Comparing the effects of different extra virgin olive oil (EVOO) doses and polyphenols concentration on the lipidemic profile and hemodynamic parameters in patients with hyperlipidemia

Extra virgin olive oil (EVOO) polyphenols have antioxidant properties by reducing free radicals, and are also able to improve inflammatory and lipidemic profile of patients. Free radicals are involved in the oxidation of LDL cholesterol, which can be captured very efficiently by the antioxidative olive oil polyphenols. EVOO has also a very good nutritional and sensorial quality. Recent studies have showed that the consumption of EVOO is associated with the primary or secondary prevention of cardiovascular diseases. However, the question whether higher dose of EVOO with lower concentration of polyphenols or lower dose of EVOO with higher concentration of polyphenols still remains unanswered.

The aim of this study was to compare and evaluate the effects of different EVOO doses and polyphenols concentration on the lipidemic profile and hemodynamic indices in patients with hyperlipidemia.

Fifty patients (24♂, 26♀) with hyperlipidemia were randomized into 2 different groups. Patients of the first group (Group 1) consumed 8ml of EVOO of higher concentration of polyphenols, while patients of the second group (Group 2) consumed 20ml of EVOO of lower concentration of polyphenols daily for a month, so that to receive the same quantity of polyphenols. EVOO in group 1 contained 2,5 times higher concentration in polyphenols compared to EVOO of group 2. EVOO was provided supplementary to their medication, with patients maintaining their usual daily habits. Blood samples were collected from all patients before and after the intervention. Primary outcomes of our study were i. hemodynamic parameters including systolic (SAP) and diastolic (DAP) arterial pressure, oxygen saturation and heart rate, ii. weight and, iii. lipidemic profile including total cholesterol, low density lipoprotein, high density lipoprotein, triglycerides, lipoprotein (a), apolipoprotein A1 and apolipoprotein B. Secondary outcomes included different variables from blood count and biochemical blood tests.

After 1 month of EVOO consumption, patients who received lower dose of EVOO with higher polyphenols concentration demonstrated statistically significant improvement in SAP (Group 1:-2.4±11.9 mmHg vs Group 2:+3.7±8.3 mmHg; p=0.049) and CHOL (Group 1:-2.6±24.8 mg/dL vs Group 2:+14.5±33.8 mg/dL; p=0.045) compared to the group that received higher dose of EVOO with lower polyphenols concentration. The other parameters of interest in hemodynamics, weight and lipidemic profile were similar between groups (p>0.05). Moreover, no differences in the indices from the blood count and biochemical blood tests were observed between groups (p>0.05).

Lower doses of EVOO with higher concentration of polyphenols present significantly higher reduction of the systolic arterial pressure and total cholesterol compared to higher doses with lower concentration of polyphenols. More randomized controlled trials including larger samples are required.

Randomized groups receiving EVOO.