08/06/09 Eating a curry once or twice a week could help prevent the onset of Alzheimer's disease and dementia. The magic ingredient in curry is curcumin, a component of the spice, turmeric.

Professor Murali Doraiswamy, director of the Mental Fitness Laboratory at the Department of Psychiatry, Duke University Medical Center, Carolina, told delegates at the Royal College of Psychiatrists' Annual Meeting in Liverpool that curcumin prevented the spread of amyloid plaques, found outside brain cells.

These plaques, along with neurofibrillary tangles, are thought to contribute to the degradation of the wiring in brain cells and lead to the subsequent symptoms of Alzheimer's disease.

Professor Doraiswamy said: "There is very solid evidence that curcumin binds to plaques, and basic research on animals engineered to produce human amyloid plaques has shown benefits. Turmeric has been studied not just in Alzheimer's research but for a variety of conditions, such as cancer and arthritis. Turmeric is often referred to as the spice of life in ancient Indian medical lore."

A clinical trial is now underway at the University of California, Los Angeles, to test curcumin's effects in human Alzheimer's patients and specifically on their amyloid plaque proteins. A small pilot trail was completed to determine the right dose and researchers have now embarked on a larger study.

Professor Doraiswamy told the Royal College of Psychiatrists' Annual Meeting: "You can modify a mouse so that at about 12 months its brain is riddled with plaques. If you feed this rat a curcumin-rich diet it dissolves these plaques. The same diet prevented younger mice from forming new plaques. The next step is to test curcumin on human amyloid plaque formation using newer brain scans and there are plans for that."

Studies looking at populations show that people who eat a curry meal two or three times a week seem to have a lower risk for dementia, he told the Annual Meeting. "Those studies seem to show that you need only consume what is part of the normal diet - but the research studies are testing higher doses to see if they can maximise the effect. It would be equivalent of going on a curry spree for a week."

However, curry may be just one of the ingredients that prevent degeneration of the brain. "If you are eating fatty burgers and smoking then don't expect an occasional curry to counterbalance a poor lifestyle. However, if you have a good diet and take plenty of exercise, eating curry regularly could help prevent dementia," he said.

Turmeric is also found in mustard and Professor Doraiswamy predicted a day when - for those unable, or unwilling, to consume curries regularly - the public might be advised to take a 'curry' pill every day if the findings are confirmed in human studies.

Professor Doraiswamy and other scientists are testing a brain PET scan which can detect the prevalence of plaques in the living brain. At the moment, a definitive diagnosis can be made only after the patient has died. A second scan also being developed can detect both plaques and tangles - both of which are present in Alzheimer's.

Many leading drugs being developed are targeting the plaques, said Professor Doraiswamy, and clinicians were prescribing these dugs "blindly" without knowing the plaque load in the brain. He said: "The hope is that with the PET scans you can scan their brains, find out whether their plaque load is high or low, and tailor treatment. If their plaque load is low, then you have to question the diagnosis."

Some 20-30 per cent of diagnoses were wrong, said Professor Doraiswamy, and the condition could be vascular dementia or any number of other conditions masquerading as Alzheimer's. "If you gave that person treatment it wouldn't help - it would be a waste of money and in some cases hurt".

The professor said it was conceivable in the near future, when preventive therapies were available, that a 50-year-old with a strong history of Alzheimer's could be screened to determine the levels of plaque in their brains and then initiate anti-plaque therapy.

Professor Doraiswamy, a leading expert on brain health and fitness, grew up in Southern Indian town of Madras famous for its fiery curries. He is currently on a lecture tour promoting his consumer book The Alzheimer's Action Plan, published in April.