Chicago, IL - When researchers first published results from the Dietary Approaches to Stop Hypertension (DASH) study in 1997, they showed that following a diet rich in fruit, vegetables, and low-fat dairy products could lower systolic blood pressure by roughly 11 mm Hg. In the ensuing decade, however, Americans with hypertension, despite growing in number, were even less likely to adhere to the DASH diet than they were before the study came out, new research suggests.
Lead author on the study, Dr Philip B Mellen (Hattiesburg Clinic, MS), previously described the results of the study at the American Society of Hypertension 2007 Scientific Sessions, as reported by heartwire. The findings are now published in the February 11, 2008 issue of the Archives of Internal Medicine.
Mellen and colleagues compared accordance with the DASH diet among people who participated in the National Health and Nutrition Examination Survey (NHANES) from 1988 to 1994 with that of participants between 1999 and 2004. Using a nine-point DASH score to express adherence with nine nutrient targets, the authors report that mean DASH score was significantly lower, by 7.3%, in the later group than in the earlier group. In particular, patients surveyed during the later period were less likely to meet nutrient targets for total fat, fiber, and magnesium.
Adherence to DASH
| Criteria | 1988-1994 | 1999-2004 |
| Mean DASH score in hypertensives | 3.22 | 2.92 |
| Hypertensives adhering to DASH diet (%)* | 26.7 | 19.4 |
*Defined as DASH score >4.5 out of 9
"The dietary quality of adults with hypertension, as measured by DASH accordance, has deteriorated since the introduction of the DASH diet, suggesting that secular trends have minimized the impact of the DASH message," Mellen et al write. "These findings highlight the need for additional public-health and clinical-science initiatives to translate an efficacious intervention into an effective tool to lower blood pressure and cardiovascular risk."
In an interview with heartwire after first presenting the results last year, Mellen explained that it is increasingly difficult and expensive for people to eat well, in the face of cheap, low-nutrition foods. "We live in a free market in which the calorie-dense and nutrient-poor foods are much more profitable," Mellen told heartwire in May 2007. "That is a major underlying force determining the diet of the population. I think that as we're hearing more and more about the impending consequences of the obesity epidemic, which we really haven't even begun to fully realize, we can't abandon these lifestyle interventions. It calls on us to evaluate whether there are more ways to get this into the population."