A diet first made famous for lowering blood pressure may also help people with type 2 diabetes keep their blood sugar in check.
That’s the finding from a new clinical trial led by Johns Hopkins Bloomberg School of Public Health researchers.
The original plan, called the DASH diet—short for Dietary Approaches to Stop Hypertension—was developed in the mid-1990s with funding from the U.S. National Institutes of Health. It was designed to help lower blood pressure in the general population.
The diet focuses on eating plenty of fruits, vegetables, and low-fat dairy, while keeping saturated fat and cholesterol low. It also limits sugary and salty foods. Over the years, it has been widely recommended by doctors for better heart health.
The Johns Hopkins team wanted to see what would happen if the DASH diet was adapted specifically for people with type 2 diabetes. They created the DASH for Diabetes plan, also called DASH4D. Like the original DASH diet, it includes lots of fruits and vegetables, but it’s lower in carbohydrates and higher in healthy unsaturated fats.
These changes aim to help control blood sugar more effectively. The researchers also lowered potassium levels in the DASH4D diet so it would be safer for people with chronic kidney disease—a condition that is common in those with diabetes.
In the new study, published August 5 in Nature Medicine, 89 adults with type 2 diabetes took part in a carefully controlled experiment lasting 20 weeks. Participants ate all their meals at a clinical research center.
Half the time they followed the DASH4D diet, and the other half they ate a “standard” diet based on what the average American eats. Everyone’s blood sugar was tracked using a wearable continuous glucose monitor, which checks glucose levels throughout the day and night.
When participants were on the DASH4D diet, their average blood sugar levels were about 11 mg/dL lower compared to when they were on the standard diet. They also spent an extra 75 minutes per day in the healthy blood sugar range.
Both of these improvements are considered important for people with diabetes, because better glucose control can reduce the risk of serious complications like heart disease, kidney failure, and vision loss.
The benefits were even greater for those who started the trial with higher blood sugar levels. For people whose HbA1c—a long-term measure of blood sugar—was above 8%, the DASH4D diet increased their time in the healthy glucose range by around three hours per day.
This trial also confirmed earlier results showing that DASH4D lowers blood pressure in people with diabetes. In addition, blood sugar levels were more stable on DASH4D, with fewer highs and lows, and no increase in dangerous low blood sugar episodes.
The trial used a “crossover” design, meaning every participant tried each diet, making the results more reliable even with fewer people in the study. Most participants—67%—were women, and 88% were African American.
The research team prepared more than 40,000 meals during the study period between 2021 and 2024. Each person spent five weeks on each diet variation, with both low-sodium and high-sodium versions tested to also study blood pressure effects.
Type 2 diabetes affects about 35 million Americans, and high blood pressure is also widespread. Both conditions are linked to diets high in animal fats, sugar, and salt.
The DASH4D diet, designed to be practical and easy to follow, may now offer a way to improve both blood pressure and blood sugar control. The researchers hope these findings will influence future dietary guidelines for people with diabetes.
This study shows that a simple change in diet can lead to meaningful improvements in blood sugar control for people with type 2 diabetes. Unlike many diet studies that rely on self-reported food intake, this trial provided all meals, ensuring accuracy.
The results were especially strong for those with poorer blood sugar control at the start, which means DASH4D could be particularly helpful for higher-risk patients. The fact that the diet is based on the already well-researched DASH plan makes it easier for healthcare providers to recommend.
However, the study involved a relatively small group and lasted only 20 weeks, so more research will be needed to see if the benefits last in real-world settings where people prepare their own food. Still, the evidence is strong enough to suggest that this eating plan could be a valuable tool in managing both diabetes and high blood pressure at the same time.
If you care about diabetes, please read studies about Scientists find a promising treatment for type 2 diabetes and findings of Certain type 2 diabetes treatment may bring heart risks.
For more information about diabetes, please read studies about New type 2 diabetes treatment could help patients stop taking insulin and findings of Scientists find true cause of inflammation in type 2 diabetes.
The study is published in Nature Medicine.
Copyright © 2025 Knowridge Science Report. All rights reserved.
