Diet modification in lowering plasma cholesterol levels. A randomised trial of three types of intervention

Abstract

Objective: To compare the efficacy of three types of diet and lifestyle interventions for lowering plasma lipid levels.

Design: Randomised parallel-group trial.

Subjects and setting: Adults with plasma cholesterol levels of 5.5-8.0 mmol/L attending two Sydney community health screening clinics were asked to participate: 179 agreed and 131 completed the study.

Interventions: A pamphlet with brief advice; group dietary counselling; or individual counselling. Counselling included three sessions with a dietitian/nutritionist over six months.

Main outcome measures: Plasma total cholesterol levels measured by Reflotron analyser; fasting serum lipid levels measured by standard laboratory methods; and calculated low-density lipoprotein cholesterol levels.

Results: Significantly lower plasma total cholesterol levels (Reflotron) were observed at two months and at six months with each of the three interventions. Additionally, both types of dietitian-based counselling resulted in small but significant decreases in plasma low-density lipoprotein cholesterol levels at six months in a subset of subjects.

Conclusion: Although there were no statistically significant differences in efficacy between the three types of intervention, dietitians have a role to play in setting up such counselling programs.