Malloy-McFall Joan, Barkley Jacob E, Gordon Karen Lowry, Burzminski Nancy, Glickman Ellen L
The School of Health Sciences, Kent State University, Kent OH, USA.
Nutr Metab Insights. 2010 Mar 31;3:15-23. doi: 10.4137/NMI.S3871. eCollection 2010.
Dietary Approaches to Stop Hypertension (DASH) has been shown to successfully reduce systolic (SBP) and diastolic blood pressure (DBP) when evaluated in clinically controlled environments but there is a lack of information regarding the efficacy of the original DASH diet when it is applied in a free-living environment.
To provide descriptive data as to the changes in blood pressure individuals could expect to achieve when following the DASH diet in a free-living environment for 4-weeks with no additional behavioral modifications.
Twenty, pre- and stage 1 hypertensive participants were randomly split into 2 groups; DASH (males N = 5, females N = 5, age = 38.5 ± 10.8) and control (males N = 7, females N = 3, age = 38.1 ± 11.1). The DASH group was instructed on how to follow the DASH diet on their own for 4-weeks while the control group continued their normal diet. SBP, DBP, body weight, 3-day food diaries and physical activity recall questionnaire data were collected pre and post intervention using a traditional person-to-person instructional technique.
Two-way ANOVA demonstrated that there was a significant group (DASH, control) by time (pre, post) interaction for SBP (P = 0.003) and no significant effects for DBP. The interaction was due to a significant reduction (P < 0.001) in SBP in the DASH group (pre: 141.3 ± 11.3 mmHg vs. post: 130.7 ± 9.1 mmHg) over the course of the intervention with no change in SBP in the control group (pre: 133.5 ± 6.6 mmHg vs. post: 131.9 ± 8.9 mmHg). Pearson's correlation analyses revealed that changes in potential moderators of blood pressure including body weight, BMI, sodium intake and total kilocalories were each not associated with changes in SBP (r ≤ 0.14, P ≥ 0.5) or DBP (r ≤ 0.10, P ≥ 0.6) pre- to post-treatment. Chi-square demonstrated no significant differences in the number of participants per group (n = 4 DASH, n = 1 control) who indicated increasing physical activity during the intervention.
DASH diet followed in a free-living environment significantly reduced SBP but not DBP. However, the changes in SBP and DBP were very similar to those noted in controlled clinical feeding evaluations of the DASH diet. Presently, none of the potential moderators of blood pressure that were assessed were independently associated with the observed changes in blood pressure which may be due to our small sample size or the possibility that it is the combined change in multiple factors that lead to reductions in blood pressure when following the DASH diet.
在临床对照环境中评估时，饮食预防高血压（DASH）方案已被证明能成功降低收缩压（SBP）和舒张压（DBP），但在自由生活环境中应用原始DASH饮食的效果相关信息却很缺乏。
提供描述性数据，说明个体在自由生活环境中遵循DASH饮食4周且无额外行为改变时，血压可能发生的变化。
20名高血压前期和1期高血压参与者被随机分为2组；DASH组（男性N = 5，女性N = 5，年龄 = 38.5±10.8）和对照组（男性N = 7，女性N = 3，年龄 = 38.1±11.1）。DASH组被告知如何自行遵循DASH饮食4周，而对照组继续其正常饮食。使用传统的面对面指导技术，在干预前后收集SBP、DBP、体重、3天食物日记和身体活动回忆问卷数据。
双向方差分析表明，SBP存在显著的组（DASH组、对照组）×时间（干预前、干预后）交互作用（P = 0.003），而DBP无显著影响。该交互作用是由于DASH组在干预过程中SBP显著降低（P < 0.001）（干预前：141.3±11.3 mmHg，干预后：130.7±9.1 mmHg），而对照组SBP无变化（干预前：133.5±6.6 mmHg，干预后：131.9±8.9 mmHg）。Pearson相关分析显示，血压潜在调节因素的变化，包括体重、BMI、钠摄入量和总千卡数，在治疗前后与SBP（r≤0.14，P≥0.5）或DBP（r≤0.10，P≥0.6）的变化均无关联。卡方检验表明，两组中表示在干预期间增加身体活动的参与者数量无显著差异（DASH组n = 4，对照组n = 1）。
在自由生活环境中遵循DASH饮食可显著降低SBP，但对DBP无影响。然而，SBP和DBP的变化与DASH饮食的对照临床喂养评估中所记录的变化非常相似。目前，所评估的血压潜在调节因素均未与观察到的血压变化独立相关，这可能是由于我们的样本量较小，或者是因为遵循DASH饮食时，可能是多种因素的综合变化导致血压降低。
