Purpose: Despite the fact that extra virgin olive oil (EVOO) is widely used in obese individuals to treat cardiovascular diseases, the role of EVOO on weight/fat reduction remains unclear. We investigated the effects of energy-restricted diet containing EVOO on body composition and metabolic disruptions related to obesity.
Methods: This is a randomized, double-blinded, placebo-controlled clinical trial in which 41 adult women with excess body fat (mean ± SD 27.0 ± 0.9 year old, 46.8 ± 0.6% of total body fat) received daily high-fat breakfasts containing 25 mL of soybean oil (control group, n = 20) or EVOO (EVOO group, n = 21) during nine consecutive weeks. Breakfasts were part of an energy-restricted normal-fat diets (-2090 kJ, ~32%E from fat). Anthropometric and dual-energy X-ray absorptiometry were assessed, and fasting blood was collected on the first and last day of the experiment.
Results: Fat loss was ~80% higher on EVOO compared to the control group (mean ± SE: -2.4 ± 0.3 kg vs. -1.3 ± 0.4 kg, P = 0.037). EVOO also reduced diastolic blood pressure when compared to control (-5.1 ± 1.6 mmHg vs. +0.3 ± 1.2 mmHg, P = 0.011). Within-group differences (P < 0.050) were observed for HDL-c (-2.9 ± 1.2 mmol/L) and IL-10 (+0.9 ± 0.1 pg/mL) in control group, and for serum creatinine (+0.04 ± 0.01 µmol/L) and alkaline phosphatase (-3.3 ± 1.8 IU/L) in the EVOO group. There was also a trend for IL-1β EVOO reduction (-0.3 ± 0.1 pg/mL, P = 0.060).
Conclusion: EVOO consumption reduced body fat and improved blood pressure. Our results indicate that EVOO should be included into energy-restricted programs for obesity treatment.
Keywords: Adiposity; Blood pressure; Body fat; Extra virgin olive oil; Monounsaturated fatty acid; Soybean oil.