Antihyperglycemic, antihyperlipidemic, anti-inflammatory and adenosine deaminase- lowering effects of garlic in patients with type 2 diabetes mellitus with obesity

Diabetes Metab Syndr Obes. 2013;6:49-56. doi: 10.2147/DMSO.S38888. Epub 2013 Jan 19.


Introduction: Type 2 diabetes mellitus is a chronic disorder characterized by chronic hyperglycemia, with long term macrovascular and microvascular complications. The treatment is lifestyle management, exercise, weight control, and antihyperglycemic drugs such as sulfonylureas, biguanides, alpha-glucosidase inhibitors, thiazolidinediones, and meglitinide. Recently, a direct association between high levels of C-reactive protein and serum adenosine deaminase levels in patients with uncontrolled diabetes with long-term complications has been seen. This study was conducted to assess the antihyperglycemic, lipid-lowering, anti-inflammatory, and improving glycemic control of garlic in type 2 diabetes patients with obesity.

Materials and methods: This was an open-label, prospective, comparative study, conducted on 60 patients having type 2 diabetes mellitus and obesity. The patients were divided into two groups of 30 each, of either sex. Group 1 was given metformin tablets, 500 mg twice a day (BD)/three times a day (TDS), after meals, and group 2 was given metformin tablets, 500 mg BD/TDS, after meals, along with garlic (Allium sativum) capsules, 250 mg BD. Patients were routinely investigated for fasting and postprandial blood glucose, glycosylated hemoglobin (HbA(1c)), serum adenosine deaminase levels and lipid profile (serum cholesterol, high-density lipoprotein cholesterol, triglycerides and low-density lipoprotein cholesterol) at the start of the study. Patients were followed up for 12 weeks, with monitoring of fasting and postprandial blood glucose at 2 week intervals, and monitoring of the other parameters at the end of study. Data obtained at the end of the study was statistically analyzed using Student's t test.

Results: It was observed that both metformin alone and metformin with garlic reduced fasting blood glucose and postprandial blood glucose significantly, with a greater percentage reduction with metformin plus garlic; however, change in HbA(1c) levels was not significant. A fall in total cholesterol, triglyceride, and low-density lipoprotein and an increase in high-density lipoprotein were more pronounced in patients treated with metformin plus garlic. Similarly, a fall in C-reactive protein and adenosine deaminase levels was greater in patients taking metformin with garlic than in patients taking only metformin.

Conclusion: Garlic has been shown to have antihyperglycemic and lipid-lowering properties. The additional lowering of C-reactive protein and serum adenosine deaminase levels with garlic suggests that garlic can be a valuable agent in providing good glycemic control and the prevention of long-term complications.

Keywords: Allium sativum; C-reactive protein; metformin.