Curcumin, is thought to be the main active ingredient in turmeric. It has both anti-inflammatory and antioxidant properties; however, the curcumin content of turmeric is low only about 2- 6%, by weight and it is very poorly absorbed and quickly broken down by the body. In practice, this means that much of the research looking at the beneficial effects of turmeric uses extracts (capsules) that contain curcumin, at high dosages (often more than a gram, a day) combined with plant oils, to improve absorption.
Most of the potential health benefits of curcumin centre around the dampening down of inflammation. Curcumin is thought to interrupt the inflammatory pathway, in a similar way to non-steroidal anti-inflammatory drugs (NSAIDS like ibuprofen, diclofenac and aspirin) by blocking inflammatory cytokines and enzymes, such as cyclooxygenase-2 (COX-2). Thus it is may be useful for the relieving pain and swelling associated with osto-arthritis (OA) and rheumatoid arthritis (RA) and for the treatment of sprains and bruises and other inflammatory conditions like, ulcerative coitus.
There is some scientific evidence to support this. A small, 2006, study showed turmeric was effective at preventing joint inflammation. A 2010 clinical trial found that a curcumin supplement (Meriva – 75% curcumin, combined with phosphatidylcholine to improve absorption) provided long-term improvement in pain and mobility in 100 patients with knee OA. In a small, 2012 pilot study, a curcumin product (BCM-95, which includes tumerone and other oils derived from turmeric) reduced joint pain and swelling in patients with active RA, better than the NSAID, diclofenac. For OA a suggested dose is: 400 – 600 mg, curcumin capsules, 3 times a day, or 0.5-1 g of powdered turmeric root, up to 3 times a day; for RA the suggested dose is: 500mg curcumin capsules, twice a day. However, these were small scale, non blinded studies; so a placebo effect could well account for the results.
COX-2 is a bi-functional enzyme and both NSAIDS and curcumin work by blocking one of these functions: the COX-2 pro-inflammatory pathway. However curcumin also blocks the second COX-2 peroxidase pathway which is important for the action of pro-carcinogens. Thus, curcumin may act as an anticancer agent. In-vitro and animal studies have supported this.
The second interesting, active ingredient in turmeric is aromatic-tumerone, which unlike carcumin, is well absorbed and makes up 20-30% of turmeric, by weight. To date there has been relatively little research into this compound; mostly in vitro and animal studies. It appears to exhibit anti-proliferative and anti-tumour activity and thus may have potential as an anti cancer agent. Some studies (in-vitro and animal) have suggested that ar-tumerone may be also useful in treating neuro-degenerative disease and seizures, due to its neuro-protective properties.