Conventional wisdom: If you eat a lot of salt, you will get thirsty to dilute the sodium level in your blood. The excess salt will be excreted in your urine.
But a new study of Russian cosmonauts is challenging this long-held belief. When the cosmonauts ate more salt, the became less thirsty. And their appetite increased - they had to eat 25 percent more to maintain their weight.
From the New York Times:
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The crew members were increasing production of glucocorticoid hormones, which influence both metabolism and immune function.
To get further insight, [Dr. Jens Titze, now a kidney specialist at Vanderbilt University Medical Center and the Interdisciplinary Center for Clinical Research in Erlangen, Germany] began a study of mice in the laboratory. Sure enough, the more salt he added to the animals’ diet, the less water they drank. And he saw why.
The animals were getting water — but not by drinking it. The increased levels of glucocorticoid hormones broke down fat and muscle in their own bodies. This freed up water for the body to use.
But that process requires energy, Dr. Titze also found, which is why the mice ate 25 percent more food on a high-salt diet. The hormones also may be a cause of the strange long-term fluctuations in urine volume.
Scientists knew that a starving body will burn its own fat and muscle for sustenance. But the realization that something similar happens on a salty diet has come as a revelation.
National Geographic calls Ethiopia's Danakil Depression "the cruelest place on Earth." It's a desert wasteland, where temperatures can push past 120 F, where ancient and current lava flows impede movement, and where water is so scarce that that people build rock domes over the top of volcanic vents to trap and condense steam.
It's also a place where Ethiopian men and boys regularly travel in order to cut slabs of salt off of the surface of the Earth and haul them back to civilization. Salt flats like this occur when entire bodies of water totally evaporate. In the Danakil Depression, you'll also find salt towers and other formations caused by evaporation off of volcanic geysers and hot springs.
The photo above was taken by Reuters photographer Siegfried Modola, who traveled with a group of salt miners into the desert and then followed their haul all the way back to the marketplace. You can see his full slideshow of images online. I chose this one because it gives you a view of the salt as it's found on the ground, and the neat, rectangular blocks the merchants cut it into for shipping.
The spot is a favorite of photographers. I'd also recommend checking out the photos and story put together by Christina Feldt, who posted about the Danakil salt flats earlier this year. Read the rest
I enjoyed my lightly peanutted salt. Read the rest
The Dead Sea's salinity of 33.7 percent makes it 8.6 times saltier than the ocean. Bordering Israel, the West Bank and Jordan, it is 423m below sea level, making it the lowest place on land on Earth. A tourist hotspot for millennia, more than 1m visitors a year visit on the Israeli & Palestinian side alone. The view from the shore is one thing, but from the air, the sheer strangeness of the salt formations in and around the lake become readily apparent. Photos by Baz Ratner, of Reuters, and others. Read the rest