Effect of carbonated beverages on pharyngeal swallowing in young individuals and elderly inpatients.
Gustatory and chemical stimulations of the oral cavity and pharyngeal mucosa by carbonated water improve pharyngeal swallowing. We compared changes in pharyngeal swallowing and sensory aspects induced by a carbonated beverage preferred by Japanese with those induced by carbonated water, a sports drink, and tap water in healthy young subjects and elderly inpatients with no swallowing problems. The duration of laryngeal elevation (DOLE) for swallowing the carbonated beverage and water in the second session was shorter compared to that for water in the first session in the elderly subjects. The DOLE and the duration of suprahyoid muscle activity for swallowing were longer in the elderly subjects than in the young subjects for all beverages. Beverages that the subjects subjectively felt were easy to swallow were the sports drink and carbonated beverage, whereas they stated that carbonated water was less easy to swallow. In the elderly subjects, swallowing ability latently decreased, even though they had no problem swallowing in their daily lives, and it was assumed that the carbonated beverage improved pharyngeal swallowing. In addition, the carbonated beverage also influenced the subsequent swallowing of water, showing a persistent effect. It was suggested that carbonated beverages are easy to swallow and effective for improving pharyngeal swallowing.