[This abstract first appeared in: Dementia: the Latest Evidence Newsletter RWHT Volume 1 Issue 3 October 2010].
High doses of B vitamins taken as daily tablets may halve the rate of brain shrinkage in older people experiencing Mild Cognitive Impairment (MCI). MCI is a precursor to Alzheimer’s and other forms of dementia.
This two year randomised double-blind clinical trial is the largest to study the effect of high doses of B vitamins (folate, B6 and B12) on MCI so far, and could be the first step in finding a treatment which delays the onset of Alzheimer’s.
This University of Oxford research identifies a particular benefit for people starting off with high levels of the amino acid homocysteine, which is a known risk factor for Alzheimer’s Disease. On average B vitamins slowed the rate of brain atrophy by 30%, and in some cases by 53%. It is hoped that this simple and safe treatment will delay the development of Alzheimer’s disease.
The trials show that B vitamins do not necessarily give the same benefits to people with normal levels of homocysteine.
The Alzheimer’s Society points out, however, that previous studies investigating B vitamins have been disappointing. More research is needed to find out how B vitamin therapy may prevent or delay dementia, focusing on people with higher levels of homocysteine and/or those at risk of developing Alzheimer’s.
Caution: People should not start taking B vitamins without consulting with a doctor, as some studies have linked B vitamins to cancer. Taking B vitamins – in particular folic acid without taking B12 – can damage the neurological system. The long-term effects of ingesting high doses of these vitamins are unknown.
Smith, AD. Smith, SM. de Jager, CA. [et al] (2010). Homocysteine-lowering by B Vitamins slows the rate of accelerated brain atrophy in mild cognitive impairment: a randomized controlled trial. Public Library of Science ONE (PLoS ONE), Vol.5(9), e12244.