Physical activity modifies associations between cerebrospinal fluid tau measures and executive function

Area of Science:

• Neuroscience
• Gerontology
• Biomarkers

Background:

• Alzheimer's disease (AD) is marked by amyloid-beta (Aβ) and tau accumulation, detectable via cerebrospinal fluid (CSF).
• Physical activity's role in modifying AD risk and its impact on biomarkers and cognition requires further understanding.

Purpose of the Study:

• To investigate if higher physical activity levels modify the association between AD CSF biomarkers and cognitive function.

Main Methods:

• 117 cognitively normal older adults wore accelerometers and provided CSF samples.
• Multivariable linear regression analyzed interactions between physical activity and CSF biomarkers (Aβ42/40, p-tau181, total tau) on cognitive scores (executive function, episodic memory).

Main Results:

• Physical activity significantly interacted with phosphorylated tau (p-tau181) and total tau in relation to executive function.
• Higher physical activity diminished the negative association between tau pathology and executive function.
• No significant interactions were found for episodic memory or with amyloid-beta (Aβ42/40).

Conclusions:

• A physically active lifestyle may offer protection against AD-related cognitive decline.
• Physical activity appears to mitigate the cognitive effects of tau pathology, potentially by enhancing cognitive reserve.