DASH Diet

NIH-funded trials of the 1990s

The DASH name comes from a multicenter clinical trial published in the New England Journal of Medicine in April 1997 by the DASH Collaborative Research Group, with research support from the US Public Health Service. The trial enrolled 459 adults whose systolic blood pressure was below 160 mm Hg and diastolic pressure was 80 to 95 mm Hg. After three weeks on a control diet, participants were randomly assigned for eight weeks to the control diet, a diet rich in fruits and vegetables, or a combination diet that added low-fat dairy foods and reduced saturated and total fat. Sodium intake and body weight were held constant.

The DASH-Sodium trial

A second trial, DASH-Sodium, was published in the same journal in January 2001. It randomly assigned 412 participants to a control diet typical of US intake or to the DASH diet, and within each diet participants ate food at high, intermediate and low sodium levels for 30 consecutive days each, in random order. The design allowed the effects of the eating pattern and of sodium to be separated and combined.

Entry into hypertension guidance

A 1999 review in Clinical Cardiology, by the lead author of the 1997 trial, reports that the sixth report of the US Joint National Committee on hypertension, published in 1997, began recommending a dietary pattern rich in fruits, vegetables and low-fat dairy products and reduced in saturated fat, total fat and cholesterol. That pattern was the one tested in the DASH trial. The review describes this as an extension of earlier lifestyle advice such as sodium reduction, weight loss, alcohol moderation and physical activity.

Name and variants

DASH is an acronym for Dietary Approaches to Stop Hypertension. The National Heart, Lung, and Blood Institute (NHLBI) calls it the DASH eating plan, while guidelines often write DASH eating pattern or DASH-style diet. In research, the original trial diets are sometimes called the control, fruits-and-vegetables and combination diets, and the combination diet is the one usually meant by DASH. Studies that describe participants as following a DASH diet may have used the trial diet exactly or may have applied scoring systems or adapted versions, so results are not always comparable.

Not a wellness tradition

Unlike many practices on Machipedia, the DASH Diet does not come from a spiritual, folk or healing tradition. It was designed and tested in clinical research, and professional bodies describe it in clinical guidance for blood pressure. Related Machipedia pages include the family page Dietary Approaches, and comparisons are often drawn with the Mediterranean Diet and the Plant-Based Diet. Registered dietitians, covered under Dietetics, usually deliver individual counseling, which differs from Nutritional Therapy as a separately named practice.

General features of the pattern

NHLBI describes DASH as a flexible and balanced eating plan that requires no special foods. It advises choosing foods that are low in saturated and trans fats, rich in potassium, calcium, magnesium, fiber and protein, and lower in sodium. The 2025 American Heart Association and American College of Cardiology guideline describes the plan as emphasizing fruits, vegetables, low-fat or nonfat dairy products and whole grains, which supply potassium, magnesium, calcium and fiber. The trial combination diet also included fish, poultry and nuts in the original design.

How it is used in practice

NHLBI publishes meal-planning materials and notes that the plan provides daily and weekly nutritional goals, but this page does not reproduce them. The sources reviewed describe DASH as one part of a heart-healthy lifestyle alongside physical activity and sodium reduction, and describe individual adaptation as a matter for a clinician or dietitian. The National Kidney Foundation advises people with kidney disease to discuss any new diet with a doctor and dietitian first.

Blood pressure and heart health

The primary use of the DASH Diet is the prevention and treatment of elevated blood pressure and hypertension, which is the purpose stated in the 2025 US high blood pressure guideline and in the trial that gave the pattern its name. Researchers have also studied it for cholesterol, metabolic syndrome, diabetes risk, heart failure, kidney outcomes and mortality, usually as secondary or observational outcomes rather than as the purpose of the original trials.

Claims outside the sources reviewed

Popular accounts sometimes describe DASH as a weight-loss diet or as a treatment for conditions beyond blood pressure and cardiometabolic risk. The sources reviewed for this page did not test these claims in the original DASH trials, in which body weight was held constant. This page therefore treats weight and other outcomes only where a cited review reports them, and with the limits that review states.

