Many chemotherapy drugs are derived from plants. It is no surprise that herbal dietary supplements are often promoted as cancer cures although few have actually been studied as drugs. Turmeric is an exception, having been extensively studied as an anticancer supplement.
What is turmeric?
Turmeric is a plant native to South Asia but is cultivated in tropical areas around the world. It is related to ginger and is used as a spice in regional cuisines. For example, curry powder has turmeric as a major ingredient. It is also used in traditional medicine for improving circulation and digestion. Turmeric or its extracts are marketed as dietary supplements to improve memory, for arthritis, and for cancer prevention.
One of the major active constituents in turmeric is the water-soluble curcumin. Numerous in vitro and animal studies suggest this compound has anti-inflammatory and antioxidant activities. Curcumin is known to inhibit cancer cell growth through different mechanisms. Its effects on colorectal cancer, pancreatic cancer, breast cancer, and prostate cancer have drawn the most attention. Curcumin appears to enhance the therapeutic effects of standard chemotherapy drugs and may help to reduce the side effects of radiation therapy. There are ongoing clinical trials to verify these effects.
Other than allergic reactions, adverse effects from curcumin have been rarely reported. However, curcumin can potentially interfere with other drugs. Due to poor absorption, a large quantity (up to 8g per day) is given to participants in clinical studies. Curcumin has a “blood thinning” property that may increase risk of bleeding when used with drugs that have similar activities. Curcumin also inhibits enzymes used in the metabolism of some prescription drugs and can increase their toxicities.
Should I take turmeric?
Turmeric is generally safe when used in small quantity as a spice. Dietary intake may have a protective effect against colorectal cancer but this has not been confirmed in large scale studies. To be effective as a cancer treatment, the dose of turmeric or curcumin would likely need to be very high and may lead to other complications. Consult with a physician or a pharmacist before using this supplement, especially if you are on other medications.