Curcumin, Curry, Diabetes Prevention, and Obesity   (August 8, 2012)

This morning's CBS TV news show mentioned a new way to prevent diabetes, with the spice curcumin – so I hastened to find out more, and to share what I’ve found.

Curcumin is otherwise known as turmeric, and is a common cooking spice obtained from a herb that is native to India, which is widely used in many curries. It has long been thought to have medical effects in various diseases, and now we can add diabetes prevention to the list.

The news story was based on a publication in the journal Diabetes Care this week: Curcumin Extract for Prevention of Type 2 Diabetes. The authors studied 240 patients with prediabetes in Thailand, giving half of them curcumin capsules, and the other half placebo capsules, for nine months. All subjects were educated in diet and exercise during a 3-month period after enrollment, before randomization. The study was appropriately double-blinded and randomized.

The curcumin and identical placebo capsules were manufactured by the Government Pharmaceutical Organization of Thailand. Participants took six capsules daily, each containing 250 mg of curcuminoids (totalling 1500 mg/day of curcuminoids) or six placebo capsules.

The authors concluded that "9-month curcumin intervention of a prediabetes population significantly lowered the number of prediabetic individuals who eventually developed T2DM. In addition, the curcumin treatment appeared to improve overall function of beta cells, with very minor adverse effects."

Whoops! "Minor adverse effects"? That's a warning bell for someone such as myself who's spent a large part of my professional career in drug safety. The authors explained "A few subjects from the curcumin-treated group reported minor symptoms such as itching (one subject), constipation (two subjects), and vertigo (one subjects[sic]). None in the curcumin treated group showed hypoglycemia symptoms. Interestingly, at the last follow-up visit (9 months after intervention), we noticed a slight reduction of mean body weight and WC [waist circumference] from the group of subjects treated with curcumin. We did not see such reductions in the placebo-treated group."

That last comment is indeed very interesting. Mean weight change of subjects on placebo was a gain of about five pounds, from a mean of 67.8 kg (149.5 lb) to 70.1 kg (154.5 lb), while subjects on curcumin lost over 8 pounds, from a mean of 67.7 kg (149.3 lb) to 63.8 kg (140.7 lb). That's a spectacular difference in nine months, given that all subjects were supposed to be on the same diets, and had been instructed in diet and exercise for 3 months before randomization occurred. BTW, waist circumference measurements showed the same trend, increasing on placebo and decreasing on circumin.

After my brief review of the study, I would conclude that people with prediabetes tend to gain weight over nine months (no big surprise), and that this weight-gain tendency is reversed spectacularly by adding 1500 mg/day of curcuminoids to the diet.

Turns out this isn't the first time that such a conclusion has been reached. In a mouse study from 2008, Dietary Curcumin Significantly Improves Obesity-Associated Inflammation and Diabetes in Mouse Models of Diabesity, it was noted that "orally ingested curcumin reverses many of the inflammatory and metabolic derangements associated with obesity and improves glycemic control in mouse models of type 2 diabetes."

Should the reader start taking curcumin? It's widely available as a supplement, and is hawked as relieving or curing just about everything from measles to worms. I'm not sure. One problem is that the study I discuss above only used one dose of curcumin, and it's therefore unclear whether that's the optimal dose, or if more would be better, or if less would be just as effective and a lot cheaper. As always, if you do plan to start this or any other supplement, be sure to discuss with your physician.

Or you could increase your consumption of curries and tandoori -- which sounds like more fun to me.