Low Folic Acid Intake May Be Linked with Increased
Alzheimer's Risk.
BALTIMORE, Md.: Folic acid
deficiency may be a factor in Alzheimer's disease risk, as well as elevated
homocysteine levels, according to a study published in the March 1 issue of
Journal of Neuroscience (22, 5:1752-62, 2002). Scientists from the Laboratory of
Neurosciences at the National Institute on Aging (NIA) noted this newly
discovered link may help researchers discover the biochemical mechanisms for why
people with high levels of homocysteine have nearly twice the risk of developing
Alzheimer's.
"These new findings establish a possible
cause-effect relationship between elevated homocysteine levels and degeneration
of nerve cells involved in learning and memory in a mouse model of Alzheimer's
disease," said Mark Mattson, Ph.D., chief of NIA's Laboratory of Neurosciences
and a principal investigator on the NIA study.
NIA researchers studied two groups of transgenic
mice, bred to develop Alzheimer's-like plaque in their brains. One group was fed
a diet that contained normal amounts of folic acid, and the second group was fed
a folate-deficient diet. In studying the mice's brains, researchers noted that
the deficient group exhibited a decreased number of neurons in the hippocampus
region. The hippocampus region of the brain was studied in particular because it
is a critical center for learning and memory that is destroyed when Alzheimer's
plaque accumulates, destroying neurons in the region.
An additional finding brought out during this
animal study demonstrated that the folate-deficient group experienced a rise in
homocysteine levels in both blood and brain. Researchers hypothesized that the
increased homocysteine levels in the brain damaged nerve cells in the
hippocampus. The mice on the folate diet also experienced DNA damage to
hippocampus brain cells because of the Alzheimer's-like plaque, but they were
able to repair the DNA damage. The folate-deficient rats, however, incurred
hippocampus damage but did not demonstrate the ability to repair cell DNA
damage.
Based on this and other emerging research,
Mattson speculated that adequate amounts of dietary folic acid could protect
brain cells during the aging process, thereby staving off Alzheimer's and other
neurodegenerative diseases. |
