Effects of Adapted Mindfulness Training on Interoception and Adherence to the Dietary Approaches to Stop Hypertension (DASH) Diet: The MB-BP Randomized Clinical Trial

BACKGROUND: Hypertension is a major cause of cardiovascular disease. The Dietary Approaches to Stop Hypertension (DASH) diet lowers blood pressure (BP). However, adherence is typically low. Mindfulness training adapted to improving health behaviors that lower BP could improve DASH adherence, in part through improved interoceptive awareness relevant to dietary consumption. The primary objective of the MB-BP trial was to evaluate effects of the Mindfulness-Based Blood Pressure Reduction (MB-BP) program on interoceptive awareness. Secondary objectives assessed whether MB-BP impacts DASH adherence, and explored whether interoceptive awareness mediates DASH dietary changes. METHODS: Parallel-group phase 2 randomized clinical trial conducted from June 2017-November 2020 with 6 months follow-up. Data analyst was blinded to group allocation. Participants had elevated unattended office BP (≥120/80 mmHg). We randomized 201 participants to MB-BP (n=101) or enhanced usual care control (n=100). Loss-to-follow-up was 11.9%. Outcomes were the Multidimensional Assessment of Interoceptive Awareness (MAIA; range 0–5) score, and the DASH adherence score (range 0–11) assessed via a 163-item Food Frequency Questionnaire. RESULTS: Participants were 58.7% female, 81.1% non-Hispanic white, with mean age 59.5 years. Regression analyses demonstrated that MB-BP increased the MAIA score by 0.54 (95% CI: 0.35,0.74; p<.0001) at 6 months follow-up vs. control. MB-BP increased the DASH score by 0.62 (95% CI: 0.13,1.11; p=0.01) at 6 months vs. control, in participants with poor DASH adherence at baseline. CONCLUSIONS: A mindfulness training program adapted to improving health behaviors that lower BP improved interoceptive awareness and DASH adherence. MB-BP could support DASH dietary adherence in adults with elevated BP. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT03859076 (https://clinicaltrials.gov/ct2/show/NCT03859076; MAIA) and NCT03256890 (https://clinicaltrials.gov/ct2/show/NCT03256890; DASH diet adherence).