Growing Older and Cognition: Your Mileage May Vary

What does current science have to offer in the way of advice on staying mentally sharp as you grow older? General guidelines and useful tips, with expectations of more to come—someday.

“Some things seem to work; exactly what doses, what combinations, and how they should be applied, is unclear,” said Marie Bernard, deputy director at the National Institute on Aging, during a forum at the American Association for the Advancement of Science (AAAS) in Washington, DC, on Wednesday.

aaas aging speakers

From left: Sevil Yasar, Marilyn S. Albert, and Marie Bernard at AAAS on Wednesday

Why so many questions? Because aging is a long process, so studies watching how people age also must be long. And they must start earlier than we once thought, said Marilyn Albert, of Johns Hopkins School of Medicine. When she and her colleagues started doing research on memory and other brain functions in the 1980s, they were surprised to find significant changes by the time people were in their 50s. These results match similar studies by others in people, other primates, and rats. “By the time they are middle-aged, they begin to have trouble,” said Albert, also a member of the Dana Alliance for Brain Initiatives. aaas aging graph

The caveat is that these results are averages, what’s typical for the group. Albert showed this generalized chart, with ages ranging younger to older from left to right: While most people in their 30s and 40s perform in the same range (top left) on a memory task, people in their 50s and on start to drop in performance – but there are still many who stay at the top level. “There is enormous amount of variability, and some people continue to perform very well,” Albert said.

How can you make sure you stay one of the dots at the top, and not one of the sinking dots? Long-term observation studies of thousands of people worldwide, and an increasing number of long-term clinical studies, offer some clues.

Four primary activities seem to be related to maintenance of mental ability: Physical activity, mental activity, social engagement, and managing vascular risk factors. Aerobic exercise and controlling vascular risk have been the most studied in the clinic, and have the strongest evidence of effect, both Albert and Bernard said.

“Exercise in older adults can increase functional connectivity within some brain regions and there are suggestions that plasma-measured biomarkers mediate this,” Bernard said. “In fact, at 12 months of exercise, connectivity appeared similar to younger adults,” in one study, she said. Much recent evidence suggests that memory troubles are not due to any loss of brain cells, but to the loss of connections among brain cells—and connections can potentially be repaired, unlike cell death. There appears to be a dose-response relationship between aerobic exercise measures of attention and visuospatial processing, for example, Bernard said, “but you really have to push it,” exercising hard 30–45 minutes 5 times a week, to get best results.

Managing vascular risk factors, such as blood pressure, blood sugar, and cholesterol levels, weight—and not smoking—is important, Albert said, “but we have trouble knowing when this intervention is important.” Should doctors intervene in middle-age? The later years? “There’s clearly much more work to do for us to be prescriptive — to tell you when to intervene” as well as how much of an intervention (drug, exercise) to prescribe and what exactly the intervention would do.

As for mental activities, randomized controlled research suggests that continuing education (like photography classes) and some cognitive training has benefits that last (ACTIVE study, the Synapse project). There’s less research on social activities, though Bernard mentioned an intriguing recent study that suggests that people who feel they are very busy and have a lot going on score better on measures of cognition. “Those of you who feel like you have too much going on—good news for you,” she said.

Sevil Yasar, also of Johns Hopkins University School of Medicine, spoke from “a practicing geriatrician’s point of view,” answering questions she often hears from her patients: What can I do to prevent memory loss? Could any of my medications–or combination of them—hurt my thinking? Should I worry about anesthesia during surgery?

For food, she suggests virgin olive oil and nuts, as well as generous helpings of fruits and vegetables and avoiding unsaturated fatty acids, citing studies of “Mediterranean” and “DASH”-style diets. But she wouldn’t recommend extra Vitamin D for cognition; the research isn’t clear but, again, it may be not have been testing the right time or dosages. A study reported just this month of coffee intake suggests that 1-2 cups of joe can be beneficial to cognition, but at four cups, “you’re not doing yourself any good,” Yasar said.

“Yes, take your statins,” she advised, and cleared benzodiazepines for those who need them, but talk to your doctor about anticholinergic medicines, which do have evidence they harm certain areas of the brain. The list of what is anticholinergic (blocking the uptake of acetylcholine at a cell’s receptor site) surprised some in the audience, who gasped at the list on Yasar’s slide, which included Benadryl, Immodium, Paxil, Sominex, Tylenol PM (and other PMs), and Zantac.

For people taking multiple medications, the few studies currently reported are equivocal, “I can’t advise more than ‘less may be better,’” she said. As for anesthesia, there is a risk of cognitive dysfunction shortly after surgery for all people, but the risk of long-term problems grows for people over 60—who also have an increased risk of death within a year of the surgery.

Research continues; Albert and Yasar are involved with multiple short- and long-term clinical studies including collaborations that cross the globe. Bernard highlighted some of the newer clinical trials supported by the National Institute on Aging and other NIH groups, as well as results from the Research Partnership on Cognitive Aging.

“I think it is exciting to know that there might be things people can do in their daily lives” that can really make a difference, Albert said. “It means that it’s something everybody could do. It means lots of people could maintain their abilities” as they age.

“We’re beginning to get a handle on those things.”

For more information, all three panelists recommended the report Cognitive Aging: Progress in Understanding and Opportunities for Action (National Academies Press, 2015, free as a PDF). To keep current, recommended web references included Global Council on Brain Health and AARP’s Brain Health and Successful Aging & Your Brain programs.

This event was part of the Neuroscience and Society series, supported by AAAS and the Dana Foundation. Previous sessions include The Science and Policy of Marijuana (story, video); Creativity, Genius, and the Brain (story, video); Mental Illness Across the Ages (story, video); The Neuroscience of Infant Development (story, video); Stress and the Brain (storyvideo); and The Science of Sleep (storyvideo). The next session will be in the fall.

– Nicky Penttila

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