Feb. 28, 2000 (New York) -- A recent study indicates that high levels of iron in the brain are linked with Alzheimer's disease, and with a new magnetic resonance imaging (MRI) technique to study that link, researchers think they are closer to understanding that link -- and, possibly, to pinpointing those most at risk of developing the disease.
George Bartzokis, MD, author of the study published in the January issue of Archives of General Psychiatry, tells WebMD that the findings of a study using the new imaging technique point toward free-radical production as part of the development of Alzheimer's. Free radicals are naturally occurring substances in the body that can bind to normal molecules and cause damage in various parts of the body.
Standard MRI scanning is a noninvasive procedure that allows neurologists to view the brain's blood vessels and soft tissue. A dye is often injected into a vein to help doctors see the area being studied.
The new imaging technique, known as FDRI (Field-Dependent R2 Increase) measures the iron content of ferritin in the brain. Ferritin is a protein that stores most of the body's iron reserves. The measurement is made through the combined use of two MRI machines with different imaging strengths, says Bartzokis, who is affiliated with the departments of psychiatry at both UCLA and the University of Arkansas for Medical Sciences in Little Rock.
Thirty-one people with mild to severe Alzheimer's disease and 68 people who served as controls participated in the study. Ferritin iron levels in different regions of the brain were compared in the two groups. In the Alzheimer's group, ferritin iron levels were significantly higher than levels in the control group -- but only in the basal ganglia, areas traditionally believed to be implicated in movement.
According to Bartzokis, this supports the theory that free radicals interacting with iron play a part in the development of Alzheimer's. This mechanism of damage has been associated with a variety of neurological degenerative disorders, including Parkinson's disease and Huntington's disease.
In fact, Bartzokis tells WebMD, he believes the link between iron and Alzheimer's is so strong that people shouldn't take iron supplements unless a doctor advises them to. "It's well known that there is no mechanism of getting rid of iron from the body. Our findings suggest that, unless medically indicated, people should not take extra iron because it may have deleterious effects," he says.
Bartzokis acknowledges that, because of the study's design, he is not able to show that increased brain iron levels actually cause Alzheimer's disease. But if elevated iron levels contribute to its development, new avenues of treatment and prevention may be possible, he tells WebMD.
The FDRI imaging technique has important applications, Bartzokis says. He suggests that it might be used to monitor the effectiveness of treatments. He is now conducting a study that investigates whether patients with high iron levels have a higher risk of developing neurological diseases.
Ramin V. Parsey, MD, of Columbia University, who has done research similar to that of Bartzokis, agrees that the imaging method may eventually allow physicians to diagnose people before symptoms appear, follow the course of treatments, and suggest new forms of treatment. Since MRI does not involve radiation, it can be repeated as often as necessary.