First direct evidence to show cost-effectiveness of salt substitutes on cardiovascular outcomes

Salt substitution has been shown to reduce stroke risk by 14 percent and the number of strokes and heart attacks combined by 13 percent, but this new analysis revealed that the costs saved as a result outweighed the cost of the intervention.

The results will be presented at the American Congress of Cardiology in Washington DC on April 3 by Professor Bruce Neal, Executive Director of The George Institute Australia, and published in Circulation.

Senior author Thomas Lung, Senior Research Fellow at The George Institute for Global Health said salt substitutes should now be considered as a key element of any salt reduction campaigns.

"Our research has already shown that salt substitutes reduce the risks of stroke, heart attack and premature death, but now we can say for the first time that they also reduce healthcare costs," he said.

"Salt substitution is a particularly low cost and effective intervention in countries where most of sodium in the diet comes from the salt added during home cooking, which can be easily substituted."

Globally, excess salt consumption (more than five grams per day) is responsible for three million deaths each year. Four out of five of these deaths occur in low- and middle-income countries, and nearly half are among people younger than 70.

First published in August 2021, the Salt Substitute and Stroke Study demonstrated a reduced risk of stroke, heart attack and premature death among people living in rural China.

Researchers enrolled 21,000 adults with either a history of stroke or poorly controlled blood pressure from 600 villages in rural areas of five provinces -- Hebei, Liaoning, Ningxia, Shanxi and Shaanxi between April 2014 and January 2015.

Participants in intervention villages were provided enough salt substitute to cover all household cooking and food preservation requirements -- about 20g per person per day -- free-of-charge. Those in the other villages continued using regular salt.

During an average follow up of almost five years, more than 3,000 people had a stroke. For those using the salt substitute, researchers found that stroke risk was reduced by 14 percent.

In this new analysis they weighed up the costs associated with the salt substitute intervention and compared them with the cost savings resulting from the reduced number of hospitalisations due to strokes prevented and associated quality of life benefits gained.

They found salt substitution would be cost-saving at the lowest local market price of salt substitute and cost-effective up to an estimated 1.5 times the current highest market price and 10.3 times the price of a widely available salt substitute in China.

"We've shown that the use of salt substitute by patients at high risk of cardiovascular disease is a practical and cost-effective way of reducing cardiovascular risk," said study author Dr Maoyi Tian, Honorary Senior Fellow at The George Institute China.

"The extent to which a patient will benefit depends on how much of their dietary salt is replaced with salt substitute, and the cost-effectiveness will depend mainly on the price of the salt substitute," he added.

"Salt substitution is now the only salt reduction intervention with what we would call 'grade one evidence' demonstrating cost-saving protection against cardiovascular disease and should now be considered by all countries planning or implementing sodium reduction campaigns."