Physical activity at any time during adulthood improves later-life cognitive status; however, sustained physical activity levels result in the highest cognitive status at age 69, according to study findings published in the Journal of Neurology, Neurosurgery, and Psychiatry.
Physical activity is believed to be a modifiable risk factor for dementia. Previous research has modestly linked physical activity with a lower risk for all-cause dementia. Yet, whether the timing, frequency, or maintenance of physical activity throughout adulthood offers a significant benefit for cognition later in life is unknown.
Researchers in the United Kingdom conducted a prospective, 30-year, longitudinal cohort study of 1,417 British participants born in 1946 (53% women; all were White) to determine if timing of physical activity affected cognitive status later in life.
During this 30-year period, participants self-reported their leisure time physical activity levels 5 times during the lifespan between the ages 36, 43, 53, 60-64, and 69. The researchers graded physical activity levels, ranging from no activity per month, moderate activity (1-4 activities per month), or most active (5 or more activities per month).
At age 69, participants underwent cognitive testing using the Addenbrooke’s Cognitive Examination-III (ACE-III) for cognitive status, word learning tests (WLTs) for verbal memory, and visual search speed (VSS) for processing speed.
Researchers noted that rates of physical activity generally decreased as age increased. People who participated in 5 or more activities per month or those in the moderate activity category scored significantly higher on cognitive testing (ACE-III and WLTs) at age 69 than those in the no activity category. Only those who participated in 5 activities or more per month at any age achieved higher processing speed scores via VSS tests at age 69.
Adults active at any time period throughout their lifespan demonstrated higher cognitive scores at age 69. Cumulative activity throughout adulthood correlated strongly with higher ACE-III scores, especially for adults who continuously participated in activity during the 5 assessed study periods.
Researchers assessed confounding factors, including education, childhood cognition, emotional mental health using the General Health Questionnaire-28, cardiovascular risk factors such as hypertension, diabetes, smoking status, and body mass index, and single nucleotide polymorphisms indicative of the APOE ε4 genotype.
They found that education, childhood cognition, and childhood socioeconomic status significantly attenuated the association between activity levels and cognitive status, while cardiovascular risk factors, APOE genotype, or mental health did not influence this relationship.
Researchers noted that “[L]ifelong maintenance of physical activity is the most optimal; the longer an individual is active, the more likely they are to have higher later-life cognitive function.” They concluded, “These relationships were partly explained by childhood cognition and education, but independent of cardiovascular and mental health and APOE-E4, suggestive of the importance of education on the lifelong impacts of physical activity.”
Study limitations included disproportionate attrition of participants with social disadvantages or who were less healthy, lack of generalizability outside of an exclusively White British cohort, dependence on self-reported leisure activity levels, and lack of assessment of exercise intensity, duration, and adherence.
James SN, Chiou YJ, Fatih N, Needham LP, Schott JM, Richards M. Timing of physical activity across adulthood on later-life cognition: 30 years follow-up in the 1946 British birth cohort. J Neurol Neurosurg Psychiatry. Published online February 21, 2023. doi:10.1136/jnnp-2022-329955