Alzheimer's patients do not benefit from taking high doses of vitamin B supplements despite previous research to the contrary, according to a new study.
The previous research indicated that B vitamins might slow progress of the disease by reducing levels of homocysteine, an amino acid produced in the body.
But research led by Dr Paul Aisen, from the University of California at San Diego in the US, shows that even though B vitamins reduce homocysteine levels, Alzheimer's Disease Assessment Scale scores did not differ significantly between treatment groups.
The authors write in the Journal of the American Medical Association (JAMA): "Many studies suggest that relative elevation of homocysteine is characteristic of Alzheimer's disease (AD), and laboratory research implicates homocysteine in neurodegenerative mechanisms.
"High-dose B vitamin supplementation in individuals with normal levels of B vitamins was effective in reducing homocysteine levels. However, our study does not support the treatment of individuals with mild to moderate AD and normal vitamin levels with B vitamin supplements."