Vitamin B Does Not Prevent Alzheimer's or Slow Age-related Dementia

found that taking B vitamins does not help elderly people slow age-related mental decline or prevent Alzheimer’s disease. Because people with Alzheimer’s disease have high blood levels of homocysteine, and people with high levels of homocysteine are at higher risk of the disease, researchers investigated whether taking folic acid (vitamin B-9) and vitamin B-12 might lower the risk of Alzheimer’s. These vitamins are known to lower homocysteine levels.

British researchers led by Robert Clarke, MD, of Oxford University, analyzed data from 22,000 people involved in 11 clinical trials that examined the effect of B vitamins on older people’s mental abilities. They found that although taking B vitamins did lower homocysteine levels by almost 25%, this reduction did not have an effect on thinking skills.

“It would have been very nice to have found something different,” Clarke said in a statement to the university. “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.”

Clarke said that about 25% to 30% of adults take multivitamins, often because they believe they are good for the brain and heart, the evidence isn’t there. He advised more fruit and vegetables in the diet, avoidance of red meat and high calorie foods, and a more balanced diet.

The study was published in the July 15, 2014, American Journal of Clinical Nutrition.