AGENCIES | Most people can significantly lower their blood pressure, even if they are already on blood pressure medication, if they cut down on salt by about a teaspoon a day, according to new findings published Nov. 11 in JAMA and presented at the American Heart Association Scientific Sessions 2023 in Philadelphia.
The study, one of the largest to look at the effects of reducing sodium on blood pressure, found that nearly 3 in 4 people saw a decline in their blood pressure in as little as one week when they went from a high salt to low salt diet, says Norrina Allen, PhD, a coauthor of the study, a professor of preventive medicine, and the director of the Institute for Public Health and Medicine at Northwestern Medicine in Chicago.
“The average amount of blood pressure lowering was about 8 millimeters of mercury (mmHg) for systolic blood pressure, which is similar to the effect produced by medications for high blood pressure,” says Dr. Allen.
High blood pressure is a major risk factor for heart attack and stroke and a leading cause of premature death around the world. Many people have blood pressure that can be difficult to control, even those taking medications, says Allen.
Although a low-sodium, heart-healthy diet is recommended for people with high blood pressure, there hasn’t been much recent research to quantify the benefits, and those studies have often excluded people on blood-pressure-controlling medications, according to the authors.
The findings confirm what is known from prior studies: A low-sodium diet lowers blood pressure, says Luke Laffin, MD, a cardiologist and the codirector of the center for blood pressure disorders at Cleveland Clinic. “This study shows us that this amount of lowering doesn’t change much, (whether or not) a patient has a diagnosis of hypertension, or what medication (or medications) the patient is taking for their blood pressure,” says Dr. Laffin, who was not involved in the study.
Most extra sodium doesn’t come from the salt shaker. Instead, over 70 percent of dietary sodium comes from packaged and prepared foods like deli meat, pizza, tacos, and chips.
Expert tips on lowering sodium intake
A low-sodium diet is the number-one lifestyle change that Dr. Laffin focuses on when first meeting a person with high blood pressure. “This study illustrates why I do this. Patients see blood pressure lowering within a day or two. The same is not true of things like exercise or weight loss; they take time,” he says.
Adopting a low-sodium diet is easy to do in the short term, but sustaining it long-term as is true for many dietary pattern changes is more difficult, says Laffin.
As a goal, Laffin suggests aiming for less than 2,300 mg daily (equivalent to one level teaspoon) and to ideally consume less than 1,500 mg daily.
But beware: Hidden sodium is everywhere, he says. “Bread, salad dressings, and cheese are foods we don’t think of as having a lot of salt, but that actually do.”
Focusing on a plant-based diet rich in fresh fruits and vegetables (and avoiding highly processed foods) is another way to reduce the amount of sodium in your diet, says Allen.
