Effects of garlic powder supplementation on insulin resistance, oxidative stress, and body composition in patients with non-alcoholic fatty liver disease: A randomized controlled clinical trial

Background: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. Insulin resistance, oxidative stress, and obesity are major contributors to NAFLD pathogenesis. The effects of garlic powder supplementation on these risk factors in patients with NAFLD was investigated. Methods: In this 12-wk, randomized controlled clinical trial, ninety patients with NAFLD were randomly assigned to two groups. The treatment group received four tablets of garlic (each coated tablet contained 400 mg garlic powder) daily and the control group received four tablets of placebo (each coated tablet contained 400 mg starch). Results: A significant decrease was seen in the treatment group compared to the control group in waist circumference (P = 0.001), body fat percent (P < 0.001), serum concentration of fasting blood sugar (P = 0.01), insulin (P < 0.001), homeostatic model assessment for insulin resistance (P < 0.001), and malondialdehyde (P < 0.001), as well as significant increase in skeletal muscle mass (P = 0.002), serum concentration of superoxide dismutase (P < 0.001), and total antioxidant capacity (P < 0.001). Conclusion: Garlic powder supplementation improved risk factors of NAFLD. Further studies are needed to determine the effects of garlic on hepatic features in patients with NAFLD. The study protocol was registered at Iranian clinical trials website under code IRCT20170206032417N4.