A new British report has found that few popular supplements have strong scientific evidence showing that they work for rheumatoid arthritis (RA), osteoarthritis (OA) or fibromyalgia. But some did rank as effective, including capsaicin, SAMe and Indian frankincense for OA, and fish oil for RA.

The lack of research data on complementary medicines “makes it very difficult for us to know whether they are effective, but equally we can’t be sure they are not effective,” says lead study author Gary J. Macfarlane, MD, PhD, professor and chair of epidemiology in the School of Medicine and Dentistry at the University of Aberdeen, in Scotland

The evidenced-based report is the second edition, updated with the latest clinical data, by Arthritis Research UK, a large medical-research organization. It was done to provide comprehensive information on the effectiveness and safety of supplements in an effort to help patients and clinicians make informed decisions.

“What this report is not about is telling arthritis patients whether to use a complementary therapy or not,” says Dr. Macfarlane. “Each individual must make that decision for themselves, and it is likely to be partly based upon how effective these therapies are, their safety and their cost.”

Researchers evaluated 31 complementary medicines taken either by mouth or applied to the skin that were found to have quality studies available. Each was scored for effectiveness based on users’ improvements in pain, disability or quality of life, with “1” suggesting the supplement is not effective and “5” suggesting consistent evidence of efficacy. Few supplements were given a “5” rating.  

For OA, capsaicin, a topical treatment extracted from chili peppers, scored 5. Two supplements scored 4 – SAMe, a compound found naturally in the body, and Indian frankincense, a plant extract that blocks the production of hormone-like substances thought to trigger joint inflammation.

For RA, nearly three-quarters of the supplements evaluated scored poorly, but fish oil scored 5.

For fibromyalgia, no supplement scored 5 or 4.  

Devil’s claw, ginger, green-lipped mussel, pine-bark extracts and rosehip all rated 3 for OA. For RA, borage seed oil and evening primrose oil also received 3.  

Glucosamine, which is very popular in the United States, showed little evidence to support reduction of pain or positive joint changes; glucosamine hydrochloride scored 1 and glucosamine sulfate was given a 2.