Hypertension and the DASH Diet

What is high blood pressure?

Blood pressure is the force of blood against artery walls. It is measured in millimeters of mercury (mm Hg) and recorded as two numbers-systolic pressure (as the heart beats) over diastolic pressure (as the heart relaxes between beats). Both numbers are important (see table on right)

Blood Pressure Categories for Adults*

(*Categories are for those age 18 and older, and come from the NHBPEP. The categories are for those not on a high blood pressure medication and who have no short-term serious illness.
**If your systolic and diastolic pressure fall into different categories, your overall status is the higher category.
The symbol < means less than. The symbol  ≥ means greater than or equal to.)

Blood pressure rises and falls during the day. But when it stays elevated over time, then it's called high blood pressure. High blood pressure is dangerous because it makes the heart work too hard, and the force of its blood flow can harm arteries.)

High blood pressure often has no warning signs or symptoms. Once it occurs, it usually lasts a lifetime. If uncontrolled, it can lead to heart and kidney disease and stroke.

High blood pressure affects about 50 million-or 1 in 4-adult Americans. High blood pressure is especially common among African Americans, who tend to develop it at an earlier age and more often than whites. It also is common among older Americans-about 60 percent of those age 60 and older have high blood pressure.

High blood pressure can be controlled if you take these steps:

• Maintain a healthy weight
• Be physically active
• Follow a healthy eating plan, which includes foods lower in salt and sodium
• If you drink alcoholic beverages, do so in moderation
• If you have high blood pressure and are prescribed medication, take it as directed

All steps but the last also help to prevent high blood pressure.

Tips to Reduce Salt and Sodium

• Use reduced sodium or no-salt-added products. For example, choose low- or reduced-sodium, or no-salt-added versions of foods and condiments whenever available.
• Buy fresh, plain frozen, or canned with "no-salt-added" vegetables.
• Use fresh poultry, fish and lean meat rather than canned, smoked or processed types.
• Choose read-to-eat breakfast cereals that are lower in sodium
• Limit cured foods (such as bacon and ham), foods packed int brine (such as pickles, pickled vegetables, olives and sauerkraut) and condiments (such as MSG, mustard, horseradish, catsup and barbecue sauce.) Limit even lower sodium versions of soy sauce and teriyaki sauce - treat these condiments as you do salt.
• Be spicy instead of salty. In cooking and at the table, flavor foods with herbs, spices, lemon, lime, vinegar, or salt-free seasoning blends. Start by cutting salt in half.
• Cook rice, pasta and hot cereals without salt. Cut back on instant or flavored rice, pasta and cereal mixes, which usually have added salt.
• Choose convenience foods that are lower in sodium. Cut back on frozen dinners, mixed dishes such as pizza, packaged mixes, canned soups or broths and salad dressings - these often have a lot of sodium.
• Rinse canned foods, such as tuna, to remove some sodium.

What is the DASH Diet?

Blood pressure can be unhealthy even if it stays only slightly above the optimal level of less than 120/80 mm Hg. The higher blood pressure rises above optimal, the greater the health risk. In the past, researchers tried to find clues about what in the diet affects blood pressure by testing various single nutrients, such as calcium and magnesium. These studies were done mostly with dietary supplements and their findings were not conclusive.

Then, scientists supported by the National Heart, Lung, and Blood Institute (NHLBI) conducted two key studies. The first was called "DASH," for Dietary Approaches to Stop Hypertension, and it tested nutrients as they occur together in food. Its findings showed that blood pressures were reduced with an eating plan that is low in saturated fat, cholesterol and total fat, and that emphasizes fruits, vegetables and lowfat dairy foods. This eating plan-known as the DASH diet-also includes whole grain products, fish, poultry and nuts. It is reduced in red meat, sweets and sugar-containing beverages. It is rich in magnesium, potassium and calcium, as well as protein and fiber.

