Nutraceuticals for Knee Osteoarthritis Pain Relief. Results from a Preliminary Randomised Clinical Trial

Osteoarthritis is the most common inflammation-based joint disease. Polyphenols are plant secondary metabolites with established antioxidant and anti-inflammatory properties. Recognizing the need for holistic approaches in the management of knee osteoarthritis, we designed a two-arm, randomised clinical trial to evaluate the efficacy of a supplement rich in phenolic compounds in OA. Primary outcomes included changes in Visual Analog Scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis (WOMAC) pain subscale. Secondary outcome measures were the changes in WOMAC stiffness and functionality subscales. Patients were randomised (1:1) to receive a mixture of phenolic compounds and ascorbic acid (PhAA,) or ascorbic acid (AA). Μedical history, biochemical profile and anthropometric measurements were obtained. Eighty-six patients were screened and 25 were randomly allocated in a pilot study to receive a mixture of phenolic compounds and ascorbic acid (PhAA,) or ascorbic acid (AA) adjunct to stable medical treatment. The nutraceutical supplements were well tolerated and no adverse events were reported. VAS decreased in the PhAA group (p < 0.001). Additionally, WOMAC composite score decreased significantly only in the PhAA group (p < 0.05). The WOMAC subscale of pain decreased in both treatment groups (p = 0.001 for the PhAA group, p < 0.05 for the AA group). The decrease in the subscales of stiffness and physical function was not significant for either group. A possible improvement in the quality of life of these patients using nutraceutical supplements is apparent. Although preliminary, our positive results support the hypothesis that treatment with nutraceuticals may be effective for pain relief in osteoarthritis. ClinicalTrials.gov Identifier: NCT04783792.