Reducing dietary salt intake an important public health target

A regulatory intervention designed to modestly reduce daily dietary salt intake has the potential to prevent 44,000 to 92,000 deaths from any cause each year and could substantially reduce CVD events and medical costs, new data indicate.

Despite the established association between salt intake, hypertension and CVD, and the adoption of regulatory policies in other developed countries, U.S. dietary salt intake continues to increase unchecked.

To determine the potential benefits of such programs, researchers from several U.S. sites simulated annual reductions in the incidence of CHD, new and recurrent MI, and incidence of stroke with a reduced sodium diet using the CHD policy model.

They projected that decreasing dietary salt by 3 g per day would result in 60,000 to 120,000 fewer cases of CHD, 32,000 to 66,000 fewer strokes and 54,000 to 99,000 fewer MIs per year — putting the potential benefits of reduced salt intake on par with population-wide reductions in tobacco use, obesity and cholesterol levels.

After modeling for race/ethnicity, gender and age subgroups, the researchers determined that although all segments of the population would benefit, blacks would benefits proportionately more, women would benefit particularly from stroke reduction, older adults from fewer CHD events and younger adults from lower mortality rates.

“The large and growing burden of hypertension, despite improved medical therapies and increased awareness that dietary salt reduction can help prevent and treat hypertension reinforce the urgent need for dietary change,” the researchers wrote. However, they noted that behavior changes are “notoriously difficult to achieve,” and that attempts on an individual basis “have largely proved to be ineffective.”

A cost-effectiveness analysis indicated that a national effort would result in estimated savings totaling $10 billion to $24 billion and would compare favorably with current antihypertensive medication therapies. Furthermore, combining both therapies would reduce the number of people who need treatment with antihypertensive medications (16%-24% reduction among women; 22%-34% reduction among men), and would reduce the cost of treating hypertension by $3 billion to $6 billion annually.

“The magnitude of the health benefit suggests that salt should be a regulatory target of the FDA […],” the researchers wrote. “Our findings underscore the need for an urgent call to action that will make it possible to achieve these readily attainable cardiovascular benefits.”

Bibbins-Domingo K. N Eng J Med. 2010; doi:10.1056/NEJMMoa0907355.

The paper by Bibbins-Domingo is an excellent of example of what needs to happen nationwide for lifestyle modification and preventive measures to reduce cardiovascular risk. We have known for years that in those with hypertension or those who are older with a family history of hypertension that salt will increase their BP to a much greater degree than younger people or those without hypertension. Moreover, persistent high salt intake directly injures the arteries and predisposes individuals to other organ injury. Thus, reducing sodium intake as the article implies will reduce the need for additional antihypertensive medication and risk for stroke and kidney disease.

Examples of this are noted in Finland, Japan and the United Kingdom where efforts to reduce sodium nationally by 35% to 50% have led to dramatic drops in CV events. Based on the current administrations' 'call to arms' for preventive health, this should be step one.

– George Bakris, MD
Cardiology Today Editorial Board