Key points from article :
High levels of physical activity slows cognitive decline and slows rate of brain tissue loss.
Reduce b-amyloid (Ab)-related cortical thinning and preserve gray matter structure.
Benefits were more at around 8,900 steps compared to modest levels of physical activity.
Assessed physical activity in 182 normal older adults, including those with high-risk of cognitive decline.
Research by Massachusetts General Hospital, published in JAMA Neurology.
