Diet plays an important role in general health and some factors can lower or raise a person’s risk for certain medical conditions. Studies by the National Heart, Lung, and Blood Institute (NHLBI) have shown that blood pressure can be lowered through dietary modification and lowering sodium (salt) intake.
The Dietary Approaches to Stop Hypertension (DASH) eating plan is a diet that is based on the findings from these studies. The DASH diet increases the intake of foods high in nutrients and limits saturated fats and cholesterol. The combination of the DASH diet and reduced sodium intake has been proven to lower blood pressure, especially in those with hypertension (high blood pressure).
The DASH diet focuses on the following guidelines:
Reduce the overall amount of fat, saturated fat and cholesterol.
Increase the number of fruits, vegetables and low-fat dairy foods.
Increase fiber intake by including whole grain products.
Reduce the amount of sodium (e.g., salt) to an upper limit of 2,400 milligrams or lowest limit of 1,500 milligrams per day.
Reduce sweets and sugar-containing beverages.
Overall, the DASH diet is rich in minerals such as magnesium, potassium and calcium, as well as protein and fiber, while low in fat, cholesterol and sodium. It provides at least the recommended daily intake of major nutrients.
Patients in the DASH study who used the diet were able to lower their blood pressure to the same extent as other patients who took antihypertensives. Patients are encouraged to speak with their physician about whether the DASH diet might be used as a replacement for medications. However, people should not abruptly stop taking their medications or begin this diet without first consulting their physician.
About the DASH diet
The DASH diet is a set of dietary guidelines for people with high blood pressure (hypertension). Not only has research shown the diet to significantly lower blood pressure, but it also appears to lower cholesterol levels and homocysteine levels.
The DASH plan presented below is based on a 2,000-calorie diet but can be adjusted according to individual needs. Additional serving sizes are also available for 1,600-, 2,600- and 3,100-calorie diets. The DASH diet guidelines are presented below for information and educational purposes only. Patients should not make any diet or medication changes before consulting with their physician. The 2000-calorie DASH guidelines are as follows:
6 to 8 servings each day of grains or grain products, with an emphasis on whole-grain products. These include breads, cereals and pastas. Grains are important sources of fiber, vitamins and minerals. Each serving should be prepared with as little added fat or sugar as possible.
4 to 5 servings of vegetables each day. Vegetables are a good source of potassium, magnesium and fiber. This category of the DASH diet includes beans, potatoes, squash and others, as well as the more common vegetables such as spinach, broccoli and corn.
4 to 5 servings of fruit each day. This category of the DASH diet includes all fruits, even exotic selections like kiwi, mangoes, currants and figs. The fruits may be eaten fresh, canned, frozen, dried, blended in 100 percent fruit juices or in any other pure form.
2 to 3 servings each day of low-fat or non-fat dairy products. These are a major source of protein and calcium. This category includes fat–free (skim) and low-fat (1 percent) milk, and milk products.
No more than 6 servings each day of meats, poultry or fish (a serving size is considered 1 ounce cooked meat, poultry or fish, or 1 egg). High in protein and magnesium, this category includes red meat and white meat, as well as meat alternatives, such as eggs or tofu.
4 to 5 servings each week of nuts, seeds and legumes. While rich in magnesium, potassium, protein and fiber, recommended portions are small because the items in this category are high in fat. It includes all types of nuts, peanut butter, beans and lentils.
No more than 2-3 servings each day of fats. These fats include butter, margarine, salad dressing and mayonnaise.
No more than 5 servings each week of sweets. These include sugar, maple syrup, jelly, hard candies, fruit punches, and more.
Lower intake of sodium. The initial DASH diet allowed for 2,300 milligrams of sodium each day, or about one teaspoon of table salt. Later studies showed that lowering the level of sodium even further, to 1,500 milligrams each day, or about 2/3 of a teaspoon, even further lowers blood pressure. This includes all sodium consumed throughout the day, in prepared and processed foods, as well as seasonings. It may be advisable to first aim for the 2,300-milligram level and gradually work down to 1,500 milligrams per day.
The DASH diet is not considered a weight-loss diet. However, it is possible to lose weight on the DASH diet by adjusting the daily servings to a calorie target that is lower than your normal intake. For example, a person who normally eats 3,100 calories a day could lose weight and lower blood pressure by following the DASH guidelines for a 2,600-calorie diet. Combining exercise with the DASH diet can also result in further weight loss, better blood pressure control and improved long-term outcomes. Currently, the government recommends that people get about 30 minutes of exercise on most days of the week. It is also important to note that the serving sizes for the DASH diet may vary from other heart-healthy diets, such as those found in the Dietary Guidelines. If you are considering beginning the DASH diet, consult your physician.
