Effects of drinking hot water, cold water, and chicken soup on nasal mucus velocity and nasal airflow resistance.

Nasal mucus velocity and nasal airflow resistance were measured in 15 healthy subjects before and at 5 and 30 minutes after drinking hot water by sip or straw, hot chicken soup by sip or straw, and cold water by sip. A sham drinking procedure with straw was also employed. Hot water by sip increased nasal mucus velocity from 6.2 to 8.4 mm per min, hot chicken soup by sip from 6.9 to 9.2 mm per min, and chicken soup by straw from 6.4 to 7.8 mm per min five minutes after administration. These increases were statistically significant compared to cold water, hot water by straw and sham. All values returned to their baseline at 30 minutes except cold water which significantly decreased the nasal mucus velocity from 7.3 to 4.5 mm per min. There were no significant changes from baseline in nasal airflow resistance 5 and 30 minutes following the above treatments. We conclude that drinking hot fluids transiently increases nasal mucus velocity in part or totally through the nasal inhalation of water vapor. Hot chicken soup, either through the aroma sensed at the posterior nares or through a mechanism related to taste, appears to possess an additional substance for increasing nasal mucus velocity. Finally, hot liquid might be superior to cold liquids in the management of fluids in upper respiratory tract infections.