Cutting Daily Sodium Intake Significantly Lowers Blood Pressure in 1 Week, According to New Research

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Decreasing daily sodium consumption by about 4000 mg significantly lowered systolic blood pressure (SBP) in approximately 73% of adults aged 50-75 years in 1 week when compared to a higher sodium diet, according to results from a new study. The authors reported the BP decline based on dietary sodium content was independent of hypertension (HTN) status and use of HTN medications.¹

Findings from the study were presented at the American Heart Association’s (AHA) Scientific Sessions 2023, held November 11-13, in Philadelphia, PA, and simultaneously published in the Journal of the American Medical Association.¹

“High blood pressure is the most common chronic disease condition in the world, and for the majority of adults, dietary sodium intake influences blood pressure,” said lead author Deepak K. Gupta, MD, associate professor of medicine and director of the Vanderbilt Translational and Clinical Cardiovascular Research Center in the division of cardiovascular medicine at Vanderbilt University Medical Center, in Nashville, Tennessee, in an AHA press release. “However, dietary sodium recommendations are debated in part due to the variability in blood pressure response to sodium consumption from food.”²

Moreover, the blood pressure effect of dietary sodium among persons already receiving antihypertensive medication is understudied, according to Gupta and coauthors. To fill this gap in research, they conducted a randomized crossover trial in Coronary Artery Risk Development in Young Adults (CARDIA) study and non-CARDIA participants between 2021 and 2023 from 2 US cities (Birmingham, AL and Chicago, IL).¹

“We examined (1) the distribution of within-individual BP response to dietary sodium, (2) the difference in BP between individuals allocated to high- or low-sodium diet first, and (3) whether these varied by baseline BP and antihypertensive medication use,” wrote investigators.¹

A total of 213 persons aged 50-75 years, including those with normotension (25%), controlled HTN (20%), uncontrolled HTN (31%), and untreated HTN (25%), attended a baseline visit while consuming their usual diet, then completed high- and low-sodium diets over the course of 1 week. In the high-sodium diet, approximately 2200 mg sodium was added daily to participants’ usual diet and in the low-sodium diet, participants consumed approximately 500 mg daily total. Participants then switched to the opposite diet for 1 week.¹

Researchers measured participants’ average 24-hour ambulatory SBP and diastolic blood pressure, mean arterial pressure, and pulse pressure.¹

FINDINGS

Among the 213 participants who completed both high- and low-sodium diet visits, the median age was 61 years, 65% were women, and 64% were Black. Researchers noted that while consuming usual, high-sodium, and low-sodium diets, participants’ median SBP measures were 125 mm Hg, 126 mm Hg, and 119 mm Hg, respectively.¹

Gupta and colleagues found that the mean systolic BP difference between those randomized to a high-sodium diet compared to low-sodium at the end of the first dietary intervention week was 8 mm Hg (95% CI, 4-11 mm Hg; P<.001), which was similar across subgroups of age, sex, race, HTN, baseline blood pressure, diabetes, and body mass index.¹

In addition, compared with the high-sodium diet, the low-sodium diet induced a decline in mean arterial pressure in 73.4% of participants. Adverse events were mild and reported by 9.9% of individuals in the high-sodium group and 8.0% of those in the low-sodium group.¹

“This reinforces the importance of reductions in dietary sodium intake to help control blood pressure, even among individuals already taking medications for hypertension,” stated Gupta in the AHA release. “Just as any physical activity is better than none for most people, any sodium reduction from the current usual diet is likely better than none.”²

References:

1. Gupta DK, Lewis CE, Varady KA, et al. Effect of dietary sodium on blood pressure: A crossover trial. JAMA. Published online November 11, 2023. doi:10.1001/jama.2023.23651

2. Reducing sodium intake significantly lowered blood pressure in as little as one week. News release. American Heart Association. Published November 11, 2023. Accessed November 15, 2023. https://newsroom.heart.org/news/reducing-sodium-intake-significantly-lowered-blood-pressure-in-as-little-as-one-week