BP-Lowering Diet Is Widely Ignored
Only about one fifth of hypertensive Americans follow the government-endorsed DASH diet.
Philip Mellen, MD, assistant professor of internal medicine at Wake Forest University in Winston-Salem, N.C., reported that only about one fifth of adult hypertensives follow the Dietary Approaches to Stop Hypertension (DASH) diet.
The diet has been endorsed in the sixth and seventh reports of the U.S. Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI and VII) as one of several therapeutic lifestyle modifications for all patients with hypertension, or at increased risk of hypertension, irrespective of antihypertensive medication use. Based on high consumption of fruits, grains, and low-fat dairy products, the diet can reduce systolic and diastolic BP by 11.4 mm Hg and 5.5 mm Hg, respectively.
Dr. Mellen's team used data from the 1999-2004 National Health and Nutrition Examination Survey (NHANES) to examine the self-reported dietary habits of 4,386 hypertensive adults. The researchers developed a DASH score that reflected patients' consumption of nine target nutrients based on 24-hour dietary recall.
The nutrients included total fat, saturated fat, protein, cholesterol, fiber, calcium, magnesium, potassium, and sodium. Individuals who met approximately half of these targets were considered accordant with the DASH diet.
Results revealed that 21.7% of those with known hypertension were DASH-compliant. In comparison, a NHANES survey of 4,556 hypertensives spanning the period between 1988 and 1994—before the DASH diet was added to JNC guidelines—showed that 29.3% were DASH-accordant.
The study also found that subjects older than 40 years were 2.8 to 4.0 times more likely to follow the diet than younger people. African Americans were 39% less likely to be DASH-compliant than other racial or ethnic groups.
Offering reasons for the decline in adherence, Dr. Mellen observed that it is easier to opt for fast food than the labor-intensive DASH diet. Another possibility is that people have grown cynical about diets. “New diets with multiple purported benefits are frequently introduced, while later studies show that the diet actually offers no benefits. So patients may be skeptical about dietary claims.”