Effects of Rosemary Oil on Osteoarthritis Symptoms in the Elderly: A Double‌-Blind Randomized Control

Background: Despite anti-inflammatory effects of rosemary, there is no broad consensus on the effects of rosemary on osteoarthritis symptoms, being among the most common causes of disability. This study aimed to determine the effects of rosemary ointment on osteoarthritis symptoms in the elderly. Materials & Methods: In this double-blind randomized trial, 75 elderly patients with knee osteoarthritis were selected from comprehensive health service centers based on inclusion criteria and assigned by the random minimization method to three groups equally. In the intervention and placebo groups, 4 cm of rosemary and Vaseline ointment were applied twice a day, respectively, for 10 days. The control group received no intervention. In addition, the Western Ontario and McMaster Universities Arthritis Index (WOMAC) was measured for the three groups, before, immediately after, and one month after the intervention. Data were analyzed using the Mann Whitney U test, a repeated measures ANOVA, and statistical modeling.  Results: There were no significant differences among the study groups based on demographic characteristics. In the rosemary and placebo groups, the mean score of the WOMAC and pain improved significantly (p = 0.001) immediately and one month after the intervention. In terms of intergroup comparisons, the WOMAC and pain scores, immediately after the intervention, were significantly higher in the rosemary group than in the other two groups (p < 0.05). However, joint performance and stiffness scores had on significant differences. Conclusions: The results showed that shortly after the intervention, WOMAC and pain scores improved in the rosemary group. However, no improvement was observed in joint stiffness and function.