For years scientists at the Harvard School of Public Health, the American Heart Association, and the Center for Science in the Public Interest have tried to get the U.S. government to lower the recommended daily limit for sodium intake from 2,300 milligrams to 1,500 milligrams—about two-thirds of a teaspoon. In particular, they warned people with high or even somewhat elevated blood pressure, people over age 40, African Americans, and diabetics not to consume more than 1,500 milligrams per day.
But a May 2013 study by the Institute of Medicine (IOM) calls those recommendations into question. That review, commissioned by the U.S. Centers for Disease Control and Prevention, found that contrary to years of anti-salt dogma, low sodium consumption may actually harm people suffering from congestive heart failure.
The IOM report noted that "the evidence on health outcomes is not consistent with efforts that encourage lowering of dietary sodium in the general population to 1,500 milligrams per day." In other words, had regulators listened to the nutrition nannies and tried to limit Americans to less than two-thirds of a teaspoon of salt per day, they might have done more harm than good.