Curcuma, or turmeric, has been cultivated for thousands of years in India and Southeast Asia. It was listed in an Assyrian medical treatise dating from about 600 BC. Cultivation in China and Africa began in the 7th and 8th centuries and in Jamaica during the 18th century. Marco Polo described turmeric in his writings. This health-promoting spice has a long history. Curcuma is related to ginger and the roots look similar, but turmeric is bright yellow to orange. To prepare turmeric, the roots are boiled, dried and ground into powder. Turmeric is used as a base flavoring in curries and other Asian cuisine. It should be noted that when used in cooking, turmeric powder is almost always preheated in oil before it is added to the food.

The active ingredient in turmeric is curcumin. Normal turmeric root may contain as much as 5 percent curcumin by weight. The curcumin extracts made for supplemental use and sold in capsules are typically concentrated to 95 percent curcumin, about 20 times as strong as the powdered spice. Researchers have suggested and documented a wide range of uses for curcumin, both for disease prevention and also for disease treatment. The common denominator for all these uses is that curcumin acts as a potent anti-inflammatory. As inflammation is now considered a factor in most acute and chronic diseases, it is easy to appreciate how many applications curcumin is suggested for.

Human clinical trials have been conducted using curcumin against post-surgical inflammation, rheumatoid arthritis, osteoarthritis, ocular conditions such as uveitis (severe inflammation of the eye), indigestion, gastric ulcers, inflammatory bowel diseases and pancreatitis—all with positive results. One of the most researched applications for curcumin is in the prevention and treatment of cancer. As this is being written, PubMed, the National Library of Medicine’s search engine, tells us that there are 1,200 articles published in peer-reviewed scientific journals on curcumin and cancer. A dozen articles have been published in the last four weeks alone. Scientists have identified multiple chemical pathways by which curcumin inhibits cancer growth; more than in any other plant-derived anticancer agent. Curcumin interacts with many cell-signaling pathways, including the chemicals that control cell cycle, apoptosis (normal cell death), proliferation, survival, invasion, angiogenesis (growth of new blood vessels that allow tumors to grow), metastasis (the spread of cancer cells) and inflammation. This multitude of interactions creates anticancer activity against a wide range of cancers including leukemia and lymphoma, gastrointestinal cancers, genitourinary cancers, breast cancer, ovarian cancer, head and neck squamous cell carcinoma, lung cancer, melanoma, neurological cancers and sarcoma. These properties volunteer curcumin as a possible therapy against cancers for which there are few options left. For example, a 2009 paper by Labbozzetta et al. suggests considering curcumin as a ―… possible lead compound against hormone-independent, multi-drug resistant breast cancer.‖

Another interesting therapeutic use for curcumin being investigated is its potential to prevent and treat Alzheimer’s disease. UCLA researchers, who have been testing curcumin against Alzheimer’s since 2001, initially looked at curcumin because of its anti-inflammatory effects and its lack of side effects. They knew that decreasing inflammation would protect against the disease but anti-inflammatory drugs were too dangerous to use long term in clinical trials.iii Experiments revealed that curcumin could not only prevent the formation of the amyloid plaques that are the hallmark of the disease, but could dissolve existing plaques. Researchers asked the obvious question: ―Do people who eat a lot of turmeric have a lower risk of developing Alzheimer’s disease? The disease is rare in India, where turmeric is a regular part of the diet; in people older than 65, only 4.7 per 1,000 had signs of Alzheimer's disease, compared to people in Pennsylvania where 17.5 people per 1,000 show signs of the disease.iv

Although curcumin is not the most bio-available of herbs, meaning that it is difficult to absorb from the digestive tract into the bloodstream, there are steps you can take to enhance its absorption. The first is to take curcumin mixed with fat. Practitioners often suggest taking a fish oil capsule at the same time one takes curcumin. Others suggest actually opening the capsules and mixing the powder with fats, such as avocado, peanut butter, coconut oil or my favorite, chocolate. This curcumin and fat mixture is better absorbed if taken when the stomach is empty, so avoid taking curcumin with food. Another trick is to take large doses. Researchers at MD Anderson Cancer Center in Texas found the benefit when they dosed pancreatic cancer patients with 8 grams per day in a 2008 study.v New research about curcumin is being published so often that it is challenging to keep up with it all. This pace is different from the slow changing traditions of medical herbalism that I was trained in just twenty-five years ago. Following these new studies is exciting, and sometimes overwhelming. I expect curcumin to become one of the most widely used and beneficial herbs there are in coming years.