Vitamin B may save victims of failing memory

The research showed that large daily doses of B vitamins can halve the rate of brain shrinkage in elderly people with mild cognitive impairment (MCI), a precursor to Alzheimer's and other forms of dementia.

Brain atrophy, which is a natural part of ageing, is known to happen faster in people with MCI who go on to develop Alzheimer's.

The British-led scientists believe the vitamin treatment could delay or even prevent development of the disease. They are now seeking funding for another trial which will put this theory to the test.

The research, published in the online 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.

Researchers at Oxford University, assisted by colleagues in Norway, used an advanced magnetic resonance imaging (MRI) technique to study brain shrinkage in 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 folate, 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.

On average, taking B vitamins slowed the rate of brain atrophy by 30 per cent, and in some cases reductions as high as 53 per cent were seen.

Professor David Smith, one of the study leaders from the Department of Pharmacology at Oxford University, 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."

Although the trial was not designed to measure thinking ability, the researchers found that individuals with the lowest rates of shrinkage had the highest mental test scores.

Around 1.5 million people over the age of 70 in the UK – 16 per cent of the total population – are believed to suffer from mild cognitive impairment.

MCI causes memory lapses and language problems that are noticeable but not bad enough to disrupt daily life. However, it is a known risk factor for Alzheimer's and other kinds of dementia.

Brain shrinkage at the rate of around 0.5 per cent per year is normal for individuals over the age of 60 without MCI. For those with MCI, it is twice as fast on average.

Prof Smith believes MCI and Alzheimer's are milder and more extreme manifestations of the same problem. "The big question is, is this a continuum?" he said. "Are we seeing a disease that begins a long time ago and gets worse and worse. I personally think so."

The scientists stress that the doses of B vitamins used in the trial are much higher than would be obtained from diet or normal health supplements.

The "TrioBe Plus" pills, prescribed under medical supervision in Sweden but not available in the UK, contain around 300 times the recommended daily intake of B12 and four times recommended folate levels.

In Sweden they are used to lower high blood levels of the amino acid homocysteine. The organic compound plays a vital role in metabolism but is also linked to Alzheimer's.

Prof Smith warned people not to rush into taking mega doses of B vitamins to ward off mental decline, even though the study results were "immensely promising".

The long-term effects of taking big doses of the vitamins were not known.