This paper offers very strong support for the hypothesis that high homocysteine levels cause brain shrinkage in those specific areas known to be affected by Alzheimer’s disease, and thereby cognitive impairment, as opposed to dementia leading to dietary changes with high homocysteine levels. Furthermore, high dose B vitamins given to people with mild cognitive impairment (MCI) reduce homocysteine and, therefore, brain shrinkage. Our data support the contention that B vitamins are probably disease-modifying in people with MCI. But as the primary outcome of this study was imaging, the next step has to be a fully powered therapeutic trial.
Professor Robin Jacoby
Elderly people could stave off Alzheimer's disease by taking Vitamin B supplements because they reduce brain shrinkage associated with the disease by up to 90 per cent, a study suggests. Consuming vitamins B6, B12 and folic acid can lower levels of homocysteine, an amino acid linked to shrinkage of the brain in conditions like Alzheimer's disease. Dr David Smith, who led the study, said: "Our work shows that a key part of the disease process that leads to Alzheimer’s disease, the atrophy of specific brain regions, might be modified by a safe and simple intervention." But experts cautioned against drawing any firm conclusions and recommended staying healthy by eating a balanced diet and getting regular exercise, rather than taking supplements.
B vitamins may slow the advance of Alzheimer's (New Scientist, Caroline Williams, 20/05/2013)
Vitamins That Cost Pennies a Day Seen Delaying Dementia (Washington Post (USA), via Bloomberg News, Andrea Gerlin, 20/05/2013)
How daily vitamin B pill fights dementia (Daily Express, p.1, Jo Willey, 21/05/2013)
Should you be taking vitamin B to protect against Alzheimer's? (Daily Mail, p.32, Jerome Burne, 21/05/2013)
Gwenaëlle Douaud, Helga Refsum, Celeste A. de Jager, Robin Jacoby, Thomas E. Nichols, Stephen M. Smith, and A. David Smith. Preventing Alzheimer’s disease-related gray matter atrophy by B-vitamin treatment. PNAS (early edition).