• Swallowing;
  • aspiration;
  • flexible endoscopic evaluation of swallowing;
  • older adults;
  • liquid;
  • delivery method;
  • bolus volume;
  • Level of Evidence: 2c



Although flexible endoscopic evaluation of swallowing (FEES) is an established diagnostic tool, little data exist on the effects of varying liquid types on the swallowing outcomes in healthy older adults.

Study Design:



Seventy-six healthy older adult volunteers participated (i.e., 18, 28, and 30 volunteers in the 7th, 8th, and 9th decades of life, respectively). The effects of age, sex, liquid type (i.e., water, skim, 2% milk, or whole milk), delivery method (i.e., cup or straw), and volume (i.e., 5, 10, 15, or 20 mL) on Penetration Aspiration Scale (PAS) scores were assessed during FEES.


Penetration and silent aspiration were observed in 83% and 28% of the participants, respectively. This represented 19% and 3% of participants' 2,432 swallows, respectively. Liquid type (P = .0001), bolus volume (P = .02), and delivery method (P = .04) significantly affected PAS scores. PAS scores were significantly (P < .05) greater for milk versus water swallows, whole- versus skim-milk swallows, 10- and 20-mL versus 5-mL volumes, and straw versus cup delivery. The risk for aspiration increased by approximately two-, three-, and seven-fold with maximal increases in bolus volume, fat content of liquids, and age, respectively.


Occasional aspiration may be an underappreciated phenomenon during FEES in healthy older adults. In addition, milk yielded a higher likelihood of aspiration than water. Accordingly, different liquid types, bolus volumes, and delivery methods should be used to ensure an accurate assessment of aspiration status in healthy older adults. Laryngoscope, 2010