DASH diet
The Dietary Approaches to Stop Hypertension or the DASH diet is a diet to control hypertension promoted by the U.S.-based National Heart, Lung, and Blood Institute, part of the National Institutes of Health (NIH), an agency of the United States Department of Health and Human Services.
[2][3] The American Heart Association (AHA) considers the DASH diet "specific and well-documented across age, sex and ethnically diverse groups.
[4] Although this diet is associated with a reduction of blood pressure and improvement of gout,[5][6] there are uncertainties around whether its recommendation of low-fat dairy products is beneficial or detrimental.
The DASH diet is mainly based on fruits, vegetables, low-fat or fat free dairy, whole grains, fish, poultry, legumes, and nuts.
[3][6] The National Heart, Lung, and Blood Institute provides sample plans with specific number of servings based on 1600, 2000 or 2600 calories per day.
[5] Some people may at first experience gas and bloating due to the high fiber content of plant foods such as fruits, vegetables and whole grains.
[3][15] The first modifications recommended by guidelines for people at risk of cardiovascular disease are typically lifestyle changes, such as diet and physical activity followed by pharmacotherapy.
Using the average values for reductions in cholesterol levels and BP, the review concluded that the DASH diet was found to reduce the 10-year Framingham risk score for cardiovascular disease by about 13%.
[24] The prevalence of hypertension led the U.S. National Institutes of Health (NIH) to propose funding to further research the role of dietary patterns on blood pressure.
[4] Two DASH trials were designed and carried out as multi-center, randomized, outpatient feeding studies with the purpose of testing the effects of dietary patterns on blood pressure.
[26] Contemporary epidemiological research had concluded that dietary patterns with high intakes of certain minerals and fiber were associated with low blood pressures.
The combination or “DASH” diet was also high in whole grains, poultry, fish, and nuts while being lower in red meat content, sweets, and sugar-containing beverages.
[27] The DASH diet was designed to provide liberal amounts of key nutrients thought to play a part in lowering blood pressure, based on past epidemiologic studies.
[25] The DASH diet also features a high quotient of antioxidant-rich foods thought by some to retard or prevent chronic health problems, including cancer, heart disease, and stroke.
[28] Participants ate one of the three aforementioned dietary patterns in 3 separate phases of the trial, including (1) Screening, (2), Run-in and (3) Intervention.
At this point, subjects who were compliant with the feeding program during the screening phase were each randomly assigned to one of the three diets outlined above, to begin at the start of the 4th week.
Blood pressures and urine samples were collected again during this time together with symptom & physical activity recall questionnaires.
The data indicated that reductions in blood pressure occurred within two weeks of subjects’ starting their designated diets,[27] and that the results were generalizable to the target sample of the U.S.
The 30-day intervention phase followed, in which subjects ate their assigned diets at each of the aforementioned sodium levels (high, intermediate and low) in random order, in a crossover design.
[29] During the 30-day dietary intervention phase, each participant therefore consumed his or her assigned diet (either DASH or control) at all three sodium levels.
[dubious – discuss] The primary outcome of the DASH-Sodium study was systolic blood pressure at the end of the 30-day dietary intervention periods.
The DASH-Sodium study found that reductions in sodium intake produced significantly lower systolic and diastolic blood pressures in both the control and DASH diets.
