DASH Diet for High Blood Pressure: What Is It and Does It Work?
If you have high blood pressure, you may have been told to reduce your salt intake.
Reducing excess sodium can be important, but nutrition for high blood pressure involves more than simply putting down the salt shaker. One of the most researched dietary approaches for managing blood pressure is the DASH diet.
What is the DASH diet?
DASH stands for Dietary Approaches to Stop Hypertension.
Rather than focusing on one particular food or nutrient, DASH is an overall eating pattern that emphasises:
vegetables and fruit
wholegrains
legumes and nuts
low-fat dairy products
fish and other lean protein sources
It also limits foods high in sodium, added sugars and saturated fat.
This creates a dietary pattern naturally rich in nutrients including potassium, calcium, magnesium and fibre.
Is the DASH diet just a low-sodium diet?
No and this is one of the interesting things about the research.
The landmark DASH-Sodium trial included 412 adults who were assigned either a DASH diet or a typical US control diet. Participants then consumed three different sodium levels. This allowed researchers to investigate the effects of DASH and sodium reduction separately.
Both mattered.
DASH lowered systolic blood pressure at each sodium level, while reducing sodium provided additional benefit. Combining DASH with lower sodium produced the greatest reduction.
Compared with the high-sodium control diet, low-sodium DASH resulted in average systolic blood pressure that was 7.1 mmHg lower in participants without hypertension and 11.5 mmHg lower in those with hypertension.
This was a tightly controlled study, so it doesn't mean everyone following DASH will experience the same result.
What does more recent research show?
More recent research continues to support DASH for blood pressure management.
A 2021 systematic review and meta-analysis included 10 randomised controlled trials and 2,416 participants. Modified DASH interventions reduced systolic blood pressure by around 3.3 mmHg and diastolic blood pressure by around 2.1 mmHg compared with control diets.
Reductions tended to be greater when participants started with higher blood pressure.
There is also observational evidence suggesting that people who more closely follow a DASH-style diet may have a lower risk of developing hypertension, although this type of research cannot establish cause and effect.
What foods are included in the DASH diet?
You don't necessarily need to follow a strict meal plan.
Moving towards a DASH-style diet could be as simple as:
adding more vegetables to meals
choosing wholegrains more often
regularly including beans, chickpeas or lentils
including fruit, nuts and appropriate calcium-rich foods
choosing lean protein sources
comparing sodium levels when buying packaged foods
limiting foods particularly high in sodium and saturated fat
It's less about eating a “perfect” DASH diet and more about improving your overall dietary pattern.
What about salt?
Sodium still matters.
A review of randomised controlled trials found that reducing sodium consistently lowered blood pressure, although the size of the effect varied between studies.
The key point is that it doesn't need to be DASH or sodium reduction. Research suggests both can contribute to blood pressure management.
The takeaway
Nutrition for high blood pressure is about more than salt.
The DASH diet provides an evidence-based framework built around vegetables, fruit, wholegrains, legumes, nuts, appropriate dairy and lean protein foods while limiting sodium, added sugars and saturated fat.
And you don't have to change everything at once. Small, sustainable changes that move your usual diet towards a DASH-style pattern can be a practical place to start.
If you have high blood pressure or take blood-pressure medication, nutrition should form part of appropriate healthcare rather than replace medical management.
Book a consultation today to get personalised nutrition advice tailored to your goals.
References:
Sacks FM, Svetkey LP, Vollmer WM, et al. (2001). Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) diet. New England Journal of Medicine, 344, 3–10. DOI: 10.1056/NEJM200101043440101.
Guo R, Li N, Yang R, et al. (2021). Effects of the Modified DASH Diet on Adults With Elevated Blood Pressure or Hypertension: A Systematic Review and Meta-Analysis. Frontiers in Nutrition, 8, 725020. DOI: 10.3389/fnut.2021.725020.
Filippou C, Tatakis F, Polyzos D, et al. (2022). Overview of salt restriction in the Dietary Approaches to Stop Hypertension (DASH) and the Mediterranean diet for blood pressure reduction. Reviews in Cardiovascular Medicine, 23(1), 036. DOI: 10.31083/j.rcm2301036.
Theodoridis X, Chourdakis M, Chrysoula L, et al. (2023). Adherence to the DASH Diet and Risk of Hypertension: A Systematic Review and Meta-Analysis. Nutrients, 15, 3261. DOI: 10.3390/nu15143261.
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