A publication of the Kentucky Center for Public Service Journalism

Study shows combination of low-salt, heart-healthy diet as good as drug therapy for high blood pressure

A new study finds that cutting back on salt and following the heart-healthy DASH diet can lower blood pressure, a disease that affects almost two out of every five Kentuckians.

“Our results add to the evidence that dietary interventions are as effective as—or more effective than—anti-hypertensive drugs in those at highest risk for high blood pressure, and should be a routine first-line treatment option for such individuals,” Dr. Stephen Juraschek, a study co-author, said in a news release. Juraschek is an instructor of medicine at Harvard Medical School and an adjunct assistant professor at Johns Hopkins University School of Medicine.

Previous guidelines defined high blood pressure as 140/90 milligrams of mercury (mm/Hg) or higher, but guidelines released this year have re-defined it as 130/80 mm/Hg or higher. High blood pressure increases the risk of stroke, kidney disease, heart attacks and heart failure.

The four-week study, published in the Journal of the American College of Cardiology, included 412 adults between the ages of 23 and 76 who had high blood pressure or were at risk of having it. They were asked to either stay on a “regular” diet or to switch to the Dietary Approaches to Stop Hypertension, or DASH, diet. DASH limits foods high in saturated fat and sugar and is high in fruits, vegetables, whole grains, low or fat-free dairy, fish, poultry, beans, seeds, and nuts.

They were also divided into three groups that received varying amounts of salt. One was allowed about a half a teaspoon per day, another was allowed about a teaspoon per day and the third group was allowed about 1.5 teaspoons a day. To reduce the risk of heart disease and stroke, the U.S. Food and Drug Administration recommends a maximum of about 2,300 mg of sodium per day, which is nearly one teaspoon of salt.

None of the study participants took blood-pressure medicines. Their baseline systolic blood pressures (the top number) ranged from 120 to 159 and their diastolic blood pressure (the bottom number) was between 80 and 95.

The participants were sorted into four groups: 120–129 mm Hg, 130–139 mm Hg, 140–149 mm Hg, and 150 mm Hg or greater.

The results varied based on which regimen the participants followed.

Those who followed the DASH diet with high sodium and had a systolic pressure of 150 or greater, had an 11-point average drop in systolic pressure. The effect was much less, a 4-point drop, among those whose beginning systolic pressure was less than 130.

The effect was even greater for those who were on the low-sodium DASH diet. Those who started with a systolic pressure of less than 130 had a 5-point drop in pressure; those who started between 130 and 139 had a 7-point drop; and those who began between 140 and 149 had a 10-point reduction.

The biggest impact was among those who followed the low-sodium DASH diet and started out with a systolic blood pressure of 150 or greater. They had an average drop of 21 points.

Juraschek called the findings “huge” and said they suggest that those at highest risk for serious hypertension achieve the greatest benefit from the combination diet.

The researchers said further research is needed to determine how the combination diet affects people with a systolic blood pressure of 160 or greater or in persons with prior heart disease or diabetes.

Related Posts

Leave a Comment