Walking can delay Alzheimer’s - and you don't need 10,000 steps

A little extra walking might buy years of sharper thinking for people on the earliest path toward Alzheimer’s disease. 

In a new study, researchers at Mass General Brigham report that older adults with elevated brain amyloid who were more physically active showed slower cognitive decline.

The individuals had a slower buildup of tau, the protein most closely linked to symptom progression.

Walking can slow Alzheimer’s progression

People who logged just 3,000-5,000 steps a day experienced, on average, a three-year delay in cognitive decline.

Those reaching 5,000-7,500 steps saw about a seven-year delay. Sedentary participants, by contrast, accumulated tau faster and lost cognitive and daily function more quickly.

“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 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.”

Who was studied and how

The team examined data from 296 adults between the ages of 50 and 90 who participated in the Harvard Aging Brain Study. All participants were cognitively healthy at the beginning of the study.

The researchers established each participant’s baseline amyloid-beta plaques and tau tangles with PET scans, then tracked physical activity with simple waistband pedometers.

Cognitive testing recurred annually for two to 14 years, averaging 9.3 years of follow-up, and a subset underwent repeat tau PET imaging to monitor changes over time.

Higher step counts, slower decline

The key pattern emerged in those with elevated amyloid at baseline. In this group, higher daily step counts were tied to slower cognitive decline and a slower rise in tau.

Statistical modeling suggested that the cognitive benefit of activity largely emerged through its association with reduced tau accumulation. 

Among people with low amyloid at baseline, cognitive scores and tau changed very little over time, and physical activity was not significantly related to outcomes.

This is consistent with the idea that exercise’s protective signal shows up most clearly when pathology is already brewing.

Why steps might matter for the brain

Alzheimer’s pathology is often detectable years before memory problems appear. Amyloid tends to accumulate first, followed by tau changes that track more closely with symptoms. 

The new findings align with that staging: in people already showing elevated amyloid, being more active was linked to less tau buildup, which in turn related to a slower slide in cognition and daily function. 

While the study cannot prove causation, the pathway is biologically plausible and echoes evidence that physical activity supports brain blood flow, reduces inflammation, and may modulate protein homeostasis.

Walking to delay Alzheimer’s

Study co-author Reisa Sperling is a neurologist in the Mass General Brigham Department of Neurology and co-principal investigator of the Harvard Aging Brain Study. 

“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 Sperling.

“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.”

From research to practical steps

One notable feature of the results is how attainable the activity thresholds are. The delays in decline were observed at step counts well below the often-cited 10,000-step goal. 

For people with elevated amyloid but no symptoms, that suggests an actionable window. Adding a few thousand steps per day could stack up to a meaningful buffer over years.

The experts plan to probe which dimensions of activity matter most. Intensity, day-to-day consistency, and long-term patterns could differ in their relationship to tau dynamics and cognition. 

Empowering people to protect their brain

The researchers also aim to clarify the biological links between movement, tau accumulation, and neural resilience. Such work could inform clinical trials testing exercise prescriptions as disease-modifying interventions for those at heightened risk.

“We want to empower people to protect their brain and cognitive health by keeping physically active,” said first author Wai-Ying Wendy Yau, 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.”

Small steps for long-term protection

For individuals with preclinical Alzheimer’s pathology, movement may be one of the few levers available before symptoms emerge.

This study links everyday physical activity to slower tau buildup and delayed cognitive decline, with benefits detectable at modest step counts. 

While randomized trials are needed to confirm causality and refine dosing, the message for the present is clear and encouraging: start early, keep moving, and let small daily steps add up to long-term protection.

The study is published in the journal Nature Medicine.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–