Experts viewed B vitamins as a potential way to lower the risk of Alzheimer's disease or slow its progression because the vitamins can cut the amount of the amino acid homocysteine, found in high levels in the blood of Alzheimer's patients. But when the researchers gave people with mild to moderate Alzheimer's disease high-dose supplements of vitamins B6 and B12 and the B vitamin folic acid for 18 months, they did no better on tests assessing cognitive skills such as memory and language than similar patients who were given a placebo, researchers wrote in the Journal of the American Medical Association. "Our results give a very clear answer that these vitamins should not be taken to treat Alzheimer's disease. They're ineffective," said Dr. Paul Aisen of the University of California San Diego, who led the study.
The study involved 409 people with Alzheimer's disease at 40 sites throughout the United States. Some got daily doses of five milligrams of folic acid, one milligram of vitamin B12 and 25 milligrams of vitamin B6. The rest got daily placebo pills. Those doses are far above the recommended daily allowance. The people who took the B vitamins saw their homocysteine levels decline, but that did not translate into any benefits in terms of cognitive abilities compared to the placebo group. Dr. Lon Schneider of the Keck School of Medicine of the University of Southern California, another of the researchers, said the study did not look at whether lowering homocysteine much earlier in life would prevent or delay Alzheimer's. The study was part of an initiative funded by the U.S. National Institutes of Health testing promising ideas for Alzheimer's treatment not being pursued by drug companies. "This is closing down one strategy, but we fortunately have many others," Aisen said.
Bonnie - I'm glad they wasted taxpayer dollars to discover this. As I have said time and time again, if we study vitamins and minerals to treat disease, we will continually be disappointed. Low B-vitamins and high homocysteine levels are predictors of cognitive decline. They should be part of a screening process, especially in those with cognitive decline in their family history. B-vitamin supplementation is meant to be taken as a long-term preventative, not a disease treatment. Unfortunately, there are few research studies following this model. Tracking a small group with mild to moderate Alzheimer's for 18 months while on B-vitamins is not going to produce a miracle cure. Until we adapt to a more balanced approach to Alzheimer's research (between prevention and miracle cure), we are bound to be disappointed. I alluded to this in my Alzheimer's public health paradigm.