In the current study, published in the open access journal PLOS ONE, Monell researchers investigated several oral sensations to identify which have an impact on thirst and influence the amount of liquid people drink. To induce thirst, participants abstained from liquid and food overnight and then ate a small breakfast of toast and jelly. Because thirst and its cessation contribute to how much fluid a person drinks, the current findings could help guide sensory approaches to increase fluid intake in populations at risk for dehydration, including the elderly, soldiers, and athletes. It is generally believed that drinking fluids diminishes thirst because it leads to rehydration and consequently reduced physiological thirst signals. While it is commonly believed that rehydration alleviates thirst, in actuality thirst is relieved, and the act of drinking ceases, long before a consumed liquid is absorbed by the body. Sensory cues in the mouth appear to play a role in thirst quenching, but the specific signals that the body uses to determine the amount of liquid consumed and when to stop drinking remain largely unknown. SEE ALSO: This website allows you to make the La Croix flavor of your dreams 
 
 The study, funded by Japanese drink giant Suntory, took place at the nonprofit Monell Chemical Senses Center. The center says it is, "dedicated to interdisciplinary basic research on the senses of taste and smell." After a 5 min rest period, participants were offered an excess of RT, still, unflavored water to drink from a jug until they no longer wished to continue. Carbonated beverage: The carbonated water used was a commercially available soda water (Vintage Seltzer water®). The relatively small study (98 people between the ages of 20 and 50 participated), had participants fast overnight, then rate their thirst after a breakfast of jelly and white toast. (A), Three beverages were tested: room temperature water (RT), cold water (CD) and cold carbonated water (CC). — Jackie Vingan (@jving) September 28, 2016 
 
 The experiment showed that, "the thirst-quenching effects of astringency, sweetness, and mild acidification," had no impact on relieving participants' thirst. And your relief might only be perception, but it is sweet relief. Each then had five minutes to drink 400 ml (13.5 oz) of water under one of four conditions, varying temperature (room-temperature or cold refrigerator-temperature) and carbonation (plain or carbonated). Self-reported thirst ratings were used to verify that on average participants started the sessions with comparable levels of thirst (mean value was 35, just above the descriptor “strong” on an LMS). Using this functional measure, the researchers found that cold liquid reduced thirst more effectively than room temperature. The study says, "By measuring how much plain water was consumed after the experimental beverage, the researchers could evaluate how well the experimental beverage had quenched participants' thirst." Adding carbonation to a cold beverage further enhanced the beverage's thirst quenching properties. Researchers found cold water was more satisfying than lukewarm water and, interestingly, more carbonation added to the perceived thirst-quenching properties. Experiments testing the thirst-quenching effects of astringency, sweetness, and mild acidification showed no effect, supporting the specific effects of cold and carbonation on thirst reduction. A separate experiment showed that using menthol to chemically create the sensation of cooling had a similar thirst quenching effect to the water actually being at a cold temperature. Perceived volume was further increased when the beverage was cold and carbonated (> 20% increase). Our data also have implications for groups who are known for clinical underhydration, such as laborers, soldiers, and the elderly, possibly due to their ignoring or cognitively mishandling important sensory cues that guide thirst and its quenching.
– If you're feeling uncomfortably thirsty, you may want to grab a La Croix, or so suggests a new study that looks at the "Perception of Drinking and Thirst Quenching in Thirsty Adults." Science Daily explains the assumption that rehydration alleviates thirst isn't really true: "In actuality thirst is relieved, and the act of drinking ceases, long before a consumed liquid is absorbed by the body." As for what does relieve our thirst, researchers with the Monell Center in Philadelphia have identified two sensory cues in our mouths: People tend to feel more quenched after they drink cold water than room temp, and carbonation enhances that effect. Reporting in the journal PLOS ONE, researchers write that they had 98 healthy participants aged 20 to 50 abstain from any food or fluid intake overnight before eating toast and jelly. At this point the subjects rated their thirst as "strong" and were allotted five minutes to drink 13.5 fluid ounces of water that was either room temperature or cold and either flat or bubbly. Five minutes later, they could drink as much plain water as they wished. Turns out those who drank the cold seltzer water felt the most quenched and required less water later, confirming that the combo provides the greatest "sensation of relief," the study's lead author says. So even though the bubbles aren't actually more hydrating, as Mashable reports, the fizz is more convincing, a trick that could prove useful in situations where thirst must be quenched with limited supply. (This boy never feels thirsty or hungry.)