How Walking Can Keep Cognitive Decline Away for Years

Increase in walking steps and modest workout can help hold off cognitive decline for several years, according to findings by Mass General Brigham researchers. The study shows how physical activity is connected to Alzheimer’s symptoms and eliminates the build-up of amyloid beta protein in the brain. Amyloid beta protein is a main component of the amyloid plaques that accumulate in the outside nerve cells in the brain of people with Alzheimer's disease. (1^✔ ✔Trusted Source
Physical Activity as a Modifiable Risk Factor in Preclinical Alzheimer’s Disease

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Older people who aged 50 and above (who already have baseline amyloid plaques in the extracellular nerves) with sedentary lifestyles displayed faster accumulation of toxic tau proteins in the brain, which significantly reduces the cognition.

Participants who walked approximately 5,000-7000 steps per day showed delay in cognitive decline for seven years, while those who walked 3000-5000 steps a day showed delay in cognition for only three years.

The research reveals the power of walking or physical activity against the Alzheimer's disease and brain aging. The findings were published in Nature Medicine.

Lifestyle Factors May Slow Cognitive Decline

“This sheds light on why some people who appear to be on an Alzheimer’s disease trajectory don’t decline as quickly as others,” said senior author Jasmeer Chhatwal, MD, PhD, of the Mass General Brigham Department of Neurology.

“Lifestyle factors appear to impact the earliest stages of Alzheimer's disease, suggesting that lifestyle changes may slow the emergence of cognitive symptoms if we act early.”

The researchers analyzed data from 296 participants aged 50-90 years old in the Harvard Aging Brain Study who were all cognitively unimpaired at the beginning of the study.

They used PET (Positron Emission Tomography to reveal biochemical function of tissues and organs) brain scans to measure baseline levels of amyloid-beta in plaques and tau in tangles and assessed the participants’ physical activity using waistband pedometers.

The participants received annual follow-up cognitive assessments for between two and 14 years (average = 9.3 years), and a subset received repeated PET scans to track changes in tau.

Physical Activity Curbs Tau Buildup in the Brain

Higher step counts were linked to slower rates of cognitive decline and a slower buildup of tau proteins in participants with elevated baseline levels of amyloid-beta. The researchers’ statistical modeling suggested that most of the physical activity benefits associated with slowing cognitive decline were driven by slower tau buildup.

By contrast, in people with low baseline levels of amyloid-beta, there was very little cognitive decline or accumulation of tau proteins over time and no significant associations with physical activity.

“We are thrilled that data from the Harvard Aging Brain Study has helped the field better understand the importance of physical activity for maintaining brain health,” said co-author Reisa Sperling, MD, a neurologist in the Mass General Brigham Department of Neurology and co-principal investigator of the Harvard Aging Brain Study.

Designing Exercise-Based Interventions for Cognitive Resilience

“These findings show us that it’s possible to build cognitive resilience and resistance to tau pathology in the setting of preclinical Alzheimer’s disease. This is particularly encouraging for our quest to ultimately prevent Alzheimer’s disease dementia, as well as to decrease dementia due to multiple contributing factors.”

Looking ahead, the researchers plan to dive deeper into which aspects of physical activity may be most important, for example exercise intensity and longitudinal activity patterns. They also plan to investigate the biological mechanisms linking physical activity, tau buildup, and cognitive health.

Critically, the authors believe that this work may help design future clinical trials that test exercise interventions to slow late-life cognitive decline, especially in individuals who are at heightened risk due to preclinical Alzheimer’s disease.

“We want to empower people to protect their brain and cognitive health by keeping physically active,” said first-author Wai-Ying Wendy Yau, MD, a cognitive neurologist in the Mass General Brigham Department of Neurology.

“Every step counts — and even small increases in daily activities can build over time to create sustained changes in habit and health.”

Reference:

1. Physical Activity as a Modifiable Risk Factor in Preclinical Alzheimer’s Disease - (https://www.nature.com/articles/s41591-025-03955-6)

Source-Eurekalert