So how's your memory? Pretty normal for your age?
Uh-oh.
"Normal" is not ideal when it comes to the ability to form and retain new memories as we age, said Dr. Riley McCarten, an associate professor in the Department of Neurology at the University of Minnesota.
"As people get older, particularly in late life, 80s and older, it may in fact be normal to have significant memory loss," McCarten said. "But that doesn't mean it's healthy."
A healthy aging brain remains fully functional, McCarten said; it might process information more slowly, but memory remains intact, as does the ability to learn and retain new information.
Still, age is the greatest risk factor for Alzheimer's Disease, the most common form of dementia, said Michelle Barclay, vice president of program services for the Azheimer's Association Minnesota-North Dakota (www.alz.org/mnnd). Among the aging, Alzheimer incidence rises sharply, she said, affecting about one in 10 people at age 65 and nearly half of 85-year-olds.
The disease remains incurable for now, its causes mysterious. Although Alzheimer's is partly linked to heredity, many people with slightly higher genetic risk factors never develop the disease. Healthy habits may help postpone its onset or slow its progress, if not prevent it, Barclay said. "I think a better term would be risk reduction."
But exactly which habits best reduce the risk, unfortunately, is still something of a guessing game. "I don't think we really understand why some people get Alzheimer's Disease and others don't," Barclay said. A couple of years ago, a team from Duke University combed through 25 years of research, examining nearly 300 studies on various interventions that might forstall cognitive decline, from ginkgo biloba supplements to crossword puzzles, and found little solid proof that any of them worked. Researchers have found some evidence of benefits from exercise and formal brain-training programs. (Nicotine users, perhaps surprisingly, are less likely to get dementia, but McCarten suspects that might be because they die of other things first.)