Low-Sodium Salt Substitutes and Stroke Recurrence
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Reviewed by Dat Tien Nguyen, B.A, ScM.
Translated by Nhi Phuong Quynh Le, B.A |
Posted on July 9th, 2025
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With the increase in the frequency of cardiovascular disorders in developing and recently developed nations, the rate of stroke has also risen. High sodium diet is a risk factor for these conditions, due to its contribution to fluid accumulation that increases blood pressure. A study was conducted with funding from the Chinese government to explore the potential of using a salt substitution in preventing stroke recurrence.
The randomized control trial was conducted in China, and it included around 15 thousand participants with an average age of 64 years old who self-reported to have experienced a stroke episode in the past. Additionally, more than 80% of the cohort had a history of hypertension, with around 15% having previously experienced transient ischemic attack or ischemic heart disease. Medications such as calcium antagonist, ACE inhibitor, beta-blockers, and diuretic are used by the participants to manage their cardiovascular disorders.
The participants were randomly assigned into two groups; one group was provided with normal salt with 100% sodium chloride, and the other group was given a salt substitute mixture with 75% sodium chloride and 25% potassium chloride. After 5 years of follow-up, the researchers found that those in the salt substitution group report a 14% lower risk of recurrent stroke and 12% lower risk of all-cause mortality. Subgroup analysis found that the lower sodium salt was associated with more benefit in preventing hemorrhagic stroke, with little but no statistical significant effect in ischemic stroke. Furthermore, greatest clinical benefit can be observed in participants above 65 years of age with a baseline systolic blood pressure above 146 mmHg. The researchers noted that they did not observe an increase in hyperkalemia risk.
Being a large-scale study with a long follow-up period, the yielded result is no doubt promising; however, there are several limitations to the study. First, the history of stroke was self-reported; thus, there is an inherent risk of bias and mistake. Future study which aims to replicate these findings can amend this shortcoming by using electronic health records to confirm a diagnosis, and include other factors such as duration length, and other quantitative index to evaluate severity and risk. Additionally, it would be useful for future studies to also look at other cardiovascular diseases such as hypertension and heart failure. Last, a more robust method of adherence assessment might be warranted; the study analyzed urinary sodium and potassium content to gauge adherence. However, shifts in diet composition and the change between home cooked food and outside foods might muddle the true effectiveness of salt substitutes.
The randomized control trial was conducted in China, and it included around 15 thousand participants with an average age of 64 years old who self-reported to have experienced a stroke episode in the past. Additionally, more than 80% of the cohort had a history of hypertension, with around 15% having previously experienced transient ischemic attack or ischemic heart disease. Medications such as calcium antagonist, ACE inhibitor, beta-blockers, and diuretic are used by the participants to manage their cardiovascular disorders.
The participants were randomly assigned into two groups; one group was provided with normal salt with 100% sodium chloride, and the other group was given a salt substitute mixture with 75% sodium chloride and 25% potassium chloride. After 5 years of follow-up, the researchers found that those in the salt substitution group report a 14% lower risk of recurrent stroke and 12% lower risk of all-cause mortality. Subgroup analysis found that the lower sodium salt was associated with more benefit in preventing hemorrhagic stroke, with little but no statistical significant effect in ischemic stroke. Furthermore, greatest clinical benefit can be observed in participants above 65 years of age with a baseline systolic blood pressure above 146 mmHg. The researchers noted that they did not observe an increase in hyperkalemia risk.
Being a large-scale study with a long follow-up period, the yielded result is no doubt promising; however, there are several limitations to the study. First, the history of stroke was self-reported; thus, there is an inherent risk of bias and mistake. Future study which aims to replicate these findings can amend this shortcoming by using electronic health records to confirm a diagnosis, and include other factors such as duration length, and other quantitative index to evaluate severity and risk. Additionally, it would be useful for future studies to also look at other cardiovascular diseases such as hypertension and heart failure. Last, a more robust method of adherence assessment might be warranted; the study analyzed urinary sodium and potassium content to gauge adherence. However, shifts in diet composition and the change between home cooked food and outside foods might muddle the true effectiveness of salt substitutes.