Effects of orally administered cetylated fatty acids on symptoms and functional capacity in patients with knee osteoarthritis: results of a randomized, double-blind, placebo-controlled study.

Background/objectives: The development and implementation of new treatments for knee osteoarthritis in routine practice remains an unmet need. The aim of this study was to assess the efficacy and safety of a Cetylated Fatty Acids (CFA)-based dietary supplement in patients with knee osteoarthritis (OA), a prevalent and difficult-to-treat condition.

Subjects/methods: 60 patients (mean age: 66.0 ± 7.7 years, 85% female) with grade 3-4 knee osteoarthritis and a pain intensity of > 4 cm on the visual analog scale (VAS) were enrolled and randomized in a 1:1 ratio to receive either 1.5 g of oral CFA or a placebo for 60 days. The primary outcome was the change in pain intensity (VAS), secondary outcomes included changes in range of motion (ROM), in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the safety profile of the food supplement.

Results: After 60 days of CFA assumption, the mean reduction in pain intensity (VAS) was -1.7 cm (95% CI [-2.0, -1.4]), showing a statistically significant difference compared to placebo (-0.6 cm, 95% CI [-1.0, -0.2]; p < 0.005). The mean decrease in the WOMAC total score was also greater in the CFA group (-19.5 vs. -15.8), although the placebo-corrected effect was not statistically significant (-3.7, 95% CI [-8.3, 0.8]; p = 0.108). Observed improvements in flexion (3.8° [95% CI: 2.6, 5.0]) and external rotation (2.9° [95% CI: 2.1, 3.8]) were both statistically significant in favor of CFA (p ≤ 0.001) compared to placebo. Differences in extension and internal rotation were negligible. The safety profile of the investigational product resulted favorable, considering that only 4 out of 30 patients reported mild adverse events, and none withdrawn from the study due to adverse events.

Conclusion: In patients with knee osteoarthritis, incorporating a CFA oral supplement into the treatment regimen provides superior efficacy in pain relief and range of motion improvement compared to placebo, while maintaining a favorable safety profile.