A view of dementia
For the past 30 years, scientists have labored mightily to find a way to halt Alzheimer's disease, the relentless brain-destroying disorder that afflicts 4.5 million Americans. But triumphs have been few and frustrations many. In fact, it's still impossible to tell for sure if people even have the disease until they're dead and autopsied.
But last week brought a spate of good news, including a new brain-imaging technique that lets scientists peek harmlessly into people's brains and detect amyloid plaques, the accumulations of deformed proteins that are the hallmark of Alzheimer's. The new brain-scanning technique, developed by researchers at the University of Pittsburgh, uses a chemical that has been specially jiggered to bind to amyloid.
The PET scans should help with both treatment and, eventually, diagnosis. "It's been very difficult to understand the Alzheimer's process," says John Morris, a neurologist at Washington University in St. Louis and board member of the Alzheimer's Association. Many companies are developing antiamyloid drugs but have been stymied by the inability to tell if they work. "Now we can look directly at what the drugs are doing. That will be a tremendous benefit to drug discovery," Morris says.
The new scanning technique could someday be used to identify people in the earliest stages of Alzheimer's, decades before symptoms become visible and damage to the brain is irreversible. Researchers also want to use this new tool to unravel some big questions about Alzheimer's, including whether amyloid really causes the disease and how much amyloid is a part of normal aging. "No one knows," says Chet Mathis, a radiochemist at Pitt and one of the inventors of the scan. "There's a lot of work to be done."
Drugstore. Last week also brought news in another hot area of Alzheimer's research: prevention. In recent years, scientists have tested many different compounds, including anti-inflammatory drugs, statins, and hormone replacements, in the hope that they would reduce the risk of Alzheimer's--with decidedly mixed results. Last week, researchers led by a group at Johns Hopkins University found that people who took high doses of vitamin E and C supplements were less likely to develop the disorder. A high dose meant more than 400 international units of vitamin E daily and at least 500 mg of vitamin C--far, far more than the 22 IU of E and 75 to 90 mg of C currently recommended by the Institute of Medicine. Both vitamins are antioxidants, compounds that have long intrigued Alzheimer's researchers because tissue damage caused by oxidative stress is a major factor in diseases of old age. But this study, which appeared in the Archives of Neurology, is hardly the last word. Previous studies have found less clear benefits for antioxidants, and the researchers tracked their subjects for just three years.
A third study showed that memantine, an Alzheimer's drug approved by the Food and Drug Administration last October, improved thinking, behavior, and quality of life for mid- and late-stage Alzheimer's patients who were already taking donepezil, a standard Alzheimer's drug. Although a cure for Alzheimer's remains far off, last week's discoveries made significant strides toward that elusive goal.
This story appears in the February 2, 2004 print edition of U.S. News & World Report.
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