A validated frailty index—measuring accumulated deficits across multiple body systems—emerged as a stronger predictor of mortality and institutionalization than cognitive assessments in Alzheimer's patients. The index tracked physical decline independently of neurodegeneration markers, suggesting two parallel but distinct pathways of deterioration in dementia. This finding challenges the conventional focus on cognitive metrics as primary prognostic tools in Alzheimer's care. The research adds substantial weight to the growing recognition that physical resilience, not just brain function, determines quality-of-life outcomes in neurodegenerative disease. For families and clinicians, this suggests that maintaining physical health—through exercise, nutrition, and medical management of comorbidities—may be as crucial as cognitive interventions for preserving independence. The frailty index's predictive power likely stems from its comprehensive assessment of systemic vulnerability, capturing cardiovascular health, muscle function, and metabolic stability that cognitive tests miss. However, this was observational research that cannot establish whether improving frailty scores would actually delay institutionalization. The disconnect between physical and cognitive decline also raises questions about whether current Alzheimer's treatments targeting amyloid pathology address the most clinically relevant aspects of disease progression.