Salt tax could massively reduce US mortality rates, healthcare costs

11 March 2010

MedWire News: A nationwide tax on sodium could save over a million life years and billions of dollars, results of a US cost-analysis published in the Annals of Internal Medicine indicate.

The average adult in the USA consumes almost 4.0 grams of sodium each day, nearly double the daily recommendation of 2.3 grams.

Although the benefits of reduced sodium intake on blood pressure and the risk for heart disease are well established, the routine addition of sodium to foods makes it difficult for individuals to regulate their sodium intake, write Crystal Smith-Spangler (Stanford University, California, USA) and colleagues.

For the present study, Smith-Spangler and team estimated what effect nationwide sodium restriction would have on the incidence of stroke and myocardial infarction in the USA, and consequent savings for healthcare systems.

“Although no country has implemented a tax to decrease sodium consumption, economic incentives affect consumer behavior, and taxes have been successful in reducing tobacco and alcohol consumption,” explain the researchers.

For the analysis, they used a Markov statistical model and data on adults aged 40–85 years from the 2006 Medical Panel Expenditure Survey and studies including the Framingham Heart Study. The analysis assumed that sodium intake was reduced either by taxing sodium or by voluntary collaboration between government and industry.

In the UK, voluntary collaboration between government and industry led to a decrease in typical sodium intake of 9.5%. Smith-Spangler and associated calculate that a similar decrease in the USA would prevent 513, 885 strokes and 480, 358 myocardial infarctions over the lifetime of the adults studied. The reduction in intake would also save 2.1 million quality-adjusted life years and over US$32 billion.

A tax on sodium was calculated to reduce intake by 6% and lead to proportionally similar improvements in health and cost savings.

In a related editorial, Thomas Frieden and Peter Briss from the Centers for Disease Control and Prevention in Atlanta, Georgia, USA suggest that food package labeling and warning on items with high sodium content could be useful complementary strategies “to support industry-wide reductions in sodium content and to help consumers make informed choices.”

In their conclusion, Smith-Spangler and co-workers note that, although the potential benefits of sodium reduction are great, their analysis “does not account for unintended consequences of reducing sodium, such as a compensatory increase in consumption of calories.”

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

Ann Intern Med 2010; Advance online edition