- Greater physical activity and lower vascular risk had independent, additive effects in slowing β-amyloid (Aβ)-related cognitive decline and neurodegeneration.
Why this matters
- Lack of interventions to prevent and treat dementia, coupled with aging of the population.
- Relative simplicity and safety of lifestyle interventions.
- Significant interaction seen between physical activity, Aβ burden on both cognitive decline (P<.001 and gray matter volume loss>
- Greater physical activity associated with slower:
- Aβ-related cognitive decline (β, 0.03; P<.001>
- Gray matter volume loss (β, 482.07; P=.002).
- Aβ-related cognitive decline (β, –0.04; P<.001>
- Gray matter volume loss (β, –483.41; P=.01).
- Prospective longitudinal cohort study of 182 clinically normal older adults (mean age, 73.4 years) from the Harvard Aging Brain Study.
- Main outcomes: cognition (measured annually with Preclinical Alzheimer Cognitive Composite), neurodegeneration (assessed with longitudinal structural MRI over median 4.5 years, with a focus on total gray matter volume, regional cortical thickness).
- Funding: National Institute on Aging; others.
- Individuals with high levels of cerebrovascular disease excluded.
- Population generally well-educated.
- Physical activity assessed only at baseline, for a limited period.