Q: Does turmeric have proven health benefits?
A: Curcumin, the plant compound that gives turmeric its bright yellow-orange color, has demonstrated antioxidant, anti-inflammatory, anti-cancer and neuroprotective properties in laboratory and animal studies. But "claiming that it can be useful for humans is premature, given the current evidence," said Barbara Delage, a scientist with the Linus Pauling Institute's Micronutrient Information Center who reviewed the published literature on the spice.
Few good human clinical trials have been completed, Delage said. Curcumin has "very poor bioavailability," she said -- that is, it does not stick around in the human body for very long, and little of the plant compound is absorbed. Attempts to develop forms of the compound that are better absorbed are underway, she said, but will need to be tested.
Lab studies have shown that curcumin inhibits mediators of inflammation, and mouse studies found that, in rodents at least, it can ease colitis, blunt the immune responses in rheumatoid arthritis and reduce nerve inflammation in traumatic brain injury.
A few small trials in people have found curcumin to be as effective as nonsteroidal anti-inflammatory drugs for the joint pain of rheumatoid arthritis, and it was more effective than some standard drugs used to reduce flare-ups of ulcerative colitis.
But, Delage said, "You can't conclude anything with one or two small studies, and you have to be very skeptical because the bioavailability is terrible."
A trial that examined curcumin and other compounds found it alleviated nausea, bloating and gastric pain but not acid reflux in people with H. pylori infections. But that study had no control group, and other studies have found curcumin may worsen digestive upset.
Other trials found curcumin may improve insulin sensitivity and reduce inflammation in people with diabetes or prediabetes, though larger studies are needed.
Trials of curcumin in people with Alzheimer's disease and depression have had mixed results.
ActiveStyle on 05/02/2016
Print Headline: Spice's health benefits hard to test in people