EMBARGOED FOR RELEASE UNTIL 4 PM ET, May 27, 2002
Homocysteine Related to Brain Atrophy, Vascular Disease
St. Paul, Minn. -
People with elevated blood levels of the amino acid homocysteine are more likely to experience brain atrophy and vascular disease, according to two studies published in the May 28 issue of Neurology, the scientific journal of the American Academy of Neurology. Both brain atrophy and vascular disease are related to the development of dementia, including Alzheimer''''s disease. "This is exciting information, because homocysteine levels can be reduced by taking the vitamins B6, B12 and folic acid," said neurologist James Toole, MD, of Wake Forest University School of Medicine in Winston-Salem, NC, who wrote an editorial accompanying the studies. Mild elevations of homocysteine levels have been reported to occur in five to seven percent of the general population. Toole is leading a study examining whether taking these vitamins to lower these levels can reduce the risk of stroke. "Another area that needs to be studied is whether taking vitamins to lower homocysteine levels can reduce the risk of Alzheimer''''s and other dementia," he said. "There''''s a long way to go before we know the answers to these questions, but it''''s an exciting possibility." The study finding that high homocysteine levels are related to brain atrophy involved 36 healthy elderly people. The participants'''' blood was tested for homocysteine levels. MRI brain scans were used to measure the amount of brain atrophy, or loss of brain cells and volume. The study found that elderly people who had greater brain atrophy (those in the top 50 percent of the study group) were twice as likely to have high homocysteine levels as those with less atrophy, according to study author Perminder Sachdev, MD, PhD, of the University of New South Wales in Sydney, Australia. Sachdev said more, long-term studies are needed to determine whether high homocysteine levels cause brain atrophy. The study finding that high homocysteine levels are related to vascular disease involved 43 people with Alzheimer''''s disease and 37 healthy people. People with high levels were 10 times more likely to have vascular disease, according to study author Joshua W. Miller, PhD, of the University of California, Davis. "The study didn''''t find a relationship between high homocysteine levels and Alzheimer''''s disease per se - as has been reported previously - but rather suggests that in studies that did demonstrate this association, the effect may be mediated by vascular disease," Miller said. The Alzheimer''''s patients were also found to be 12 times more likely to have low levels of vitamin B6 than the healthy people. "This finding will need to be confirmed by other studies, but it is interesting," Miller said. "Vitamin B6 has been shown to play a role in brain function and memory, so it''''s possible that taking B6 supplements could help Alzheimer''''s patients." The University of California study was supported by a grant from the National Institute on Aging. The Australian study was supported by grants from the National Health and Medical Research Council of Australia, the New South Wales Institute of Psychiatry and the Fairfax Foundation. Homocysteine occurs normally in the body. Both genetic and environmental factors determine an individual''''s homocysteine level. The level is affected by the consumption of vitamins, especially folic acid, B6 and B12. According to researchers, people who follow a well-balanced diet should get enough of these vitamins. Important sources of folic acid include citrus fruits, tomatoes, vegetables and grain products. Major sources of B6 are meat, poultry, fish, fruits, vegetables and grain products. Major sources of B12 are meat, poultry, fish and milk and milk products.