Reduced salt intake rapidly reduces blood pressure, experts reveal

15 Nov 2023 --- Akin to antihypertensive medication, US-based researchers suggest that restricting dietary sodium lowers blood pressure among middle-aged and elderly patients significantly. In a clinical trial, participants reduced their systolic blood pressure by an average of 8 mm/Hg after just one week.

“Our results indicated that with dietary sodium reduction, lowering of blood pressure can occur safely and rapidly. The amount of reduction we found was comparable to that of a first line antihypertensive medication,” Deepak K. Gupta, co-author of the study, assistant professor of medicine at Vanderbilt University Medical Center, tells Nutrition Insight.

The trial study included 213 participants aged between 50 and 75 which were allocated to a high-sodium diet group and a low-sodium diet group. In the second group, nearly 75% of participants lowered their systolic blood pressure.

Further discussing the clinical significance of the average 8 mm/Hg reduction in systolic blood pressure and its relevance to overall cardiovascular health, Gupta says that prior studies have indicated that a 5 mm Hg reduction in systolic blood pressure is associated with 15 to 25% reduction in death, so an 8 mm Hg reduction would be expected to be meaningful. The average 8 mm/Hg reduction in systolic blood pressure is said to be significantly meaningful clinically. 

Health implications
The trial outcome, published in Jama, may carry significant implications for public health and personalized treatment for hypertension. 

“I think we can tell patients for whom blood pressure is a concern that reduction in dietary sodium will likely lower their blood pressure and for some it may achieve a similar result to a single blood pressure medication. This may motivate patients who are particularly interested in cutting down on their number of medications, but they have to reduce dietary sodium intake to get there,” says Gupta. 

Addressing the time span of the trial, the medical professor explains: “We did not examine dietary sodium reduction beyond the one-week of low-sodium diet, but the results we obtained on blood pressure lowering were of similar magnitude to studies that have looked at dietary sodium reduction for one to six months. “

“We conducted our study with the larger Coronary Artery Risk Development in Young Adults study cohort, which has been ongoing for nearly 40 years now. As a result, the cohort was aged 50 to 75 years. We are fairly diverse in that two out of three participants were female and two out of three were black. Our study was conducted at two sites, Chicago, Illinois and Birmingham, Alabama, US.”Low-sodium diet lowered systolic blood pressure in nearly 75% of participants in the trial. 

 Individual variability 
Gupta explains that variability in the blood pressure response to dietary sodium reduction can make it challenging to know who will benefit and who will not. However, he emphasizes that “for the vast majority of individuals, dietary sodium reduction does lower blood pressure. Moreover, this can be done safely and quickly.”   

“For any individual, the recommendation is to make a good effort at lowering dietary sodium intake for a week and see what happens with your blood pressure. If you really adhere to a low-sodium diet and your blood pressure comes down, then it works for you. Since this can be done safely, it is worth trying.” 

Meanwhile, the research highlights several confounding variables that may affect the trial’s findings as these influence blood pressure. These variables include lifestyle factors, medication adherence and other dietary components. 

“We cannot exclude the contributions of other dietary components, but our results for blood pressure are similar to those of a fully controlled dietary Sodium Intake and Blood Pressure Trial,” he concludes.  

By Milana Nikolova