Turmeric supplement more effective than placebo for osteoarthritis knee pain

An extract of Curcuma longa (CL), commonly known as turmeric, was found to be more effective than placebo for reducing knee pain in patients with knee osteoarthritis. However, CL did not affect structural aspects of knee osteoarthritis, such as swelling or cartilage composition assessed using MRI. Findings from a randomized, double-blind, placebo-controlled trial are published in Annals of Internal Medicine.

Despite its large disease burden, no approved disease-modifying drugs currently are available to treat osteoarthritis. Common treatments, such as acetaminophen and nonsteroidal anti-inflammatory drugs have only mild to moderate effects and are associated with adverse events. As such, an urgent need exists for safer and more effective drugs to treat osteoarthritis.

Researchers from the University of Tasmania, Australia randomly assigned 70 participants with symptomatic knee osteoarthritis and ultrasound evidence of effusion (swelling inside the knee joint) to receive either 2 capsules per day of CL (n = 36) or matched placebo (n = 34) for 12 weeks to determine the efficacy CL for reducing knee symptoms and joint swelling. Changes in pain and knee effusion-synovitis volume were assessed by standardized questionnaire and MRI, respectively, over 12 weeks. The researchers also looked for changes in cartilage composition, pain medication usage, quality of life, physical performance measures, and adverse events. After 12 weeks, they found that patients taking the turmeric supplements reported less pain than those in the placebo group with no adverse events. Besides, participants in the turmeric group consumed fewer pain medications compared to the participants in the placebo group. There was no difference in the structural aspects of knee osteoarthritis between the groups. Due to the modest effect of the turmeric extracts on knee pain, small sample size of the study, short-duration of follow-up and the single research center, the researchers suggest that multicenter trials with larger sample sizes and long duration of follow-up are needed to assess the clinical significance of their findings.