Could walking be the key to lowering Alzheimer’s risk?

If you’ve been debating whether to get up and stretch your legs today, new research may give you the nudge you need. A fresh study, planned to be presented at the Alzheimer’s Association International Conference this week, suggests that simply walking more could slow cognitive decline, especially in people genetically predisposed to Alzheimer’s disease.

Researchers followed nearly 3,000 adults between the ages of 70 and 79 for a decade and tracked their walking habits and how those habits correlated with brain function over time.

Participants who either maintained or increased their walking levels showed notable improvements in executive function and processing speed, according to the study, which is currently available as a preprint and hasn’t yet undergone peer review.

The findings appeared especially promising among individuals with the APOE4 genotype, a known genetic risk factor for Alzheimer’s. According to Dr. Cindy Barha, senior study author and assistant professor of kinesiology at the University of Calgary, the results highlight the danger of inactivity as we age.

The genetic link

Alzheimer’s disease, the most common form of dementia, is believed to result from a buildup of toxic plaques in the brain that interfere with how nerve cells communicate. Over time, those neurons die, leading to memory loss, confusion, behavioral changes, and eventually, physical deterioration. There is no cure.

The genetic story behind Alzheimer’s is complex, but APOE genes play a central role. One particular variant, APOE4, is linked to a reduced ability to clear those brain plaques. According to the U.S. National Institutes of Health, between 15% and 25% of people carry this gene, though it can only be identified through genetic testing.

What’s compelling is that those at higher risk may benefit the most. “Before the study started, we thought APOE4 carriers had more room to grow in terms of cognition, since they may already have been experiencing some cognitive decline,” Barha explained. “They also have more room to show improvement.”

She also speculated that participants who knew they carried APOE4 may have been more motivated to change their behavior during the study. Either way, the cognitive benefits were clear.

But how does movement in the body affect what's happening in the brain?

Experts believe exercise may increase the production of brain-derived neurotrophic factor (BDNF), a protein often compared to fertilizer for brain cells. “We’re thinking there are proteins released from the muscle that travel to the brain and, either across the blood-brain barrier or at the blood-brain barrier, start a reaction that eventually leads to increases in BDNF within the brain,” Barha explained.