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The research investigated the impact of vitamin B supplements on the rate of brain atrophy in people with mild cognitive decline, an early indicator of potential Alzheimer’s disease onset in later life.
Paul Matthews, Professor of Clinical Neurology, Imperial College, London, said:
“This well-conducted study adds substantial new data to previous information suggesting that dietary B vitamins could have beneficial effects on neurodegeneration with aging.
“Smith and his colleagues studied a mixed group of patients with mild cognitive impairment (MCI) and showed that 2 years of treatment with folic acid and vitamins B12 and B6 slowed rates of brain atrophy. Trends identified in their report suggest that the treatment could slow deterioration of cognition, but this was not demonstrated directly in this small study.
“It is important to appreciate that only some of the patients studied would be expected to develop Alzheimer’s disease; the results therefore should not be interpreted as providing evidence for a new treatment for this most common form of late life dementia.
“The association between better treatment effects and blood levels of homocysteine- which can be elevated with a deficiency of B vitamins and an increased risk of stroke- raises the question of whether any benefits are related to effects on blood vessels supplying the brain.
“Although the vitamins used are generally safe and inexpensive, the study should not drive an immediate change in clinical practice. Instead, it sets out important questions for further study and gives new confidence that effective treatments modifying the course of some dementias may be in sight.”
Dr Nicholas Timpson, MRC CAiTE Centre (Centre for Causal Analyses in Translational Epidemiology), University of Bristol , said:
“The trial based investigation of a series of homocysteine-lowering B vitamins (including folate and B12) and brain atrophy is of great interest. Authors note a reduction in the rate of atrophy in participants randomly allocated to treatment which is itself of great interest, however there are aspects of the work which need to be approached cautiously. These include comparison of observed effects to natural atrophy by age and the the actual relationship between cognitive ability and the use of B vitamins. As to the latter of these, there is no direct analysis of cognition and whilst it is alluded to, the lack of this is a clear limitation. This work is good evidence of a causal relationship, but the reporting of mean effects in a study such as this does not guarantee impact at the level of the individual given adherence to the same vitamin regime.”
Prof John Hardy, Professor of Neuroscience, University College London, said:
“The data is very interesting and I have seen it presented. Homocysteine is known to be involved in stroke-related diseases and so involvement in Alzheimer’s disease is plausible. But it is important to note that the study is rather small and needs replicating in a larger study.”
Chris Kennard, chair of the Medical Research Council’s Neurosciences and Mental Health Board, said:
“We welcome the findings of this MRC-funded study which bring us a step closer to unravelling the complex neurobiology of ageing and cognitive decline and holds the key to the development of future treatments for conditions like Alzheimer’s disease. However, we must be cautious when recommending supplements like Vitamin B as there are separate health risks if taken in too high doses. Further research is required before we can recommend the supplement as a treatment for neurodegenerative diseases, such as Alzheimer’s.”
Homocysteine-lowering by B vitamins slows the rate of accelerated brain atrophy in mild cognitive impairment – a randomized controlled trial by Smith et al., published in PLoS ONE.