Pass the Salt, Please

I don’t spend much time thinking about salt, but maybe I should: sodium intake is critical for myriad biological processes including nerve conduction, muscle contraction, and maintaining the fluid balance that is necessary to ensure proper blood flow and delivery of oxygen and nutrients to every single cell in the body.  If we consume too little sodium, our kidneys go to extremes to conserve it; too much and it is eliminated through skin, intestines and kidneys.  Getting the right amount seems to be on some level automatic - whether we know it or not, we listen to our bodies: the average U.S. sodium intake is between 3600 and 3700 mg per day, in contrast to the National Academy of Medicine’s advice to limit daily intake to 2300 mg (about a teaspoon) of salt per day, and just 1500 for those at risk of cardiovascular disease. 

This recommendation (and the FDA’s current push for limiting sodium content across 150 food categories) may fly in the face of science, as outlined in a recent article in The Lancet, summarizing six decades of research on the subject.  The authors of the article found that there was a “sodium sweet spot” associated with the lowest risk of disease and the longest life expectancy of somewhere between 3000 and 5000 mg per day.  They found that once sodium intake falls below 3200 mg (significantly higher than the recommended daily allowance), mortality increases and life expectancy dramatically decreases.  This proved true for all people, but especially for middle-aged men, the ill, and the elderly, for whom a lower sodium intake nearly doubled their risk of disease and death from all causes.

The federal dietary guidelines are currently being deliberated, with release slated for 2020.  If new restrictions on sodium are successful in reducing salt intake, the results could actually magnify health risks for Americans.  Lucky for us, the government’s recommendations are not generally top of mind when we are craving a salty snack.