The original randomized trials

In the 1997 trial the combination diet lowered systolic and diastolic pressure by 5.5 and 3.0 mm Hg more than the control diet. The fruits-and-vegetables diet lowered systolic pressure by 2.8 mm Hg more than control. Among the 133 participants with hypertension the combination diet lowered systolic and diastolic pressure by 11.4 and 5.5 mm Hg more, and among those without hypertension by 3.5 and 2.1 mm Hg. Participants were fed study meals for eight weeks, so results reflect supervised feeding.

In DASH-Sodium the DASH diet gave lower systolic pressure at each sodium level than the control diet, with a larger difference at high sodium than at low sodium. Compared with the control diet at high sodium, DASH at low sodium produced a mean systolic pressure 7.1 mm Hg lower in participants without hypertension and 11.5 mm Hg lower in those with hypertension. The authors noted that long-term benefit depends on whether people can sustain dietary change.

Later reviews of blood pressure trials

A 2026 systematic review and meta-analysis of randomized trials in adults with elevated blood pressure compared DASH with other structured diets or usual care. It included 22 trials, 10 in the meta-analysis, and found no statistically significant advantage for DASH over comparators on systolic blood pressure (mean difference 1.30 mm Hg, 95% confidence interval -1.54 to 4.14) or diastolic pressure, with substantial heterogeneity. It reported benefits for LDL cholesterol and HbA1c, with certainty of evidence from moderate to very low, and concluded the findings should be interpreted cautiously.

A 2026 meta-analysis of 14 randomized trials (1,062 participants) in metabolic syndrome found lower systolic pressure with DASH than with non-DASH diets (mean difference -5.52 mm Hg), with moderate certainty for most outcomes. The 2025 US guideline reports that blood pressure reduction with the DASH eating plan varies across trials, from 1 to 13 mm Hg for systolic and 1 to 10 mm Hg for diastolic pressure. Comparators and populations differ among these reviews.

Observational findings on other outcomes

Cohort studies relate people's self-reported eating to later outcomes and cannot show that the diet caused them. A dose-response meta-analysis of 17 prospective cohort studies linked closer DASH adherence to lower all-cause, cardiovascular, stroke and cancer mortality. A meta-analysis of 11 cohorts (450,451 participants) found the highest DASH adherence associated with a hazard ratio of 0.81 for heart failure, and a meta-analysis of 15 studies found a relative risk of 0.82 for diabetes. The diabetes authors called for trials to validate their findings.

A meta-analysis of eight prospective cohorts found a lower risk of kidney disease with higher adherence to healthy dietary patterns, significant for DASH in subgroup analysis. A 2026 meta-analysis of five studies found no statistically significant effect of the DASH diet on gestational hypertension, with a relative risk of 1.03 and too few studies for firm conclusions.

What guidelines say

The 2025 AHA/ACC multisociety guideline states that, in adults with or without hypertension, a heart-healthy eating pattern such as the DASH eating plan is recommended to prevent or treat elevated blood pressure and hypertension. It lists diet among lifestyle changes strongly recommended for all adults. NICE guideline NG136 (last updated February 2026) advises clinicians to ask about diet and exercise, offer lifestyle advice and encourage low sodium intake. The recommendations reviewed for this page do not name DASH specifically.

Kidney disease, potassium and medicines

The DASH pattern is rich in potassium. The National Kidney Foundation states that people with chronic kidney disease should speak with a doctor and dietitian before starting any new diet because they may have special restrictions, and that DASH should not be used by people on dialysis. NICE advises that salt substitutes containing potassium chloride should not be used by people with kidney disease or people taking some antihypertensive drugs such as ACE inhibitors and angiotensin II receptor blockers. The 2025 US guideline likewise advises extra monitoring for potassium-based salt substitutes in chronic kidney disease or with drugs that reduce potassium excretion. These statements concern salt substitutes and kidney disease, and the sources reviewed do not quantify hyperkalemia risk from the DASH diet itself.

Other care boundaries and training

People who take blood pressure medicines should discuss diet changes with a clinician, since sources describe diet as complementing, not replacing, assessment and prescribed treatment. Pregnancy findings are limited to one small meta-analysis. In the United States, the Academy of Nutrition and Dietetics describes the registered dietitian nutritionist credential as requiring a graduate degree, accredited supervised practice, a national examination and continuing education. The sources reviewed do not describe a separate DASH-specific training or certification.