Daily Steps Linked to Delayed Alzheimer’s Progression, Study Finds
New research suggests that even a relatively small amount of daily walking may significantly delay the cognitive decline associated with Alzheimer’s disease in at-risk individuals. A 14-year study, lead by researchers at Mass General Brigham hospital in Boston, found a correlation between step count and the rate of cognitive deterioration.
The study, published in Nature medicine, analyzed data from 296 participants aged 50-90 who were cognitively healthy at the study’s outset. Researchers tracked annual cognitive assessments,daily step counts using pedometers,and levels of amyloid-beta plaques and tau tangles – proteins linked to Alzheimer’s – in participants’ brains via PET imaging.
Results indicated that individuals who walked between 3,000 and 5,000 steps per day experienced, on average, a three-year delay in cognitive decline. Those who walked 5,000 to 7,000 steps daily saw an even more substantial benefit, with cognitive decline delayed by an average of seven years.
The protective effect of walking was most pronounced in individuals who had elevated levels of amyloid at the beginning of the study. Those with higher step counts exhibited slower rates of cognitive decline and a delayed buildup of tau proteins. Conversely, those with sedentary lifestyles experienced a substantially faster buildup of tau and a quicker decline in cognitive function.
While acknowledging the possibility of reverse causation – that early brain changes might lead to reduced activity – researchers believe the data suggests physical activity is protective. dr. Wai-Ying Yau, the study’s first author, emphasized the need for randomized clinical trials to definitively prove cause and effect, but stated the findings are “very encouraging.”
The study did not determine how exercise provides this benefit, but researchers note that physical activity is known to improve blood flow, reduce inflammation, and increase levels of beneficial hormones and growth factors, all of wich could perhaps play a role in brain health.
Alzheimer’s disease is the most common cause of dementia, affecting an estimated 50 million people worldwide, including over 500,000 in the UK. Dr. Julia Dudley of Alzheimer’s Research UK highlighted the importance of these findings, stating thay provide a clearer understanding of how everyday activity may support brain health and impact the underlying causes of the disease. Further research, including clinical trials, is needed to confirm these findings and explore the potential for lifestyle interventions in preventing and slowing dementia progression.
