A brain-healthy lifestyle has been associated with better cognitive functioning and a lower risk of dementia in longitudinal studies, but the underlying mechanisms remain unclear. In particular, associations with neuropathological markers and cerebral volumes have not been well established. A recent article published in Alzheimer’s and Dementia assessed longitudinal associations between lifestyle, biomarker trajectories, and cognitive outcomes, using data from 324 participants from the Wisconsin Registry for Alzheimer's Prevention. Lifestyle was quantified using the LIfestyle for BRAin Health (LIBRA) index, a multicomponent score that summarizes modifiable risk and protective factors for dementia. Information on various brain biomarkers (levels of tau protein, white matter hyperintensities, and brain volumes) was collected at multiple timepoints, alongside data on cognitive performance across several domains. This information was used to assess trajectories in all measures over time.
The researchers then examined associations between LIBRA scores and these trajectories, both in the full sample and stratifying by amyloid status (positive vs. negative). The study found no associations between lifestyle and any of the brain changes assessed. Associations with cognitive outcomes were inconsistent. Specifically, modest links were observed with executive functioning, but not with memory or a composite cognitive measure. By contrast, higher tau burden in the temporal lobe was consistently associated with poorer performance across all three cognitive measures. The authors suggest that the absence of strong associations between lifestyle and either brain changes or cognition may reflect the preclinical stage of Alzheimer’s disease in the cohort. They note that the potential effects of lifestyle on disease pathology and cognitive decline may take longer to become apparent, underlining the need for continued longitudinal investigation.
