Individuals with hypertension will do well to emphasize dietary measures involving fat, vegetables and fruit, a study suggests.

The Dietary Approaches to Stop Hypertension (DASH) study, supported by the National Institutes of Health (NIH), revealed that a diet low in fat and high in vegetables, fruits and low-fat dairy foods significantly and quickly lowers blood pressure. The diet worked particularly well for those with high blood pressure, producing reductions similar to those from single-drug therapy; however, it also proved effective for those with high normal blood pressure, who are at substantial risk of developing hypertension, NIH noted.

The DASH trial compared the effects of three diets: a control diet similar in nutrients to what many Americans consume; a diet high in fruits and vegetables; and a "combination" diet low in saturated and total fat, and high in fruits, vegetables and low-fat dairy foods. The latter two diets each had eight to 10 daily servings of fruits and vegetables, about twice the average U.S. consumption. The combination diet also had two to three daily servings of predominantly low-fat dairy foods, about twice the current consumption, NIH said.

All three diets had about three grams of sodium daily — slightly below the average U.S. consumption — and all included fresh, frozen, canned and dried foods.

At the end of eight weeks, the combination diet produced the largest reductions in blood pressure, found the study, the final results of which appeared in "The New England Journal of Medicine." Overall, the combination diet reduced blood pressure by an average of 5.5 mm Hg for systolic and an average of 3.0 mm Hg for diastolic. For those with hypertension, the results were more dramatic: blood pressure reductions of an average of 11.4 mm Hg for systolic and an average of 5.5 mm Hg for diastolic.

In comparison, over the same time period, the fruits and vegetables diet reduced blood pressure for all participants by 2.8 mm Hg for systolic and 1.1 mm Hg for diastolic, and for those with hypertension by 7.2 mm Hg for systolic and 2.8 mm Hg for diastolic.

These blood pressure reductions occurred without changes in weight, or alcohol or sodium consumption, NIH noted.

Moreover, the blood pressure reductions happened quickly — within two weeks after starting the diet — and were maintained for the rest of the eight weeks on the diet, the study found. Researchers estimated that if Americans followed the DASH diet and had the degree of blood pressure reductions seen in the trial, there would be about 15 percent less coronary heart disease and 27 percent fewer strokes in the United States.

"If added to other lifestyle recommendations, the DASH diet should help prevent hypertension and may reduce some persons' need for medication to control the condition," said Dr. Claude Lenfant, director of the National Heart, Lung, and Blood Institute, which was a major funder of the project.

The other lifestyle recommendations are: to maintain a healthy weight, choose foods lower in salt and sodium, drink alcohol in moderation (for those who drink), and be physically active.

Researchers offered the following tips for "eating the DASH way":

Start small. Make gradual changes in your eating habits.

Center your meal around carbohydrates, such as pasta, rice, beans or vegetables.

Treat meat as one part of the whole meal, instead of the focus.

Use fruits or low-fat, low-calorie foods such as sugar-free gelatin for desserts and snacks.

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