Perhaps you’ve seen headlines about a promising new study in national and local newspapers: “Walking may reduce Alzheimer’s risk” and wondered about the science of this claim. While the link between exercise and dementia is well-established, the recent headlines referred to a new study in the journal Nature Medicine.
The new research focused on walking and cognition and has been heralded as groundbreaking. As Kirk Erickson, chair of neuroscience at the Adventist Health Research Institute, explained, this new study “is really quite important and quite unique,” identifying how walking might be influencing some of the proteins implicated in Alzheimer’s.
While this study was not large, it was long-lasting, following 300 older adults between 50 and 90 years old for nine years. None of the participants had cognitive impairment, but brain scans showed a surprising thirty percent had considerable plaque (build-up of amyloid protein) in their brains. Plaques are thought to be responsible for increased Alzheimer’s risk, but until now the connection wasn’t clear.
Connecting plaque, tau tangles, walking, and cognition,
researchers have been focusing on another protein related to Alzheimer’s – tau. Earlier studies indicated amyloid build-up triggers “tangles” of tau. It appears that it is primarily the tau tangles, not the plaques, that cause the brain cells to malfunction, resulting in cognitive impairment.
Because exercise has been shown to positively affect clear thinking, the designer of the study wanted to see if regular walking might affect the development of those harmful tau tangles, especially for those who have already developed amyloid plaques. And that involves lots of Americans: 10 percent of 50-year-olds and 44 percent of 90-year-olds have plaques without showing evidence of cognitive impairment (or tangled up thinking.)
Results of the study
• Participants with more amyloid plaques in their brains who got little to no physical activity developed more tangles and had worse cognition after nine years.
• Those walking 3000-5000 steps a day had less tau accumulation and slower cognitive decline.
• Participants who took more than 5000 steps had even less tau accumulation and less cognitive loss. Getting more than 7500 steps did not seem to affect cognitive decline. (Although due to the many other benefits of walking, that shouldn’t discourage walkers from aiming for more steps.)
Commenting on the implications of this study, Dr. Jasmeer Chhata, who led the study, stated, “The good news is that even kind of moderate levels of activity are protective.”
Other research has reinforced this message that exercise improves cognition. Brisk walking not only slows down development of tau tangles but also increases the flow of blood to the brain. Increased blood flow results in general health improvements, including brain health. Walking offers significant cognitive benefits including improved memory and executive functions as well as increased volume, especially in the frontal lobe.
And it doesn’t take much time
One study (The 2019 study published by Contemporary Clinical Trials) found even short periods of vigorous physical activity can improve brain function. Increasing daily moderate-to-vigorous physical activity day to six minutes produced the largest predicted improvements in the domains of executive function/attention control, processing speed, and working memory.”
A more recent June 2025 study published in Age and Aging showed that even five minutes of brisk physical activity can improve cognition. An earlier study showed the difference of blood flow to critical regions of the brain. One telling graphic compared electrical activity in the brain after 20 minutes of sitting quietly to 20 minutes of walking. The electrical activity not only doubled in outcome but increased significantly, especially in areas essential for clear thinking. This was especially true for older adults.
Reader takeaway
Now that spring has finally arrived, these studies provide motivation to get out those walking shoes, lace them up and head out the door. Your goal: untangled thinking.
