Effects of extra virgin olive oil supplementation at two different low doses on lipid profile in mild hypercholesterolemic subjects: a randomised clinical trial.

Olive oil, the principal fat of Mediterranean Diet, is known to improve several cardiovascular risk factors at relatively high doses together with intensive modifications of dietary habits. Since this is hard to obtain in the long term, an intervention with encapsulated oil supplements might be more feasible. Aim of this preliminary study was to investigate the effects of the supplementation of a moderate amount of encapsulated extra virgin olive oil vs a lower dose in mildly hypercholesterolemic subjects, as part of their established diet, on blood lipid profile. A prospective randomized study was performed. Thirty-four mildly hypercholesterolemic subjects [age, mean+/-SD: 46+/-7 yr; total cholesterol (TC): 235+/-28 mg/dl] were randomly assigned to receive 2 g (group A) or 4 g (group B) per os of extra-virgin olive oil for 3 months. TC, triglycerides (TG), LDL cholesterol, HDL cholesterol, apolipoprotein A1 (Apo-AI), apolipoprotein B (Apo-B), and atherogenic index of plasma (AIP) were evaluated at the beginning and at the end of the study. In group B, but not in group A, a significant reduction of Apo-B values (7%) was observed; TG concentrations showed a trend towards reduction and Apo-A1 values a trend towards increase (9%). A significant decrease in Apo-B/Apo-A1 ratio (p<0.01) was also observed in group B. Extra virgin olive oil supplementation significantly decreased AIP from baseline in group B (p<0.05). The results of the present study seem to suggest that the daily supplementation, on top of the normal diet, of at least 4 g of extra virgin olive oil, in mildly hypercholesterolemic subjects, is associated to favorable modifications of the plasmatic lipid profile.