The researchers, writing in the Annals of Internal Medicine, sought to compare the cost effectiveness of two different strategies to reduce sodium consumption in the US – a voluntary sodium reduction scheme for industry, as is already in place in the United Kingdom, and a sodium tax.
The average American adult consumes about 4,000mg of sodium a day, according to the US Department of Agriculture, as opposed to the maximum recommended daily amount of 2,300mg. Excessive sodium intake has been linked to increased risk of high blood pressure, heart disease and stroke. And with an estimated 75 percent of sodium in the average US diet coming from packaged foods, industry is already under pressure to reformulate foods to contain less sodium.
In the UK, government has been working with industry since 2003 to create voluntary sodium targets for specific foods. As a result, it is estimated that sodium intake has declined by 9.5 percent.
Using a computer model, the researchers calculated that using such a collaborative strategy to decrease sodium intake across the American population by 9.5 percent could prevent 513 885 strokes and 480 358 heart attacks over the lifetime of people aged 40 to 85 today. In addition, they said that such a scheme could save $32.1bn in direct medical costs.
The authors also considered a sodium tax that could be levied at the industrial level, but their calculations showed it to be less effective than voluntary reduction targets.
“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,” they wrote. “Persons often ignore large future costs when offered smaller, immediate benefits, and a tax on sodium could theoretically increase awareness of the long-term costs of sodium consumption.”
They suggested a tax of 40 percent on sodium, envisaging that food companies would pass the cost onto consumers. Such a strategy would reduce sodium consumption by 6 percent, they calculated, resulting in 327,892 fewer strokes and 306,173 fewer heart attacks.
“Collaboration with industry to establish voluntary sodium targets in processed foods is likely to be more effective than a sodium tax and seems to be an appropriate first step toward reducing population sodium intake and the burden of CVD,” they wrote.
The full study can be accessed online here.
In January, New York City launched a campaign along with other cities and health organizations called the National Salt Reduction Initiative to curb the amount of sodium in packaged and restaurant food by 25 percent over the next five years through voluntary reductions of salt in packaged and restaurant foods.