Vitamin B could be new weapon against Alzheimer's disease

The research showed that large doses of the supplement could halve the rate of brain shrinkage – a physical symptom associated memory loss and dementia in the elderly. The effects were so dramatic that the scientists behind the study believe it could revolutionise the treatment of the disease, The Telegraph reported.

Professor David Smith, a pharmacologist who co-authored the study, said: "This is a very striking, dramatic result. It's much more than we could have predicted. "It is our hope that this simple and safe treatment will delay the development of Alzheimer's disease in many people who suffer from mild memory problems."

"It is a very simple solution: you give someone some vitamins and you protect the brain," he said. Brain shrinkage or atrophy is a natural part of ageing but it is known to be accelerated in people with Mild Cognitive Impairment (MCI) – a kind of memory loss and forgetfulness – and Alzheimer's.

Scientists at the University of Oxford conducted a trial on 168 people and found that taking high doses of three vitamin B supplements every day reduced brain shrinkage associated with dementia by up to 53 per cent.

The researchers used an advanced magnetic resonance imaging (MRI) technique to study brain shrinkage on the 168 volunteers over the age of 70 with diagnosed MCI. Over a period of two years, half were given a daily tablet containing high doses of the B vitamins folic acid, B6 and B12. The rest received a "dummy" placebo pill with no active ingredients.

At the end of the trial the effects of the vitamin treatment were found to be dramatic, and most pronounced in participants who started out with the highest rates of brain shrinkage, the researchers were quoted as saying.

On average, taking B vitamins slowed the rate of brain atrophy by 30 per cent, and in many cases reductions was as high as 53 per cent were seen. The researchers said the results were so strong that it should open up a debate as to whether the tablets should be prescribed to everyone with MCI – half of whom develop Alzheimer's disease.

MCI affects 16 per cent of people over 70 – 1.5 million people in the UK, the paper said. Prof Smith said it was still early to say exactly how vitamin B worked. "The treatment lowers homocysteine, lower homocysteine reduces brain shrinkage and that reduces cognitive decline," he said.

"This is the first trial that has shown a glimmer of hope and success. It is the first one of its kind that has worked so clearly. I think it will change the whole direction of Alzheimer's research," Smith said.

The long-term effects of taking big doses of the vitamins were not known, and there was some evidence that high folic acid intake could be linked to cancer, he said. While Prof Smith said anybody thinking of taking them should consult their doctor first, he personally felt they would be effective.

Professor Helga Refsum, his co-author at University of Oslo who is a visiting academic at Oxford, said more trials were needed but the evidence was strong. The research, published in the journal Public Library of Science ONE, is controversial because it defies current scientific dogma about the way to tackle Alzheimer's.

It suggests simply taking vitamins can achieve results that have so far evaded pharmaceutical companies, despite millions of pounds being spent on experimental dementia drugs.

The study was cautiously welcomed by other scientists although they said more studies were needed to back up the findings. Rebecca Wood, chief executive of the Alzheimer's Research Trust, which co-funded the study, said: "These are very important results, with B vitamins now showing a prospect of protecting some people from Alzheimer's in old age. "The strong findings must inspire an expanded trial to follow people expected to develop Alzheimer's, and we hope for further success.