Any amount of exercise in middle age is associated with better cognition in later life, new research suggests.
A prospective study of 1400 participants showed that those who exercised to any extent in adulthood had significantly better cognitive scores later in life compared with their peers who were physically inactive.
Maintaining an exercise routine throughout adulthood showed the strongest link to subsequent mental acuity.
Although these associations lessened when investigators controlled for childhood cognitive ability, socioeconomic background, and education, they remained statistically significant.
“Our findings support recommendations for greater participation in physical activity across adulthood,” lead investigator Sarah-Naomi James, PhD, research fellow at the Medical Research Council Unit for Lifelong Health and Ageing at the University College London, United Kingdom, told Medscape Medical News.
“We provide evidence to encourage inactive adults to be active even to a small extent…at any point during adulthood,” which can improve cognition and memory later in life, James said.
The findings were published online February 21 in the Journal of Neurology, Neurosurgery and Psychiatry.
Previous studies have established a link between fitness training and cognitive benefit later in life, but the researchers wanted to explore whether the timing or type of exercise influenced cognitive outcomes in later life.
The investigators asked more than 1400 participants in the 1946 British birth cohort how much they had exercised at ages 36, 43, 60, and 69 years.
The questions changed slightly for each assessment period, but in general, participants were asked whether in the past month they had exercised or participated in such activities as badminton, swimming, fitness exercises, yoga, dancing, football, mountain climbing, jogging, or brisk walks for 30 minutes or more; and if so, how many times they participated per month.
Prior research showed that when the participants were aged 60 years, the most commonly reported activities were walking (71%), swimming (33%), floor exercises (24%), and cycling (15%).
When they turned 69, researchers tested participants’ cognitive performance using the Addenbrooke’s Cognitive Examination–III, which measures attention and orientation, verbal fluency, memory, language, and visuospatial function. In this study sample, 53% were women, and all were White.
Physical activity levels were classified as inactive, moderately active (one to four times per month), and most active (five or more times per month). In addition, they were summed across all five assessments to create a total score ranging from 0 (inactive at all ages) to 5 (active at all ages).
Overall, 11% of participants were physically inactive at all five time points; 17% were active at one time point; 20% were active at two and three time points; 17% were active at four time points; and 15% were active at all five time points.
“Cradle to Grave” Study?
Results showed that being physically active at all study time points was significantly associated with higher cognitive performance, verbal memory, and processing speed when participants were aged 69 (P < .01).
Those who exercised to any extent in adulthood ― even just once a month during one of the time periods, fared better cognitively in later life compared with physically inactive participants. (P < .01)
Study limitations cited include a lack of diversity among participants and a disproportionately high attrition rate among those who were socially disadvantaged.
“Our findings show that being active during every decade from their 30s on was associated with better cognition at around 70. Indeed, those who were active for longer had the highest cognitive function,” James said.
“However, it is also never too late to start. People in our study who only started being active in their 50s or 60s still had higher cognitive scores at age 70 compared to people of the same age who had never been active,” she added.
James intends to continue following the study sample to determine whether physical activity is linked to preserved cognitive aging “and buffers the effects of cognitive deterioration in the presence of disease markers that cause dementia, ultimately delaying dementia onset.
“We hope the cohort we study will be the first ‘cradle to grave’ study in the world, where we have followed people for their entire lives,” she said.
Commenting for Medscape Medical News, Joel Hughes, PhD, professor of psychology and director of clinical training at Kent State University, in Kent, Ohio, said the study contributes to the idea that “accumulation of physical activity over one’s lifetime fits the data better than a ‘sensitive period’ ― which suggests that it’s never too late to start exercising.”
Hughes, who was not involved in the research, noted that “exercise can improve cerebral blood flow and hemodynamic function, as well as greater activation of relevant brain regions such as the frontal lobes.”
While observing that the effects of exercise on cognition are likely complex from a mechanistic point of view, the finding that “exercise preserves or improves cognition later in life is encouraging,” he said.
The study received funding from the UK Medical Research Council and Alzheimer’s Research UK. The investigators and Huges report no relevant financial relationships.
J Neurol Neurosurg Psychiatry. Published online February 21, 2023. Full article