- Past studies have shown that certain healthy lifestyle choices, such as being physically active, may help individuals lower their risk of Alzheimer’s disease.
- A new study found that older adults may be able to lower their risk of Alzheimer’s disease by taking as few as 3,000 steps a day.
- Scientists reported this benefit was also seen in older adults with high levels of amyloid-beta in their brains.
Past studies have shown that certain
However, it can sometimes be difficult for older adults to be as active as they were when they were younger, and even hitting 10,000 steps a day can be challenging, despite its numerous health benefits.
A new study, recently published in the journal
This modest amount of physical activity, scientists say, also helps to slow cognitive decline risk in older adults with high levels in their brains of a protein called
For this study, researchers analyzed medical data from almost 300 participants of the Harvard Aging Brain Study. Participants ranged in age from 50 to 90 years and did not have any cognitive deficits before the start of the study. They also had PET scans to measure the amount of amyloid-beta plaques in their brains.
Study participants were followed up for a median of about nine years with cognitive assessments and additional PET brain scans to look for signs of another protein associated with Alzheimer’s disease called tau.
“Our participants actually included a wide range of amyloid levels in the brain, from none to substantial amounts,” Wai-Ying Wendy Yau, MD, a neurologist in the Department of Neurology Memory Division at Mass General Brigham, instructor at Harvard Medical School, and both first-author and co-corresponding author of this study, told Medical News Today.
“This design allowed us to study how early amyloid buildup relates to brain changes and cognitive performance. From neuropathological studies, we know that some people remain cognitively normal despite having Alzheimer’s disease changes in their brains,” she said.
“With the development of amyloid PET imaging in the early 2000s, researchers could visualize and track these changes in living people for the first time, revealing that amyloid accumulation begins many years before symptoms appear and progresses slowly,” Yau continued.
“The Harvard Aging Brain Study, launched in 2010, was designed to understand how this early amyloid buildup contributes to brain dysfunction and cognitive decline, and why people with similar amyloid levels can differ in their cognitive trajectories,” she explained.
At the study’s conclusion, researchers found that older study participants who walked fewer than 3,000 steps a day and had higher levels of amyloid-beta in their brains exhibited faster cognitive decline and tau brain buildup than participants who walked 3,000 to 5,000 steps a day.
Overall, scientists discovered that participants who walked 3,000 to 5,000 steps per day delayed cognitive decline by an average of three years, and those who walked 5,000 to 7,500 steps per day slowed cognitive decline by an average of seven years.
“The significance of these findings is that even modest levels of physical activity were linked to differences in Alzheimer’s-related brain changes,” Yau explained.
“Among older adults with elevated amyloid, those who were very sedentary, taking 3,000 steps or fewer per day, showed the fastest buildup of tau proteins and the greatest cognitive decline. Even a modest amount of physical activity, between 3,001 and 5,000 steps per day, was associated with slower changes in both tau and cognition.”
— Wai-Ying Wendy Yau, MD
“This suggests that the potential benefits of physical activity may begin at relatively achievable levels rather than requiring very high step counts,” she said.
“While clinical trials are needed to confirm causation, these results are encouraging and suggest that small, consistent increases in daily activity may be meaningful for brain Health, particularly for those at higher risk of Alzheimer’s-related changes,” she added.
MNT spoke with Manisha Parulekar, MD, FACP, AGSF, CMD, director of the Division of Geriatrics at Hackensack University Medical Center and co-director of the Center for Memory Loss and Brain Health at Hackensack University Medical Center in New Jersey, about this study.
“The link between physical activity and cognitive health is something we consistently emphasize to our patients and their families,” Parulekar commented.” This study provides ongoing evidence that further solidifies this connection, particularly for individuals already on the path of Alzheimer’s pathology with elevated brain amyloid-beta.”
“The finding that even a modest increase in daily steps — from under 3,000 to a range of 3,000-5,000 — can significantly slow cognitive decline is an actionable and attainable message. It offers a sense of agency to patients who often feel powerless in the face of a daunting diagnosis. This research reinforces the growing body of evidence that points to the rol
— Manisha Parulekar, MD, FACP, AGSF, CMD
Parulekar said that this study opens up several exciting avenues for future research that she would be keen to see explored.
“First, I would like to see longitudinal studies that follow individuals over a longer period to better understand the sustained impact of different levels of physical activity on cognitive function and the accumulation of both amyloid and tau proteins,” she detailed.
Does 10,000 steps lower Alzheimer’s risk further?“It would be valuable to determine if there is a dose-response relationship — does increasing daily steps from 5,000 to 8,000 or 10,000 confer even greater protection, as some research has suggested for lowering dementia risk in the general population?”
— Manisha Parulekar, MD, FACP, AGSF, CMD
“Second, it would be beneficial to investigate the underlying biological mechanisms at play,” Parulekar said.
“How exactly does walking and physical activity slow the buildup of tau proteins and protect against cognitive decline in brains already burdened with amyloid? Understanding these pathways, whether they involve reduced inflammation, improved blood flow, or the release of neuroprotective factors, could lead to the development of new, targeted therapies,” she added.
