WINSTON-SALEM, N.C. -- A diet rich in fruits, grains and low-fat dairy products has been shown to significantly lower blood pressure, but few Americans with high blood pressure are following it, according to research from Wake Forest University School of Medicine reported at the 22nd Annual Scientific Meeting of the American Society of Hypertension.
A review of self-reported dietary habits of more than 4,000 adults with hypertension found that only 22 percent were following the Dietary Approaches to Stop Hypertension (DASH) diet. National guidelines call for the diet to be part of lifestyle changes recommended for all hypertensive patients.
“Our study highlights the need to find better ways to implement these recommendations – from clear public health messages to reimbursement for dietary counseling for high-risk patients,” said lead researcher Philip Mellen, M.D., M.S., an assistant professor of internal medicine.
The DASH study, published in 1997, demonstrated that the diet significantly lowers blood pressure. But little is known about how well patients follow the diet. Using national survey data from 1999-2004 (National Health and Nutrition Examination and Survey – NHANES), Mellen and colleagues evaluated accordance with the DASH diet among adults with known hypertension. They also compared these findings to dietary patterns in hypertensive adults before the DASH study.
“Clinical studies have shown eating a diet rich in fruits, vegetables, grains and low-fat dairy can have a positive impact on vascular health, including lowering blood pressure,” said Mellen. “We wanted to know if hypertensive Americans were following this dietary approach.”
Based on self-reported dietary habits, Mellen and colleagues generated a DASH score that reflected intake of nine target nutrients (total fat, saturated fat, protein, cholesterol, fiber, calcium, magnesium, potassium and sodium). Individuals meeting approximately half of these targets were considered accordant with the DASH diet.
In the survey period covering 1999-2004 – the period after the DASH study – 22 percent of individuals with known hypertension were DASH-accordant. After accounting for a variety of factors that could have influenced the results, such as diabetes status and demographics, they found that blacks had 39 percent lower odds of being DASH-accordant than non-Hispanic whites. Individuals with more than a high-school education had 80 percent higher odds of DASH-accordance than those without a high-school diploma, and DASH-accordance was higher in older individuals and those with diabetes.
Compared to the survey period preceding the DASH study (1988-94), DASH-accordance was 8 percent lower in the current survey period. This difference was partially due to fewer people meeting dietary targets for intake of fat, fiber, and magnesium.
“We found low accordance with the diet and that the dietary patterns of adults with hypertension have actually deteriorated since the diet was introduced,” said Mellen. “Additional efforts are clearly needed to translate DASH into an effective tool to lower blood pressure and cardiovascular risk in hypertensive adults.”
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Media Contacts: Karen Richardson, krchrdsn@wfubmc.edu, or Shannon Koontz, shkoontz@wfubmc.edu, 336-716-4587.
Wake Forest University Baptist Medical Center is an academic health system comprised of North Carolina Baptist Hospital and Wake Forest University Health Sciences, which operates the university’s School of Medicine. U.S. News & World Report ranks Wake Forest University School of Medicine 18th in primary care and 44th in research among the nation's medical schools. It ranks 35th in research funding by the National Institutes of Health. Almost 150 members of the medical school faculty are listed in Best Doctors in America.