Summary
Olive oil is often praised for its heart-healthy fats, but part of its power actually comes from special plant compounds called polyphenols. Two of the most important—oleocanthal and oleacein—have strong anti-inflammatory and antioxidant effects in lab studies. This research set out to see whether those benefits also show up in real people, especially those who need extra metabolic support, like individuals with prediabetes and obesity.
In this study, adults between 40 and 65 swapped out their usual cooking oil for either a polyphenol-rich extra virgin olive oil (EVOO) or a more common olive oil (OO) for one month. They didn’t have to change anything else about their diet or lifestyle. Because the study was randomized, double-blind, and crossover, every participant tried both oils at different times—making it easier to see which effects came from which oil.
The results were pretty striking. When people used the high-polyphenol EVOO, their bodies showed signs of lower inflammation, including a measurable drop in interferon-γ, a key inflammatory marker. Their antioxidant status improved, and harmful lipid and organic peroxides went down. Even more compelling, participants lost a small amount of weight, lowered their BMI, and had better blood glucose levels—benefits that did not appear with the regular olive oil.
In short, adding EVOO rich in oleocanthal and oleacein to the daily diet helped improve inflammation, oxidative stress, and some metabolic markers in people at high risk for diabetes. While both oils are technically “olive oil,” this study shows that the type of olive oil matters, and that polyphenol-rich EVOO can offer meaningful health advantages.
PMID: 37421852
DOI: 10.1016/j.clnu.2023.06.027
Abstract
Background: Oleocanthal and oleacein are olive oil phenolic compounds with well known anti-inflammatory and anti-oxidant properties. The main evidence, however, is provided by experimental studies. Few human studies have examined the health benefits of olive oils rich in these biophenols. Our aim was to assess the health properties of rich oleocanthal and oleacein extra virgin olive oil (EVOO), compared to those of common olive oil (OO), in people with prediabetes and obesity.
Methods: Randomised, double-blind, crossover trial done in people aged 40-65 years with obesity (BMI 30-40 kg/m2) and prediabetes (HbA1c 5.7-6.4%). The intervention consisted in substituting for 1 month the oil used for food, both raw and cooked, by EVOO or OO. No changes in diet or physical activity were recommended. The primary outcome was the inflammatory status. Secondary outcomes were the oxidative status, body weight, glucose handling and lipid profile. An ANCOVA model adjusted for age, sex and treatment administration sequence was used for the statistical analysis.
Results: A total of 91 patients were enrolled (33 men and 58 women) and finished the trial. A decrease in interferon-γ was observed after EVOO treatment, reaching inter-treatment differences (P = 0.041). Total antioxidant status increased and lipid and organic peroxides decreased after EVOO treatment, the changes reaching significance compared to OO treatment (P < 0.05). Decreases in weight, BMI and blood glucose (p < 0.05) were found after treatment with EVOO and not with OO.
Conclusions: Treatment with EVOO rich in oleocanthal and oleacein differentially improved oxidative and inflammatory status in people with obesity and prediabetes.
Keywords: Inflammation; Obesity; Oleacein; Oleocanthal; Olive oil; Prediabetes.
Ruiz-García I, Ortíz-Flores R, Badía R, García-Borrego A, García-Fernández M, Lara E, Martín-Montañez E, García-Serrano S, Valdés S, Gonzalo M, Tapia-Guerrero MJ, Fernández-García JC, Sánchez-García A, Muñoz-Cobos F, Calderón-Cid M, El-Bekay R, Covas MI, Rojo-Martínez G, Olveira G, Romero-Zerbo SY, Bermúdez-Silva FJ. Rich oleocanthal and oleacein extra virgin olive oil and inflammatory and antioxidant status in people with obesity and prediabetes. The APRIL study: A randomised, controlled crossover study. Clin Nutr. 2023 Aug;42(8):1389-1398. doi: 10.1016/j.clnu.2023.06.027. Epub 2023 Jun 28. PMID: 37421852.