An inexpensive supplement will halt the progress of Alzheimer's disease, scientists hope, after a trial suggested that patients stopped deteriorating while taking it.
Resveratrol is a naturally occurring compound found in red grapes, raspberries, dark chocolate and red wine.
Although quantities in food are tiny, high-dose supplements are available over the counter in most health food shops for just a few pounds and purer forms can be bought from pharmacists.
Scientists enrolled 119 people with mild to moderate Alzheimer's in a trial in which they were given 1g of high-grade resveratrol twice a day for 12 months while a control group received a placebo.
Normally, as Alzheimer's progresses, the level of a protein called Abeta40 decreases in the blood. But those taking the supplement showed no alteration, suggesting the disease had stabilised. They were also found to have improved at dressing themselves, cooking and using public transport.