DASH-Style Diet Lowers Blood Pressure in Type 2 Diabetes

Adults with type 2 diabetes (T2D) face a heightened risk of cardiovascular events, yet few trials have explored dietary strategies beyond weight loss to manage blood pressure.¹ New evidence from a randomized clinical trial revealed that a modified Dietary Approaches to Stop Hypertension (DASH) diet tailored for diabetes—especially when combined with sodium reduction—significantly lowered both systolic and diastolic blood pressure, even in patients already on multiple antihypertensive medications.

The findings were published in JAMA Internal Medicine.

Sodium reduction is key to lowering blood pressure in adults with type 2 diabetes, a study finds. | Image credit: Albi - stock.adobe.com

“In this context, we developed the Dietary Approaches to Stop Hypertension for Diabetes (DASH4D) diet, a DASH-style dietary pattern optimized for the nutritional needs of adults with T2D,” wrote the researchers of the study. “This article reports the main results of the DASH4D randomized feeding study that tested the effects of the DASH4D diet and dietary sodium reduction on BP [blood pressure] among adults with T2D.”

The DASH diet is a nutritional plan rich in fruits, vegetables, and low-fat dairy products, designed to reduce saturated and total fat intake.¹ Clinical trials have shown that this diet significantly lowers blood pressure in both hypertensive and non-hypertensive adults, offering an effective dietary strategy to prevent and manage hypertension.

The DASH4D study was conducted from June 2021 to June 2024 at a community-based study center.¹ It enrolled adults with T2D who had systolic blood pressure between 120- and 159-mm Hg and diastolic blood pressure below 100 mm Hg. Participants were provided all their meals and instructed to eat no outside food, with their weight maintained constant throughout the study. Each participant underwent 4 dietary interventions, each lasting 5 weeks: a DASH4D diet with lower sodium, a DASH4D diet with higher sodium, a typical US comparison diet with lower sodium, and a comparison diet with higher sodium.

As an adaptation of the original DASH diet, the DASH4D diet was optimized for T2D with lower carbohydrates, higher unsaturated fats, and reduced potassium. The primary outcomes measured were systolic and diastolic blood pressure at the end of each diet period.

Compared with the typical US diet with higher sodium, the DASH4D diet with lower sodium reduced systolic blood pressure by 4.6 mm Hg (95% CI, 7.2-2.0; P < .001) and diastolic pressure by 2.3 mm Hg (95% CI, 3.7-0.9; P = .002). Most of the blood pressure reduction occurred within the first 3 weeks of each diet period. Sodium reduction appeared to have a stronger impact on lowering blood pressure than the DASH4D diet alone. Importantly, these effects were observed even among participants—66% of whom were taking 2 or more antihypertensive medications—indicating that dietary changes can offer meaningful benefits in addition to pharmacologic treatment. Adverse events were rare across all diet periods.

However, the researchers noted several limitations. First, the study was conducted at a single center with a study population less diverse than originally planned, although it did enroll a significant number of Black participants, a group at higher risk for hypertension-related complications. Additionally, the COVID-19 pandemic posed challenges by interrupting participant feeding at various points during the trial.

Despite these limitations, the researchers believe the study finds clinically significant benefits of a DASH-style diet for adults patients with T2D.

“The findings in DASH4D have public health implications,” wrote the researchers. First, they provide evidence of the efficacy of BP lowering through dietary change in people with T2D, including those treated with multiple antihypertensive and glucose-lowering medications. High adherence to the DASH4D lower sodium diet suggests that the diet is acceptable…Second, the magnitude of BP lowering has clinical and public health relevance for reducing cardiovascular and kidney outcomes. Third, our results highlight the importance of dietary sodium reduction in people with T2D, for which there are cost-effective population-level interventions.”

References

1. Pilla SJ, Yeh H, Mitchell CM, et al. Dietary patterns, sodium reduction, and blood pressure in type 2 diabetes: The DASH4D randomized clinical trial. JAMA Intern Med. Published online June 09, 2025. doi:10.1001/jamainternmed.2025.1580

2. Appel LJ, Moore TJ, Obarzanek E, et al. A clinical trial of the effects of dietary patterns on blood pressure. N Engl J Med. 1997;336(16):1117-1124. doi:10.1056/nejm199704173361601