Apart from this one: https://en.wikipedia.org/wiki/MARS-500 https://en.wikipedia.org/wiki/MARS-500 From : " "A reduction in salt intake led to a significant fa

Apart from this one: https://en.wikipedia.org/wiki/MARS-500 https://en.wikipedia.org/wiki/MARS-500 From : " "A reduction in salt intake led to a significant fall in blood pressure, even in the healthy volunteers," explains Jens Titze, from Erlangen-Nuremberg University." .. "Titze gradually reduced the daily salt intake of the 'cosmonauts' during the course of the world's longest metabolism study, while keeping all other nutrients unchanged." But well, it's not something every study can do. [] http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10525/873_read-753/year-all/ http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10525/873...