Research Paper Title

Effect of Longer Term Modest Salt Reduction on Blood Pressure: Cochrane Systematic Review and Meta-analysis of Randomised Trials.

Study Question

Does a longer term modest reduction in salt intake have a significant effect on blood pressure, hormones, and lipids?

Summary Answer

A modest reduction in salt intake for four or more weeks causes significant and, from a population viewpoint, important falls in blood pressure in both hypertensive and normotensive individuals, irrespective of sex and ethnic group.

There were small physiological increases in plasma renin activity, aldosterone, and noradrenaline and no significant change in lipid concentrations.

What is Known and What this Paper Adds

Salt reduction can lower blood pressure and thereby reduces cardiovascular risk. A recent meta-analysis of randomised trials implied that salt reduction had adverse effects on hormones and lipids, which might mitigate any benefit that occurs with the reduction in blood pressure.

That meta-analysis included a large number of trials with a big change in salt intake for only a few days. The current meta-analysis shows that a longer term modest reduction in sal

t intake lowers blood pressure without adverse effects on lipids and hormones.

Furthermore, there is a dose-response relation between the reduction in salt intake andthe fall in systolic blood pressure. Reduction in salt intake to the recommended level of 5-6 g/day will have a major effect on blood pressure, and a further reduction to 3 g/day will have a greater effect.

Source: BMJ 2013;346:f1325.