Here's Your Step Count Goal to Slow Cognitive Decline

Walking just a few thousand steps a day might help delay the onset of Alzheimer's symptoms in those at higher risk for the disease, according to a new study. Researchers followed nearly 300 older adults—none of whom had dementia at the study's start—for about nine years, tracking their daily steps and monitoring their brains for signs of Alzheimer's-related proteins. They found those who walked 3,000 to 5,000 steps a day slowed their cognitive decline by around three years, while those hitting 5,000 to 7,000 steps saw a delay of about seven years, compared to less active peers, per the Washington Post.

Wai-Ying Wendy Yau, a cognitive neurologist at Mass General Brigham and lead author of the study published Monday in Nature Medicine, cautions that the research only shows an association, not direct cause and effect. But she says the takeaway is clear for anyone worried about brain health: even modest physical activity could have benefits. "Every step you take in the right direction helps with brain health," Yau says.

The study, part of the long-running Harvard Aging Brain Study, found that more active participants had slower buildup of tau, a protein linked to Alzheimer's. Exactly why exercise helps the brain isn't certain, but Yau points to improved blood flow, reduced inflammation, and certain elevated hormones as possible factors, per the Guardian. There are caveats: The step counts were only measured for a week at the study's start, and the group was mostly highly educated, non-Hispanic white individuals, which could limit how widely the results apply. Still, outside experts see the research as more support for the idea that—regardless of age—regular movement offers broad health benefits and no downside.