India exported 4,000 tons of turmeric in October 2009. This popular spice has been part of Asian cuisine for thousands of years. The health benefits have attracted researchers and practitioners around the world. Currently, there are 37 clinical trials in progress in the United States evaluating its active ingredient, curcumin, for inflammatory conditions and other uses.
Many spices have antioxidant properties; turmeric demonstrates anti-inflammatory benefits as well. A recent review identifies multiple mechanisms, including:
1. Down-regulation of COX-2, which is the enzyme targeted by celecoxib (Celebrex);
2. Inhibition of the production of TNF-alpha, which is the cytokine targeted by etanercept (Enbrel), infliximab (Remicade) and newer drugs; and
3. Down-regulation of enzymes that produce nitric oxide.
Research on animal models has demonstrated anti-inflammatory effects of curcumin in treating edema, ulcerative colitis, rheumatoid arthritis and pancreatitis. Clinical trials in humans have demonstrated benefits for post-surgical edema, arthritis, eye inflammation and gastrointestinal conditions. One disadvantage of curcumin for some uses is its poor absorption from the digestive system into the bloodstream. However, this is a plus for treating gastrointestinal illness. One study showed that both normal and malignant colorectal tissue absorb pharmacologically significant amounts of curcumin.
Inflammatory bowel disease comes in several forms. The most common types are Crohn's disease and ulcerative colitis. Clinical trials have shown that curcumin in doses of 1 to 2 grams per day can be helpful, either alone or in combination with standard drugs, in reducing symptoms. Irritable bowel syndrome is a less severe illness with similar symptoms of abdominal pain, bloating and altered bowel habits. Low-grade inflammation is a possible cause. A lower dose of curcumin, 72 mg of standardized turmeric extract, reduced symptoms in a pilot study for this condition.
A larger dose of curcumin, 3 g per day in divided doses (600 mg five times) a day, was tried on 25 patients with endoscopically diagnosed peptic ulcers. By the end of twelve weeks, 19 patients (76%) were free of ulcers.
As a backhanded compliment to curcumin, researchers in Philadelphia showed that long-term use of curcumin as a dietary supplement exacerbated symptoms of the parasitic disease leishmaniasis, which is spread by infected sand flies. Inflammation is valuable in the type 1 immune response, so any type of anti-inflammatory has the potential to weaken our defense against infection. It is an ongoing balancing act for our immune systems to provide just the right amount of inflammation and nutritional support.
References:
Jurenka JS, “Anti-inflammatory properties of curcumin, a major constituent of Curcuma longa: A review of preclinical and clinical research”, Alternative Medicine Review 2009; 14(2): 141-153.
Adapala N et al, “Long-term use of an antiinflammatory, curcumin, suppressed type 1 immunity and exacerbated visceral leishmaniasis in a chronic experimental model”, Lab Invest. 2008 Dec; 88(12): 1329-39.
Ongoing clinical trials of curcumin in the U.S.
http://clinicaltrials.gov/ct2/results?term=curcumin
News about turmeric futures prices
http://in.reuters.com/article/domesticNews/idINBOM40980620091123
Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.