Have you ever been beaten at the classic word game Scrabble by an 85-year-old grandmother? (I have, and I’m usually pretty good at wordsmithing.) Some elderly people with super-sharp memory don’t seem to suffer the memory loss that assails most people as they age. Why? New research points to the lack of destructive “tangles” that are associated with Alzheimer’s disease as a significant factor. Here’s Dr. Brian Bacskai of Harvard Medical School describing tangles:
Looking like the gnarled roots of upside-down tree stumps under a microscope, tangles consist of an abnormal form of a protein called “tau” that damages and eventually kills nerve cells. For reasons not yet clear, some individuals are immune to tangle formation. And, as you might guess, tangles appear to influence cognitive performance on standard memory tests. “Individuals who have few tangles perform at superior levels, while those who have more tangles appear to be normal for their age,” says Dr. Changiz Geula, principal investigator of an earlier study on tangles and a research professor of neurology at the Cognitive Neurology and Alzheimer’s Disease Center at Northwestern’s Feinberg School.
You’ve probably seen images of the ghostly, creeping plaque associated with Alzheimer’s patients. Plaque is an aggregation of amyloid protein that becomes deposited outside the brain cell and disrupts communication between neurons. Like tangles, plaque is also found in the brains of aged individuals and shows a dramatic increase with Alzheimer’s disease. But it is the lower number of tangles, not plaque, in elderly people with super-sharp memory that appears to be the critical difference in maintaining memory skills.
Is there much you can do to minimize the formation of tangles? The famous Nun Study — a longitudinal study of aging and Alzheimer’s disease funded by the National Institute on Aging — may offer some clues. More than 600 sisters from 75 to 106 years of age, many of them from the School Sisters of Notre Dame in Mankato, Minnesota, donated their brains to research upon their deaths. Information gathered from the research suggests that “a healthy lifestyle and positive childhood experiences can protect a person from developing debilitating memory loss.” Here’s Sister M. Celine Koktan talking about her motivation for participating in the study:
Dr. David Snowdon, an epidemiologist and professor of neurology at the Sanders-Brown Center on Aging at the University of Kentucky, details the Nun Study in his book Aging with Grace: What the Nun Study Teaches Us About Leading Longer, Healthier, and More Meaningful Lives. The book describes Sister Nicolette, who lived the longest without Alzheimer’s of all of the nuns who participated in the study. Why did Sister Nicolette remain Alzheimer’s free longer than the other nuns? The answer turns out to likely be good old-fashioned exercise. Dr. Snowdon asserts that Sister Nicolette’s exercise regime helped her preserve cardiovascular health (including avoiding stroke) and mobility. She walked several miles a day, which she started to do when she was 70 years of age.
Sister Blanche Becker also remained sound of mind, but rather than walking, her activity centered on crossword puzzles and reading Danielle Steel novels. Recent evidence supports the common sense notion that reading and solving puzzles may help keep the tangles away. Charles B. Hall, Ph.D., of Albert Einstein College of Medicine in New York led a 5-year study of 488 people who were in their 70s and 80s. Free from Alzheimer’s at the start of the study, each participant filled out questionnaires on their activities during the week: reading books, magazines or newspapers, writing, doing crossword puzzles, playing board or card games, participating in group discussions or playing music. Activity points were awarded based on participation: seven points for participating every day of the week; four points for several days a week; and one point for once-a-week participation. The researchers found that for every additional activity a person participated in, the onset of rapid memory loss was delayed by about two months. “The point of accelerated decline was delayed by 1.29 years for the person who participated in 11 activities per week compared to the person who participated in only 4 activities per week,” says Dr. Hall.
Another study of the world’s oldest woman (who died at age 115) questions the inevitability of Alzheimer’s disease or other forms of dementia. The researchers compared her mental functioning at age 82, 112, and 113. She apparently kept quite active until she was 105. After her death they found her brain had very little plaque and only mild growth of tangles. “Our observations suggest that, in contrast to general belief, the limits of human cognitive function may extend far beyond the range that is currently enjoyed by most individuals, and that improvements in preventing brain disorders of aging may yield substantial long-term benefits,” says Dr. Gert Holstege of University Medical Centre Groningen, The Netherlands.
The Research Partnership in Cognitive Aging — a public-private effort to promote the study of brain function with age — recently announced that they will award 17 research grants of up to $28 million over five years “to examine the neural and behavioral profiles of healthy cognitive aging and explore interventions that may prevent, reduce or reverse cognitive decline in older people.”
The researchers found that for every additional activity a person participated in, the onset of rapid memory loss was delayed by about two months.
The partnership, led by the National Institute on Aging (NIA), part of the National Institutes of Health, and the McKnight Brain Research Foundation (MBRF), will seek ways to maintain cognitive health — the ability to think, learn, and remember — into old age. Reading, walking, and regular Scrabble games are likely to be high on the list to keep those nasty tangles at bay. It appears we can at least delay the onset of dementia and Alzheimer’s disease by regular physical and mental exercise — even if the law of accelerating returns doesn’t result in tangle-eating nanobots in the next 20 years.