Efforts to reduce sodium intake in Canada: why, what, and when?

Abstract

This review addresses the rationale for lowering dietary sodium intake in Canada and recent progress in this direction. Data from trials involving moderate and sustained (≥ 4 weeks) reductions in sodium intake demonstrated significant dose-dependent effects on blood pressure (BP) with larger effects in hypertensive individuals. Average sodium intake in Canada (approximately 3500 mg per day) is well above currently recommended intake targets (≤ 1500 mg per day). Approximately one-eighth of sodium intake is a natural component of food, with the remainder added by food industries (approximately 3/4) or at home (approximately 1/8). Modelling results suggest that lowering Canadian sodium intake to near recommended levels would reduce hypertension prevalence by approximately 30%, prevent approximately 15,500 cardiovascular events per year, and yield savings of approximately CAD$2 billion per year. These estimates do not include the potential additional benefits of long-term sodium restriction on BP, nor BP-independent effects. Actions to facilitate lower sodium intakes in Canada included dietary intake recommendations, mandatory nutritional labelling, a national intake survey, and recommendations of a Government-appointed Sodium Working Group (SWG) that aims to reduce Canadian intakes below 2300 mg per day by 2016. SWG strategies included voluntary reductions in sodium added by food industries, increased education, and research. However, the SWG has recently been disbanded, its responsibilities passed to a Federal-Provincial-Territorial Committee and to a new Food Regulatory Advisory Committee, and the significance for implementing recommendations is unclear. Health care practitioners are encouraged to promote lower dietary sodium intake in their patients and to advocate continued Government efforts to reduce the sodium content of the Canadian food supply.