Salt substitutes improve CVD outcomes: Study

New findings published in the BMJ’s Heart journal show that increased use of salt substitutes could lower the risk of heart attack, stroke and death from all causes and cardiovascular disease (CVD) worldwide.
 
According to the research, substituting salt (sodium chloride) with potassium chloride reduced the risks of heart attack, stroke and early death from any cause by 11% and the risk of CVD by 13%.
 
‘With this recent paper we have established that the impact of salt substitutes is similar around the world,’ the study’s lead author Professor Bruce Neal told newsGP.
 
The latest research was a follow up to significant findings from the 2021 China-based Salt Substitute and Stroke Study (SSaSS) that followed more than 20,000 participants taking salt substitutes and found significant reductions in CVD and death outcomes.
 
Professor Neal, who is Executive Director at The George Institute for Global Health Australia and was also the SSaSS lead author, said the new study was designed to see if the practice could have a similar public health impact, regardless of location.
 
To do so, the team analysed 21 relevant international clinical trials involving nearly 30,000 people in Europe, the Western Pacific Region, the Americas, and South-East Asia.
 
Reductions in blood pressure seemed to be consistent, irrespective of geography, age, sex, history of high blood pressure, weight (BMI), baseline blood pressure, and baseline levels of urinary sodium and potassium.
 
Additionally, each 10% lower proportion of sodium chloride in the salt substitute was associated with a 1.53 mmHg greater fall in systolic blood pressure and a 0.95 mmHg greater fall in diastolic blood pressure. There was also no evidence that higher dietary potassium was associated with any health harms.
 
The proportion of sodium chloride in the salt substitutes in the Heart analysis varied from 33–75%; the proportion of potassium ranged from 25–65%.
 
Approximately 1.28 billion people globally have hypertension and dietary salt is known to increase blood pressure and the risk of CVD.
 
Other people who may benefit from these findings include pregnant women, as approximately 3–4% of pregnant women in Australia develop pre-eclampsia.
 
‘Animal and epidemiological studies suggest that high sodium and low potassium levels may both independently increase the risk of pre-eclampsia during pregnancy,’ dietitian Melanie McGrice told newsGP.
 
‘[However], as yet no research has been undertaken to determine whether or not potassium-based salt substitutes are effective or safe in pregnant women.’
 
There were no differences in the risks of hyperkalaemia between salt and salt substitutes in the SSaSS or new Heart findings, although high-risk patients were excluded from SSaSS.
 
‘We didn’t measure kidney function and though biochemical hyperkalaemia may have been missed, it wasn’t clinically relevant,’ Professor Neal said.
 
Nonetheless, he says those with serious kidney or heart disease should avoid salt anyway, including salt substitutes, and suggests the use of other potential terminology such as ‘potassium-enriched’ or ‘sodium-reduced’.
 
Salt substitutes can also be iodised, which is important in pregnancy. But for now, Ms McGrice encourages pregnant women to use other flavour enhancers.
 
‘The best advice is to minimise salt use in pregnancy and opt for natural flavour enhancers, such as garlic, onions and fresh herbs,’ she said.
 
Meanwhile, cardiologist Professor Hosen Kiat told newsGP it is surprisingly common to find people taking potassium salts.
 
‘It’s a very low risk for the general population to use potassium chloride or other potassium salts,’ he said.
 
‘My clinical practice is to document the use of the type of salt and estimated quantity when they have electrolytes abnormalities or hypertension.
 
‘This information helps to mitigate risk, establish a surveillance regimen and offer diet advice when they might need ace-inhibitors, ARBs [angiotensin receptor blockers], aldosterone antagonists or NSAIDs [non-steroidal anti-inflammatory drugs] if they have heart failure and renal dysfunction.’
 
Professor Neal hopes the findings around salt substitutes lead to a change in how the world consumes salt.
 
He says the first change was from salt to iodised salt, and ‘the next change will be from iodised salt to salt substitutes.’
 
Log in below to join the conversation.

blood pressure CVD hypertension potassium chloride salt