[Scientific Statement]Report of the Salt Reduction Committee of the Japanese Society of Hypertension/(1) Role of salt in hypertension and cardiovascular diseases

Dietary salt consumption is closely associated with the level of blood pressure (BP); stricter salt reduction more markedly decreased BP. Obesity/metabolic syndrome, Dietary Approach to Stop Hypertension (DASH) diet, exercise and mental stress influence the BP-elevating effect of high-salt diet. Observational and intervention studies suggested that salt restriction improved the risk of cardiovascular diseases. However, the effects may differ among the types of the hypertensive complications; salt reduction may decrease the risk of stroke more than that of ischemic heart disease. Small-scale studies demonstrated that excess salt increased the risk of the left ventricular hypertrophy, heart failure, the urinary protein/albumin levels and end-stage renal failure. These diverse beneficial effects of salt reduction are probably because low-salt diet is an effective strategy to decrease BP and body fluid volume but is less effective to ameliorate the other cardiovascular risk factors. A mean salt intake in Japan is markedly high. Considering the present condition, salt reduction is essential for the prevention and treatment of hypertension and for the prevention of cardiovascular diseases.