Led by scientists from the University of California, San Francisco, the new study reported that a three gram reduction in daily salt intake in the US, described as “hardly detectable” to the palate, would prevent nearly 100,000 heart attacks and 92,000 deaths each year.
“It's clear that we need to lower salt intake, but individuals find it hard to make substantial cuts because most salt comes from processed foods, not from the salt shaker,” said lead author Dr Kirsten Bibbins-Domingo from UCSF.
“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.
Timing
Publication of the findings in the prestigious New England Journal of Medicine coincides with an announcement from New York City to lead the way in a partnership of cities and national health organizations to promote a voluntary program of salt reduction in packaged and restaurant foods.
The campaign aims to curb the amount of salt in packaged and restaurant food by 25 percent over the next five years. The sodium in salt is a major contributor to high blood pressure, which in turn causes heart attack and stroke, the nation’s leading causes of preventable death.
Although Americans consume about twice the recommended limit of salt each day, only 11 per cent of sodium in the national diet comes from saltshakers; nearly 80 per cent is added to foods before purchase.
“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 Bibbins-Domingo.
The team used a computer simulation of heart disease called the Coronary Heart Disease Policy Model to estimate and predict the benefits from public health interventions.
“It was a surprise to see the magnitude of the impact on the population, given the small reductions in salt that we were modeling,” added Bibbins-Domingo.
Big results
Using their computer simulation, the researchers found that a three grams per day reduction in salt intake, equivalent to about 1,200 milligrams of sodium, would reduce the number of new heart disease cases by 11 per cent, the number of heart attacks by 13 per cent, the incidence of stroke by 8 per cent, and the number of deaths by 4 per cent.
Moreover, the benefits for African Americans are likely to be higher, since this group are more likely to have high blood pressure and may be more sensitive to salt, said the researchers.
“Reducing dietary salt is one of those rare interventions that has a huge health benefit and actually saves large amounts of money. 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,” said study leader Dr Lee Goldman from Columbia University.
European-wide implications
Commenting independently on the study’s findings, the European Society of Cardiology (ESC) welcomed the results as underlining “the urgent need for European Union public health measures to substantially reduce the population’s salt intake across Europe”.
Professor Frank Ruschitzka, a cardiologist from the University of Zurich and spokesperson for the ESC said: “This study provides excellent ammunition both to convince patients about the benefits of reducing their individual salt intakes and also to persuade the EU of the urgent need to introduce legislation to restrict the salt content of processed foods.
“This study represents the evidence that a reduction of salt intake not only lowers blood pressure but also prevents cardiovascular events. The case for population-wide salt reduction is now compelling,” he added.
Source: New England Journal of Medicine
Published online ahead of print, doi: 10.1056/NEJMoa0907355)
“Projected Effect of Dietary Salt Reductions on Future Cardiovascular Disease”
Authors: K. Bibbins-Domingo, G.M. Chertow, P.G. Coxson, A. Moran, J.M. Lightwood, M.J. Pletcher, L. Goldman