Researchers found that over nine months, a daily dose of curcumin seemed to prevent new cases of diabetes among people with so-called prediabetes - abnormally high blood sugar levels that may progress to full-blown type 2 diabetes, which is linked to obesity.

Curcumin is a compound in turmeric spice, and lab research has suggested it can fight inflammation and so-called oxidative damage to body cells. Those two processes are thought to feed a range of diseases, including type 2 diabetes.

The study, published in the journal Diabetes Care, included 240 Thai adults with prediabetes who were randomly assigned to take either curcumin capsules or a placebo (identical-looking capsules with no active ingredient).

After nine months, 19 of the 116 placebo patients had developed type 2 diabetes. That compared with none of the 119 patients taking curcumin.

The researchers, led by Dr. Somlak Chuengsamarn of Srinakharinwirot University in Nakornnayok, Thailand, see the findings as an endorsement.

"Because of its benefits and safety, we propose that curcumin extract may be used for an intervention therapy for the prediabetes population," the researchers write.

They did not respond to an email request for an interview.

A diabetes expert not involved in the study, however, said it's too early for people to head to the health food store for curcumin supplements.

"This looks promising, but there are still a lot of questions," said Constance Brown-Riggs, a certified diabetes educator and spokesperson for the Academy of Nutrition and Dietetics.

One issue is that the trial lasted only nine months, Brown-Riggs told Reuters Health. And it's already known from longer-lasting, larger trials that lifestyle changes - including calorie-cutting and exercise - can prevent or delay type 2 diabetes in people with prediabetes.

Brown-Riggs said her concern is that people with prediabetes will see a quick fix in curcumin capsules.

"If I was talking to a patient about this," she said, "I'd say concentrate on eating healthy and overall lifestyle. Include more herbs and spices in your diet, and use them in place of sodium."

WHAT'S IN YOUR SUPPLEMENTS?

Brown-Riggs also noted that dietary supplements are not closely regulated in the U.S., and consumers cannot be sure that a product actually contains the ingredients, or the amount of the ingredient, listed on the label.

In this study, people took six supplement capsules per day, each of which contained 250 milligrams of "curcuminoids."

Last year, the testing company ConsumerLab.com found that 20 percent of curcumin and turmeric supplements it tested failed the company's quality review. And the cost of getting the amount of curcumin used in this study would range from 39 cents to $1.50 per day, depending on the supplement used.

But beyond those issues, Brown-Riggs said that her worry is that people will ignore the diet and exercise changes they need for overall health in favor of a "magic bullet."

"I think right now the best way to include this is in your diet," she said. "Try experimenting with Asian cuisines" - which often contain turmeric and curcumin.

That said, Brown-Riggs thought research into curcumin capsules should continue. "This study is compelling, and the good news is there seemed to be minimal adverse effects."

One study participant on curcumin reported "itching," two had constipation and one reported vertigo. It's not clear that the supplement was to blame.

And if curcumin does help battle diabetes, the reason for that is not fully clear.

But the researchers did find that the supplement seemed to improve the function of beta-cells - cells in the pancreas that release the blood-sugar-regulating hormone insulin.

They speculate that the anti-inflammatory effects of curcumin help protect beta-cells from damage.

SOURCE: bit.ly/MFHRTl Diabetes Care, online July 6, 2012.

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