— Model suggests cognitive scores rise with 7 to 9 more minutes of intense movement daily
Judy George, Deputy Managing Editor, MedPage Today
January 23, 2023
Moderate and vigorous physical activity was linked with midlife cognition, a U.K. study showed.
Among nearly 4,500 people born in 1970, time spent performing moderate and vigorous physical activity was associated with higher verbal memory and executive function scores relative to time spent sleeping, being sedentary, or engaging in light activity, according to John Mitchell, MSci, a doctoral candidate at University College London, and colleagues.
A model that reallocated time components in a day showed cognition scores rose by 1.31% when moderate and vigorous physical activity theoretically replaced 9 minutes of sedentary behavior, they reported in the Journal of Epidemiology & Community Health.
Similarly, scores rose by 1.27% when moderate and vigorous physical activity replaced 7 minutes of light intensity physical activity, and by 1.2% when it replaced 7 minutes of sleep. Trends were greater with higher reductions in sedentary activities, the researchers noted.
“We identified that individuals in midlife spending even very small amounts and more time performing more vigorous movement, compared to sitting, sleeping, or gentle activities, had higher cognition scores,” Mitchell told MedPage Today.
“Although we report the smallest differences in daily movements which are linked to modest changes — 1% to 2% changes in cognition scores — we do predict that bigger changes in the day were linked to bigger changes to cognition,” he added.
The study combined data from accelerometer devices with novel statistical techniques, Mitchell noted. “Importantly we cannot distinguish cause-and-effect here because this study looks at just a single snapshot in time, but trials in the past have demonstrated that healthy movement behaviors do support cognitive function,” he said.
“Given that we don’t monitor participants cognition over many years, it may be simply that those individuals who move more tend to have higher cognition on average,” Mitchell observed. “However, it could also imply that even minor differences in our daily lives are linked to healthier cognition.”
The study evaluated 1970 British Cohort Study participants, a cohort of people born in England, Scotland, or Wales during a single week in 1970.
When participants were about age 47, they completed detailed health, background, and lifestyle questionnaires and wore a thigh-mounted accelerometer for up to 7 days, for at least 10 consecutive hours a day. They also underwent verbal memory tests to assess immediate and delayed word recall, and executive function evaluations of verbal fluency, processing speed, and processing accuracy.
Moderate-to vigorous-activity time involved a step cadence of 100 or more steps a minute. Sedentary behavior was defined as non-sleep time spent sitting or lying. Sleep time was the longest reclining period that lasted at least 2 hours, or any bouts lasting 5 hours or longer. Light intensity activity was derived as the residual from total movement activity in a day.
Of 4,481 people in the study, just over half (52%) were female. Most were married (66%) and 51% had an occupation that largely involved sitting.
Accelerometer data showed participants spent an average of 51 minutes a day in moderate to vigorous physical activity, 5 hours and 42 minutes in light intensity physical activity, 9 hours and 16 minutes in sedentary behavior, and 8 hours and 11 minutes sleeping.
Movement profiles were associated with their overall cognition scores. These associations were stronger for executive function than memory.
Sedentary behavior was linked with positive cognitive scores, which may be due to what was being accomplished while sitting. “More and more studies are drawing a distinction between types of sitting activities,” Mitchell said. “There is likely to be a different association between cognition and television viewing for instance, compared to sitting at work. A study of this kind, using devices, would not be able to distinguish various types of sitting.”
Replacing moderate to vigorous activity with 6 to 7 minutes of light intensity activity or sedentary behavior every day was associated with poorer cognitive performance, the model suggested.
The study “corroborates a critical role for moderate to vigorous activity in supporting cognition, and efforts should be made to bolster this component of daily movement.”
Activity trackers captured only time spent in bed, not sleep duration or quality, the researchers acknowledged. Future such studies could apply a similar analytic approach to longitudinal cognition and 24-hour movement data, they said.
Researchers were funded by the Medical Research Council and the British Heart Foundation.
Mitchell and co-authors disclosed no relationships with industry.
Journal of Epidemiology & Community Health
Source Reference: Mitchell JJ, et al “Exploring the associations of daily movement behaviours and mid- life cognition: a compositional analysis of the 1970 British Cohort Study” J Epidemiol Community Health 2023; DOI: 10.1136/jech-2022-219829.