Double-blind, randomized feedback controls fails to improve the hypocholesterolemic effect of a plant-based low-fat diet in patients with moderately elevated total cholesterol levels

Abstract

Objective: To determine whether the cholesterol-lowering effect of a plant-based low-fat diet can be improved by a flexible control design that controls the extent of fat reduction based on the individual response of blood cholesterol. Design: Randomized, double-blind intervention study. Setting: A hotel in Prerow, Germany. Subjects: A total of 32 participants (21 female and 11 male participants) with total cholesterol level > 5.7 mmol/l. Intervention: The control group consumed a plant-based low-fat diet with constantly 20% of energy as fat; the intervention group received a diet with either 20 or 15% of energy as fat, depending on the serum cholesterol response of the preceding week. A flexible control design based on the individual cholesterol response during a run-in period of 1 week was used within a low-fat intervention. Results: During the run-in period, the consumption of a plant-based low-fat diet led to a reduction in total cholesterol by 18±6 mmol /l (P<0.001), in LDL cholesterol by 19±9 mmol/l (P<0.001) and triglycerides by 13±3 mmol/l (P<0.001). During the feedback control period, an additional reduction in total cholesterol by 13±8 (P<0.001) and in LDL cholesterol by 17±11 (P< 0.001) was observed compared to 15±15 and 7±18 in the control group. The effect of an additional feedback control was only marginal and not statistically significant compared to the effect of the low-fat diet alone. Conclusions: On a level of fat intake already reduced to 20% of energy, the use of a feedback control to adapt the fat content of the diet depending on the individual serum cholesterol response was not more effective in reducing blood cholesterol levels than a plant-based low-fat diet alone. © 2004 Nature Publishing Group. All rights reserved.