History of the DASH diet
Funded by the National Heart, Lung and Blood Institute, Dietary Approaches to Stop Hypertension (DASH) was a major research study to determine whether diet can lower blood pressure. High blood pressure (hypertension) is a major risk factor for coronary artery disease (which can lead to heart attack) and carotid artery disease (which can lead to stroke). The goal of the DASH study was to determine whether a particular diet could lower blood pressure, reducing the risk of potentially fatal events.
The DASH study examined the impact of three different dietary patterns on a group of 459 subjects with blood pressures of less than 160/80-95. The participants included men and women (Caucasian and black American) averaging 45 years old. They were placed in one of three dietary plans: typical American diet, typical diet plus more fruits and vegetables, and the DASH diet.
All three groups consumed the same amount of salt (3,000 mg per day, slightly less than the average intake of Americans at 3,600 to 4,000 mg per day) and calories. Alcohol was limited to one to two drinks a week in all groups.
At the end of the study, there was a significant difference among the groups. The participants who incorporated fruits and vegetables into their diet and those who followed the DASH diet lowered their blood pressure. The DASH followers, however, had the greatest reduction in blood pressure, especially for those with hypertension.
Follow-up research suggested that the DASH diet is even more effective for black Americans than it is for Caucasians. Identifying an effective treatment for black Americans is particularly important because they are at higher risk of developing high blood pressure.
Before the introduction of the DASH diet, the main dietary change recommended for patients with high blood pressure was a reduction of salt. However, the DASH study demonstrated that other dietary changes could also be effective in reducing blood pressure.
To further investigate the effects of salt on blood pressure, a second phase of research was performed. The DASH-Sodium trial investigated the relationship between blood pressure and sodium intake. Participants in this study followed either a typical American diet or the DASH diet. In addition, they were instructed to modify their sodium intake in one of the three ways:
High sodium diet (3,300 milligrams of sodium per day)
Intermediate sodium diet (2,300 milligrams of sodium per day)
Low sodium diet (1,500 milligrams of sodium per day)
The results indicated that reducing sodium intake lowered blood pressure for both the typical diet and the DASH plan. In fact, the more the sodium level was reduced, the greater the blood pressure fell. The biggest reduction in blood pressure was found in the group that followed the DASH diet at the lowest level of sodium intake, or 1,500 milligrams daily.
Sample DASH menu
The following sample menu is provided by the National Heart, Lung and Blood Institute. It is based on a 2,000-calorie diet and provides for about 2,300 milligrams of sodium. Adjustments can be made for a lower sodium target (e.g., 1,500 milligrams) or for higher calorie diets. This menu is only a sample to give you an idea of what a typical day on the DASH diet might look like.
Breakfast:
1 cup whole grain oat rings cereal (e.g., Cheerios)
1 medium banana
1 cup low-fat milk
1 medium raisin bagel
1 tablespoon peanut butter
1 cup orange juice
Lunch:
Tuna salad plate containing 1/2 cup tuna salad, 1 large leaf romaine lettuce and 1 slice whole wheat bread
Cucumber salad with 1 cup fresh cucumber, 1/2 cup tomato wedges and 1 tablespoon vinaigrette dressing
1/2 cup low-fat cottage cheese
1/2 cup canned pineapple juice
1 tablespoon unsalted almonds
Dinner:
3 ounces turkey meatloaf
1 small baked potato, topped with 1 tablespoon fat-free sour cream, 1 tablespoon reduced-fat cheddar cheese, and 1 chopped scallion
1 cup collard greens, sauteed with 1 teaspoon canola oil
1 small whole wheat roll
1 medium peach
Snacks:
1 cup fat-free, no added sugar fruit yogurt
1 tablespoons sunflower seeds
Dos and Don'ts for the DASH diet
Making adjustments to your diet may be difficult. To follow the DASH eating plan, it may be best to start making the changes gradually, such as adding an additional serving of vegetables to your lunch, then dinner. Also, don't worry about occasionally slipping from the program. Because DASH represents a lifestyle change, one day of eating poorly will not cause any long-term problems. The important thing is to start the next day back on the program.
In addition, some individuals do better with specifically planned menus. It may be helpful to keep a record of all your meals and snacks to determine how closely you are following the plan. Using a dietitian may also help you with meal planning and monitoring.
