Objective: To investigate the lipid-lowering potential of a butter-fat modified through manipulations in bovine feeding to increase the unsaturated:saturated fatty acid ratio.
Design: Double-blind, randomised, cross-over intervention trial.
Setting: University of Auckland Human Nutrition Unit, New Zealand.
Subjects: Twenty healthy, male subjects.
Intervention: A residential trial in which all foods and beverages were provided during two intervention periods, comprising 3 weeks of high unsaturated 'modified' vs. 3 weeks of saturated 'control' butter feeding separated by a 4 week washout. Diets were of typical composition of 39 percentage energy (en%) fat (20 en% butter-fat), 48 en% CHO, 13 en% protein.
Results: There was a significant decrease in both total (P<0.05, -7.9%) and LDL-cholesterol (P<0.01, -9.5%) during modified butter feeding. There was no significant effect of treatment on a range of other risk factors including HDL-cholesterol, triglyceride, apolipoprotein A or B, nonesterified fatty acids (NEFA), haemostatic clotting factor VII and fibrinogen or glucose (P>0.05). Subjects were maintained in energy balance and there was no significant change in body weight during intervention. Butter-fat composition alone differed between treatments.
Conclusions: A significant improvement in cardiovascular risk can be achieved by moderate changes in dietary fatty acid profile, achieved through a common and well accepted food source, butter-fat.