Study Shows One Teaspoon Less Salt a Day Can Significantly Lower Blood Pressure

In a new study, researchers at Northwestern University Feinberg School of Medicine have reported that reducing sodium intake by as little as one teaspoon of salt a day can lower blood pressure nearly as effectively as standard medication. This research is particularly noteworthy because it includes participants who were already on blood pressure medication, a group often excluded from dietary studies.

Professor Norrina Allen, a specialist in preventive medicine, emphasized the broad impact of dietary sodium on blood pressure, highlighting that a substantial proportion of the population, irrespective of whether they are on blood pressure medication, stand to benefit from reducing sodium in their diets.

The study observed a mix of 213 men and women ranging in age from their 50s to 70s. These participants were randomly assigned to either a high-sodium diet, adding an additional 2,200 milligrams to their regular intake, or a low-sodium diet capped at 500 milligrams per day. After a week on one diet, they switched to the other. Throughout the study, participants monitored their blood pressure and provided urine samples for a comprehensive analysis.

The results were telling: a reduction in systolic blood pressure by approximately 6 millimeters of mercury was noted when participants cut back on salt, an effect that rivals the performance of some first-line blood pressure medications. Systolic blood pressure, which measures the force of blood against artery walls while the heart is beating, is the first number reported in blood pressure readings. High systolic pressure is a risk factor for heart failure, heart attacks, and strokes due to the additional strain it places on the cardiovascular system.

A Significant Reduction in Blood Pressure

A remarkable 72% of participants experienced lower systolic blood pressure on the low-sodium diet compared to their usual diet. Furthermore, when compared to the high-sodium diet, the drop in systolic pressure ranged from 7 to 8 millimeters of mercury. This significant reduction was consistent across nearly all individuals, regardless of whether they had normal or high blood pressure, and irrespective of treatment status.

The findings, researchers assert, underscore the profound importance of dietary sodium restriction. The observed reduction in blood pressure was not only substantial but also achieved swiftly within a week, and was well tolerated by participants. These insights reinforce the potential benefits of sodium reduction for public health, particularly given the global prevalence of high blood pressure and its associated risks.


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