A vitamin pill that costs about a dime a day could help prevent millions of people from developing Alzheimer's disease. Researchers at Britain's Oxford University found that seniors who took a combination of three B vitamins for two years did 70 percent better on memory tests than those who took a placebo.
Specific B vitamins — B-6, folic acid (B-9), and B-12 — are known to control the levels of homocysteine, an amino acid in the body that rises with age. High levels of homocysteine are a known risk factor for Alzheimer's. The researchers decided to see if supplementing seniors with homocysteine-lowering vitamins could slow the rate of brain shrinkage seen in dementia and Alzheimer's.
For the double-blind study, scientists divided 270 senior citizens who had been diagnosed with mild memory problems into two groups. One group took a placebo daily for two years, and the other took a high-dose B vitamin tablet every day. The pill contained 0.5 mg of B-12, 0.8 mg of folic acid, and 20 mg of vitamin B-6. Although B vitamins are found in many foods, including meats and whole grains, the amounts used in the study were much higher than can be obtained from a normal diet.
The progression of the patients' disease was monitored by MRI scans that measured brain shrinkage or atrophy, and they were also given a series of cognitive tests.
After two years, the research team found that the brains of those taking the vitamins shrank 30 percent less than the brains of those taking a placebo. Seniors who had the highest levels of homocysteine to begin with got the best results; their rates of atrophy were 50 percent less than those who took a placebo. In one subject, blood levels of homocysteine were reduced by 500 percent.
