Why Everything We Know About Salt May Be Wrong - The New York Times
Their urine volumes went up and down in a seven-day cycle. That contradicted all he’d been taught in medical school: There should be no such temporal cycle.
In 1994, the Russian space program decided to do a 135-day simulation of life on the Mir space station. Dr. Titze arranged to go to Russia to study urine patterns among the crew members and how these were affected by salt in the diet.
A striking finding emerged: a 28-day rhythm in the amount of sodium the cosmonauts’ bodies retained that was not linked to the amount of urine they produced. And the sodium rhythms were much more pronounced than the urine patterns.