Are you up for taking a salt substitute?
A salt substitute reduced stroke and cardiovascular events in older subjects with hypertension and/or a history of stroke. Will this reduce the incidence of dementia?
Are we what we eat or are made to eat?
An interesting study in rural China showing that a salt substitute (75% sodium chloride and 25% potassium chloride by mass) reduced stroke and cardiovascular events in older subjects (average age 65 years old) with hypertension (88%) and/or a history of stroke (73%).
The logistics of doing this type of study are not insignificant. The main question for me is what is the mode of action of the salt substitution? Is it the reduction in sodium intake or the increase in potassium intake? This matters in terms of taking this intervention forward and exploring the underlying biology.
Salt intake does not affect everyone in the same way. In normal people, an increase in salt intake has a minimal effect on BP in comparison to people with hypertension (an increase of 4-5mmHg). However, some people with hypertension are particularly sensitive to the effect of salt with an increase in the blood pressure of 10 mmHg or more. So the results of this study may be even more impressive if targeted to the latter salt-sensitive group only. In terms of dementia prevention, this may be another strategy to reduce the vascular component to the pathogenesis of dementia. All these modifiable risk factors may be additive and have a large impact when added together. I often forget the salt hypothesis of hypertension when discussing and thinking about dementia prevention.
The question I have is this data generalizable to other populations and in those populations to all subjects or only subjects with hypertension?
Neal et al. Effect of Salt Substitution on Cardiovascular Events and Death. N Engl J Med. 2021 Sep 16;385(12):1067-1077.
Background: Salt substitutes with reduced sodium levels and increased potassium levels have been shown to lower blood pressure, but their effects on cardiovascular and safety outcomes are uncertain.
Methods: We conducted an open-label, cluster-randomized trial involving persons from 600 villages in rural China. The participants had a history of stroke or were 60 years of age or older and had high blood pressure. The villages were randomly assigned in a 1:1 ratio to the intervention group, in which the participants used a salt substitute (75% sodium chloride and 25% potassium chloride by mass), or to the control group, in which the participants continued to use regular salt (100% sodium chloride). The primary outcome was stroke, the secondary outcomes were major adverse cardiovascular events and death from any cause, and the safety outcome was clinical hyperkalemia.
Results: A total of 20,995 persons were enrolled in the trial. The mean age of the participants was 65.4 years, and 49.5% were female, 72.6% had a history of stroke, and 88.4% a history of hypertension. The mean duration of follow-up was 4.74 years. The rate of stroke was lower with the salt substitute than with regular salt (29.14 events vs. 33.65 events per 1000 person-years; rate ratio, 0.86; 95% confidence interval [CI], 0.77 to 0.96; P = 0.006), as were the rates of major cardiovascular events (49.09 events vs. 56.29 events per 1000 person-years; rate ratio, 0.87; 95% CI, 0.80 to 0.94; P<0.001) and death (39.28 events vs. 44.61 events per 1000 person-years; rate ratio, 0.88; 95% CI, 0.82 to 0.95; P<0.001). The rate of serious adverse events attributed to hyperkalemia was not significantly higher with the salt substitute than with regular salt (3.35 events vs. 3.30 events per 1000 person-years; rate ratio, 1.04; 95% CI, 0.80 to 1.37; P = 0.76).
Conclusions: Among persons who had a history of stroke or were 60 years of age or older and had high blood pressure, the rates of stroke, major cardiovascular events, and death from any cause were lower with the salt substitute than with regular salt. (Funded by the National Health and Medical Research Council of Australia; SSaSS ClinicalTrials.gov number, NCT02092090.).
MS Research MS-Selfie Newsletter
General Disclaimer: Please note that the opinions expressed here are those of Professor Giovannoni and do not necessarily reflect the positions of the Barts and The London School of Medicine and Dentistry nor Barts Health NHS Trust and are not meant to be interpreted as personal clinical advice.
Are you up for taking a salt substitute?
Fab newsletter, anything we can do to preserve brain, we should. This ties in nicely with the need to cut out UPF’s and PF’s and just eat simply and homemade. Preservatives in general seem to be a problem. I read somewhere in the past that high salt was implicated in increased relapse rates for pwMS too? lemon juice, vinegar, sumac all lift flavour without adding salt.