Modest reductions in dietary salt could substantially reduce heart attacks, strokes, deaths, and medical costs.
Reducing salt in the American diet by as little as one-half teaspoon (about 3 g) per day could reduce the annual number of new cases of cardiovascular disease by 60,000, prevent 32,000 strokes and 54,000 myocardial infarctions, and reduce mortality from any cause by 44,000, according to a report in the February 18 New England Journal of Medicine. Such benefits could save the United States around $24 billion in health care costs, researchers estimated.
Investigators from the University of California, San Francisco (UCSF), Stanford University Medical Center, and Columbia University Medical Center used the Coronary Heart Disease Policy Model (a computer simulation of heart disease in US adults ages 35 to 84 and an extension of the model that is used to assess stroke) to quantify the benefits of potentially achievable, population-wide reductions in dietary salt of up to 3 g per day (1,200 mg of sodium per day). They estimated the rates and costs of cardiovascular disease in subgroups defined by age, sex, and race; compared the effects of salt reduction with those of other interventions aimed at reducing cardiovascular disease; and determined the cost-effectiveness of salt reduction as compared with the pharmacologic treatment of hypertension.
Small Change, Large Rewards
The Coronary Heart Disease Policy Model showed that reducing dietary salt by 3 g per day would result in 11% fewer cases of new heart disease, 13% fewer heart attacks, 8% fewer strokes, and 4% fewer deaths. All segments of the population would benefit, the researchers said, with blacks benefiting proportionately more, women benefiting particularly from stroke reduction, older adults from reductions in coronary heart disease events, and younger adults from lower mortality rates.
“A very modest decrease in the amount of salt, hardly detectable in the taste of food, can have dramatic health benefits for the US,” said Kirsten Bibbins-Domingo, PhD, MD, lead author of the study and an Associate Professor of Medicine and Epidemiology and Co-Director of the UCSF Center for Vulnerable Populations at San Francisco General Hospital. “It was a surprise to see the magnitude of the impact on the population, given the small reductions in salt we were modeling,” Dr. Bibbins-Domingo said.
Benefits on Par With Reductions in Tobacco Use and Cholesterol Levels
According to the researchers, the cardiovascular benefits of reduced salt intake are on par with the benefits of population-wide reductions in tobacco use, obesity, and cholesterol levels.
A regulatory intervention designed to achieve a reduction in salt intake of 3 g per day would save 194,000 to 392,000 quality-adjusted life-years and $10 billion to $24 billion in health care costs annually, they reported. Such an intervention would be cost-saving even if only a modest reduction of 1 g per day were achieved gradually between 2010 and 2019 and would be more cost-effective than using medications to lower blood pressure in all patients with hypertension.
“Reducing dietary salt is one of those rare interventions that has a huge health benefit and actually saves large amounts of money,” said Lee Goldman, MD, MPH, senior author of the study and Executive Vice President for Health and Biomedical Sciences and Dean of the faculties of Health Sciences and Medicine at Columbia University. “At a time when so much public debate has focused on the costs of health care for the sick, here is a simple remedy, already proven to be feasible in other countries,” he said.
Reductions in Salt Consumption Lead to Health Care Savings
“It’s clear that we need to lower salt intake,” Dr. Bibbins-Domingo commented, “but individuals find it hard to make substantial cuts because most salt comes from processed foods, not from the salt shaker.
“Our study suggests that the food industry and those who regulate it could contribute substantially to the health of the nation by achieving even small reductions in the amount of salt in these processed foods,” she added.
Further, according to Dr. Bibbins-Domingo, “Our project suggests that those regulatory efforts could both improve health and save money because of the health care costs avoided. For every dollar spent in regulating salt, anywhere from seven to 76 health care dollars could be saved.”
—Glenn S. Williams