Randomised blind controlled trial of a high fibre, low fat and low sodium dietary regimen in mild essential hypertension.

Thirty-four patients with essential hypertension were allocated, in a controlled trial, to a treatment diet of high fibre, low fat and low sodium composition, or to a control diet by the hospital dietitian. Clinical observations were made by a separate 'blinded' nursing sister. After three months treatment, the modified diet-treated group showed a significant reduction in mean systolic (169.4 +/- 23.4 to 150.6 +/- 16.1 mmHg) and diastolic blood pressure (101.5 +/- 7.3 to 89.4 +/- 6.8 mmHg), accompanied by significant reductions in urinary sodium excretion (140.4 +/- 34.6 to 93.7 +/- 44 mmol/day) and weight (73.1 +/- 10 to 71.2 +/- 8.4 kg). The changes in control were; systolic 171.2 +/- 14.1 to 162.1 +/- 19.5 mmHg and diastolic pressure 97.2 +/- 10.8 to 91.7 +/- 9.7 mmHg. The mean differences in reductions between treated and control were 8.8 mmHg Systolic (95% confidence intervals: -2.6 to 21.2 mmHg) and 7.0 mmHg diastolic blood pressure (95% confidence intervals: 0.4 to 14.4 mmHg). The number of patients with normal blood pressure in the diet treated group at three months was double that in the control (eleven versus five). No relationships were shown between blood pressure changes and those of weight or urinary sodium excretion during the trial. The findings in this study are broadly in agreement with similar ones in essential hypertension and suggest that this form of dietary regimen has a clinically worthwhile hypotensive effect and this should be readily achievable in routine clinical practice.