Researchers have identified a "swallowing inhibition" that helps keep people from drinking too much fluid. Photo by priyanka98742.
MELBOURNE, Oct. 10 (UPI) -- Scientists from Monash University and other institutions identified a "swallowing inhibition" that helps regulate fluid intake in the human body.
The swallowing inhibition was discovered for the first time as part of a collaboration between researchers at Monash University, Florey Institute of Neuroscience and Mental Health, the University of Melbourne, and Baker IDID & Diabetes Heart Institute. The paper was published online in the journal Proceedings of the National Academy of Sciences.
Subjects in the study were asked to swallow water under two conditions: following exercise, and after being persuaded to drink an excess amount of water. Monash University Associate Professor Michael Farrell says subjects who had consumed excess water had to put in considerable effort to swallow.
"Here for the first time we found effort-full swallowing after drinking excess water which meant they were having to overcome some sort of resistance," Farrell explained in a press release.
Farrell, who works in the Department of Medical Imaging and Radiation Sciences, used functional magnetic resonance imaging, or fMRI, to measure brain activity in the moments before swallowing. When participants had to put more effort into swallowing, the right prefrontal areas of the brain were more active, which researchers say suggests the frontal cortex acts to override the swallowing inhibition.
Researchers have called the study the latest refutation of the belief that consuming large quantities of water is a healthy habit. The appropriate amount of water, Farrell went on to add, varies from person to person.
"If we just do what our body demands us to we'll probably get it right -- just drink according to thirst rather than an elaborate schedule," he said.
In very rare circumstances, drinking too much water has been tied to hyponatremia, a condition characterized by extremely low levels of sodium in the blood resulting in lethargy, nausea, convulsions, and coma.
