If you live long enough you'll probably get Alzheimer's disease, according to a scientist at UCLA.
But you can take steps to preserve the health of your brain, and thereby postpone the disease, he says.
After the age of 45 or so, the fatty white insulation around the "wires" in your brain starts to break down, according to George Bartzokis, a professor of neurology at UCLA's David Geffen School of Medicine in Los Angeles.
Fortunately, your brain has the ability to repair myelin, but over time the repair process becomes less vigorous. Myelin becomes thinner, which means that the signals that travel along those wires, known as axons, slow down or even stop completely. The resulting stress on your brain cells may then trigger a cascade of problems that can lead to Alzheimer's and other diseases.
What can you do to slow the deterioration of myelin and enhance its repair?
"First, make sure your brain doesn't get damaged," said Bartzokis. "Hypertension, diabetes, cholesterol — all of those things damage the brain by not allowing it to maintain itself in one way or another."
Second, you can enhance the myelin repair process by ingesting DHA, found in fish oil.
"As people get older they need more fish oil because they're repairing their myelin more," Bartzokis said. "Go to the store and you'll find fish oil enriched with DHA."
Third, get some exercise. It not only helps keep your heart and lungs healthy, it also stimulates the production of insulinlike growth factor in your brain, which promotes myelination.
"Exercise seems to have a protective effect," said Bartzokis.
Vitamins and minerals, especially antioxidants, may be helpful to the aging body, but avoid supplements that contain iron, Bartzokis advises. Iron tends to build up in the aging brain, especially among people with Alzheimer's disease, probably because of myelin breakdown followed by myelin repair.
As much as 70 percent of the brain's iron is associated with myelin, according to Bartzokis, and some of that iron is released into the brain environment when myelin deteriorates. On top of that myelin is repaired by special cells called oligodendrocytes, which contain more iron than any other cell in the brain.
This creates a dangerous environment, Bartzokis believes.
"Don't take supplements with metals unless your doctor recommends it," he said. "I think supplements containing iron should be by prescription only."
Dave Morgan, director of the Alzheimer Research Laboratory at the University of South Florida in Tampa, believes Bartzokis' myelin model provides an interesting perspective on Alzheimer's disease, although, he adds, many things besides the deterioration of myelin seem to promote the disease process.
"The whole problem in Alzheimer's is that almost everything can impact it," said Morgan. "I would view the failure of myelin repair as one more thing. Alzheimer's is a chronic degenerative condition, like heart disease. Therefore anything that impacts aging will impact the risk of Alzheimer's.
Tom Valeo is a freelance writer living in St. Petersburg. You can reach him in care of LifeTimes, St. Petersburg Times, P.O. Box 1121, St. Petersburg, FL 33731.