November 14, 2023: Lowering sodium intake can reduce blood pressure regardless of whether one is on medication, a study reveals.
Researchers at Northwestern Medicine, Vanderbilt University Medical Center and the University of Alabama at Birmingham found reducing salt by a teaspoon a day resulted in a decline in systolic blood pressure by about six millimeters of mercury (mm Hg).
This was “comparable to the effect produced by a commonly utilised first-line medication for high blood pressure,” said Deepak Gupta, MD, associate professor of medicine at Vanderbilt University Medical Center and co-principal investigator.
Middle-aged to elderly individuals in their fifties to seventies from Birmingham, Alabama, and Chicago were randomized to either a high-sodium diet (2,200 mg per day on top of their usual diet) or a low-sodium diet (500 mg in total per day) for one week.
Blood pressure monitors
After that, they crossed over to the opposite diet for a week. On the day before each study visit, participants wore blood pressure monitors and collected their urine for 24 hours.
Among 213 participants, systolic blood pressure was significantly lowered by seven to eight mm Hg when they ate the low-sodium diet compared with the high-sodium diet, and by 6 mm Hg compared with their usual diet.
“The effect of reduction in dietary sodium on blood pressure lowering was consistent across nearly all individuals, including those with normal blood pressure, high blood pressure, treated blood pressure and untreated blood pressure,” Deepak Gupta said.
Co-principal investigator Norrina Allen, PhD, the Quentin D. Young Professor of Health Policy in the Department of Preventive Medicine said: “We found that 70-75% of all people, regardless of whether they are already on blood pressure medications or not, are likely to see a reduction in their blood pressure if they lower the sodium in their diet.”
The total daily sodium intake recommended by the American Heart Association is below 1,500 milligrams, and this study was designed to decrease it even lower than that, Ms Allen said.
“It can be challenging but reducing your sodium in any amount will be beneficial,” she said.
High blood pressure is the leading cause of morbidity and mortality in the world.
“High blood pressure can lead to heart failure, heart attacks and strokes because it puts extra pressure on your arteries,” she said. “It affects the heart’s ability to work effectively and pump blood.”
The study was presented this week at the American Heart Association Scientific Sessions 2023 in Philadelphia.