Cutting down on salt could mean 17,000 fewer cases of strokes, heart attacks, and heart failure, according to a new Canadian study.

Researchers at Simon Fraser University and the University of Calgary found that reducing dietary salt levels to about half of their current consumption rates will significantly decrease heart-related disease levels.

The study -- published this week in the Canadian Journal of Cardiology -- claims that Canadians consume about 3,500 mg of dietary sodium per day.

A press release by SFU says researchers Michel Joffres and Norm Campbell found that reducing salt intake to about 1,200 to 1,500 mg "would result in 8,300 to 17,000 fewer people suffering from strokes, heart failure and heart attacks each year."

"(The figures) could be much bigger if sodium was reduced more. Or if there was a smaller reduction in sodium, fewer patients would benefit," Campbell told CTV's Canada AM Thursday.

Most people only require about 200 mg of sodium daily. Researchers estimate their recommended salt reductions could:

  • reduce major strokes by 10-20 per cent
  • reduce heart failures by 10-25 per cent
  • reduce heart attacks by three to seven per cent

Campbell, a researcher at the University of Calgary's Libin Cardiovascular Institute, said Canadians may not even be aware of how much salt they eat because it's added to a variety of processed products.

"About 80 per cent of the salt that we eat is added to food in processing, either by the manufacturer or by a restaurant," Campbell said.

"Any canned vegetable will have approximately 300 times as much sodium as the natural product."

Joffres, Campbell and other researchers found in an earlier study that reducing salt intake by half would eliminate hypertension in one million Canadians. Such a measure could save the health care system $430 million annually.

Campbell and Joffres say the government can improve the overall health of Canadians and save money by actively working to control sodium levels in processed foods.

"As governments focus on improving the health of Canadians and reducing health care expenditures, they need to continue the dialogue with industry officials over levels of salt in food products," Joffres said in a press release.

ABSTRACT: The 2008 Canadian Hypertension Education Program recommendations for the management of hypertension: Part 2 - therapy

NA Khan, B Hemmelgarn, RJ Herman, et al; for the Canadian Hypertension Education Program

OBJECTIVE: To update the evidence-based recommendations for the prevention and management of hypertension in adults.

OPTIONS AND OUTCOMES: For lifestyle and pharmacological interventions, evidence was preferentially reviewed from randomized controlled trials and systematic reviews of trials. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. However, for lifestyle interventions, blood pressure lowering was accepted as a primary outcome given the lack of long-term morbidity and mortality data in this field. Progression of kidney dysfunction was also accepted as a clinically relevant primary outcome among patients with chronic kidney disease.

EVIDENCE: A Cochrane collaboration librarian conducted an independent MEDLINE search from 2006 to August 2007 to update the 2007 recommendations. To identify additional published studies, reference lists were reviewed and experts were contacted. All relevant articles were reviewed and appraised independently by content and methodological experts using prespecified levels of evidence.

RECOMMENDATIONS: For lifestyle modifications to prevent and treat hypertension, restrict dietary sodium intake to less than 100 mmol/day (and 65 mmol/day to 100 mmol/day in hypertensive patients); perform 30 min to 60 min of aerobic exercise four to seven days per week; maintain a healthy body weight (body mass index 18.5 kg/m2 to 24.9 kg/m2) and waist circumference (smaller than 102 cm for men and smaller than 88 cm for women); limit alcohol consumption to no more than 14 units per week in men or nine units per week in women; follow a diet that is reduced in saturated fat and cholesterol, and one that emphasizes fruits, vegetables and low-fat dairy products, dietary and soluble fibre, whole grains and protein from plant sources; and consider stress management in selected individuals with hypertension.

For the pharmacological management of hypertension, treatment thresholds and targets should be predicated on by the patient's global atherosclerotic risk, target organ damage and comorbid conditions. Blood pressure should be decreased to lower than 140/90 mmHg in all patients, and to lower than 130/80 mmHg in those with diabetes mellitus or chronic kidney disease. Most patients will require more than one agent to achieve these target blood pressures. For adults without compelling indications for other agents, initial therapy should include thiazide diuretics. Other agents appropriate for first-line therapy for diastolic and/or systolic hypertension include angiotensin-converting enzyme (ACE) inhibitors (in nonblack patients), long-acting calcium channel blockers (CCBs), angiotensin receptor antagonists (ARBs) or beta-blockers (in those younger than 60 years of age). A combination of two first-line agents may also be considered for initial treatment of hypertension if systolic blood pressure is 20 mmHg above target or if diastolic blood pressure is 10 mmHg above target.

Other agents appropriate for first-line therapy for isolated systolic hypertension include long-acting dihydropyridine CCBs or ARBs. In patients with angina, recent myocardial infarction or heart failure, beta-blockers and ACE inhibitors are recommended as first-line therapy; in patients with cerebrovascular disease, an ACE inhibitor/diuretic combination is preferred; in patients with proteinuric nondiabetic chronic kidney disease, ACE inhibitors are recommended; and in patients with diabetes mellitus, ACE inhibitors or ARBs (or, in patients without albuminuria, thiazides or dihydropyridine CCBs) are appropriate first-line therapies. All hypertensive patients with dyslipidemia should be treated using the thresholds, targets and agents outlined in the Canadian Cardiovascular Society position statement (recommendations for the diagnosis and treatment of dyslipidemia and prevention of cardiovascular disease). Selected high-risk patients with hypertension but who do not achieve thresholds for statin therapy according to the position paper should nonetheless receive statin therapy. Once blood pressure is controlled, acetylsalicylic acid therapy should be considered.

VALIDATION: All recommendations were graded according to strength of the evidence and voted on by the 57 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here achieved at least 95% consensus. These guidelines will continue to be updated annually.