B Vitamins Not Linked to Alzheimer Benefits
High-dose supplements of folate, B6, B12 didn't slow subjects' cognitive decline
TUESDAY, Oct. 14 (HealthDay News) -- High-dose B vitamin supplementation wasn't associated with slower cognitive decline in patients with mild to moderate Alzheimer's disease, according to research published in the Oct. 15 issue of the Journal of the American Medical Association.
Paul S. Aisen, M.D., of the University of California San Diego, and colleagues analyzed data from 409 subjects randomized to receive placebo or 5 mg of folate, 25 mg of B6 and 1 mg of B12 daily for 18 months. All had normal levels of folic acid, B12 and homocysteine. The primary outcome measure was 18-month change on the Alzheimer Disease Assessment Scale's cognitive subscale.
The treatment had no benefit on the primary outcome measure, although homocysteine levels were significantly reduced in the treatment group compared to the placebo group, the investigators found. Nor did the supplementation regimen have a beneficial effect on any secondary measures, including the Mini-Mental State Examination and an activities of daily living scale, the authors report.
"There has been considerable interest in trials assessing whether dietary supplementation with B vitamins slows the rate of cognitive decline," write the authors of an accompanying editorial. "The precise reasons the Alzheimer Disease Cooperative Study failed to detect any beneficial effect of B vitamins on the rate of cognitive decline remain unclear. However, these results provide further support for the conclusion that B vitamins are not effective in slowing cognitive decline in individuals with normal folate and vitamin B12 levels in societies with folate-enriched foods."
Several of the co-authors listed a number of disclosures related to pharmaceutical companies.