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Alzheimer’s disease not prevented with B vitamin use

Taking B vitamins did not slow mental decline and is not likely to prevent Alzheimer’s disease, according to recent study findings published in The American Journal of Clinical Nutrition.

Robert Clarke, MD, FRCP, of the clinical trial service unit and the epidemiological studies unit at Oxford University, and colleagues evaluated 11 randomized clinical trials that included 22,000 people and compared the effects of B vitamins on cognitive function in older adults against placebo.

Robert Clarke

Although taking B vitamins reduced homocysteine levels by 28%, no effects were found on mental abilities.

Researchers said people with higher levels of homocysteine have been shown to be at increased risk for Alzheimer’s disease, and B vitamins with folic acid reduce those levels.

“It would have been very nice to have found something different,” Clarke said in a press release. “Our study draws a line under the debate: B vitamins don’t reduce cognitive decline as we age. Taking folic acid and vitamin B-12 is sadly not going to prevent Alzheimer’s disease.”

Researchers found that, overall, no significant effects were found between B vitamins and changes in memory, executive function or the domain-composite score.

“Overall, homocysteine-lowering treatment with B vitamins did not substantially slow the rate of cognitive aging in older people with or without vascular disease, irrespective of how cognitive function was assessed,” the researchers wrote. “As with ischemic heart disease, the discrepant results of the observational studies and the randomized trials for the effects of B vitamins on cognitive function suggest that elevated plasma homocysteine is probably a marker of underlying cognitive aging rather than a causal risk factor.”

Disclosure: The researchers report no relevant financial disclosures.