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.
The researchers also gave all of the subjects a series of cognitive tests. They found that scores were the highest in the patients with the lowest rates of shrinkage — they performed 70 percent better on memory tests than those who took the placebo. In addition, some of the patients who took the highest doses found that their memory lapses had completely disappeared by the end of the two-year study.
To keep homocysteine levels in check, the researchers suggested people eat more meat and green vegetables, and to reduce their intake of alcohol, which depletes the body of vitamin B-12.
Study leader Dr. Celeste de Jager of Oxford University advises people in their 40s and 50s to consider taking vitamins. "A lot of the time brain changes start in your forties and fifties before you get clinical symptoms," she said at the British Science Festival. "I would ask the doctor to check my B-12 and my folic acid levels for starters."
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