When it comes to looking after our health, most of us have heard that getting our steps in each day is good for the body and mind. Now, new research suggests that even modest increases in daily movement could do more than just keep us fit — it might actually help slow the progression of Alzheimer’s disease.
A study published in Nature Medicine by Mass General Brigham researchers found that physical activity was linked to slower rates of cognitive decline in older adults who were at a higher risk of developing Alzheimer’s due to elevated levels of amyloid-beta, a protein associated with the disease.
The results were striking. People who walked between 3,000 and 5,000 steps a day saw cognitive decline delayed by an average of three years. Those who took 5,000 to 7,500 steps a day experienced a delay of around seven years. In contrast, sedentary individuals showed a faster buildup of tau proteins in the brain — another key marker of Alzheimer’s — and a quicker decline in memory, thinking skills, and daily functioning.
“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 findings come from the Harvard Aging Brain Study, which followed 296 participants aged 50–90 who were cognitively healthy at the start. Researchers used PET brain scans to measure amyloid-beta and tau levels, while participants wore pedometers to track their daily steps. Over an average of 9.3 years, the team conducted annual cognitive tests — and for some, repeat brain scans — to monitor changes over time.
Those with higher step counts not only experienced slower mental decline but also showed a slower buildup of tau proteins. The researchers’ models indicated that most of the benefit from physical activity stemmed from this slower tau accumulation. Interestingly, participants with low amyloid-beta levels showed little decline overall, suggesting that early activity may be most crucial for those already at elevated risk.
“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.
“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.”
Moving forward, researchers plan to explore which types of exercise may matter most — whether it’s intensity, consistency, or long-term patterns that make the biggest difference. They’ll also continue to examine the biological connections between physical activity, tau buildup, and brain health.
For now, their message is simple but powerful.
“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.”
Read more: The surprising step count older women need for better health
IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.
Proudly Australian owned and operated