How much will you actually spend in retirement? That depends on a lot of factors,…
Why do some people’s mental faculties decline rapidly with age, while others remain mentally sharp and active well into their senior years? That’s the question researchers are trying to answer in a study at Northwestern University and funded by the National Institutes of Health. They have identified several biological differences between those who retain their mental abilities and those who don’t.
Northwestern’s Cognitive Neurology and Alzheimer’s Disease Center first identified so-called cognitive superagers in 2007 whose memories and processing speed don’t decrease significantly as they age. Studies of these individuals’ brains shows the anterior cingulate cortex was significantly thicker than others of the same age with normal cognitive performance, and even some younger individuals (ages 50 to 60). This area of the brain is related to executive function, motivation, and perseverance, as well as memory.
The analyses also found this brain region in superagers had 87 percent fewer protein tangles than other individuals. These protein tangles strangle and eventually kill neurons. The area also had up to five times the number of von Economo neurons, which are critical in processing information related to social interactions.
Although scientists haven’t yet found a way to turn someone into a superager, there are several habits that seem to be common among them.
Social interactions appear to be one key. Says University of Miami neuropsychologist David Loewenstein, “Epidemiological studies show that people with a lifetime of cognitively stimulating activities and social connections are much less at risk for cognitive decline as they age.”
Reviews of published studies suggest that marriage, social interactions, and avoiding loneliness have a protective effect against developing dementia. Mary Helen Abbott, 77, one of the superagers in the study, moved to an active retirement home to avoid loneliness after her husband died. “One of the big reasons I like being here is I got tired of eating by myself”, she said. She now heads the welcoming committee and knows all the residents, plays golf and rides the bus to church each week.
Abbott also participates in aerobic classes at the retirement home. Regular exercise promotes healthy circulation and lower blood pressure, which are physiological factors associated with mental acuity. Recent research by Cambridge University found that just one hour of vigorous exercise per week can reduce the incidence of Alzheimer’s disease by more than half.
The same effect can be achieved with 150 minutes of moderate exercise per week, the study found. High blood pressure increased the risk by 61 percent, according to the research. “Geriatricians I know say that if we could put exercise in a pill form it would be the most sought-after drug on the market,” says Laura Carstensen, founding director of the Stanford University Center on Longevity.
Just as important as regular exercise is staying busy. Says Carstensen, “Work — paid or unpaid — may improve cognitive functioning.” Work enables people to maintain a sense of purpose and contributing to society. Gwen North, an 85-year-old retired kindergarten teacher, lives at an upscale retirement home in south Florida and runs its thrift store, working six days a week. Her husband Art, 86, is often seen socializing around town or fixing people’s broken appliances. Both have taken memory tests and donated samples of spinal fluid to help researchers study the biology of aging.
It’s undeniable that genes and external factors play a huge role in aging. Many of the subjects in the study are educated and relatively affluent. The poor are often more susceptible to physical and mental effects of aging. African-Americans and Latinos also have disproportionately higher rates of dementia than Caucasians in the U.S. But these new studies suggest that mental declines aren’t necessarily inevitable and there are simple things people can do to help maintain their quality of life.