even Modest Daily Walking May Benefit Those at Risk of Alzheimer’s, Study Finds
A new study published in Nature Medicine suggests that even a small amount of daily physical activity can offer benefits to individuals at higher risk of developing Alzheimer’s disease. Researchers from Harvard Medical School found that walking, even just a few thousand steps a day, can slow the progression of the disease in those already showing signs of amyloid-beta buildup in the brain.
The research,part of the ongoing Harvard Aging Brain Study,followed 296 participants aged 50-90 for up to 14 years. Participants, who initially showed no cognitive impairment, underwent regular cognitive testing and brain imaging while also wearing pedometers to track their daily step count.
The study focused on the accumulation of two key proteins linked to Alzheimer’s: amyloid-beta and tau.While amyloid-beta deposits often appear earlier in the disease process,the accumulation of tau protein is more strongly associated with cognitive decline.
Researchers discovered that exercise had a noticeable effect only in participants with elevated levels of amyloid-beta, indicating a higher risk for Alzheimer’s. In this group, increased physical activity – specifically walking – was linked to a slower rate of tau protein accumulation. Though, exercise did not reduce the levels of amyloid-beta itself.
Conversely, individuals with low levels of amyloid-beta showed no cognitive benefit from increased physical activity. The study highlighted that a sedentary lifestyle combined with high amyloid-beta levels posed the greatest risk for cognitive decline.
“This group represents those most likely to experience decline and where interventions to increase activity levels could have the biggest impact,” explained Jasmeer Chhatwal, a co-author of the study.
The findings offer the first clear evidence of how exercise impacts the biological processes underlying Alzheimer’s,suggesting the protective effect stems from slowing the buildup of tau protein. Wai-Ying Wendy Yau, a physician and memory disorders researcher and co-author, emphasized that the results suggest the commonly cited goal of 10,000 steps per day isn’t necessary, and “even a little movement helps.”
The researchers recommend encouraging older adults,particularly those identified as being at risk,to gradually increase their physical activity. Even a few thousand steps daily can contribute to a meaningful difference in slowing cognitive decline.
