Study: Protein Breakdown in Middle Age May Lead to Alzheimer's Disease

A breakdown of the protein myelin during the middle-age years may lead to Alzheimer's disease later in life, according to a study reported in the January issue of Neurobiology of Aging.

Myelin is a sheet of fat with a very high cholesterol content that coats the brain's internal wiring and speeds messages through the brain.

Study author Dr. George Bartzokis, visiting professor of neurology at the University of California at Los Angeles David Geffen School of Medicine, said the brain's wiring develops until middle age and then begins to decline as myelin breaks down.

This breakdown disrupts the transfer of messages through the axons and eventually leads to the mind-destroying plaques and tangles that are visible years later in the cortex of Alzheimer's patients, according to Bartzokis.

"The body was designed to myelinate through the natural lifespan," said Bartzokis. "Medical advances, however, have expanded the lifespan well beyond the brain's natural capacity to operate in a healthy, efficient manner. Our time at the peak is short indeed. The challenge for science and medicine is to figure out how to extend the brain's peak performance so that our minds function as long as our bodies."

The best time to address the inevitability of myelin breakdown is when it begins in middle age, according to Bartzokis. Otherwise, by the time the effects of Alzheimer's disease become apparent, it may be too late to reverse the course of the disease, he added.

Preventive therapies worth investigating, according to the researchers, include cholesterol- and iron-lowering medications, anti-inflammatory medications, diet and exercise programs and possibly hormone replacement therapy designed to prevent menopause rather than simply ease the symptoms. Education or other activities designed to keep the mind active may stimulate the production of myelin, they added.

Other sources: University of California at Los Angeles