Policy options to reduce population salt intake

Blood pressure and cardiovascular disease

Raised blood pressure is the dominant cause of death and disability in adults worldwide,1 responsible for approximately 50% of deaths from coronary heart disease and over 60% of those from stroke. The risk of cardiovascular disease increases with increasing blood pressure,2 and causality is supported by randomised controlled clinical trials, in which lowering blood pressure over five years reduces cardiovascular disease by approximately the amount predicted from larger observational studies.3 But the majority of cardiovascular disease events attributable to blood pressure occur in people with untreated “normal” pressure (about 130/80 mm Hg), with additional events occurring even with blood pressure levels down to 115/75 mm Hg. 2 Even a small downward shift in the distribution of blood pressure in the whole population would achieve a large drop in cardiovascular disease.2

Evidence relating salt to blood pressure

Evidence from a very wide variety of studies shows a consistent direct relation between salt intake and blood pressure. A 4.6 g reduction in daily dietary intake of salt (equivalent to a 1840 mg reduction in daily sodium) decreases blood pressure by about 5.0/2.7 mm Hg in individuals with hypertension and by 2.0/1.0 mm Hg in normotensive people.4 Randomised controlled trials have consistently shown dose-response effects.5 The blood pressure lowering effect of reducing salt intake is effective in men and women, in all ethnic groups, in all age groups, and all starting blood pressures.

Population based interventions indicate that when salt intake is reduced, blood pressure in the community falls. An …