Moderately vigorous physical activity in midlife is linked to better cognition 25 years later, according to a new study involving 3,050 twins from the Finnish Twin Cohort.
While traditional vascular risk factors (elevated blood pressure, hypercholesterolemia, obesity, diabetes, and lack of exercise) have been associated with dementia risk, until now it has remained unclear whether exercise carries other unique benefits for cognition other than reducing these risks. But the link remained even after factoring these out.
“This suggests that the beneficial influence of physical activity on the brain and cognition is not solely based on decreasing vascular risk factors,” says researcher Paula Iso-Markku from the University of Helsinki.
The study was conducted by scientists at the universities of Helsinki, Jyväskylä, and Turku. The twins reported information on their physical activity through questionnaire surveys between 1975 and 1981 (mean age of participants in 1981 was 49), while cognition was assessed by validated telephone interviews between the years 1999 and 2015.
First, the link between exercise and cognition was examined in all participants, and then by comparing later cognition in pairs where one twin was more physically active than the other.
Iso-Markku says that “few long-term, high-quality, follow-up studies on physical activity and cognition have been published, and it has remained unclear what type and amount of exercise is needed to safeguard cognition.”
Importantly, the researchers discovered that cognitive benefits in old age did not continue to increase the more vigorously one had exercised in midlife. In other words, extremely vigorous exercise in midlife did not result in the most superior cognitive abilities later in life.
Instead, a moderate amount of physical activity was sufficient for memory-protecting benefits, and only the most inactive group of twins stood out with a significantly higher risk for cognitive impairment.
“Overall, the study shows that moderately vigorous physical activity, meaning more strenuous than walking, is associated with better cognition after an average of 25 years,” said Professor Urho Kujala from the University of Jyväskylä.
The new results are in accordance with findings on animals which have shown that physical activity increases the amount of growth factors in the brain and improves synaptic plasticity.
Cases of dementia have been on the increase among aging populations worldwide. Although the incidence of dementia seems to have decreased in younger seniors, the total prevalence of the disease is still expected to rise. While no cure exists for dementia as of yet, researchers have produced an abundance of new evidence regarding dementia prevention in the last decade.
The findings are published in the Journal of Alzheimer’s Disease.