Managing High Blood Pressure with the DASH Diet

What you eat can help lower your blood pressure and reduce your risk for stroke and heart disease.

One such diet, the Dietary Approaches to Stop Hypertension (DASH) diet, has been shown to reduce blood pressure. This diet is low in saturated fat, cholesterol, and total fat. The diet emphasizes fruits, vegetables, and low-fat dairy products.

Your blood pressure can be unhealthy even if it stays only slightly above 120/80 mm Hg. The higher above that level, the greater your health risk. Over time, high blood pressure makes your heart work too hard. This can cause stroke, heart disease, heart failure, kidney disease, and even blindness.

Blood pressure measurements are given as 2 numbers. Systolic blood pressure is the upper number. This is the pressure when the heart contracts. Diastolic blood pressure is the lower number. This is the pressure when the heart relaxes between beats. Blood pressure is categorized as normal, elevated, or stage 1 or stage 2 high blood pressure:

• Normal blood pressure is systolic of less than 120 and diastolic of less than 80 (120/80)

• Elevated blood pressure is systolic of 120 to 129 and diastolic less than 80

• Stage 1 high blood pressure is systolic of 130 to 139 or diastolic between 80 to 89

• Stage 2 high blood pressure is when systolic is 140 or higher or the diastolic is 90 or higher

High blood pressure is diagnosed when multiple, separate readings show blood pressure above 130/80 mmHg. Talk with your healthcare provider if you have questions or concerns about your blood pressure readings.

Why this diet works

Why is the DASH diet so effective at reducing blood pressure? It combines many nutrients that have been shown to help reduce blood pressure. Those nutrients include calcium, potassium, magnesium, protein, and fiber, as well as lower total fat and saturated fat.

The DASH diet is naturally low in salt. The DASH diet recommends menus containing 2,300 mg of sodium. The lower sodium DASH diet contains up to 1,500 mg of sodium a day. (One teaspoon of salt contains 2,300 mg of sodium.) 

Further, following the DASH diet may delay your need to take blood pressure lowering medicine, and may even keep you from needing to take it at all. And if you're already on medicine, it may help you reduce the amount you take.

Doing the DASH

The DASH diet is a 2,000-calorie diet that includes:

• Six to 8 daily servings of grains and grain products, such as whole-wheat bread, cereal, oatmeal, crackers, unsalted pretzels, and popcorn. A serving size is 1 slice of bread, 1 cup of ready-to-eat cereal, or 1/2-cup of rice, pasta, or cereal.

• Four to 5 daily servings of vegetables, the darker in color, the better. A serving size is 1 cup of raw leafy vegetables, a 1/2-cup of cooked vegetables, or 6 ounces of vegetable juice.

• Four to 5 daily servings of fruit. A serving is 1 medium fruit, 1/4-cup of dried fruit, 1/2-cup of fresh, frozen, or canned fruit, or 6 ounces of fruit juice.

• Two or 3 daily servings of low-fat or fat-free dairy products. A serving is 8 ounces of milk, 1 cup of yogurt, or 1½ ounces of cheese.

• Six or fewer daily servings of lean meat, poultry, or fish. A serving is 1 ounce of cooked meats, skinless poultry, or fish.

• Four to 5 servings per week of nuts, seeds, and dry beans. A serving is 1/3-cup or 1½ ounces of nuts, 1 tablespoon or 1/2-ounce of seeds, or 1/2-cup cooked dried beans.

• Two to 3 small daily servings of fats and oils like olive oil and low-fat salad dressing. A serving is 1 teaspoon soft margarine, 1 tablespoon low-fat mayonnaise, 2 tablespoons light salad dressing, or 1 teaspoon vegetable oil. Don't have fats that are saturated (animal fats) or trans fats.

• Five or fewer servings per week of sweets like maple syrup, sorbet, or gelatin. A serving is 1 tablespoon sugar, 1 tablespoon jelly or jam, 1/2-ounce jellybeans, or 8 ounces of lemonade.

The DASH diet isn't designed for weight loss, it can promote it if you reduce the number of servings you eat. Most of the food the diet features is big on volume and low in calories.

Still, there are parts of the DASH diet that may not be easy to follow. For one, it's packed with dark-colored fruits and vegetables. So be prepared to be choosier at the supermarket. Also, if it's very different from what you normally eat, it may be hard to adjust.

If you're serious about following the diet, it's a good idea to work with a registered dietitian (RD) for support and guidance. (For the names of RDs in your area who know about the DASH diet, visit the Academy of Nutrition and Dietetics at www.eatright.org .)

Moving forward

If you decide to go it alone, adopt the DASH diet slowly. By doing so, you'll be more likely to stick to it long-term. For instance, add 1 more serving of vegetables at lunch and dinner if you eat only 1 or 2 servings a day now. You might also add fruit to meals and snacks if you now only have juice for breakfast. In addition, slowly increase your dairy products to 3 servings per day. Try drinking skim milk with lunch or dinner, instead of soda, alcohol, or tea.

To get the most out of the DASH, lose weight if you need to and exercise regularly. Thirty to 40 minutes of moderate to vigorous intensity aerobic exercise 4 to 5 days a week is recommended. 

More dish on the DASH

The "DASH Eating Plan" is an online guide published by the NHLBI. It offers a reader-friendly explanation of high blood pressure, detailed daily servings charts to help you plan your menus, a week of suggested DASH menus, plus tips to reduce sodium.

For more information about diet and other lifestyle factors to reduce hypertension, visit the DASH Eating Plan at www.nhlbi.nih.gov/health-topics/dash-eating-plan.