Population dietary salt reduction and the risk of cardiovascular disease. A scientific statement from the European Salt Action Network

The publication in the last few years of a number of prospective observational studies suggesting a J-shaped association between levels of salt (sodium) consumption and cardiovascular outcomes has opened a debate on the pertinence of population-wide salt reduction policies to reduce cardiovascular disease burden, and some have even questioned the global World Health Organization guidelines, that recommend a 30% reduction in salt consumption by 2025, aiming at an ideal target of no more than 5 g of salt consumption per day. In September 2018 the European Salt Action Network (E.S.A.N.), after appraising the quality of publications questioning the appropriateness of population salt reduction, discussed the scientific evidence and identified the pitfalls of recent data. The new evidence was deemed inadequate and, in places, biased by flawed methodology. These were identified in the biased assessment of sodium intake from spot urine and the use of the Kawasaki formula, the biased assessment of the sodium–outcome relationships in prospective observational studies using spot urine samples, the impact of reverse causality in such studies, the inadequate analytical approaches to data analysis, the lack of biological plausibility and the lack of precision in assessing long-term salt consumption, as recently demonstrated in studies using more stringent quality features in their study designs. On the basis of such appraisal, the E.S.A.N. agreed a statement confirming the support to the implementation of national and regional programmes of moderate reduction in salt intake, as recommended by the World Health Organization.