LONDON, June 16 (Xinhua) -- A herbal extract from the ginkgo biloba tree used by an estimated 10 percent of people with dementia is not an effective treatment for the disease, according to a British study published on Monday.
Ginkgo biloba is commonly marketed as an aid to memory and some studies have reported benefits. But a six-month trial of 176 people with mild to moderate dementia found no difference between those taking ginkgo biloba and those taking placebo, the study by researchers at Britain's Imperial College London showed.
The researchers tested 120 miligrams daily of ginkgo biloba in patients recruited from London general practices and measured participants cognitive skills and quality of life at two, four and six months.
Tests included exercises such as recalling words from memory or answering questions about time or places. There was no evidence that the standard dose of the herbal extract had any benefit on memory, according to the study which said quality of life as reported by the patient or by their carer did not improve over the course of the research.
According to study leader Rob McCarney who carried out the research at Imperial College London, the lack of drug treatments in early dementia meant patients would try anything to slow down the progression of the disease.
"This isn't a hugely expensive treatment but if you're living on a state pension it can make a considerable dent in your budget. The findings add to the growing evidence that ginkgo provides no benefit," he said.
Thousands of people with dementia, who are already struggling to make ends meet, may buy ginkgo biloba expecting an improvement in their memory, he said.
A Cochrane review published in 2002 which had taken all relevant evidence into account found ginkgo may be a small beneficial effect on memory in dementia patients.
But the researchers say that is being updated in view of this latest research and has found that it is unlikely to provide benefits.
