Potassium-enriched salt lowers blood pressure and is the new recommendation from the WHO.
Efforts to reduce salt intake haven’t yielded great results, so the WHO is recommending people switch their table sodium chloride lower-sodium salt substitutes that contain potassium.
“For the first time, GPs have got something that they can ask their patients to do, that they can actually expect patients to be able to achieve,” Professor Bruce Neal, executive director at The George Institute for Global Health, told TMR.
Just under a quarter of the eight million annual deaths associated with poor diet worldwide are attributable to salt intake, according to the WHO. The George Institute says switching to potassium-enriched salt will prevent at least five million heart attacks and strokes globally every year.
These figures are borne out in real-world studies, with research from China published this week in JAMA Cardiology finding that people who’d had a stroke and switched to substitute salt had a 14% lower chance of a recurrent stroke compared to those who stuck with regular salt and 30% lower chance of a haemorrhagic stroke. They also had a 21% lower chance of dying from stroke.
Substitute salts replace 25-50% of the sodium chloride in regular table salt with potassium chloride. Potassium lowers blood pressure and is mainly found in fresh fruits, vegetables and fish – things we don’t tend to get enough of.
“[T]he only cautions [around adding potassium] based on strong evidence are patients with stage 3 or 4 chronic kidney disease or patients taking a potassium-sparing diuretic,” says a JAMA Cardiology editorial accompanying the Chinese study above.
“The debate about the importance of increased potassium or reduced sodium as the primary driver of the benefit of the potassium-based salt substitute will continue but should not delay use of this strategy as it is proven to be effective and safe for most people.”
The George Institute’s Professor Neal said switching salt is a lot easier than cutting. How much salt people add into their cooking is “embedded through decades of cooking practices”, he said.
Importantly, the substitution does not change the taste.
Related
“That’s the key thing. If you use a mix that’s 25-50% potassium chloride, and still 75-50% sodium chloride, then most people can’t actually tell the difference when they use it for seasoning or cooking. And again, that’s absolutely vital, because if people do get that different taste and that less salty taste, then they’re unlikely to persist with it,” he said.
The substitutes do cost more than regular salt. There are three available in Australia through the two dominant supermarkets at the time of writing: Diet Rite Lite Salt ($3.00 for 170g, 18c for 10g, compared to around 2-6c for 10g of regular table salt); Heart Salt ($3.00 for 150g, 20c for 10g); and Heart Salt chicken salt (23c for 10g).
This is not likely to cause hardship for most Australians when it comes to putting salt on the table.
However, much of our salt intake is not discretionary. It comes already added to the packaged and processed foods we buy and the meals we eat out.
“So what we need in Australia is for the food industry to actually start using this as an alternative as well,” he said.
The mining and mineral sector has a role to play in that, he said, by starting to produce potassium enriched salt at scale in Australia.
“The industry doesn’t want their quantities and flavours to change, and if they use potassium enriched salt, they get around those problems,” said Professor Neal.
However, a George Institute global survey of prices showed that potassium enriched salt costs double the amount of regular salt, and that could be an issue.
“The amount of salt in most products is usually less than 1% or 2% of any product. So even if you double the price of that at an individual item level, it makes no difference really to the price of a product.
“But when you’re buying a tonne of salt, or 10 tonnes of salt, you will see a difference. So the food industry has to overcome that barrier, and the best way to do that will be to get the price of the bulk material down.”
In 2013, South Africa took the decision out of industry’s hands, initiating legislation mandating a reduction in salt levels in 13 food categories that account for 55% of food consumption in that country: bread, breakfast cereals, butter and fat spreads, three types of crisps or savoury snacks, raw sausage, two types of processed meats, three types of soup powders and sauces and stock cube concentrate.
Data published in the same issue of JAMA Cardiology as the Chinese study and editorial cited above showed a 10% reduction in daily sodium intake among the sample of people aged 40 and over from the rural area of Mpumalanga Province, and a corresponding mean reduction in systolic blood pressure of about 1.5mmHg for each 1g reduction in sodium. The proportion of people who were within the recommended amount of 2g or less of sodium daily went from 7% to 17%.
