Both studies were led by Lewis Dahl, a highly respected researcher, and as a result, the health care industry soon concluded that low-sodium diets were the key to better heart health. After all, a population-based study and a laboratory study both demonstrated that salt could cause adverse health reactions. Case closed.
Scientists can be wrong, too
Unfortunately, being respected and being right aren't always the same thing. In the years since those studies, the first has been debunked, and the second gave already sick rats the equivalent of 20 to 50 times the sodium most people eat in a day, making the results, well, just a bit outside of what most people would consider a reasonable extrapolation. And that's being generous.
Over the next 40 years, claims about sodium only became more confusing. One study would state that sodium reduction leads to lower blood pressure. Another report suggested that sodium reduction is actually a danger to certain populations. In 2011, a review found no link to high sodium intake and poor health outcomes, but also noted that it couldn't say with certainty that a lower sodium intake didn't provide health benefits. A ringing endorsement.