Effect of dietary protein supplementation on blood pressure: a randomized, controlled trial.

Study answer

What this study found

Soy and milk protein both lowered systolic blood pressure versus carbohydrate control, with no significant difference between the two proteins. The net change versus carbohydrate control was -2.0 mm Hg (95% CI -3.2 to -0.7; P = 0.002) for soy and -2.3 mm Hg (95% CI -3.7 to -1.0; P = 0.0007) for milk. Overall systolic BP change during the intervention phases was -1.5 (95% CI -2.4 to -0.6) for soy and -1.8 (95% CI -2.7 to -1.0) for milk, while carbohydrate changed 0.5 (95% CI -0.4 to 1.3); P = 0.0007. Diastolic BP changes were not significant. The authors concluded that partially replacing…

Study & population

Randomized controlled crossover trial in adults with prehypertension or stage 1 hypertension enrolled in New Orleans, Louisiana, and Jackson, Mississippi.

Intervention

Participants received either soy protein powder or milk protein powder, 40 g/day orally in water or juice, split twice daily in the morning and evening for 8 weeks per phase.

Key limitation

Each intervention phase was only 8 weeks, so long-term blood pressure effects are unknown.

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Original abstract