Abstract
OBJECTIVE
1) Learn about the swallow apnea duration and appreciate how it may serve as a protective function during the swallow. 2) Assess how swallowing apnea duration is affected by changes in chemesthesis, age, and genetic taste differences.
METHOD
Based on a bitterness rating of 6-n-propythiouracil to identify genetic taste differences, 80 healthy adult women ages 18-35 yrs (n = 40) and 60 yrs and older (n = 40) were identified as non-tasters and supertasters. The KayPentax Swallowing Signals Lab (KayPentax Copr, Lincoln Park, NJ) was utilized to acquire SAD via nasal canula during randomized swallows of 5 ml deionized water, 2.7% w/v citric acid, seltzer water, and 50/50 diluted ethanol/water. Data were analyzed using path analyses with potential mediators of bolus intensity, palatability, and mouth-feel and adjusted for repeated measures.
RESULTS
Significant main effects of chemesthesis (p = 0.002), age (p < 0.001), and genetic taste differences (p = 0.04) were found. Older women and supertasters had longer SADs than young women and non-tasters. Post-hoc analyses revealed alcohol and acid boluses elicited significantly longer SADs than water boluses. Intensity, palatability, and mouth-feel (p > 0.05) were not significant mediators of the total effects found in the original path analyses.
CONCLUSION
This study found that acidic and alcoholic bolus types increase the SAD when compared to water. Given that increased SAD may serve as a protective function against aspiration, future research should utilize these chemesthetic changes in bolus properties to assess if increased SAD decreases aspiration in patients with dysphagia.