Increased efficacy of a garlic supplement on knee osteoarthritis symptoms in patients with obesity

Obesity is a major risk factor for the incidence, progression, and poor outcomes of osteoarthritis (OA). It is unknown if obese patients could have different outcomes with complementary interventions. This study investigated joint symptoms following supplementation with a garlic tablet in obese women with knee OA. In this secondary analysis of a randomized, double-blind, placebo-controlled trial, 50 obese (BMI ≥ 30 Kg/m2) women with knee OA received either a 1000 mg garlic supplement or placebo for 12 weeks. The outcomes were joint symptoms, measured using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and pain severity based on a visual analogue scale (VAS). Garlic supplementation decreased WOMAC total score (29.2 ± 14.5 vs. 36.4 ± 14.3, P = 0.013), joint stiffness (1.3 ± 1.3 vs. 2.5 ± 2, P = 0.019), and physical function (20.5 ± 10.9 vs. 24.8 ± 10.3, P = 0.018) in the garlic compared with the control group. Pain severity decreased marginally (2 ± 3.1 vs. 0.4 ± 2.8, P = 0.073) in the garlic than the control group, which seemed to be clinically important. Additionally, all joint clinical outcomes improved remarkably in the garlic group compared to the baseline. There were no significant changes in anthropometric indices, body composition, and reported dietary intakes between the two groups at the end of the trial. A 12-week 1000 mg garlic supplementation exerted significant improvements in joint symptoms in the obese women with knee OA. Future studies should address the potential better response of obese patients to interventions as well as relevant underlying mechanisms. The study was registered with the Iranian Registry of Clinical Trials (http://www.irct.ir, registration code IRCT201307179543N2).