Omega-3 fatty acids have small analgesic effect

General

Clinical Question:
Can long-term dosing of omega-3 fatty acids decrease inflammatory joint pain?

Bottom Line:
In patients with joint pain due to rheumatoid arthritis, inflammatory bowel disease, or dysmenorrhea, continuous therapy with fish oil or other sources of omega-3 fatty acids produced statistically significant decreases in pain. The onset of action is approximately 3 months. Even though the benefit may be small, the lack of significant side effects and the beneficial effect on cardiovascular disease (Circulation 2002;106:2747-2757) make fish oil and other sources a useful option in patients with pain due to inflammation. (LOE = 1a)

Reference:
Goldberg RJ, Katz J. A meta-analysis of the analgesic effects of omega-3 polyunsaturated fatty acid supplementation for inflammatory joint pain. Pain 2007;129;210-223.  [PMID:17335973]

Study Design:
Meta-analysis (randomized controlled trials)

Setting:
Various (meta-analysis)

Synopsis:
Omega-3 fatty acids may decrease inflammation by competing with arachidonic acid, the precursor to the inflammatory prostaglandins. To identify research for inclusion, the researchers searched several databases for English-language randomized clinical trials, also searching references of retrieved articles for additional relevant studies. The data were abstracted by a single person but 2 researchers independently assessed study quality. The resulting meta-analysis included 17 studies enrolling a total of 823 patients, though not all studies evaluated all outcomes. The studies used fish, seal, or flaxseed oil to provide various amounts of omega-3 fatty acid. High dose was defined as greater than 2.7 g daily. All comparisons were against inactive placebo or olive oil, which might have antiinflammatory property. Daily supplementation for 3 to 4 months reduced patient-reported joint pain intensity, minutes of morning stiffness, number of painful joints, and analgesic consumption. The benefit was not striking and was not found in physician-reported scores or the Ritchie articular index. The quality of included studies was satisfactory.