It has long been known that turmeric possesses several health giving properties. Now scientists may have found how it works.
India has one of the world's lowest rates of Alzheimer's disease among the elderly, in dramatic comparison to the West. Diets rich in turmeric, may be one of the benefiting factors. Indians use turmeric widely, as a food colourant, a preservative, and a flavourant in curries, not to mention as an ingredient in traditional beauty care treatments and herbal medicines. Curcumin, the main active ingredient of turmeric, may be the key.
Over the years, curcumin has gained much attention in the scientific world for its benefits on maladies including HIV, cancer and Alzheimer's disease. It is well known that curcumin has a number of medicinal properties. It is an antioxidant and has anti-inflammatory properties. Research conducted in the Pharmacy department by postgraduate student Sheril Daniel under the supervision of Prof Santy Daya and Dr Janice Limson of Rhodes University in South Africa suggests that curcumin may have additional benefits previously unknown.
Daniel conducted experiments in rats which showed that curcumin is able to protect the brain against oxidative damage induced by cyanide, quinolinic acid and toxic metals such as lead and cadmium. These toxins are all capable of causing intensive oxidative damage to the brain. Oxidative damage has been implicated in various neurodegenerative diseases such as Alzheimer's and Parkinson's disease.
The hippocampus, a region of the brain, is linked to vital behaviour and intellectual activities and is known to be a primary target for neuronal degeneration in the brains of patients with Alzheimer's disease. Lead has been shown to disrupt structural features of the cells in this region of the brain, leading to various problems including loss of memory and of learning skills.
Daniel's studies showed that curcumin significantly protected the hippocampal cells that were treated with the toxic metal, lead. It is believed that the anti-inflammatory property of curcumin contributed to the reduced amount of swelling observed within neuronal cells.
Using electrochemistry and a range of spectroscopic techniques, the team assisted by Dr Gary Watkins and Ami Dairam also of Rhodes University, investigated any direct interactions between curcumin and the metals lead, cadmium, and iron.
Curcumin was shown to directly chelate these metals with the formation and isolation of two new curcumin complexes with lead, and one complex each with cadmium and iron. These results suggest that one of the mechanisms by which curcumin provides protection to the brain, is by directly binding to toxic metals and forming new complexes.
These findings, published this year in the Journal of Inorganic Biochemistry, point toward a potential role of curcumin in neuroprotection. Daniel's research suggests the need for more research in this area.
Curcumin is only one of three known curcuminoids in turmeric, which are known to possess varying degrees of antioxidant and anti-inflammatory properties. The commercial sample of curcumin available on the market is known to contain traces of the minor curcuminoids, demethoxycurcumin and bisdemethoxycurcumin.
Further studies are being conducted at Rhodes University to separate these components and investigate and compare the neuroprotective properties and metal-binding capabilities of each of the individual curcuminoids to assess precisely which one is the key.
In the meantime, if you are one of those who enjoy spicy foods take a lesson from the East. Curry could be food for thought, quite literally.