Ginkgo biloba for Alzheimer's disease - 'promising evidence'

The systematic review has identified 33 previous clinical trials of Ginkgo, dating back to 1976.

This new research provides promising evidence that taking Ginkgo biloba can improve memory and overall function for people with dementia.

The review published today, 21 October 2002, by the Cochrane Collaboration has concluded that:

'Ginkgo biloba appears to be safe in use with no excessive side effects compared with a placebo. Many of the early trials used unsatisfactory methods, were small, and we cannot exclude publication bias. But overall there is promising evidence of improvement in cognition and function associated with Ginkgo. Our view is that there is need for a large trial using modern methodology to provide robust estimates of the size and mechanism of the treatment effects.'

Dr Mike Clarke, speaking on behalf of the Cochrane Collaboration, said:

'Cochrane Reviews, such as this one, aim to bring together all the relevant evidence, so that it is easier to make well-informed decisions about health care. This review helps to identify the types of research that are now needed to find the best treatments for people with dementia.'

Michael McIntyre, a Trustee of the Prince of Wales Foundation for Integrated Health, Chair of the European Herbal Practitioners Association and one of the UK's best known medical herbalists said:

'On behalf of the Prince of Wales Foundation for Integrated Health and the European Herbal Practitioners Association, I can only express my delight at this comprehensive review by the Alzheimer's Society and Cochrane Collaboration on the use of Ginkgo for the treatment of dementia. This work is bound to have a major impact, drawing the attention of the medical community to the benefits of this ancient oriental remedy.'

These findings have provided the green light for a major new clinical trial of Ginkgo in people with early dementia who are looked after by their GP. The new study, supported by more than £¼ million from the Alzheimer's Society, will recruit 400 people with dementia, following them over a period of six months while they receive treatment either with Ginkgo or a placebo.

The trial is being jointly run by Imperial College and the Royal London Homeopathic Hospital.

Dr Richard Harvey, director of research for the Alzheimer's Society, said:

'The work of the Cochrane Collaboration has been instrumental in gathering together evidence accumulated over the past 26 years that taking Ginkgo supplements probably has real benefits for people with dementia. Our new clinical trial will apply modern methods and robust quality controls to finally answer a question that has been hanging in the air for 5000 years.'

Ginkgo biloba is an extract from the leaves of the Ginkgo tree, which in the UK is more commonly called the maidenhair tree. This tree has survived unchanged in China for more than 200 million years and there is a history of its medicinal use for almost 5000 years.

Dr Peter Fisher, Director of Research at the Royal London Homeopathic Hospital, said:

'Ginkgo contains a number of organic biologically active components. It is the ginkgolides that are unique to the Ginkgo tree although it is not fully known which component or components are the ones that give the leaves their medicinal properties.'

Dr James Warner, senior lecturer and consultant in Old Age Psychiatry at Imperial College London, said:

'The medicinal effects of Ginkgo are believed to be gained by causing blood vessels to dilate, improving blood flow to the brain, and through thinning the blood and making it less likely to clot. Ginkgo probably also has some anti-oxidant effects, protecting nerve cells against biological 'rusting'. All of these effects would suggest that Ginkgo might slow down a degenerative process.'

Available for interview by arrangement through the public affairs team are:

• Dr Richard Harvey - director of research for the Alzheimer's Society
• U Hla Htay - consumer/carer involved in the Cochrane Review
• Jean Barton - consumer/carer incolved in the new trial
• Dr James Warner - Imperial College London
• Dr Peter Fisher - Royal London Homeopathic Hospital

Notes for editors

• The Alzheimer's Society is the UK's leading care and research charity for people with dementia and their carers.
• Over 700,000 people in the UK have dementia. More than half have Alzheimer's disease.
• Dementia affects one in 20 people over the age of 65 and one in five over the age of 80.
• For information and advice on Alzheimer's disease or other forms of dementia call the Alzheimer's Society national helpline on 0845 300 0336.
• Our website address is: http://www.alzheimers.org.uk/
• The Cochrane Collaboration is an international organisation that aims to help people make well-informed decisions about healthcare by preparing, maintaining and promoting the accessibility of systematic reviews of the effects of healthcare interventions. It is a not-for-profit organisation
• The Cochrane Collaboration website is at http://www.cochrane.org/
• The full text of the review will be available on the Cochrane library from 13:00 on 21 October, 2002.
• Pre-release copies can be supplied by the Alzheimer's Society press office on request.