Robin Hanson points to new work showing that folks on low salt diets are more likely to die than folks eating normal or high amounts of salt. The study follows over 3600 people for about eight years and controls for baseline health correlates like blood pressure, BMI, smoking, and being on blood pressure medication.
I still wonder though whether the "sick quitter" hypothesis raised as explanation for the alcohol J-curve (and thoroughly refuted in that case) might need to be checked. If a couple years after starting in the sample group, your doctor tells you to cut the salt from your diet because your blood pressure's blowing out and you then have a heart attack two years later despite having reduced salt intake, the finding could be spurious.
I'd need to check the actual JAMA paper to see how well they've ruled that out. Off campus access to gated resources is such a pain though.
Full disclosure: I eat a lot of salt. Sometimes, but rarely, I'll even eat a teaspoon of salt if the mood strikes me. BP's fine though. I tend to figure that evolution gave me a taste for salt for a damned good reason and that I'd be overthrowing the wisdom of 30,000 generations were I to hold back. I do compensate somewhat by eating a lot of potassium.