Known by experts as the “silent killer,” high blood pressure has a way of sneaking up on people. Condiments, cereals and breads are just a few examples of unassuming sodium sources. But identifying and cutting out these salty culprits can quickly improve someone’s health.
Lowering sodium intake by around 4,000 mg per day “significantly” reduced blood pressure for most participants in a recent study published in JAMA, the flagship journal of the American Medical Association. That’s equivalent to a little less than 2 teaspoons of fine table salt.
The findings also suggest that a wide range of people can benefit from reducing their sodium intake, not just those who already have high blood pressure — also known as hypertension.
The research team, funded by the National Institutes of Health, studied more than 200 Americans between 50 and 75 years of age, including people with and without hypertension. They monitored these participants’ sodium intake and blood pressure while on their usual diets, and during a two-week trial.
Participants were randomly assigned low- or high-sodium diets for the first week. Individuals following the high-sodium diet incorporated an additional 2,200 mg of sodium per day into their usual diets. Meanwhile, those on the low-sodium diet received a week’s supply of low-sodium meals, snacks and beverages, amounting to 500 mg of sodium per day.
Researchers measured their blood pressure at the end of the first week. Afterward, the participants swapped diets — meaning those who ate a high-sodium diet the first week ate a low-sodium diet the second week, and vice versa — and their blood pressure was measured again.
About 75% of the participants experienced a decrease in systolic blood pressure on the low-sodium diet compared with the high-sodium diet, with an average reduction in the reading of 7 mm Hg. (Systolic blood pressure is the top number in a reading, representing the pressure during heartbeats, measured in millimeters of mercury.)
In comparison with their typical diets, 72% of the participants experienced a decline in systolic blood pressure on the low-sodium diet, with the average drop being 6 mm Hg.
While experts recommend that adults consume less than 2,300 mg of sodium daily, participants’ sodium intake from their usual diets was about 4,500 mg per day.
“This reinforces the importance of reductions in dietary sodium intake to help control blood pressure, even among individuals already taking medications for hypertension,” says lead researcher Dr. Deepak K. Gupta, associate professor of medicine and director of the Vanderbilt Translational and Clinical Cardiovascular Research Center. “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.”