Finding yourself confused by the seemingly endless promotion of weight-loss strategies and diet plans? In this series, we take a look at some popular diets—and review the research behind them. Show What Is It?The DASH (Dietary Approaches to Stop Hypertension) diet is sometimes prescribed by doctors to help treat high blood pressure. Blood pressure is the amount of pressure that blood places against the walls of arteries. It will normally vary throughout the day but if it remains too high, this is called high blood pressure or hypertension. Untreated high blood pressure can lead to heart disease, stroke, congestive heart failure, kidney disease, and blindness. [1] DASH was first introduced at a meeting of the American Heart Association in 1996 and later published in the New England Journal of Medicine in 1997. [2] The DASH trial randomly assigned 456 people to different diets to test the effects of dietary patterns on lowering blood pressure. The authors surmised that eating a diet with many different foods with blood pressure-lowering nutrients would show a greater effect on blood pressure than eating single nutrients, such as found in supplements or in a limited diet. Three diets were tested: 1) a control diet, or a standard American diet, 2) a fruits and vegetables diet, similar to the control diet but providing more fruits and vegetables and less snacks and sweets, and 3) a combination diet rich in fruits, vegetables, nuts, and low-fat dairy foods with reduced amounts of saturated fat, total fat, and cholesterol. The last two diets were richer in nutrients associated with lower blood pressure, such as potassium, magnesium, calcium, fiber, and protein. All three diets provided about 3000 mg sodium, which is more than the recommended amount from the Dietary Guidelines for Americans but less than the average sodium intake for Americans. [3] Despite no weight changes, the combination diet reduced blood pressure more than the other two diets. Those with hypertension showed greater decreases in blood pressure than those without hypertension. The reduction of blood pressure in the DASH combination diet was comparable to that of people on medication for stage 1 hypertension. The results of this landmark study contributed much of the scientific basis for the Dietary Guidelines for Americans 2010 and later editions. Podcast: Reduce Blood Pressure with the DASH DietHear from Drs. Frank Sacks and Larry Appel about the origins of the DASH Diet in this True Health Initiative Podcast. How It WorksDASH is based on the following foods: fruits, vegetables, low fat milk, whole grains, fish, poultry, beans, and nuts. It recommends reducing sodium, foods and beverages with added sugars, and red meat. The diet is heart-friendly as it limits saturated and trans fat, while increasing the intake of potassium, magnesium, calcium, protein, and fiber, nutrients believed to help control blood pressure. [1] The diet suggests a specific number of servings of the recommended foods listed above. The sample plans provided by the National Heart Lung and Blood Institute (NHLBI) are based on 1600, 2000, or 2600 calories daily. For 2000 calories a day, this translates to about 6-8 servings of grains or grain products (whole grains recommended), 4-5 servings vegetables, 4-5 fruits, 2-3 low fat dairy foods, 2 or fewer 3-ounce servings of meat, poultry, or fish, 2-3 servings of fats and oils, and 4-5 servings of nuts, seeds, or dry beans per week. It advises limiting sweets and added sugars to 5 servings or less per week. The plan defines the serving sizes of each these food groups. Eating less carbohydrate but more protein or unsaturated fats may also benefit the heart. The OmniHeart (Optimal Macronutrient Intake Trial to Prevent Heart Disease) clinical trial found that swapping out about 10% of calories from carbohydrates with protein (especially plant proteins like legumes, nuts, seeds) or monounsaturated fats (olive oil, canola oil, nuts, seeds) lowered blood pressure, LDL cholesterol, and triglycerides among adults with early or stage 1 hypertension. [4] Swapping carbohydrates specifically with unsaturated fats also helped to increase “good” HDL cholesterol. The benefit did not come from simply eating more fats and protein, but swapping an equal amount of calories so that the total calorie level stayed about the same. For 2000 calories a day, this translates to eating daily about 4-5 servings of whole grains, 5 servings of vegetables, 2-3 fruits, 2 low fat dairy foods, one 