• Public health

To the Editor It is quite incredible how far the notion of a population-wide benefit accruing from salt reduction has gone in view of the contradictory clinical evidence. In the first instance we know that the population response to salt reduction is rather limited (2–6 mm Hg) and heterogeneous, with 30% experiencing a small drop in blood pressure (BP), ∼20% experiencing an increase in BP and the residual 50% of the population undergoing no impact at all.1

Indeed, the most recent evidence seems to indicate that so-called salt sensitivity on either side of the response is due to a genetically based imbalance of aldosterone production. Those with abnormally high production of aldosterone show a slight reduction in BP with decreased salt intake,2 while abnormally low aldosterone levels may …