Eating a curry once or twice a week could help prevent the onset of Alzheimer's disease and dementia, a US researcher suggests.
Curcumin appears to prevent the spread of amyloid protein plaques – thought to cause dementia – in the brain.
But the theory, presented at the Royal College of Psychiatrists' annual meeting, has been given a lukewarm reception by UK experts.
"If you have a good diet and take plenty of exercise, eating curry regularly could help prevent dementia"
Professor Murali Doraiswamy
Amyloid plaques, along with tangles of nerve fibres, are thought to contribute to the degradation of the wiring in brain cells, eventually leading to symptoms of dementia.
Professor Murali Doraiswamy, of Duke University in North Carolina, said there was evidence that people who eat a curry meal two or three times a week have a lower risk of dementia.
He said researchers were testing the impact of higher doses – the equivalent of going on a curry spree for a week – to see if they could maximise the effect.
Professor Doraiswamy told the meeting: "There is very solid evidence that curcumin binds to plaques, and basic research on animals engineered to produce human amyloid plaques has shown benefits."
"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."
Professor Doraiswamy said a clinical trial was now underway at the University of California, Los Angeles, to test curcumin's effects in Alzheimer's patients.
He said research had also examined turmeric's therapeutic potential for treating conditions such as cancer and arthritis.
He stressed that eating a curry could not counter-balance the increased risk of dementia associated with a poor diet.
"Indian communities that regularly eat curcumin have a surprisingly low incidence of Alzheimer's disease but we don't yet know why"
Dr Susanne Sorensen
However, he said: "If you have a good diet and take plenty of exercise, eating curry regularly could help prevent dementia."
Professor Doraiswamy predicted it might be possible to develop a curry pill which had the same therapeutic effect.
However, Rebecca Wood, of the Alzheimer's Research Trust, stressed that people would need to eat a lot of curry – over 100g of turmeric curry powder – to get a clinical dose of curcumin.
She said: "Professor Doraiswamy's unpublished research applies only to animal models; his hypothesis has not been confirmed in human clinical trials.
"We look forward to the results of the human curcumin trial at UCLA."
Dr Susanne Sorensen, of the Alzheimer's Society, said: "Indian communities that regularly eat curcumin have a surprisingly low incidence of Alzheimer's disease but we don't yet know why.
"Alzheimer's Society is keen to explore the potential benefits of curcumin in protecting the brain and we are conducting our own research into this area.
"A cheap, accessible and safe treatment could transform the quality of life of thousands of people with the condition."