Sitting is not always bad for older people’s brain health, study finds

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In a new study, researchers found that when it comes to the brain and cognition, sitting is not always bad for older people, so long as basic physical activity benchmarks are being met.

They examined the association between sensor-measured physical activity and cognitive performance in a sample of 228 healthy older adults, aged 60 to 80.

They found that, as expected, adults who engaged in more moderate-to-vigorous activity had better speed, memory, and reasoning abilities.

However, the results also showed that adults who spent more time sedentary performed better on vocabulary and reasoning tasks.

The findings could be a bit of good news for a population of Americans who spend a significant amount of time sitting for work and for leisure.

The research was conducted by a team at Colorado State University.

Researchers know that as people grow older, even if they do not have any cognitive impairments, people aged 60 and up already show some decreases in speed, executive functioning, and memory.

Those decreases are totally within a normal range, but this study was looking to understand how our behaviors and habits may correlate with cognitive outcomes in older age.

What differentiates this study from others is the way the researchers measured daily physical activity, using scientifically validated sensors that are more accurate than your average, consumer-based activity tracker.

Further, where other studies might use only one or two measures of cognition and a general definition of physical activity, this study employed a broad assessment that tested 16 cognitive tasks.

The cognitive assessment prompted participants to select patterns, fill-in-the-blanks, and identify shapes, among other tasks—the results of which helped researchers gauge if there was a correlation between physical activity and fluid vs. crystallized cognition.

So-called “fluid” abilities, such as speed and memory, problem-solving, and reasoning skills, tend to decline throughout adulthood.

In the study, the team found people who engaged in the moderate-to-vigorous physical activity performed better on fluid tasks, suggesting that exercise might stave off some of the typical effects of brain aging.

However, most people in the study did not spend a significant amount of time in physical activity; in fact, data showed that, on average, most participants spent less than 2.7% of their time engaged in moderate-to-vigorous activities.

Those older adults who instead sat more hours each day performed better on knowledge-based activities, like vocabulary tests or reading comprehension.

These “crystallized” abilities tend to strengthen with age as adults acquire more knowledge and experience.

Interestingly, the researchers found no associations between light physical activities—such as doing laundry, cooking, or other household chores—and cognition.

Although replacing sedentariness with light physical activity has been recommended for better metabolic health, there is no evidence of such a link at the cognitive level.

One author of the study is Assistant Professor Aga Burzynska.

The study is published in Psychology and Aging.

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