Folic Acid Deficiency Linked to Parkinson's

By Biotechdaily staff writers
Posted on 20 May 2002

Folic acid deficiency may increase the brain's susceptibility to Parkinson's disease, according to a mouse study conducted by scientists at the National Institute on Aging (NIA, Bethesda, MD, USA). The findings were reported in the January 2002 issue of the Journal of Neurochemistry.

The investigators fed one group of mice a diet that included folate, while a second group was fed a diet lacking this vitamin. The mice were then given moderate amounts of MPTP, a chemical that can cause symptoms similar to Parkinson's disease. In the mice fed folate, MPTP caused only mild symptoms of disease, but mice fed the folate-deficient diet developed severe symptoms of Parkinson's disease. The scientists found that mice with low amounts of dietary folic acid had elevated levels of homocysteine in the blood and brain. They suspect that increased homocysteine levels in the brain damaged the DNA of nerve cells in the substantia nigra, which produces dopamine.

Loss of dopamine causes nerve cells to dysfunction, resulting in the inability of patients to direct or control their movements in a normal way. In the folate-fed mice, dopamine-producing nerve cells were able to repair their damaged DNA and counteract the adverse effects of homocysteine. In folate-deficient mice, however, similar nerve cells were not able to repair their extensive DNA damage, so they died. The scientists noted that people with Parkinson's disease often have low levels of folic acid in their blood, but it is not known if this is a result of the disease process or if they are simply malnourished because of their illness. Based on this study, it would appear that consuming adequate amounts of folic acid could help protect the aging brain against Parkinson's and other neurodegenerative diseases.

"This is the first direct evidence that folic acid may have a key role in protecting adult nerve cells against age-related disease,” said Mark Mattson, Ph.D., chief of the NIA's
Laboratory of Neurosciences.

Related Links:
National Institute on Aging (NIA)