[Editor’s Note. This article is based on reports in the British press in mid-September following a presentation at the British Science Festival in Bradford, England].
Large doses of B-vitamins could slow the cognitive decline in older people that is the precursor to dementias such as Alzheimer’s disease, according to a study.
Speaking at the British Science Festival in Bradford on Tuesday, Celeste de Jager, a neuropsychologist at Oxford University, said that taking vitamins B6, B12 and folic acid in medicinal quantities reduced the overall shrinkage of a person’s brain by 30% over the course of the two-year study.
Her work, published recently in the International Journal of Geriatric Psychiatry, was carried out on 270 men and women over 70 who had mild cognitive impairment (MCI), a condition that affects one in six elderly people and which can interfere with memory, language and other mental functions. About half of the people with MCI go on to develop Alzheimer’s within five years of the initial diagnosis.
Taking B vitamins and folic acid is known to control the levels of an amino acid called homocysteine in the blood. High levels of this chemical can damage blood vessels and are associated with increased risk of dementia.
“High homocysteine is a known risk factor for cognitive decline in the elderly and Alzheimer’s disease and also for other kinds of dementia like vascular dementia,” said de Jager. “It can be damaging to the endothelial lining of the blood cells. It also binds to receptors in the brain that are on the neurons and it seems to contribute the atrophy that’s associated with Alzheimer’s.”
The elderly are more susceptible to this effect of high homocysteine, she added, because levels rise with older age, possibly due to poorer absorption of B vitamins in diet as people age.
To keep homocysteine levels down, she said, people should eat more meat, fish and green vegetables, and reduce consumption of alcohol, which is known to deplete the body of vitamin B12.
In the study, the volunteers were split into two groups, with one group given placebo pills and the second group given a cocktail of vitamins made from 0.5 milligrams of B12, 0.8mg of folic acid and 20mg of vitamin B6 – all several times more than the standard amount recommended by doctors for a healthy diet. The participants’ brains were scanned at the start of the experiment and at two years, and they went through a regular battery of cognitive tests.
The British study found that among the group of people taking the vitamins there was a 30% reduction in the decline of brain cells during the period of the study when compared to results for the group of people who took a placebo. For those people tested who were found to have the highest risk factors for dementia later on the results were even higher.
Researchers warned that older people should not start consuming lots of vitamin B as a result of the work done so far. There is a concern that folic acid in particular may activate cancerous cells in the body. There is also more work that needs to be done with respect to determining an optimal age to start taking a larger dosage of Vitamin B. Scientists do know that in general significant changes in brain composition frequently begins when people are in their 40s and 50s.
Anyone interested in reading a full report on this study can click here to go to the British newspaper, The Guardian.