According to a clinical trial led by researchers at the Johns Hopkins Bloomberg School of Public Health, a modified version of the diet known to lower blood pressure, is also effective at lowering glucose in adults with type 2 diabetes.
The study is based on the dash diet developed in the mid-1990s by an interdisciplinary team of researchers supported by the National Institutes of Health to address hypertension in the general population. The dash diet highlights fruits, vegetables and low-fat dairy products, with low saturated fats and cholesterol.
To understand the impact of the dash diet in diabetic patients, a team led by Johns Hopkins researchers revised their diet for people with type 2 diabetes. Diabetes Dash-Dash4D-Diet is similar to the dash diet, but with low carbohydrates and high unsaturated fats. The researchers also reduced potassium levels in the DASH4D diet to improve safety in people with chronic kidney disease.
new studyIt will be released online on August 5th. Natural Medicinefound that the DASH4D diet helps participants with type 2 diabetes control glucose levels.
In this study, 89 participants with type 2 diabetes prepared meals for 20 weeks at a clinical research center for half the time on the Dash4D diet, modeled on what US adults normally eat. Participants' blood glucose levels were measured using a wearable continuous glucose monitoring (CGM) device.
A new study named Dash4D CGM found that when participants consumed the Dash4D diet, there was a clinically meaningful reduction in mean blood glucose levels and an increase in the average time associated with blood glucose in the recommended range compared to when consuming a standard diet. Participants who eat the Dash4D diet had blood glucose levels averaged 11 mg/dl lower than when eating standard diets, staying in an extra 75 minutes a day in the optimal blood glucose range.
Both effects are considered clinically meaningful for diabetic patients. This is because it can reduce the risk of heart disease, kidney disease, and other long-term negative effects of diabetes. Researchers hope that the results will incorporate the DASH4D diet into clinical guidelines and improve type 2 diabetes management in more populations.
“The original dash diet has long been recommended for people with diabetes and other health conditions because of its effectiveness in lowering blood pressure, but this is the first time a controlled study has shown significant improvements in glucose control,” said the senior study author. Elizabeth SelvinPhD, MPH, Director of Welch Center for Prevention, Epidemiology and Clinical Research, and Professor at the Department of Epidemiology at Bloomberg School.
“We saw greater improvements in participants with high blood sugar levels at the start of the trial.” Michael FanPhD, MHS, assistant professor at the Department of Epidemiology at Bloomberg School. “For those with the highest glucose levels (HBA1c above 8%), the Dash4D diet increased the optimal blood glucose range time for about three hours a day. This is a huge advantage.”
Diabetes and hypertension are prevalent due to unhealthy diets, mainly high in animal fat, sugar and salt. An estimated 35 million Americans suffer from type 2 diabetes, according to the Centers for Disease Control and Prevention. Several large clinical trials have shown that the dash diet limits meat, sugar salt, salty foods and sugar drinks, is rich in fruits, vegetables and whole grains, and is effective in lowering hypertension.
The Dash4D CGM research led by Selvin was part of a large Hopkins-led one Clinical trialsIt was released this spring. The main trials found that Dash4D diet lowered blood pressure among people with type 2 diabetes.
Of the 89 people who completed the Dash4D CGM study, 67% were women and 88% were African-American. Trained staff eventually prepared over 40,000 meals for participants on the central test site during the 2021-2024 study period. Each participant spent five weeks on the low-sodium Dash4D diet, five weeks on the high-sodium Dash4D diet, five weeks on the low-sodium and high-sodium standard diet in a random order. (Sodium levels were different to test the effect of sodium on hypertension.) Participants wore CGM devices for the third and fourth weeks of each 5-week meal period. All meals had the same calorie count.
“This trial design is what is called a 'crossover' design. We can compare participants to themselves under different dietary conditions, reduce interpersonal variability, increase statistical power, and detect meaningful treatment effects despite what sample sizes may initially appear small,” Selvin says.
For participants on the Dash4D diet, blood glucose levels generally did not change and were less likely to fall into the hypoglycemic range than standard diets.
“We are encouraged by these outcomes and believe this could have a significant impact on population health,” Fang said. “The Dash4D diet is specially designed to be sustainable and easy to follow.”
“Dash4D diet for glycemic control and glucose fluctuations in type 2 diabetes: a randomized crossover trial” co-authored by Michael Hun, Dan Wang, Casey Rebholz, Justin Ekov Chugui, Olive Tan, Nae Yo Wang, Christine Mitchell, Scott Pira, Lawrence Appel and Elizabeth Selvin.
This study was funded by the National Institutes of Diabetes and Gastrointestinal and Kidney Diseases (R01DK128900, K23DK128572, and K01DK138273) and the National Institutes of Heart, Lung and Blood (T32HL007024 and K23HL153774). Abbott Diabetes Care provided a CGM system for research.
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Media Contact: Jon Eichberger je@jhu.edu or Chris Henry khenry39@jhu.edu
