Exploring the Link Between Body Physiology and Cognition: The Role of the Brain and Ageing
Authors
Affiliations (1)
Affiliations (1)
- University of Otago
Abstract
Epidemiologists often report associations between cognitive functioning and bodily physiology in older adults, but the strength and drivers of this relationship remain unclear. Which systems - from body composition to cardiovascular, pulmonary, renal, hepatic, immune, metabolic, and musculoskeletal - best predict cognition, and to what extent is the cognition-body link related to brain variation as we age? Using data from over 30,000 UK Biobank participants, we analysed 19 body physiology phenotypes and three neuroimaging modalities. Machine learning models integrating all body measures explained 16% (r=0.40) of cognitive variation, with body composition and bone health emerging as the strongest predictors. Neuroimaging captured 85.1% of the cognition-body link, driven mainly by white matter characteristics. Body and brain phenotypes explained 82.3% and 87.2% of age-related cognitive decline, respectively, with substantial overlap. Together, these findings provide a comprehensive understanding of how body physiology and the brains structure and function jointly contribute to cognitive ageing.