chronic disease and the prevalence of diabetes mellitus is rapidly increasing as a result of population ageing, urbanization and associated lifestyle changes. Recently, the use of natural products in chronic diseases such as diabetes has gained more attention. Chlorella is a single-celled green algae that contains essential nutrients including amino acids and fatty acids as well as some vitamins and minerals. There have been some studies on the effects of chlorella supplementation in chronic diseases such as NAFLD, prediabetes and diabetic mice, but none of them examined the effects of chlorella in patients with type 2 diabetes. Thus the present study designed to evaluate the effects of chlorella supplementation on glycemic control, lipid profile and anthropometric measurements in type 2 diabetic patients.

This study is a double-blind, randomized controlled trial. 84 patients with type 2 diabetes are recruited. After informing the patients about this study and filling the consent letters, they are randomly assigned into intervention group (n=42) or placebo group (n=42) receiving 1500 mg chlorella Vulgaris or placebo daily for 8 weeks. Patients are asked not to change their regular physical activity, diet, medicine and dosage during the study. Anthropometric and blood pressure measurements are collected and 24-hour food intake recall, IPAQ physical activity, Pittsburgh Sleep Quality Assessment (PSQI) and Beck anxiety and depression questionnaires are filled by each patients at the beginning and end of the study. In addition, blood samples are collected at the beginning and end of the study to determine the changes of FBS, HbA1c, insulin concentration and insulin resistance (HOMA-IR) and lipid profile.

Inclusion Criteria:

• Tendency to participate
• Clinical diagnosis of T2DM
• Having T2DM for at least 1 year
• Range of HbA1c between 6.5% and 8.5%
• Triglyceride range lower than 300 mg/dl

Exclusion Criteria:

• Insulin dependent patients
• Smoking and alcohol consumption
• Patients with cardiovascular disease, liver disease, renal and thyroid diseases
• Pregnancy, lactation and menopause
• Intake of multivitamin and mineral supplements

This study is a double-blind, randomized controlled trial. Subjects will be randomly allocated into two groups and each one will receive the supplement (Chlorella Vulgaris) or placebo for 8 weeks. To prevent selection bias, the study participants, investigators and the laboratory staff will be all blinded to treatment assignment.