3-ounce serving of fish, poultry, or meat, and 2-3 servings of unsaturated fats, and eating weekly 7-8 servings of beans, nuts, or seeds. To follow the plan, one must decide their calorie level and then divide the suggested servings of each food group throughout the day. This requires meal planning ahead of time. The NHLBI guide provides many tips on how to incorporate DASH foods and to lower sodium intake; a one-day sample menu following a 2300 mg sodium restriction and a 1500 mg sodium restriction; and one week’s worth of recipes. The NHLBI also publishes an online database of “heart healthy” recipes. Sample meal plan This sample meal plan is roughly 2000 calories, the recommended intake for an average person. If you have higher calorie needs, you may add an additional snack or two; if you have lower calorie needs, you may remove a snack. If you have more specific nutritional needs or would like assistance in creating additional meal plans, consult with a registered dietitian. Breakfast:
Snack: ¼ cup lightly salted or unsalted nuts Lunch:
Snack: String cheese, medium apple Dinner:
Snack: 3 ½ cups air-popped popcorn The Research So FarNumerous studies show wide-ranging health benefits of the DASH diet. A consistent body of research has found that DASH lowers blood pressure in people with high blood pressure but also normal blood pressure even without lowering sodium intake. [5] It can produce greater reductions in blood pressure if sodium is restricted to less than 2300 mg a day, and even more so with a 1500 mg sodium restriction. [6, 7] When compared with a standard American diet (e.g., high intake of red and processed meats, beverages sweetened with sugar, sweets, refined grains) DASH has also been found to lower serum uric acid levels in people with hyperuricemia, which places them at risk for a painful inflammatory condition called gout. [8] Because people with gout often also have high blood pressure and other cardiovascular diseases, DASH is optimal in improving all of these conditions. Adherence to the DASH-style pattern may also help prevent the development of diabetes, as analyzed in a recent meta-analysis, and kidney disease as found in the Atherosclerosis Risk in Communities (ARIC) cohort that followed more than 3700 people who developed kidney disease. [9, 10] Dietary components of DASH that were protective in the ARIC cohort included a high intake of nuts, legumes, and low-fat dairy products. A high intake of red meat and processed meats increased kidney disease risk. Potential Pitfalls
Bottom LineResearch supports the use of the DASH diet as a healthy eating pattern that may help to lower blood pressure, and prevent or reduce the risk of cardiovascular diseases, diabetes, kidney disease, and gout. Related
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Terms of UseThe contents of this website are for educational purposes and are not intended to offer personal medical advice. You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website. The Nutrition Source does not recommend or endorse any products. What foods are allowed on the DASH diet?This plan recommends: Eating vegetables, fruits, and whole grains. Including fat-free or low-fat dairy products, fish, poultry, beans, nuts, and vegetable oils. Limiting foods that are high in saturated fat, such as fatty meats, full-fat dairy products, and tropical oils such as coconut, palm kernel, and palm oils.
What foods are not allowed on the DASH diet?When following the DASH plan, you should limit how much you eat of these foods:. Foods with added salt (sodium) and adding salt to foods.. Alcohol.. Sugar-sweetened beverages.. Foods high in saturated fats, such as whole fat dairy and deep-fried foods.. Packaged snacks, which are often high in fat, salt, and sugar.. What are 5 components of the DASH diet?The DASH diet is rich in vegetables, fruits and whole grains. It includes fat-free or low-fat dairy products, fish, poultry, beans and nuts. It limits foods that are high in saturated fat, such as fatty meats and full-fat dairy products. The DASH diet also limits sodium to between 1,500 and 2,300 milligrams a day.
Who is the DASH diet not recommended for?That is, if a patient has high-normal or elevated serum potassium and phosphorus values, the DASH eating pattern should not be initiated. These patients should be advised to follow a low potassium or low phosphorus diet, and the DASH eating pattern would negate those recommendations.
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