Statement of CSPI Nutrition Director Bonnie Liebman
The new study published in the Lancet this evening by Mente, et al. suffers from the same flaws as earlier studies by the same authors. The new study purported to find an increased risk of deaths and cardiovascular events among people who consume the least sodium. That observation is likely due to reverse causation. In other words, people who are already ill eat less food, and therefore less sodium, but it is illness, not the low sodium intake, that increases their risk of cardiovascular events.
Furthermore, the study relies on a single urine sample to estimate the long-term sodium intake of each study’s participants, despite the poor validity of those estimates. Studies like the Trials of Hypertension Prevention indicate that when those flaws are avoided, people with the lowest sodium intakes have the lowest risk of cardiovascular events.
It is unfortunate that studies like this one distract people from the well-established fact that a high-sodium diet increases the risk of high blood pressure, which is a major risk factor for heart disease and stroke.