Nutritional intervention targeting muscle-brain axis in dementia continuum: from mechanisms to practice.

Rapid aging of global population has led to an attention increasingly focusing on age-related changes in muscle and cognitive functions, specifically the interplay between sarcopenia, frailty and cognitive impairment as the interconnected geriatric syndromes with major health consequences. Despite being the central pathophysiological substrate across these geriatric syndromes, skeletal muscle loss is still insufficiently prioritized as a treatment objective. Incorporating the "malnutrition-sarcopenia-frailty" triad into dementia care is essential for continuity of management, as muscle preservation is fundamental to sustaining cognitive function within an active aging paradigm. This perspective reframes longevity by shifting emphasis from anticipating frailty to living with strength, valuing added years through resilience rather than decline. This narrative review, prepared by experts in neurology and geriatrics, explores the muscle-brain crosstalk and highlights skeletal muscle loss as a modifiable target for nutritional intervention in cognitive impairment and dementia. In conclusion, given the bidirectional links between malnutrition, sarcopenia, frailty, and cognitive decline through shared aging mechanisms, a high protein oral nutritional supplement [enriched with beta-hydroxy-beta-methylbutyrate (HMB)] and vitamin D emerges as a practical, compliant strategy to support muscle health and potentially contribute to preservation of cognitive health in older adults with or at risk of dementia, although direct evidence for cognitive benefit remains limited.