A long-term study suggests that maintaining an exercise routine throughout adulthood is the best way to preserve mental acuity and memory. Although factors such as childhood cognitive ability, household income, and education weakened the observed associations, the results remained statistically significant. The study showed that being physically active at all adult ages was linked to higher cognitive performance, verbal memory and processing speed at age 69. The strongest association was observed for sustained cumulative physical activity and cognition later in life, with the most significant benefits for those who were most physically active at all ages.
Any regular physical activity at any age is linked to better brain function later in life. But maintaining an exercise routine throughout adulthood is best for preserving mental acuity and memory.
Any regular leisurely physical activity at any age is linked to better brain function later in life, but maintaining an exercise routine throughout adulthood appears to be the best way to preserve acuity. mental health and memory, suggests a long-term study published online in the Journal of Neurology Neurosurgery and Psychiatry.
Although controlling for childhood cognitive abilities, household income, and education weakened the observed associations, the results remained statistically significant.
Physical activity is modestly associated with a lower risk of dementia, cognitive decline, and loss of mental acuity later in life. But it’s unclear whether the timing, frequency, or maintenance of leisure-time physical activity across the lifespan might hold the key to cognitive abilities later in life.
The researchers were particularly keen to find out whether physical activity might be more beneficial in specific ‘sensitive’ periods throughout life, or over multiple time periods.
To try to find out, they looked at the strength of associations between a series of cognitive tests at age 69 and self-reported leisure-time physical activity at ages 36, 43, 53, 60-64, and 69 in 1417 people (53% women ) participant in the 1946 UK birth cohort study.
Physical activity levels were categorized as follows: inactive; moderately active (1–4 times/month); most active (5 or more times/month) and summed across the 5 ratings to create a total score ranging from 0 (inactive at all ages) to 5 (active at all ages).
Approximately 11% of participants were physically inactive at all 5 time points; 17% were active at one; 20% were active at two and three years; 17% were active at four years and 15% at every five years.
Cognitive performance at age 69 was assessed using the validated ACE-111, which tests attention and orientation, verbal fluency, memory, language, and visuospatial function, as well as tests verbal memory (word learning test) and processing speed (visual search speed).
Factors associated with an increased risk of cognitive decline – cardiovascular and mental health, and carriage of the APOE-ε4 gene – were also assessed to see if these modified the observed associations.
Analysis of the results showed that being physically active at all 5 time points was associated with higher cognitive performance, verbal memory and processing speed at age 69.
Effect sizes were similar at all adult ages, and for those who were moderately and most physically active, “suggesting that being physically active at all times in adulthood, even if only participating once a month is linked to higher cognition”. write the researchers.
But the strongest association was seen for sustained cumulative physical activity and cognition later in life, and for those who were most physically active at all ages.
The positive association between cumulative physical activity and cognitive performance later in life was partly explained by childhood cognition, socioeconomic position, and education.
But the effect remained significant when these were taken into account, and the associations were not explained by differences in cardiovascular or mental health later in life.
“Together, these results suggest that the initiation and maintenance of physical activity in adulthood may be more important than the timing…or frequency of physical activity at a specific time period,” the researchers say. .
This is an observational study and as such cannot establish causation, and the researchers acknowledge various limitations to their findings.
The study only included white participants and had a disproportionately high attrition rate among those who were socially disadvantaged. No information was available on exercise intensity, duration, or compliance either.
But they nevertheless conclude: “Our results support guidelines for recommending participation in any physical activity in adulthood and provide evidence that encouraging inactive adults to be more active at all times and encouraging already active adults to maintain an activity, could confer benefits on cognition later in life.”
Reference: “Time of physical activity in adulthood on later cognition: 30 years of follow-up in the 1946 UK birth cohort” by Sarah-Naomi James, Yu-Jie Chiou, Nasri Fatih, Louisa P Needham, Jonathan M Schott and Marcus Richards, February 21, 2023, Journal of Neurology Neurosurgery and Psychiatry.
DOI: 10.1136/jnnp-2022-329955