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

BACKGROUND AND AIM

Compared 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 RESULTS

241 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).

CONCLUSIONS

Consumption 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.

Nut consumption, serum fatty acid profile and estimated coronary heart disease risk in type 2 diabetes

BACKGROUND AND AIMS

Nut consumption has been associated with decreased risk of coronary heart disease (CHD) and type 2 diabetes which has been largely attributed to their healthy fatty acid profile, yet this has not been ascertained. Therefore, we investigated the effect of nut consumption on serum fatty acid concentrations and how these relate to changes in markers of glycemic control and calculated CHD risk score in type 2 diabetes.

METHODS AND RESULTS

117 subjects with type 2 diabetes consumed one of three iso-energetic (mean 475 kcal/d) supplements for 12 weeks: 1. full-dose nuts (50-100 g/d); 2. half-dose nuts with half-dose muffins; and 3. full-dose muffins. In this secondary analysis, fatty acid concentrations in the phospholipid, triacylglycerol, free fatty acid, and cholesteryl ester fractions from fasting blood samples obtained at baseline and week 12 were analyzed using thin layer and gas chromatography. Full-dose nut supplementation significantly increased serum oleic acid (OA) and MUFAs compared to the control in the phospholipid fraction (OA: P = 0.036; MUFAs: P = 0.024). Inverse associations were found with changes in CHD risk versus changes in OA and MUFAs in the triacylglycerol (r = -0.256, P = 0.011; r = -0.228, P = 0.024, respectively) and phospholipid (r = -0.278, P = 0.006; r = -0.260, P = 0.010, respectively) fractions. In the cholesteryl ester fraction, change in MUFAs was inversely associated with markers of glycemic control (HbA1c: r = -0.250, P = 0.013; fasting blood glucose: r = -0.395, P < 0.0001).

CONCLUSION

Nut consumption increased OA and MUFA content of the serum phospholipid fraction, which was inversely associated with CHD risk factors and 10-year CHD risk.

CLINICAL TRIAL REG NO

NCT00410722, clinicaltrials.gov.