The PREMIER Intervention Helps Participants Follow the Dietary Approaches to Stop Hypertension Dietary Pattern and the Current Dietary Reference Intakes Recommendations

Abstract

Objective To examine the influence of the PREMIER study lifestyle interventions on dietary intakes and adherence to the Dietary Approaches to Stop Hypertension (DASH) dietary pattern and the Dietary Reference Intakes (DRI). Design An 18-month multicenter, randomized controlled trial comparing two multicomponent lifestyle intervention programs to an advice only control group. Subjects/setting A total of 810 participants were recruited from local communities and randomized into the study. Individuals were eligible if they were aged 25 years or older, had body mass index between 18.5 and 45.0, not taking antihypertensive medication, and had prehypertension or stage 1 hypertension (systolic blood pressure 120 to 159 mm Hg and diastolic blood pressure 80 to 95 mm Hg). Intervention The two active intervention programs were a behavioral lifestyle intervention that implements established recommendations, and an established intervention plus the DASH dietary pattern. Both interventions consisted of intensive group and individual counseling sessions. The control group received a brief advice session after randomization and again after 6 months of data collection. Dietary intakes were collected by two random 24-hour recalls at baseline, 6 months, and 18 months. Main outcome measures The primary outcome of the PREMIER study was change in systolic blood pressure at 6 months. The main outcomes examined here include dietary variables collected by 24-hour recall at each time point. Statistical analyses Nutrient intakes were calculated and compared among the time points and the three intervention groups using mixed models with repeated measures at 6 and 18 months. Proportion of participants who met or achieved the original DASH nutrient intake levels and the DRIs were calculated and compared among the three intervention groups. P<0.01 was considered statistically significant. Results Participants in both the established intervention and established intervention plus DASH dietary pattern groups substantially reduced energy, total fat, saturated fat, and sodium intake and these reductions persisted throughout the study. Established intervention plus DASH dietary pattern group participants increased intakes of fruits, vegetables, dairy, and many vitamins and minerals; these increases were significantly greater than that of the control and established intervention groups. A majority of established intervention plus DASH dietary pattern group participants achieved at least two thirds of the DRI recommendations for most nutrients at 6 months, despite their reduction in total energy intake. Some but relatively small recidivism occurred at 18 months. Conclusions Both the established intervention and established intervention plus DASH dietary pattern group intervention were effective in helping participants follow established recommendations to control blood pressure. The advice-only control group also made some behavior changes, mainly decreasing energy and sodium intake. Only the established intervention plus DASH dietary pattern group significantly increased intakes of DASH-specific food groups, including fruits, vegetables, and dairy products, and nutrients, including protein, fiber, calcium, potassium, and magnesium. Most of the increases did not reach the levels consumed in the original DASH feeding studies. Whereas the established intervention plus DASH dietary pattern group intervention provides a useful platform to achieve the DASH dietary pattern and current DRI recommendations, intervention enhancements, including a greater emphasis on nutrient-dense foods, would likely improve this intervention.