How far should salt intake be reduced?

The current public health recommendations are to reduce salt intake from 9 to 12 g/ d to 5 to 6 g/ d. However, these values are based on what is feasible rather than the maximum effect of salt reduction. In a meta- analysis of longer- term trials, we looked at the dose response between salt reduction and fall in blood pressure and compared this with 2 well- controlled studies of 3 different salt intakes. All 3 studies demonstrated a consistent dose response to salt reduction within the range of 12 to 3 g/ d. A reduction of 3 g/ d predicts a fall in blood pressure of 3.6 to 5.6/ 1.9 to 3.2 mm Hg ( systolic/ diastolic) in hypertensives and 1.8 to 3.5/ 0.8 to 1.8 mm Hg in normotensives. The effect would be doubled with a 6 g/ d reduction and tripled with a 9 g/ d reduction. A conservative estimate indicates that a reduction of 3 g/ d would reduce strokes by 13% and ischemic heart disease ( IHD) by 10%. The effects would be almost doubled with a 6 g/ d reduction and tripled with a 9 g/ d reduction. Reducing salt intake by 9 g/ d ( eg, from 12 to 3 g/ d) would reduce strokes by approximately one third and IHD by one quarter, and this would prevent approximate to 20 500 stroke deaths and 31 400 IHD deaths a year in the United Kingdom. The current recommendations to reduce salt intake from 9 to 12 g/ d to 5 to 6 g/ d will have a major effect on blood pressure and cardiovascular disease but are not ideal. A further reduction to 3 g/ d will have a much greater effect and should now become the long- term target for population salt intake worldwide.