The beneficial effects may apply to people around the world, the researchers say.
Dietary salt substitutes reduce the risk of heart attack, stroke and death from all causes, as well as cardiovascular disease, according to a pooled data analysis of available evidence.The findings were published Aug. 9 in the journal BMJ Heart.
The researchers believe that the beneficial effects of these alternatives may apply to people around the world.
Hypertension is an important risk factor for premature death, and cardiovascular disease is the leading cause of death worldwide. A diet high in sodium and low in potassium is known to increase blood pressure.
About 1.28 billion people worldwide have high blood pressure, although more than half of them go undiagnosed, the researchers said.
Salt substitutes that replace a portion of sodium chloride (NaCl) with potassium chloride (KCl) can help lower blood pressure.
A large recently published study in China (Salt Substitution and Stroke Study; SSaSS) found that salt substitution reduces the risk of heart attack, stroke and premature death. However, it is unclear whether these benefits apply to the rest of the world.
To shed light on this, the scientists searched research databases for randomized clinical trials published through August 2021 that reported the effects of salt substitution on blood pressure, cardiovascular health, and premature death.
Blood pressure is measured in mm Hg and consists of two numbers: systolic blood pressure – the higher number represents the force with which the heart pumps blood around the body; and diastolic blood pressure – the lower value of arterial pressure when the heart is full of blood.
They pooled the results of 21 relevant international clinical trials involving nearly 30,000 people. These were conducted in Europe, the Western Pacific, the Americas and Southeast Asia.
Study periods ranged from 1 month to 5 years. The proportion of sodium chloride in the salt substitutes varies from 33% to 75%; the proportion of potassium varies from 25% to 65%.
Salt substitution lowered blood pressure in all participants, according to a pooled data analysis. There was an overall reduction of 4.61 mmHg in systolic blood pressure and 1.61 mmHg in diastolic blood pressure.
The reduction in blood pressure appeared to be consistent regardless of geographic location, age, gender, history of hypertension, body weight (BMI), baseline blood pressure, and baseline levels of urinary sodium and potassium.
Each 10% reduction in the proportion of sodium chloride in the salt substitute was associated with an additional 1.53 mm Hg drop in systolic blood pressure and an additional 0.95 mm Hg drop in diastolic blood pressure. There is no indication that consuming more potassium is bad for your health.
An analysis of pooled data from the results of five of the trials involving more than 24,000 participants showed that salt replacement was associated with an 11% reduction in the risk of all-cause premature death, a 13% reduction in the risk of cardiovascular disease, and a reduction in the risk of heart attack or stroke by 13%. 11% lower risk.
The scientists acknowledged certain limitations of their findings, including that the studies in the pooled data analysis were different in design and that there were relatively few data on people without high blood pressure.
But they still stress that their findings echo those of SSaSS, the largest trial of potassium-rich salt substitutes to date.
“Since lowering blood pressure is the mechanism by which salt substitution confers cardiovascular protection, the observed sustained reduction in blood pressure provides a strong rationale for the generality of the cardiovascular protection observed in SSaSS outside of China and elsewhere,” ‘ the authors wrote.
“These findings are unlikely to reflect chance and support the adoption of salt substitutes in clinical practice and public health policy as a strategy to reduce dietary sodium intake, increase dietary potassium intake, lower blood pressure and prevent major cardiovascular events,” The researchers concluded.
Reference: “The impact of salt substitution on clinical outcomes: a systematic review and meta-analysis” by Yin Xuejun, Anthony Rodgers, Adam Perkovic, Liping Huang, Ka-Chun Li, Jie Yu, Yangfeng Wu, JHY Wu, Matti Marklund, Mark D Huffman, J Jaime Miranda, Gian Luca Di Tanna, Darwin Labarthe, Paul Elliott, Maoyi Tian and Bruce Neal, August 9, 2022, Heart.