Swapping some sodium for potassium in table salt could prevent millions of deaths, flags study

30 Aug 2021 --- Nutrition groups worldwide are urging the F&B industry to replace table salt with a reduced-sodium, added-potassium substitute. The call follows a large-scale dietary intervention study, which concluded that millions of deaths could be prevented each year with the “simple swap.” 

“This study provides further ‘strong evidence’ that such interventions can work in real life,” Sonia Pombo, campaign manager at Action on Salt, tells NutritionInsight.

“The food and nutrition industry should make this switch immediately for the benefit of public health.” 

This recommendation is echoed by lead investigator of the latest study, Professor Bruce Neal of The George Institute for Global Health: “Switching table salt to salt substitute is a highly feasible and low-cost opportunity to have a massive global health benefit.”

The study of 21,000 adults found that for those who used salt substitutes, there was a 14 percent risk reduction in stroke, 13 percent risk reduction in cardiovascular events (stroke and heart attack combined) and 12 percent risk reduction in premature death. 

Action on Salt notes that many foods can be reduced by 20 percent without noticeable changes.Building on previous findings
It is well-established that a reduction in sodium intake and an increase in potassium consumption lowers blood pressure, which in turn reduces the risk of strokes and heart diseases, explains Pombo. 

Using a salt substitute – where part of the sodium chloride is replaced with potassium chloride – addresses both problems at once. Salt substitutes are known to lower blood pressure, but their effects on heart disease, stroke and death were unclear prior to the latest study.

Reducing risks 
The Salt Substitute and Stroke Study enrolled 21,000 adults with either a history of stroke or poorly controlled blood pressure from 600 villages in rural areas of five provinces in China – 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 20 g 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, total cardiovascular events (strokes and heart attacks combined) by 13 percent and premature death by 12 percent. 

Easier said than done? 
Sodium and potassium are not one-to-one replacements for each other, but a combination of both enables sodium reduction overall. 

“Most salt substitutes used by the food industry contain 25 to 30 percent potassium chloride and 70 to 75 percent sodium chloride,” details Pombo. 

“Potassium-based salt replacers are also widely available in the UK for the general public. These typically have around 60 percent less sodium than standard table salt.”Salt substitutes are relatively inexpensive.

Building on industry salt reduction
Pombo further explains that salt reduction is often possible without salt substitutes at all. She notes that reductions of up to 20 percent often go unnoticed by the consumer. 

The benefit of salt substitutes is that they can help companies to reduce the sodium content of their food further, especially those categories that have struggled to make reductions to date.

This is particularly relevant for foods with technological or safety requirements for salt, such as bacon and meat products, points out Pombo. 

Cost of replacement 
When it comes to implementation barriers, Pombo adds that price is most likely a key factor, as salt itself is such a cheap commodity. 

“Despite this, many potassium salts are still affordable by all households in almost all countries.”

Neal chimes in that salt substitutes are “a bit more expensive” than regular salt. However, they’re still very low-cost – just a few dollars a year for households to make the switch.

Other risks
The study also revealed there were no harmful effects from the salt substitute.

However, Neal points out that patients with serious kidney disease should not use salt substitutes, adding that they also need to keep away from regular salt. 

Overall the benefits of salt substitutes outweigh the potential risks, according to the UK’s Scientific Advisory Committee on Nutrition (SACN), in collaboration with the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT). 

SACN and COT carried out a comprehensive review and concluded the benefits of salt replacements would have a large impact at the population level. 

“These organizations recommend that the government encourage the food industry to consider the use of salt substitutes to reduce the salt content of food,” Pombo says. 

The advice is in line with The George Institute for Global Health’s recommendations. Notably, the World Health Organization also recently set global benchmarks across food categories to limit salt intake to 5 g per day.

Potassium chloride is just one ingredient of several that can aid in sodium reduction. This is according to Klaus Brockhausen, sales director business unit food at mineral salt supplier Dr. Paul Lohmann. He names potassium acetate, citrate, carbonate and tartrate as other ingredients to consider in replacement solutions. 

By Missy Green