Do turmeric supplements really treat pain, boost mood, and improve allergies? Experts say they work best for 2 conditions

While a lot of research has highlighted turmeric’s antioxidant and anti-inflammatory properties, the wide range of supplement potencies and doses used in studies has made it hard to confirm any health claims.

Keith Singletary, Ph.D., professor emeritus of nutrition at the University of Illinois Urbana-Champaign, has reviewed the evidence on turmeric. His take? “I think it’s promising,” he says, but he stresses that it isn’t “the cure-all that marketing would make it appear.”

What is turmeric good for?

The health properties attributed to turmeric come from natural compounds called curcuminoids. “Curcumin, which is the major one, is believed to be largely responsible for the health benefits of turmeric,” says Singletary.

What might curcumin do? The best evidence centers on two conditions: arthritis and metabolic syndrome.

Does turmeric help with arthritis?

Considering turmeric’s anti-inflammatory properties, it’s not surprising that researchers have investigated its use for arthritis. The supplement does appear to reduce pain and stiffness from osteoarthritis, the most common form of this achy joint disease.

“It’s not a miracle drug, but it probably works as well as ibuprofen or acetaminophen,” says Dr. Janet L. Funk, professor of medicine and vice chair of research for the Department of Medicine at the University of Arizona College of Medicine–Tucson. Her lab studies plant-derived dietary supplements for inflammatory diseases.

Does turmeric lower blood pressure?

Metabolic syndrome is a cluster of conditions like obesity, high blood pressure, high blood sugar, and high triglycerides that collectively increase the risk for diabetes, heart disease, and stroke. About one in three American adults have metabolic syndrome, according to the National Heart, Lung, and Blood Institute (NHLBI).

Studies have looked at the effects of turmeric on blood sugar, triglycerides, and insulin levels, as well as on inflammation (which also plays a role in metabolic syndrome). “In general, there was a strong preponderance of evidence that it might help reduce all those things. So it might have some benefit in people who are overweight and concerned about inflammation and diabetes,” Funk says. For people looking to lower their blood pressure, turmeric could be worth trying.

But there’s a very big caveat. “There’s a lot of inconsistency between studies,” Singletary says. And therein lies the problem in evaluating turmeric.

An imperfect science

Though plenty of research is being done on turmeric, the studies aren’t consistent. Researchers have tested different amounts of the supplement in different groups of people for different lengths of time. Some studies added a compound like piperine, found in black pepper, to make turmeric more active in the body (researchers call this increased “bioavailability”).

For example, one study on knee osteoarthritis had participants take 180 milligrams (mg) of curcumin for eight weeks. Another one used doses of 500 mg plus 5 mg of BioPerine (black pepper) extract three times a day for six weeks.

Because most of the studies have lasted four months or less, researchers don’t know what might happen with long-term use. “The bottom line is, there’s no definitive, well-designed studies at this point,” Funk says. She’s skeptical that there ever will be, given that the nutraceutical industry and the National Institutes of Health aren’t funding them.

What are the risks of turmeric?

Turmeric is probably safe if you get it from the spice or you take only the recommended amount in supplements, says the National Center for Complementary and Integrative Health. In larger quantities, it could cause GI side effects such as nausea or diarrhea.

Piperine poses its own set of issues, because it increases the bioavailability of curcumin by inactivating an enzyme in the liver that would otherwise break it down. “That enzyme is really important for [breaking down] most drugs people take,” says Funk. Theoretically, piperine might cause a buildup of medications in the body, thus increasing the risk for side effects. “Generally speaking, if you’re taking other medications, I would shy away from any product that has piperine in it, just in case it could interfere with the metabolism of your other drugs,” she adds.

An even bigger concern is a rare but serious risk of liver damage from turmeric supplements, as well as high levels of lead in these products. Several studies, including one that Funk coauthored, found excessive amounts of lead in some turmeric supplements—especially those that contained turmeric root. Exposure to lead in large quantities can have toxic effects on the body, including heart and kidney problems.

Is turmeric good for you?

Is it worth taking turmeric? “That’s the million-dollar question,” says Singletary. Given the lack of clear evidence on its benefits and the potential risks, he says you’re safest getting turmeric through your diet. You can add the spice to soups, stews, sauces, and smoothies. Top them with a pinch of black pepper or cook turmeric in oil to enhance its bioavailability.

If you do use turmeric supplements, it can be difficult to know which form is best, or how much to take. The best advice is to ask your health care provider, says Singletary. Start out with a low dose to see how your body responds to it. And don’t expect turmeric to be a “cure-all for all your ailments, which is unlikely to be the case,” he adds.

A version of this story originally published on Fortune.com on March 30, 2024.

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