Task-Based Eating and Drinking Interventions in Animal Models: A Narrative Review of Functional Improvements and Neuromuscular Adaptations in Age-Related Dysphagia.

Background/objectives: Age-related dysphagia involves sarcopenia and nervous system changes affecting ingestion. The ACT-ING program, a novel task-based occupational therapy intervention, has been developed to improve strength, endurance, and ingestive skills using real-world eating and drinking tasks for older adults with age-related dysphagia. This narrative review evaluates the outcomes and neuromuscular adaptations of task-based eating and drinking interventions in aging animal models to inform potential refinements of the ACT-ING program and interpret results from an ongoing proof-of-concept study.

Methods: Publications were obtained from PubMed, SCOPUS, CINAHL, and EMBASE, and selected following the PRISMA guideline. Thirteen randomized trials investigated a task-based fluid-licking intervention in rats, combining strength, endurance, and skill training.

Results: Results suggested benefits in improving muscle strength, endurance, and swallowing skills in terms of quantity and speed. Although neuromuscular adaptations were less conclusive, the intervention appeared to induce cortical plasticity and increase fatigue-resistant muscle fibers in the involved muscles.

Conclusions: While these findings are promising, methodological concerns and potential biases were identified. Therefore, further research is necessary to refine the ACT-ING program, including both clinical studies in humans and preclinical studies in aging animal models that clearly define interventions targeting all aspects of ingestion-related skills within a motor learning and strength training framework.