We’ve all been there. It’s a hot summer day and there’s a bag of chips staring up at us...but with no water bottle in sight, we force ourselves to look away. After all, eating salty food will only make us thirstier. Right?
Maybe not. In a recent study, scientists found that participants who consumed more salt were not as thirsty as their counterparts. The study, conducted by an international group of scientists during a simulated mission to Mars and reported in the most recent issue of The Journal of Clinical Investigation, also showed that the men and women who ate more salt retained more water, too.
- Salt-Crusted Snapper with Eggplant-Raisin Puree
- Salty Almond Rice Krispie Bites
- Sweet and Salty Desserts
Prof. Jens Titze, MD of the University of Erlangen and Vanderbilt University Medical Center and Natalia Rakova (MD, PhD) of the Max Delbrück Center for Molecular Medicine (MDC) were two of the scientists who headed the study, in which two groups of 10 male volunteers were asked to experience two simulated flights to Mars. The first group was observed for 105 days and the second group for over 205, and all participants stayed in mock spaceships. Each was given the same diet, but the salt content of their food varied.
(If you’re curious why all this was studied in relation to the Mars journey, it’s simply important for the researchers to notice the small effects of added nutrients and minerals on the bodies of space voyagers—especially ones who will be traveling for so long. Plus, the Mars simulation provided the perfect environment in which to isolate and study something like salt intake.)
The results showed, as expected, that a higher salt intake led to a higher salt content in the participants’ urine. There was also an unsurprising correlation between salt intake and amount of urine (the more salt ingested, the more urine produced). However, researchers realized that the participants weren’t urinating more because they’d been drinking more. In fact, the reverse was true: The salty diet actually caused volunteers to drink less.
Yes, this might be a little more detail than we all need to know, but the results are actually quite significant. The experiment ended up reversing a lot of the ways in which scientists view the role of both urea and general homeostasis in the body, which are both important to our daily existence.
As Prof. Friedrich C. Luft, MD of the Charité and MDC said, "[Urea is] not solely 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. Its function is to keep water in when our bodies get rid of salt.”