In 2013, the Institute of Medicine published a major review of the evidence connecting salt consumption and health outcomes. There was insufficient proof, the panel concluded, that heeding the U.S. recommended limit on sodium consumption improved health outcomes.
Then, this past August, the New England Journal of Medicine published the results of a massive research effort known as the PURE study. It indicated that people who conform to the U.S. recommended limits actually have more heart trouble.
To explain their findings, these researchers pointed to studies suggesting that low sodium may stimulate the production of renin, a hormone that may have harmful effects on blood vessels.