Can dietary interventions change diet and cardiovascular risk factors? A meta-analysis of randomized controlled trials.
OBJECTIVE
This study evaluated the effectiveness of dietary advice in primary prevention of chronic disease.


METHODS
A meta-analysis was conducted of 17 randomized controlled trials of dietary behavior interventions of at least 3 months' duration. Results were analyzed as changes in reported dietary fat intakes and biomedical measures (serum cholesterol, urinary sodium, systolic and diastolic blood pressure) in the intervention group minus changes in the control group at 3 to 6 months and 9 to 18 months of follow-up.


RESULTS
After 3 to 6 months, mean net changes in each of the five outcomes favored intervention. For dietary fat as a percentage of food energy, the change was -2.5% (95% confidence interval [CI] = -3.9%, -1.1%). Mean net changes over 9 to 18 months were as follows: serum cholesterol, -0.22 (95% CI = -0.39, -0.05) mmol/L; urinary sodium, -45.0 (95% CI = -57.1, -32.8) mmol/24 hours; systolic blood pressure, -1.9 (95% CI = -3.0, 0.8) mm Hg; and diastolic blood pressure, -1.2 (95% CI = -2.6, 0.2) mm Hg.


CONCLUSIONS
Individual dietary interventions in primary prevention can achieve modest improvements in diet and cardiovascular disease risk status that are maintained for 9 to 18 months.
Brunner
E
E
Department of Epidemiology and Public Health, University College London, England.
White
I
I
Thorogood
M
M
Bristow
A
A
Curle
D
D
Marmot
M
M
D002318:Cardiovascular Diseases / Q000517:prevention & control*; D002784:Cholesterol / Q000097:blood; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008297:Male; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D012964:Sodium / Q000652:urine; D012982:Sodium, Dietary / Q000008:administration & dosage
D004041:Dietary Fats; D012982:Sodium, Dietary; D002784:Cholesterol; D012964:Sodium