Although first published almost 300 years ago, Swift's fantasy represents the worst fears of the huge swath of baby boomers turning 50 who can't recall where they left their keys. Thanks to enormous medical advances in the treatment of heart disease and cancer, Americans today are living longer than ever--and falling victim to Alzheimer's disease in record numbers. About 3% of the U.S. population from 65 to 74 suffers from Alzheimer's, and the incidence rises to 50% in those 85 and over. The Alzheimer's Assn. predicts that, based on projected life expectancies, the number of victims will rise from 4 million today to 12 million by 2050.MANY TOOLS. Recent studies, however, indicate that early diagnosis and treatment of age-related memory loss may delay, and possibly prevent, more serious deterioration. Lifestyle changes, such as exercise, continued learning, and adequate sleep can keep mental decline at bay, while sophisticated imaging technologies can identify the start of Alzheimer's long before symptoms appear.
At that point, a number of drugs in clinical trials could be administered that may postpone or perhaps prevent the onset of dementia. "I think it's probable that within five years, we will have treatments for Alzheimer's that will at the very least slow the rate of decline by as much as one-third," giving victims an additional three to five years of near-normal functioning, says Dr. Leon Thal, chairman of the neurosciences department at the University of California at San Diego Medical School.
It is a momentous prediction. Throughout recorded history, mental decline in the aged has been accepted as inevitable and not preventable. Once humans reach age 50, the portion of the brain known as the hippocampus--responsible for creating, storing, and accessing new information--starts to shrink, and its ability to process information slows. Ergo, missing keys and forgotten names.
This type of memory loss, known as age-associated memory impairment (AAMI), is well within the realm of normal aging and rarely impedes day-to-day living. More worrisome is the next stage of mental decline, a condition called mild cognitive impairment (MCI), that the medical community only officially defined this past May.
People with MCI still have sharp thinking and reasoning skills, but their ability to retain recently acquired information is short-circuited. They regularly forget appointments or cannot easily recall what happened the day before. These lapses may not seem significant, and indeed, the difference between AAMI and MCI can be difficult to discern. Medical experts recommend that patients over 50 who are concerned about ongoing memory problems should come in for a cognitive checkup. Why? About 80% of MCI sufferers develop Alzheimer's within 10 years of diagnosis.
This dire figure may tempt people with memory lapses to do nothing on the assumption that nothing can be done. In fact, early diagnosis of Alzheimer's is the only hope for most victims because by the time the dementia that accompanies this dire disease appears, the brain is usually too damaged to repair. In the past few years, a number of studies have shown that Alzheimer's starts eating away at the brain as much as a decade or more before symptoms appear. A range of drugs, some already available and others in clinical trials, may delay that process.
Doctors usually diagnose MCI by administering a battery of cognitive tests and following up with further tests every year or six months. Several recent studies, however, indicate that magnetic resonance imaging (MRI) scans of the brain may be a far more accurate early-diagnostic tool. One significant report published this summer by British researchers found that MRI scans of four patients with the gene for a rare form of inherited Alzheimer's revealed progressive cell death in the hippocampus three years or more before symptoms appeared. A more recent study by researchers at New York University found similar results.
Once MCI is diagnosed, by any method, patients might ask their doctors about four drugs that are now on the market for Alzheimer's and also in clinical trials for MCI. The four--Exelon, Aricept, Reminyl, and Cognex--all slow the breakdown of key brain chemicals that transmit information to the hippocampus. Doctors are hopeful the trials will show that, if given before symptoms appear, these drugs may delay, and possibly even prevent, the onset of Alzheimer's. This theory has yet to be proven, however.ANTIOXIDANTS, TOO. The scope of clinical trials of protective agents goes well beyond these drugs. The National Institute on Aging is sponsoring trials on many different treatments involving more than 4,000 people at 83 sites around the U.S. Under study are antioxidants, particularly vitamin E, which protect the body from free radicals associated with age-related neuron death. A number of anti-inflammatories, including the popular Cox-2 arthritis drugs, are being tested to see if they reduce brain inflammation, another cause of neuron death, while a large study of estrogen's ability to protect the brain of postmenopausal women is under way as well.
The Institute for the Study of Aging, funded by the Est?e Lauder Foundation, is sponsoring trials of the effects on memory retention of statins, the popular cholesterol-lowering drugs, based on research that links high cholesterol levels with Alzheimer's. In fact, says Dr. Howard Fillit, the Institute's executive director: "All of the things you can do that help keep the heart healthy also help the brain." Fillit notes that a number of population studies have indicated a link between dementia and such vascular diseases as high blood pressure, arteriosclerosis, and diabetes. Depression, stress, insomnia, and alcoholism are also associated with severe memory loss.
That's why neurologists are increasingly recommending exercise and a healthy diet as key ways to stay mentally as well as physically fit. Even more important is mental activity. Several studies have shown that the greatest risk factor for Alzheimer's is a low level of education. Lifelong learning, continuing social engagement, and regular mental challenges can go a long way toward holding at bay the mental decline of aging. So the best advice to aging baby boomers may be to turn off the TV and pick up a copy of Gulliver's Travels. By Catherine Arnst