By Cynthia Sass, M.P.H., R.D.
For decades we’ve been told that limiting sodium would improve blood pressure and reduce risk for cardiovascular disease. But a new analysis, published in the American Journal of Medicine, revealed that Americans who said they followed dietary recommendations to limit sodium to 2,300 milligrams had a 37 percent higher cardiovascular mortality rate than those who said they consumed higher levels. Don’t pick up the salt shaker just yet.
Hillel Cohen, Dr.PH., the study’s lead author and associate professor of epidemiology and population health at Albert Einstein College of Medicine in New York City, acknowledges limitations of the study. First, the subjects’ sodium intakes were self-reported. (Do you have any idea how much sodium you consume each day?) The study’s design also didn’t ensure that people in the two comparison groups (restrictors versus nonrestrictors) had similar intakes of potassium and alcohol. Potassium blunts sodium’s effects on blood pressure; alcohol can boost blood pressure significantly. Finally, the findings don’t prove that sodium restriction caused mortality; low sodium intake simply could be a marker for a poor diet overall.
But the findings are important, says Cohen. “There is evidence that substantial sodium restriction might help some people lower blood pressure modestly,” he says. “But there is little evidence of a general, long-term benefit of sodium restriction for longer life.”
Most experts agree that there is no one-size-fits-all plan to achieve healthy blood pressure, but “we shouldn’t ignore the extensive body of research that links sodium to high blood pressure,” says Jeannie Moloo, Ph.D., R.D., a spokesperson for the American Dietetic Association. “We have to be careful about making blanket recommendations based on one study.” With your doctor, discuss the sodium approach that’s right for you.
The following behaviors also may help control blood pressure:
• Eating 8 to 10 daily servings of fruits and vegetables: they’re low in sodium, rich in potassium.
• Consuming low-fat dairy; calcium is linked with blood pressure regulation.
• Replacing some carbohydrates in your diet with healthy fats (think: a slice of toast with peanut butter vs. a big plain bagel)—a recent study suggests that this shift benefits blood pressure.