The DASH study involved 459 adults with systolic blood pressures of less than 160 mm Hg and diastolic pressures of 80-95 mm Hg. About 27 percent of the participants had hypertension. About 50 percent were women and 60 percent were African Americans.

DASH compared three eating plans: A plan similar in nutrients to what many Americans consume; a plan similar to what Americans consume but higher in fruits and vegetables; and the DASH diet. All three plans used about 3,000 milligrams of sodium daily. None of the plans were vegetarian or used specialty foods.

Results were dramatic: Both the fruits and vegetables plan and the DASH diet reduced blood pressure. But the DASH diet had the greatest effect, especially for those with high blood pressure. Further, the blood pressure reductions came fast-within 2 weeks of starting the plan.

The second study was called "DASH-Sodium," and it looked at the effect on blood pressure of a reduced dietary sodium intake as participants followed either the DASH diet or an eating plan typical of what many Americans consume. DASH-Sodium involved 412 participants. Their systolic blood pressures were 120-159 mm Hg and their diastolic blood pressures were 80-95 mm Hg. About 41 percent of them had high blood pressure. About 57 percent were women and about 57 percent were African Americans. Participants were randomly assigned to one of the two eating plans and then followed for a month at each of three sodium levels. The three sodium levels were: a higher intake of about 3,300 milligrams per day (the level consumed by many Americans); an intermediate intake of about 2,400 milligrams per day; and a lower intake of about 1,500 milligrams per day.

Results showed that reducing dietary sodium lowered blood pressure for both eating plans. At each sodium level, blood pressure was lower on the DASH diet than on the other eating plan. The biggest blood pressure reductions were for the DASH diet at the sodium intake of 1,500 milligrams per day. Those with hypertension saw the biggest reductions, but those without it also had large decreases.

Those on the 1,500-milligram sodium intake, as well as those on the DASH diet, had fewer headaches. Other than that and blood pressure levels, there were no significant effects caused by the two eating plans or different sodium levels.

DASH-Sodium shows the importance of lowering sodium intake -whatever your eating plan. But for a true winning combination, follow the DASH diet and lower your intake of salt.

How do I make the DASH?

The DASH diet used in the studies calls for a certain number of servings daily from various food groups. The number of servings you require may vary, depending on your caloric need. You should be aware that the DASH diet has more daily servings of fruits, vegetables, and whole grain foods than you may be used to eating. This makes it high in fiber, which can cause bloating and diarrhea in some persons. To avoid these problems, gradually increase your intake of fruit, vegetables, and whole grain foods.

Twenty-four hundred milligrams of sodium equals about 6 grams, or 1 teaspoon, of table salt (sodium chloride); 1,500 milligrams of sodium equals about 4 grams, or 2/3 teaspoon, of table salt. These amounts include all salt consumed-that in food products, used in cooking, and added at the table. Only small amounts of sodium occur naturally in food. Processed foods account for most of the salt and sodium Americans consume. So, be sure to read food labels to choose products lower in sodium.

You may be surprised at many of the foods that have sodium. They include soy sauce, seasoned salts, monosodium glutamate (MSG), baking soda, and some antacids-the range is wide.

Since it is rich in fruits and vegetables, which are naturally lower in sodium than many other foods, the DASH diet makes it easier to consume less salt and sodium. Still, you may want to begin by adopting the DASH diet at the level of 2,400 milligrams of sodium per day and then further lower your sodium intake to 1,500 milligrams per day.

How can you get started on the DASH diet?

It's easy. The DASH diet requires no special foods and has no hard-to-follow recipes.

Remember that some days the foods you eat may add up to more than the recommended servings from one food group and less from another. Similarly, you may have too much sodium on a particular day. But don't worry. Just be sure that the average of several days or a week comes close to what's recommended for the food groups and for your chosen daily sodium level.

One note: If you take medication to control high blood pressure, you should not stop using it. Follow the DASH diet and talk with your doctor about your drug treatment.

