Usefulness of Extra Virgin Olive Oil Minor Polar Compounds in the Management of Chronic Kidney Disease Patients

Abstract

Chronic kidney disease (CKD) is one of the most common chronic non-communicable degenerative diseases and it represents an important risk factor for cardiovascular morbidity and mortality. The Mediterranean diet, in which extra virgin olive oil (EVOO) is the main source of vegetal fats, represents a nutritional-diet regimen that is useful for the treatment of CKD and its comorbidities. We tested two different EVOOs, characterized by a high (Synergy) and medium (Luxolio) content of minor polar compounds (MPCs), detected by HPLC-DAD-MS analysis, in 40 nephropathic patients, at a dose of 40 mL/day for 9 weeks. We evaluated the effects of these two EVOOs on renal function, body composition, oxidative stress, and inflammatory state, after 9 weeks of EVOOs consumption (T1) and after 2 months of wash-out (T2). We observed an improvement of renal function biomarkers (estimated-glomerular filtration rate, albuminuria, azotemia, uric acid), lipid profile, oxidative stress, inflammatory parameters (erythrocyte sedimentation rate, C-reactive protein) and in body composition at T1. These healthy effects were greater and persisted over time after the wash-out period in Synergy patients. The high MPC EVOO content seems to exert an antioxidant and anti-inflammatory effect in nephropathic patients and these protective actions are maintained over time.

Keywords: antioxidant activity; chronic kidney disease; extra virgin olive oil; hydroxytyrosol; oleocanthal; polyphenols.

Figure 1

Flow-chart of the study. Abbreviations: BMI, body mass index; CKD, chronic kidney disease; EVOO, extra virgin olive oil; FORD, Free Oxygen Radical Defense; FORT, Free Oxygen Radical Test; IPAQ, International Physical Activity Questionnaire; MPCs, minor polar compounds; PREDIMED, Prevención con Dieta Mediterránea.

Figure 2

PREDIMED and IPAQ questionnaires. Abbreviations: IPAQ, International Physical Activity Questionnaire; PREDIMED, Prevención con Dieta Mediterránea.

Figure 3

Outline of the study results. Abbreviations: BCMI, body cell mass index CKD, chronic kidney disease; CRP, C-reactive protein; ECW, extra cellular water; e-GFR, estimated glomerular filtration rate; ESR, erythrocyte sediment rate; FORT, Free Oxygen Radical Test; ICW, intracellular cell water; IL, interleukin; MM, muscle mass; TBW, total body water; TG, triglycerides; UA, uric acid.