A pooled data analysis of the existing evidence suggests that dietary salt replacements reduce the risk of heart attack, stroke, and mortality from all causes including cardiovascular disease, according to the conclusions of a new research.
The findings were reported in the journal Heart online. According to the experts, the favourable effects of these alternatives are likely to apply to people all over the world.
Cardiovascular disease is the largest cause of mortality globally, and high blood pressure is a significant risk factor for premature death. A high salt, low potassium diet is known to raise blood pressure.
According to the study, around 1.28 billion people worldwide have excessive blood pressure, with more than half of them going untreated.
Salt substitutes that replace a portion of the sodium chloride (NaCl) with potassium chloride (KCl) are known to help reduce blood pressure.
A significant Chinese research (Salt Substitute and Stroke Study; SSaSS) released recently indicated that salt replacements reduce the incidence of heart attacks, stroke, and premature mortality, but it was unclear whether these advantages would extend to other regions of the world.
In order to shed light on this, the researchers combed through research databases for randomised clinical studies published up to the end of August 2021 that reported on the effects of a salt replacement on blood pressure, cardiovascular health, and premature mortality.
Blood pressure is measured in millimetres of mercury (mmHg) and is composed of two numbers: systolic—the larger number indicating the power with which the heart pumps blood around the body—and diastolic—the lower number indicating arterial pressure while the heart is filled with blood.
They combined the findings of 21 relevant worldwide clinical studies involving over 30,000 participants from Europe, the Western Pacific Region, the Americas, and Southeast Asia.
The research periods ranged from one month to five years. The amount of sodium chloride in the salt replacements ranged from 33% to 75%, whereas the quantity of potassium ranged from 25% to 65%.
The examination of pooled data revealed that salt replacements reduced blood pressure in all subjects. The total systolic blood pressure drop was 4.61 mm Hg, while the overall diastolic blood pressure reduction was 1.61 mmHg.
Blood pressure reductions appeared to be constant regardless of region, age, gender, history of high blood pressure, weight (BMI), baseline blood pressure, and baseline urine salt and potassium levels.
Each 10% reduction in sodium chloride in the salt replacement was related with a 1.53 mmHg increase in systolic blood pressure and a 0.95 mmHg increase in diastolic blood pressure. There was no indication that consuming more potassium was harmful to one’s health.
A pooled data analysis of the outcomes of five of these trials involving over 24,000 individuals found that salt replacements reduced the odds of early mortality from any cause by 11%, cardiovascular disease by 13%, and heart attack or stroke by 11%.
The researchers recognise that their findings have limitations, such as the fact that the studies in the pooled data analysis differed in design and that there were very limited data for those who did not have high blood pressure.
Nonetheless, they emphasise that their findings are consistent with those of the SSaSS, the biggest study of a potassium-enriched salt replacement to date.
“Because blood pressure lowering is the mechanism by which salt substitutes confer cardiovascular protection,” they write, “the observed consistent blood pressure reductions make a strong case for the generalisability of the cardiovascular protective effect observed in the SSaSS both outside of China and beyond.”
“These findings are unlikely to be due to chance,” they write, “and support the use of salt replacements in clinical practise and public health policy as a strategy to reduce dietary sodium intake, increase dietary potassium intake, lower blood pressure, and avoid major cardiovascular events.”