In the largest trial of its kind, Oxford University researchers have discovered that B vitamins significantly reduced the risk of mild cognitive impairment in a population of subjects 70 and older. Mild cognitive impairment often leads to dementia and Alzheimer’s disease.
According to researchers, an increased rate of brain atrophy is often observed in older subjects, particularly those who suffer from cognitive decline. And 16% of those over 70 years old have mild cognitive impairment and half of these develop Alzheimer's disease. Homocysteine is a risk factor for brain atrophy, cognitive impairment and dementia. Plasma concentrations of homocysteine can be lowered by dietary administration of B vitamins.
During the two-year trial, 271 individuals with mild cognitive impairment were enrolled and asked to take either a combination of high-dose folic acid, vitamin B6 and vitamin B12 or a placebo. A subset (187) volunteered to have cranial MRI scans at the start and finish of the study. The researchers were looking to evaluate the change in the rate of brain atrophy over the period.
The accelerated rate of brain atrophy in elderly with mild cognitive impairment can be slowed by treatment with homocysteine-lowering B vitamins. Since accelerated brain atrophy is a characteristic of subjects with mild cognitive impairment who convert to Alzheimer's disease, researchers believe trials are needed to see if the same treatment will delay the development of Alzheimer's disease.