Getting Started

Change gradually.

• If you now eat one or two vegetables a day, add a serving at lunch and another at dinner.
• If you don't eat fruit now or have only juice at breakfast, add a serving to your meals or have it as a snack.
• Gradually increase your use of fat-free and low-fat diary products to three servings a day. For example, drink milk with lunch or dinner instead of soda, sugary tea, or alcohol. Choose low-fat (1 percent) or fat-free (skim) milk products to reduce your intake of saturated fat, total fat, cholesterol and calories.
• Read food labels on margarine and salad dressings to choose those lowest in unsaturated fats. Some margarine are now trans-fat free.

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

• Limit meat to 6 ounces a day (2 servings) - all that's needed. Three to four ounces is about the size of a deck of cards.
• If you now eat large portions of meat, cut them back gradually - by a half or a third at each meal.
• Include two or more vegetarian style (meatless) meals each week.
• Increase servings of vegetables, rice, past, and dried beans in meals. Try casseroles, pasta and stir-fry dishes, which have less meat and more vegetables, grains and dried beans.

Use fruits or other foods low in saturated fat, cholesterol, and calories as desserts and snacks.

• Fruits and other low-fat foods offer great taste and variety. Use fruits canned in their own juices. Fresh fruits required little or no preparation. Dried fruits are a good choice to carry with you or to have ready in the car.
• Try these snack ideas: unsalted pretzels or nuts mixed with raisins; graham crackers; low-fat and fat-free yogurt and frozen yogurt; popcorn with no salt or butter; and raw vegetables.

Try these other tips:

• Choose whole grain foods to get added nutrients, such as minerals and fiber. For example, choose whole wheat bread or whole-grain cereals.
• if you have trouble digesting dairy products, trying taking lactose enzyme pills or drops (available at drugstores and groceries) with the dairy foods. Or buy lactose-free mild or milk with lactase enzyme added to it.
• use fresh, frozen or no-salt-added canned vegetables.

How to Lower Calories on the DASH Eating Plan

The DASH eating plan was not designed to promote weight loss. But it is rich in lower-calorie foods, such as fruits and vegetables. You can make it lower in calories by replacing higher-calorie foods with more fruits and vegetables, and that also will make it easier for you to reach your DASH goals. Here are some examples:

To increase fruits:

• Eat a medium apple instead of four shortbread cookies. You'll save 80 calories.
• Eat 1/2 cup of apricots instead of a 2-ounce bag of pork rinds.

To increase vegetables:

• Have a hamburger that's 3 ounces of meat instead of 6 ounces. Add 1/2 cup serving of carrots and 1/2 cup serving of spinach. You'll save more than 200 calories.
• Instead of 5 ounces of chicken, have a stir-fry with 2 ounces of chicken and 1 1/2 cups of raw vegetables. Use a small amount of vegetable oil. You'll save 50 calories.

To increase low-fat or fat-free dairy products

• Have a 1/2 cup serving of low-fat frozen yogurt instead of a 1 1/2 ounce milk chocolate bar. You'll save about 100 calories.

And don't forget these calorie-saving tips:

• Use low-fat or fat-free condiments.
• Cut portions of vegetable oil, soft or liquid margarine or salad dressing, or choose fat-free versions.
• Eat smaller portions. Cut back gradually.
• Choose low-fat or fat-free dairy products to reduce total fat intake.
• Check the food labels to compare fat content in packaged foods. Items marked low-fat or fat-free are not always lower in calories than their regular versions.
• Limit foods with lots of added sugar, such as pies, flavored yogurts, candy bars, ice cream, sherbet, regular soft drinks, and fruit drinks.
• Eat fruits canned in their own juices.
• Add fruit to plain yogurt.
• Snack on fruit, vegetable sticks, unbuttered and unsalted popcorn, or bread sticks.
• Drink water or club soda.

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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 6/6/2006