Elderly individuals with mild cognitive impairment who take huge doses of B vitamins everyday may reduce the rate at which their brains shrink by 50%, resulting in a much slower progression toward dementia, and eventually Alzheimer’s disease, say researchers from Oxford University, England, in an article published in Plos One (Public Library of Science One), a peer-reviewed medical journal.
The investigators say this two-year clinical trial is the largest ever which examined the effect of B vitamins on “mild cognitive impairment” (MCI). Individuals with MCI have a higher risk of progression to Alzheimer’s disease and other forms of dementia.
People with mild cognitive impairment can function in everyday activities, but they may have problems with memory, such as recalling people’s names, losing the flow of a conversation, and not remembering where they left things. Approximately 16% of individuals aged over 70 years are affected by mild cognitive impairment, the authors wrote.
David Smith, University Department of Pharmacology and Department of Physiology, Anatomy & Genetics, University of Oxford, trial co-leader, said:
This is a very dramatic and striking result. It’s much more than we could have predicted.
It is our hope that this simple and safe treatment will delay development of Alzheimer’s in many people who suffer from mild memory problems.
The single-center, randomized, double-blind controlled trial involved 168 volunteers who all had been diagnosed with mild cognitive impairment. They had also agreed to and completed cranial MRI scans.
They were split into two groups:
One group, consisting of 85 participants, received high daily doses of vitamins B6 (0.5 mg/d) and B12 (20 mg/d), as well as folic acid (0.8 mg/d). This was 300 times the recommended daily intake for B12, 15 times daily recommended amounts of B6, and 4 times daily recommended intake of folic acid.
The other group, consisting of 83 participants, received a placebo (tablets without any active ingredients)
Treatment lasted 24 months.
The principal outcome measure was the change in the rate of atrophy of the whole brain, assessed by serial volumetric MRI scans.
Homocysteine is an amino acid which is a risk factor for brain atrophy (wasting), cognitive impairment and dementia. The administration of B vitamins are known to lower blood concentrations of homocysteine, the researchers explained.
The scientists stressed that the levels of administered B vitamins was so high that they were classed as drugs, not simply a vitamin intervention.
The researchers found that:
The B vitamin with folic acid group had an average brain shrinkage of 0.76% per year.
The placebo group had an average brain shrinkage of 1.08% per year.
Those with the highest homocysteine blood levels at the start of the trial who took the B vitamins and folic acid experienced half the brain shrinkage compared to individuals with the highest homocysteine blood levels at the start and who received the placebo, the authors wrote.
The authors also found that those with the greatest rate of brain wasting (atrophy) had the lowest final cognitive test scores.
There was no difference in adverse events between those in the B vitamin plus folic acid group and those taking the placebo.
The authors concluded:
The accelerated rate of brain atrophy in elderly with mild cognitive impairment can be slowed by treatment with homocysteine-lowering B vitamins.
They added that with the 16% of seniors over 70 with mild cognitive impairment, and half of them going on to develop Alzheimer’s disease, further trials are needed to determine whether the same treatment might delay the development of Alzheimer’s disease.
Written by Christian Nordqvist
Medical News Today