One of the latest stories in the news about nutritional supplements is that curcumin may help prevent the progression of pre-diabetes to type 2 diabetes. The facts have been pretty badly mangled by the news media (including the ConsumerLab site, where I first noticed the story), but here's the scoop.
Dr. Somlak Chuengsamarn and collaborators at several prestigious universities in Thailand tested curcumin (not turmeric, as the news reports have been saying) as a possible preventive agent for type 2 diabetes. The Thai researchers recruited 240 people with prediabetes to take a daily dose of 1500 mg of either curcumin or a placebo for nine months.
At the end of the nine-month trial, the researchers found that 16% of volunteers who had been taking the placebo had developed full-blown, type 2 diabetes, but none of the volunteers who took curcumin had. The researchers also found better beta-cell function in the volunteers who had been taking curcumin.
This finding is being reported as "curcumin gave beta-cells a boost," but actually that's probably the exact opposite of what happened. In type 2 diabetes, the insulin-making beta-cells of the pancreas work so hard they eventually "burn out." Probably curcumin did not so much give the beta-cells a boost as protect them from free radical processes that destroy the ability of the cells to "unzip" stored insulin.
The researchers also found that taking curcumin raised levels of adiponectin, which tends to lower levels of body fat.
So is curcumin a cure for type 2 diabetes? No, but it probably helps a lot.
The best way to preserve beta-cell function is simply not to give your beta-cells too much to do. Don't eat sweets. Don't overeat carbs--or anything else.
If you just can't control your appetite, curcumin can still help. Evidently it can help a lot, but it is also possible that there is something about the Thai diet or the genetics of the test participants that makes curcumin uniquely effective in diabetes prevention.
If I were prediabetic, I'd definitely give curcumin a try. It's inexpensive, it's largely without side effects, and it helps in a variety of conditions ranging from inflammatory bowel disease to the early stages of colon cancer and lung cancer.
Just be sure you are getting 1500 mg of curcumin daily, not 1500 mg of turmeric. Turmeric is about 3% curcumin, and if you are relying on the spice, not the supplement, you aren't getting enough curcumin. It's OK to take a supplement that contains both curcumin and turmeric (most do) as long as you get 1500 mg of curcumin per day.