B vitamins may slow the rate of brain breakdown

Supplementation with B vitamins may halve the rate of brain shrinkage in people with mild memory problems, says a new UK study.

In the randomized controlled trial, 168 people over 70 years old with mild cognitive impairment were randomly assigned to two groups receiving vitamin B9 (0.8 mg folic acid per day), vitamin B12 (0.5 mg/d) and vitamin B6 (20 mg/d) or placebo for 24 months (1). The rate of brain shrinkage (‘atrophy’) was assessed by serial volumetric brain scans. The results showed that participants treated with vitamins lost 30 per cent less brain tissue than those who took a placebo. In the highest risk group, they lost 53 per cent less. The reduced rates of brain atrophy were related to decreased blood concentrations of homocysteine. There was no difference in adverse events between treatment and placebo group.

An increased rate of brain atrophy is often observed in older subjects, in particular those who suffer from cognitive decline. Sixteen percent of those over 70 years old have mild cognitive impairment and half of these develop Alzheimer's disease. Homocysteine has been identified as a risk factor for brain atrophy, cognitive impairment and dementia. Dietary administration of B vitamins has been shown to lower plasma concentrations of homocysteine potentially reducing the risk of dementia.

The researchers commented that it is their hope that this simple and safe treatment will delay the development of Alzheimer’s disease in many people who suffer from mild memory problems. The treatment is only suitable for those with medically diagnosed memory impairment. Experts said that these findings should inspire an expanded trial to follow people expected to develop Alzheimer’s disease.

1. Smith A. D. et al. Homocysteine-Lowering by B Vitamins Slows the Rate of Accelerated Brain Atrophy in Mild Cognitive Impairment: A Randomized Controlled Trial. PLoS ONE. 2010; 5(9).