You may have read about the results of a recent study, from which researchers concluded that B vitamins are not effective at slowing the progression of Alzheimer’s disease. With so many people facing the threat of Alzheimer’s, you might wonder why some researchers would be so quick to discount any kind of nutritional options for Alzheimer’s prevention.
Here are the facts about the study, and the criticisms of both its design and conclusions:
The study found that high doses of folic acid, vitamin B6 and vitamin B12 did not slow the progression of Alzheimer’s disease symptoms in people with mild-to-moderate symptoms. People in the study took 5 mg of folic acid, 25 mg of B6 and 1 mg of B12 for 18 months. These amounts of vitamins are known to lower blood levels of homocysteine, a toxic amino acid that, at high levels, has been linked to loss of brain cells.
Because those in the Alzheimer’s study did not seem to show any improvement in symptoms, researchers concluded that B vitamins are not helpful when it comes to Alzheimer’s disease. (JAMA. 2008 Oct 15;300(15):1774-83.)
We have a couple of problems with that conclusion. First, it’s important to make a distinction between treating a disease and preventing it, especially when it comes to nutritional interventions.
“This study does not address the question of whether or not B vitamin supplementation can help prevent cognitive decline associated with Alzheimer’s disease in a healthy population,” says Andrew Shao, Ph.D., vice president for scientific and regulatory affairs at the Council for Responsible Nutrition, a trade organization. “By enrolling patients already diagnosed with Alzheimer’s disease, this study looks at treatment, not prevention and vitamins in general do not treat or cure disease.”
Second, the results of this study contradict previous Alzheimer’s studies, including a randomized, controlled trial, which showed that healthy subjects who took 800 mcg per day of folic acid had significantly slower cognitive decline than those who did not.
Third, all the people enrolled in this study had normal blood levels of homocysteine, and of folic acid, B6 and B12 to begin with. They weren’t deficient. They were given supplemental vitamins to see if the vitamins improved their symptoms of Alzheimer’s disease. People who would be most likely to benefit from supplemental vitamins (those with high homocysteine levels or low vitamin levels) weren’t included in the study!
Alzheimer’s disease usually develops slowly. By the time symptoms become apparent, the disease has been progressing for about 15 years. Using Alzheimer’s prevention strategies before symptoms appear is what makes most sense, and that’s what doctors who use nutritional strategies to prevent brain deterioration recommend.
What we particularly dislike about this kind of “don’t bother” reporting is that it can make people feel hopeless, and abandon perfectly reasonable approaches to healthy aging.
The Anti-Aging Bottom Line: “Consumers should not take this one, relatively short-term study as an indictment against B vitamins. They should continue to take B vitamins for the overall health benefits they provide and to help prevent cognitive decline over the long term,” Dr. Shao says. We recommend taking not just folic acid, B6 and B12, but a multivitamin that contains good amounts of all the B vitamins, along with the other vitamins and minerals that help the Bs to do their job.