March 1, 2002 -- Folic acid may be especially good for more than just moms-to-be. New research suggests the vitamin could play an important role in protecting the brain against Alzheimer's disease and other brain-related disorders.
The animal study, conducted by the National Institute on Aging (NIA), may improve understanding of the biochemical mechanisms behind Alzheimer's. The findings also shed light on earlier research that suggests people with high levels of homocysteine, an amino acid, in the blood have nearly twice the risk of developing Alzheimer's. Folic acid has been shown to lower homocysteine levels in the blood.
Researchers fed one group of mice that had Alzheimer's-like plaques in their brains a diet that included a normal amount folic acid. It's found in leafy green vegetables, citrus fruits, whole wheat bread, and other grain products. The other group was fed a diet that was deficient in this vitamin.
The study is featured in the March 1 issue of the Journal of Neuroscience.
As Alzheimer's progresses, plaques form in the brain that kill off brain cells and cause brain function to deteriorate. In the study, researchers found that the mice that were fed the folic acid-deficient diet had fewer brain cells in an area of the brain that controls learning and memory. This area, called the hippocampus, is also damaged in Alzheimer's. The same mice also had elevated levels of homocysteine in the blood and the brain.
Researchers suspect that high levels of homocysteine in the brain may damage the DNA of nerve cells in the brain. They think that folic acid may help protect the brain by allowing nerve cells to repair this DNA damage.
These new findings establish a possible cause-effect relationship between elevated homocysteine levels and degeneration of nerve cells involved in learning and memory in mouse model of Alzeheimer's," says study author Mark Mattson, PhD, chief of the NIA's laboratory of neuroscience, in a news release.
Previous research has shown that people with Alzheimer's have low levels of folic acid in their blood, but it wasn't known whether this was a result of the disease or malnourishment. Based on this study and other emerging research, Mattson says eating adequate amounts of folic acid in the diet could be beneficial to the aging brain and help protect it against Alzheimer's and other brain disorders.
Since 1998, the FDA has required the addition of folic acid to enriched breads, cereals, flours, corn meals, pastas, rice, and other grain products. Supplementation of folic acid is also recommended for women of childbearing age before and during pregnancy to reduce the risk of birth defects.