People in some parts of the world have used herbal remedies to treat diseases for centuries. But in the United States, we tend to rely heavily on traditional Western medicine.

Still, the use of dietary supplements has taken off in the last few decades. A 2011 survey from the CDC found that more than half of all adults in the U.S. take one of these products.

And in general, over half of people with rheumatoid arthritis take them, too, says Eric Matteson, MD, a rheumatologist at the Mayo Clinic in Rochester, MN.

But they can have side effects, and they don’t always work well with traditional medicines. That’s why you should always talk to your doctor before you try them to make sure they’re safe for you, Matteson says.

Although more research needs to be done on most dietary supplements used to treat rheumatoid arthritis, some can help ease both pain and inflammation.

Fish oil. Omega-3 fatty acids are found most often in fish, says Kim Larson, RD, a dietitian in Seattle. She suggests eating fish and seafood two to three times a week. “Good nutrition through food is the best avenue to health with RA,” she says.

If fish isn’t on your menu, try fish oil. The omega-3 fatty acids in these supplements have some of the same effects as nonsteroidal anti-inflammatory drugs, or NSAIDs. But they aren’t as hard on your stomach.

Fish oil comes from cold-water fish like salmon and tuna. Some of these can have high levels of mercury, so do your research before you pick a supplement. Omega-3 fatty acids can also slow blood clotting, so talk to your doctor about taking them if you’re already on blood thinners or blood pressure medications.

Borage oil. The seeds of certain plants, including borage, evening primrose, and black currant, contain an omega-6 fatty acid called gamma-linolenic acid (GLA). It can also ease joint inflammation and stiffness, says Paula Mendelsohn, RD, a dietitian and nutritionist in Boca Raton, FL. Though results from studies of GLA and rheumatoid arthritis vary, some do show less of a need for NSAIDs among people taking supplements with GLA.

Borage oil supplements can cause side effects like gas pains, constipation, or soft stools. Some products contain substances called pyrrolizidine alkaloids, which can cause liver damage.

Turmeric. Thiskey ingredient in Indian and Middle Eastern food contains the chemical curcumin, which may fight joint inflammation. A 2006 study even suggested that certain turmeric extracts were better at preventing it than easing it. Like fish oil, turmeric can act as a blood thinner if you take high doses of it, so be careful if you’re taking warfarin or other blood thinner meds.