The effect of a dietary portfolio compared to a DASH-type diet on blood pressure

- The DASH diet has become generally accepted as a hypertension and cardiovascular risk reduction strategy.
- The Dietary Portfolio, developed to lower LDL, also has food components that lower blood pressure (BP).
- A previously published study of the Dietary Portfolio suggested the possibility for a BP lowering effect.
- Thus we conducted a secondary analysis comparing a DASH (control) with a Portfolio (test) diet in relation to BP.
- This study indicates that the Dietary Portfolio has BP and cardiovascular risk reduction potential.

Background and aimCompared to a DASH-type diet, an intensively applied dietary portfolio reduced diastolic blood pressure at 24 weeks as a secondary outcome in a previous study. Due to the importance of strategies to reduce blood pressure, we performed an exploratory analysis pooling data from intensively and routinely applied portfolio treatments from the same study to assess the effect over time on systolic, diastolic and mean arterial pressure (MAP), and the relation to sodium (Na+), potassium (K+), and portfolio components.Methods and results241 participants with hyperlipidemia, from four academic centers across Canada were randomized and completed either a DASH-type diet (control n = 82) or a dietary portfolio that included, soy protein, viscous fibers and nuts (n = 159) for 24 weeks. Fasting measures and 7-day food records were obtained at weeks 0, 12 and 24, with 24-h urines at weeks 0 and 24. The dietary portfolio reduced systolic, diastolic and mean arterial blood pressure compared to the control by 2.1 mm Hg (95% CI, 4.2 to −0.1 mm Hg) (p = 0.056), 1.8 mm Hg (CI, 3.2 to 0.4 mm Hg) (p = 0.013) and 1.9 mm Hg (CI, 3.4 to 0.4 mm Hg) (p = 0.015), respectively. Blood pressure reductions were small at 12 weeks and only reached significance at 24 weeks. Nuts, soy and viscous fiber all related negatively to change in mean arterial pressure (ρ = −0.15 to −0.17, p ≤ 0.016) as did urinary potassium (ρ = −0.25, p = 0.001), while the Na+/K+ ratio was positively associated (ρ = 0.20, p = 0.010).ConclusionsConsumption of a cholesterol-lowering dietary portfolio also decreased blood pressure by comparison with a healthy DASH-type diet.Clinical Trial Reg. No.NCT00438425, clinicaltrials.gov.