For 20 years research has been accumulating about omega-3 (fish oil) supplements as a treatment for rheumatoid arthritis (RA), with mostly promising results. RA is an autoimmune disease that causes inflammation in joints and various organs. For instance, a 2007 analysis of 17 small clinical trials (lasting three to six months) concluded that the supplements may help modestly reduce joint pain and tenderness, morning stiffness, and use of pain relievers. Late last year perhaps the best study yet on the subject appeared in the Annals of Rheumatic Diseases.
Promising, but not a slam-dunk
The Australian study involved 140 people who had RA for less than a year and were not taking the standard drugs for the disease. The treatment group was given a high dose of omega-3s (5.5 grams a day, though they ended up averaging 3.7 grams a day). The rest took a low dose (0.4 grams); all started taking standard RA drugs as well. After a year, those taking high-dose omega-3s were 76 percent less likely to need an additional, newer—and very expensive—anti-rheumatic drug than the low-dose group. They were also twice as likely to go into remission, the goal of drug treatment, and more likely to stop taking pain relievers.
This suggests that omega-3s could be a useful adjunct to the standard medications and may help slow the progression of RA in some people. That is no minor matter when dealing with a hard-to-manage progressive disease like RA. Keep in mind, however, that while the study was larger and longer than earlier trials, it was still relatively small and short, and not all previous research on this has had positive results. So these findings will need to be confirmed, especially since the dose of omega-3s is so large.
How might omega-3s help? Lab research shows that these fats have quite a few anti-inflammatory effects. Notably, they inhibit pro-inflammatory chemical mediators (including certain cytokines, prostaglandins and leukotrienes) that play a role in rheumatoid arthritis and other inflammatory diseases. They also boost levels of anti-inflammatory chemicals such as resolvins, which have been the focus of recent research.
What about osteoarthritis?
Far more people have osteoarthritis (OA), characterized by the breakdown of cartilage, than RA. It used to be believed that only RA involved inflammation, which was the rationale for trying omega-3s as a treatment. It’s now known, however, that inflammation also plays a role in OA, though to a lesser degree.
Much less research has been done on omega-3s for OA than for RA. Lab studies have shown that omega-3s can improve various biomarkers for osteoarthritis and reduce enzymes that degrade cartilage. But there have been no good clinical trials showing that omega-3s reduce OA symptoms or actually reduce cartilage breakdown, as seen in X-rays or MRIs.
Bottom line: If you have RA, talk with your doctor about omega-3 supplements. Keep in mind that the longer-term safety of the high doses used in this and other studies is unknown, especially if you are immunocompromised or are taking drugs that affect your immune system. Expecting omega-3 capsules to ease osteoarthritis is just wishful thinking, at this point. Instead, we advise eating fatty fish at least twice a week.