The anti-inflammatory properties of fish oil have been demonstrated, but for patients with knee osteoarthritis, high doses of fish oil were no more effective than was low-dose fish oil, according to Dr. Catherine L. Hill and her associates.
Just over 200 patients with knee OA were included in the study, with half receiving a full anti-inflammatory dose of 15 mL of fish oil/sunola oil per day containing 4.5 g of omega-3 fatty acids, and the other group receiving 15 mL of fish oil/sunola oil per day containing 0.45 g omega-3 fatty acids.
©Clayton Hansen/iStockphoto
After 1 year, Western Ontario and McMaster Universities Arthritis Index scores were similar in both groups, but after 2 years, WOMAC pain and function scores were better in the low-dose fish oil group.
There was no difference in usage of analgesics or NSAIDs between the two groups during the 2-year study period. Cartilage volume loss was similar in both groups. Weight gain was greater in the high-dose fish oil group, but analysis showed this had no effect on pain scores in the high-dose group.
“One possible explanation could be that sunola oil with or without low-dose fish may confer a beneficial effect, but this unanticipated finding requires confirmation in further trials,” the investigators said.
Find the study here in Annals of the Rheumatic Diseases (doi: 10.1136/annrheumdis-2014-207169).