Home-delivered DASH diet improves blood pressure and cholesterol outcomes

Black adults with high blood pressure who received dietitian counseling and home deliveries of groceries aligned with the DASH diet—meaning high in fruits, vegetables, whole grains, low-fat dairy, nuts, seeds, legumes and lean proteins—had an average overall reduction in systolic blood pressure of 7 mm Hg at three months overall and a 5 mm Hg reduction compared with participants who received only basic dietary guidance and a grocery stipend, according to a study presented at the American College of Cardiology's Annual Scientific Session (ACC.26).

Participants receiving grocery deliveries also saw a drop in low-density lipoprotein (LDL) cholesterol of 7 mg/dL, on average, compared with those receiving a stipend. The findings suggest that programs that increase access to groceries aligned with the DASH (Dietary Approaches to Stop Hypertension) diet could deliver health benefits comparable to those of common blood pressure and cholesterol-lowering medications, according to researchers.

We're very excited by the magnitude of the effects—it's really above and beyond what we anticipated. This study shows a real path forward for self-management among individuals with hypertension."

Stephen Juraschek, MD, PhD, associate professor of medicine at Harvard Medical School, associate professor of nutrition at the Harvard T.H. Chan School of Public Health and the study's first author

The study evaluated Black adults with hypertension (high blood pressure) living in food deserts where access to fresh produce and high-quality foods is limited. In the United States, hypertension is more common among Black adults than any other racial or ethnic group, leading to high rates of cardiovascular disease in this population. About 58% of Black adults have hypertension, compared with 48% of the overall U.S. adult population.

Prior studies by Juraschek and colleagues highlight the benefits of adhering to the heart-healthy DASH dietary pattern, with one study suggesting the DASH diet lowers the 10-year risk of atherosclerotic cardiovascular disease by nearly 14% in Black adults. For the new study, researchers sought to assess the benefits of a DASH intervention among Black adults with hypertension who might encounter challenges obtaining DASH-adherent foods.

Researchers enrolled 176 participants living in Boston area communities characterized by lower income and few grocery stores who had a resting systolic blood pressure between 120 mm Hg and 149 mm Hg despite being actively treated for hypertension. Participants were 60 years old, on average, and 80% were women. Half received home-delivered groceries ordered with personalized guidance from a dietitian, while half received monthly grocery stipends and a pamphlet explaining the DASH diet. In the group receiving grocery deliveries, dietitians used four principles to help participants prepare grocery lists and plan meals they could cook at home: prepare foods with seasonings other than salt; aim for a potassium-sodium ratio of two to one; restrict saturated fats to less than 7% of total calories; and follow a DASH pattern of eating that also limits processed foods and sugary items, in addition to salt and saturated fats.

"Everybody got to choose their own groceries for themselves and their families according to DASH principles with the assistance of a dietitian," Juraschek said. "We tried to keep things as general and simple as possible and allow for choice, so people were able to come up with different combinations to achieve these goals based on their food preferences."

At three months, participants receiving grocery deliveries showed a significantly greater drop in systolic blood pressure compared with the group receiving a grocery stipend, meeting the study's primary endpoint. Reductions in LDL cholesterol and diastolic blood pressure were also significantly greater in the group receiving grocery deliveries. The between-group differences in systolic blood pressure were also maintained at follow-up measurements taken three months after the grocery deliveries and stipends ended.

The findings add to a growing body of evidence pointing to the effects of nutrition on cardiovascular health, as well as the importance of addressing barriers that some people face in accessing foods to maintain a heart-healthy diet. Researchers said that health insurers, urban planners and public health practitioners could focus on policies and programs to make healthy foods more affordable and accessible as a means of improving health and preventing heart disease.

"What's exciting about a nutrition approach is that not only can there be multiple effects on blood pressure and cholesterol, but it can also be preventive moving forward, without some of the adverse effects or interactions you might see with some medications," Juraschek said.

The study was limited to one metropolitan area and lasted only three months. Although the grocery home-delivery program worked well in the Boston area, Juraschek said that it might not be feasible in more rural areas. He said that further studies could examine longer-term outcomes, additional endpoints for a more detailed picture of cardiovascular health, and outcomes in other high-risk populations such as patients with diabetes or those with systolic blood pressure over 150 mm Hg.

The study was funded by the National Institute of Minority Health and Health Disparities of the National Institutes of Health.

This study was simultaneously published online in Nature Medicine at the time of presentation.

Juraschek will present the study, "DASH-patterned Groceries Reduce Blood Pressure Among Adults with Treated Hypertension: Results from the GoFreshRx Randomized Clinical Trial," on Saturday, March 28, at 3:45 p.m. CT / 20:45 UTC in the Main Tent, Great Hall.