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Exercise Lowers Total Tau in Seniors, Slowing Cognitive Decline

— August 23, 2021

Researchers report media to high levels of exercise can decrease the risk of Alzheimer’s disease and dementia.

Regular physical activity benefits the brain by slowing cognitive decline and lowering risk of developing Alzheimer’s disease.  Physical activity is also one of the most easily changeable interventions for lowing the risk of dementia, depression, and obesity.  A new study published in the August 11 online edition of JAMA Network Open suggests daily exercise can help slow cognitive decline in older adults, specifically with higher or lower total tau concentrations.  Cerebrospinal fluid levels of the total tau (t-tau) protein can reflect the intensity of the neuronal damage in neurodegeneration, including Alzheimer’s disease (AD).

Lead study author Pankaja Desai, PhD, assistant professor, Rush Institute for Healthy Aging, Chicago, Illinois, said “The examination of total tau in blood is a fairly new area of interest.” However, Desai added, “Limited research has been done to understand the relationships between total tau, physical activity, and cognitive function.  Our findings may support using blood biomarkers to further develop risk profiles and may provide the chance for intervening early.”

Exercise Lowers Total Tau in Seniors, Slowing Cognitive Decline
Photo by Anna Shvets from Pexels

The current study included “1159 participants (mean age, 77.4 years; 63% women; 60% Black) in the longitudinal, population-based Chicago Health and Aging Project (CHAP).”  Relevant data are collected every three years.  Medium activity was defined as “participating in less than 150 minutes of physical activity per week,” while high activity was defined as including “150 minutes or more of physical activity per week.”  Among all participants, “400 (35%) reported participating in a medium level of physical activity, and 402 (35%) participated in a high level of activity.  In addition, 357 (31%) reported engaging in little physical activity.”

Those with a high t-tau concentrations who engaged in medium and high levels of physical activity had “8% better cognitive function at baseline in comparison with participants with little physical activity,” the authors noted, adding, “Also among individuals with high total tau, medium physical activity was associated with a 58% slower rate of cognitive decline over time in comparison with little physical activity, and high physical activity was associated with a 41% slower rate of cognitive decline.”  In participants with low total tau levels, “medium physical activity was associated with a 2% slower rate of cognitive decline, and high physical activity was associated with a 27% slower rate of cognitive decline compared with little physical activity.”

“These results suggest that physical activity may have a positive association with cognitive function and that sedentary behavior may have a negative association with cognitive function,” the authors wrote.

“Individuals with high total tau concentrations may have increased rates of cognitive decline compared to those with low total tau concentrations,” Desai noted. “Therefore, the impact of physical activity may be less pronounced on cognitive decline among individuals with low total tau concentrations as opposed to those with high total tau concentrations.”

Claire Sexton, director of scientific programs and outreach for the Alzheimer’s Association, said the study “addresses the intriguing question of whether physical activity is associated with reduced cognitive decline among individuals with high tau levels.  The results of this study are interesting too and, if replicated, could be noteworthy.  As a single study, though, it is too early for nuanced clinical implications beyond the general recommendation to patients that exercise is good for the brain.  Evidence is strong that regular physical activity reduces cardiovascular risk factors that may contribute to dementia risk.”


Exercise Tied to Slower Cognitive Decline in Those at Risk for AD

Longitudinal Association of Total Tau Concentrations and Physical Activity With Cognitive Decline in a Population Sample

Alzheimer’s disease: Can exercise prevent memory loss?

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