Curcumin, a bright yellow compound, is a component of the Indian spice turmeric (Curcumin longa), a type of ginger. Curcumin is the principal of three curcuminoids present in turmeric, the other two being desmethoxycurcumin and bis-desmethoxycurcumin. It is sold as an herbal supplement, cosmetics ingredient, food flavoring, and food coloring.
According to the Linus Pauling Institute, mounting evidence from preclinical studies shows that curcumin modulates numerous molecular targets and exerts antioxidant, anti-inflammatory, anti-cancer, and neuroprotective activities.
In humans, curcumin taken orally is poorly absorbed and rapidly metabolized and eliminated. Therefore, the potential of curcumin as a therapeutic agent is limited by its poor bioavailability.
Current evidence suggesting that curcumin may help prevent and/or treat colorectal cancer and type 2 diabetes mellitus is very limited. Yet, several clinical trials designed to assess the safety and efficacy of curcumin alone or with first-line treatment in patients with breast, prostate, pancreatic, lung, or colorectal cancer are underway. And while a few preliminary trials suggested that curcumin may have anti-inflammatory activities in humans, larger randomized controlled trials are still needed to establish the efficacy of curcumin as an anti-inflammatory agent against rheumatoid arthritis, ulcerative colitis, and radiotherapy-induced dermatitis.
Oral supplementation with curcumin is generally regarded as safe, especially because of its low bioavailability. However, use of curcumin supplements may affect the efficacy or increase the toxicity of a wide range of drugs when taken concurrently.