Skip the Extra Salt: Study Shows Heart Healthy Diet and Sodium Reduction Lower Risk of Heart Disease

Reducing Sodium and Following Heart Healthy Diet Lower 10-Year Risk of Heart Disease

BOSTON — Most Americans consume far more sodium than recommended, with the average intake topping 3,400 milligrams (mg) per day—well above the recommended federal guideline of 2,300 mg and the American Heart Association’s goal of 1,500 mg. The bulk of American’s daily sodium doesn’t come from the saltshaker, but from processed and restaurant foods like breads, deli meats, and canned soups. Health experts warn this excess is fueling a national epidemic of high blood pressure, a major risk factor for heart disease and stroke.

A new analysis led by investigators at Beth Israel Deaconess Medical Center (BIDMC) has found that reducing dietary sodium, or following an evidenced-based heart healthy diet called the DASH diet (Dietary Approaches to Stop Hypertension), each independently lowered the 10-year estimated risk of developing atherosclerotic cardiovascular disease (ASCVD)—hardening of the arteries that can lead to chest pain, heart attack or stroke—among adults with elevated blood pressure but no prior cardiovascular disease. Moreover, the combination of the DASH diet and reducing sodium intake had additive effects, resulting in the greatest reduction in ASCVD risk. The findings appear in the American Journal of Preventive Cardiology, “Our findings support the need for ongoing public health policy prioritizing population-wide efforts at salt reduction, even at modest results,” said lead author Hanna M. Knauss, MD. “The data suggest even moderate sodium reduction can be beneficial and may be a more feasible goal to maintain.”

Developed through research sponsored by the National Institutes of Health (NIH), DASH is an evidence-based eating plan designed to prevent and lower high blood pressure. Emphasizing foods rich in potassium, calcium, magnesium, and fiber—nutrients known to help control blood pressure—while reducing sodium, saturated fat, and added sugar intake, the DASH diet includes four to five servings of fruits and vegetables each day, and encourages lean proteins like poultry, fish and beans while limiting red meat to two or fewer servings per week. It also discourages sweets and limits sodium.

To evaluate the impact of sodium reduction on blood pressure—alone and in combination with the DASH diet—Knauss and colleagues randomized 390 adults with elevated blood pressure to the DASH diet and a typical American diet. Within each arm, participants consumed each of three levels of sodium; high, representative of the typical American diet; intermediary, reflecting federal guideline recommendations; and low, intended to test the effects of sodium intake below recommendations.

After the 12-week period, analysis revealed that both the DASH diet and lower sodium intake independently reduced participants’ ASCVD risk scores. Lowering sodium intake led to meaningful risk reductions even when not meeting the most aggressive targets; both low and medium sodium intake levels were beneficial. But the greatest benefit occurred when the two interventions were combined.

“Compared to the typical American, high-sodium diet, reducing sodium to the recommended levels or even lower markedly decreased cardiovascular disease risk scores, with the greatest effects among women, Black adults and participants with baseline stage II hypertension,” said senior author Stephen P. Juraschek, MD. “These data underscore the need for stronger dietary guidelines and public health interventions that can be realistically implemented and sustained over time—especially among groups at highest risk.”

Co-authors included Kenneth J. Mukamal of BIDMC; Lara C. Kovell, of University of Massachusetts, Chan Medical School; Edgar R. Miller III and Lawrence J. Appel of Johns Hopkins University; and Timothy B. Plante of Larner College of Medicine at the University of Vermont.

This research was supported by the National Institutes of Health/National Heart, Lung, and Blood Institute (NHLBI) (grants R21HL144876, K23HL135273); the original DASH trial (grants HL50981, HL50968, HL50972, HL50977, HL50982, HL02642, RR02635, and RR00722). Additional support was provided by the Office of Research on Minority Health and the National Center for Research Resources of the NIH.

None of the study authors report any relevant financial conflicts of interest.