Some tips that may help you with the DASH eating plan include:
Do add a serving of vegetables at lunch.
Do use half the butter, mayonnaise, salad dressing or other fat items that you normally use. Trying using low-fat or non-fat alternatives as a substitute.
Do eat fruit as a snack. An apple or banana is perfect for those hungry times between meals. These foods are much healthier for you than chips and cookies.
Do watch what you drink. Replace soda, sugary teas or punches and alcoholic beverages with fat-free (skim) or 1 percent milk. This will not only help you cut back on your sweets, but will also help you meet the DASH diet’s dairy requirements.
Do learn serving sizes. Serving-sizes are a guideline to help you change not only what you are eating, but also how much of each type of food you are eating. While all the numbers and charts are initially cumbersome, they will become second nature once a daily routine has been set.
Do learn to read food labels. Much of the sodium in our diet is added to foods while processing. To lower your intake of sodium, begin by removing the salt shaker from the table. Gradually lower the amount of salt added during cooking and instead try herbs, spices, lemon or sodium-free seasoning blends to flavor your food. You can also rinse canned foods to lower their sodium content. Lastly, read food labels and compare sodium content of foods when shopping. Select the items that have the highest nutritional value with the lowest sodium content.
Do experiment with vegetarian dishes or dishes with little meat and more vegetables and grains. These include stir-fry meals, pasta dishes and casseroles. These healthy and tasty alternatives will add spice and variety to your diet.
Do change your shopping list. Increase the amount of fruits and vegetables on your weekly shopping list and buy less meat.
Do feed your cravings for sweets with sugar-free gelatin or dried fruit. Fat-free or low-fat frozen yogurt can replace high-fat ice cream.
Do keep it simple. Remember that you are not trying to stay on a short-term diet. You are changing your lifestyle. The simpler you keep your meals, your goals and your tasks, the easier they will be to maintain.
Do keep a record. Keeping a diary or a logbook can help you keep track of the number of servings you are eating in each category. Plus, seeing what you are eating in black and white is a great way to check your progress. It can also help you to identify patterns and triggering events that put you off track.
Do celebrate success. Reward yourself for every accomplishment but not with food.
Don’t make meat the center of your meal. Although meat contains nutrients that are good for the body, it is also high in saturated fat and cholesterol, not to mention calories. You can continue to enjoy meat as part of a balanced meal rather than the whole meal. Remember to make this change gradually. If you typically eat more than the suggested amount of meat, reduce your portions by a third for one week. After a week, cut back another third until your serving sizes of meat are equal to the DASH serving size of 3 ounces.
Don’t try to do it all at once. You will be more successful if you make gradual changes in your eating habits. If you are used to large portions, cut them back by a half or a third at each meal.
Don’t be discouraged by occasional lapses. They happen, but you should determine why the lapse occurred so you can avoid that same trigger in the future. Was it a holiday party that got you off track? Stress due to a problem at work? Learn from the mistake and move on; it is all a process of change, and change takes time and patience.
Lactose intolerance and the DASH diet
The DASH diet calls for two to three servings each day of low-fat or non-fat dairy products. However, some people cannot tolerate lactose (a sugar found in dairy products). Lactose intolerance can cause people to experience stomach cramps, bloating, nausea and/or diarrhea after consuming dairy products. These symptoms occur because their bodies do not produce enough of the enzyme lactase, which breaks down lactose.
Patients who are lactose intolerant can stay true to the DASH diet by using specialty products. Lactose-free or reduced-lactose milk is sold in the dairy case of most supermarkets. In addition, lactase enzymes can be purchased in liquid or pill form. The liquid can be added directly to dairy products to neutralize the lactose contained in them. Pills can be taken in capsule or chewable tablet form immediately before consuming the dairy product. Any of these methods can enable a lactose intolerant person to stay on the DASH diet.
Questions for your doctor on the DASH diet
Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about the DASH diet:
Where can I learn more about the DASH diet?
Is the DASH Diet safe for me to follow?
Is the DASH Diet safe for my family to follow?
When can I expect to see changes in my blood pressure if I am on the DASH diet?
Can I begin the DASH Diet for prevention, even if my blood pressure is normal?
What should be my daily calorie intake?
Will the DASH cause an gastrointestinal problems?
How long do I need to stay on the DASH diet?
Will the DASH diet also help me to lose weight?
Do I need to change my nutritional supplements if I am on this diet?
Can the DASH diet replace my need for blood pressure medication?
Can you recommend a dietitian to help me with this diet?
