A factorial study of salt restriction and a low-fat/high-fibre diet in hypertensive subjects.
OBJECTIVE
To compare the independent and additive effects of sodium restriction and a low-fat, high polyunsaturated: saturated fatty acids (P:S) ratio, high-fibre diet upon blood pressure.


METHODS
A randomized, parallet, double-blind, placebo-controlled (for sodium) 2 x 2 factorial trial.


METHODS
Clinical.


METHODS
Ninety-five hypertensive subjects (mean blood pressure, 137/83 mmHg), mean age 53.5 years, consuming less than 30 ml ethanol/day were selected from community volunteers. Seventy-nine treated and twelve untreated hypertensives completed the trial.


METHODS
Subjects followed either a low-sodium, low-fat/high-fibre diet (less than 60 mmol sodium/day; 30% fat energy; P:S ratio = 1; 30-50 g fibre/day) or a low-sodium, normal-fat/normal-fibre diet (less than 60 mmol sodium/day; 40% fat energy; P:S ratio = 0.3; 15 g fibre/day) for 8 weeks. Half of each group received 100 mmol/day NaCl and the remainder received placebo.


METHODS
Blood pressure and blood lipids.


RESULTS
Sodium restriction significantly reduced standing and supine systolic blood pressure, with no effect upon diastolic blood pressure. The low-fat/high-fibre diet had no effect upon blood pressure, but significantly reduced total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol.


CONCLUSIONS
Sodium restriction reduced blood pressure and did not raise low-density lipoprotein cholesterol. A low-fat/high-fibre diet did not reduce blood pressure but lowered cholesterol levels. A combination of the two regimes has the greater potential for reducing cardiovascular risk in hypertensives.
Sciarrone
S E
SE
University Department of Medicine, Royal Perth Hospital, Western Australia.
Beilin
L J
LJ
Rouse
I L
IL
Rogers
P B
PB
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001794:Blood Pressure / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D004041:Dietary Fats / Q000008:administration & dosage*; D004043:Dietary Fiber / Q000008:administration & dosage*; D005163:Factor Analysis, Statistical; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000178:diet therapy* / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012982:Sodium, Dietary / Q000008:administration & dosage*
D004041:Dietary Fats; D004043:Dietary Fiber; D012982:Sodium, Dietary