Salt lowers blood pressure even in non-hypertensive people

Eating a salt-poor, vegetable-rich diet for one month can substantially lower blood pressure in people with aboveoptimal blood pressure levels, in addition to those who are frankly hypertensive, according to findings of a US study published in the 4 January issue of The New England Journal of Medicine by Frank Sacks and fellow members of the DASH (Dietary Approaches to Stop Hypertension) Sodium Collaborative Research Group. The study, which was supported by the National Heart, Lung, and Blood Institute (NHLBI), part of the US National Institutes of Health, involved 412 people with systolic blood pressure levels between 120 mm Hg and 159 mm Hg. Participants were randomly assigned to eat either a typical US diet alone or the vegetable-rich, low-fat, low-carbohydrate, so-called DASH diet alone, at three different levels of daily sodium intake —3300 mg (average for US), 2400 mg (recommended maximum) and 1500 mg — for each diet. After 30 days, the group on the DASH diet at the lowest sodium intake showed the greatest drop in blood pressure —7.5 mm Hg and 11.5 mm Hg, for the hypertensive and non-hypertensive participants, respectively, below the final blood pressure levels of those who had eaten the typical US diet. Whichever diet was eaten, the magnitude of the mean drop in blood pressure was inversely related to daily salt intake. The study findings, commented NHLBI Director Claude Lenfant, ‘‘lay to rest the longstanding controversy over whether sodium reduction lowers blood pressure in people who do not have hypertension’’.

John Maurice
Bulletin