One, It is useful information for cosmonauts.
In order to effectively organize their food stock, and keep astronauts healthy, space teams need to accurately calculate the relationship between salt and liquid intake.
Secondly, space provided an entirely controlled environment.
But, bizarrely, no one has ever studied the connection to see if having a lot of salt makes people drink more-until now.
Researchers, including those from the German Aerospace Centre (DLR) in Germany, sealed two groups of 10 male volunteers into a mock spaceship for two simulated flights to Mars.
The first group was examined for 105 days; the second over 205 days. People in each group ate pretty much the same thing, but they were given different levels of salt in their food over several weeks.
The Institute for Quality and Efficiency in Health Care also found a correlation between reduced salt intake and lowered blood pressure in 2009, while a 2015 study by the Federation of American Societies for Experimental Biology reported a possible link between higher salt intake and the development of multiple sclerosis (MS). Higher amounts of salt also increased overall quantity of urine. But this increase was not due to the fact that the volunteers were drinking more. Evidently, salt triggers a mechanism in the kidneys to hold onto water and produce urea - a process which eats up enegery, causing hunger, not thirst.
"Before the study, the prevailing hypothesis had been that the charged sodium and chloride ions in salt grabbed onto water molecules and dragged them into the urine", a statement from the MDC read.
According to the textbooks, the excretion of dietary salt will inevitably lead to water loss into the urine and thereby reduce body water content.More news: Cops: Man kills 3 on street, says he 'hates white people'
"We have always focused on the role of salt in arterial hypertension", said Jens Titze, the senior author, an associate professor of medicine and molecular physiology and biophysics.
Experiments in mice hinted that urea might be involved.
The kidneys, researchers say, act like a "biological barrier designed for water conservation that is able to separate osmolytes from water to prevent dehydration while conducting osmolyte balance".
Salt makes you hungrier not thirstier, according to a new study.
The study will change the way scientists look at urea in the body.
"[Urine] is not exclusively a waste product, as has been assumed". "Instead, it turns out to be a very important osmolyte - a compound that binds to water and helps transport it". Right? Maybe in the short-term - but within 24 hours, you actually get less thirsty because your body starts to conserve and produce more water.
"Nature has apparently found a way to conserve water that would otherwise be carried away into the urine by salt", said Freidrich Luft from the MDC.
The researchers said that the findings should be applicable whether a body is being sent to Mars or not.