High polyphenol olive oil

The effect of high-polyphenol extra virgin olive oil on cardiovascular risk factors: A systematic review and meta-analysis

Type of study: meta-analysis

Number of citations: 126

Year: 2018

Authors: E. George, Skye Marshall, H. Mayr, G. Trakman, O. A. Tatucu-Babet, Annie-Claude M Lassemillante, A. Bramley, A. Reddy, A. Forsyth, A. Tierney, Colleen J. Thomas, C. Itsiopoulos, W. Marx

Journal: Critical Reviews in Food Science and Nutrition

Journal ranking: Q1

Key takeaways: High-polyphenol extra virgin olive oil significantly improves cardiovascular disease risk factors compared to low polyphenol olive oil, but further long-term and non-Mediterranean studies are needed.

Abstract: Abstract The polyphenol fraction of extra-virgin olive oil may be partly responsible for its cardioprotective effects. The aim of this systematic review and meta-analysis was to evaluate the effect of high versus low polyphenol olive oil on cardiovascular disease (CVD) risk factors in clinical trials. In accordance with PRISMA guidelines, CINAHL, PubMed, Embase and Cochrane databases were systematically searched for relevant studies. Randomized controlled trials that investigated markers of CVD risk (e.g. outcomes related to cholesterol, inflammation, oxidative stress) were included. Risk of bias was assessed using the Jadad scale. A meta-analysis was conducted using clinical trial data with available CVD risk outcomes. Twenty-six studies were included. Compared to low polyphenol olive oil, high polyphenol olive oil significantly improved measures of malondialdehyde (MD: −0.07µmol/L [95%CI: −0.12, −0.02µmol/L]; I2: 88%; p = 0.004), oxidized LDL (SMD: −0.44 [95%CI: −0.78, −0.10µmol/L]; I2: 41%; P = 0.01), total cholesterol (MD 4.5 mg/dL [95%CI: −6.54, −2.39 mg/dL]; p<0.0001) and HDL cholesterol (MD 2.37 mg/dL [95%CI: 0.41, 5.04 mg/dL]; p = 0.02). Subgroup analyses and individual studies reported additional improvements in inflammatory markers and blood pressure. Most studies were rated as having low-to-moderate risk of bias. High polyphenol oils confer some CVD-risk reduction benefits; however, further studies with longer duration and in non-Mediterranean populations are required.

Exploring the Cardiovascular Benefits of Extra Virgin Olive Oil: Insights into Mechanisms and Therapeutic Potential

Type of study: literature review

Number of citations: 3

Year: 2025

Authors: Esposito Milena, Mandalà Maurizio

Journal: Biomolecules

Journal ranking: Q1

Key takeaways: Extra Virgin Olive Oil (EVOO) offers robust cardiovascular benefits due to its unique composition of monounsaturated fatty acids and bioactive polyphenols, reducing major modifiable risk factors and improving endothelial function.

Abstract: Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide, driven by complex interactions among genetic, environmental, and lifestyle factors, with diet playing a pivotal role. Extra Virgin Olive Oil (EVOO), a cornerstone of the Mediterranean diet (MedDiet), is a plant-based fat that has garnered attention for its robust cardiovascular benefits, which are attributed to its unique composition of monounsaturated fatty acids (MUFAs), particularly oleic acid (OA); and bioactive polyphenols, such as Hydroxytyrosol (HT) and oleocanthal. These compounds collectively exert antioxidant, anti-inflammatory, vasodilatory, and lipid-modulating effects. Numerous clinical and preclinical studies have demonstrated that EVOO’s properties reduce major modifiable cardiovascular risk factors, including hypertension, dyslipidemia, obesity, and type 2 diabetes. EVOO also promotes endothelial function by increasing nitric oxide (NO) bioavailability, thus favoring vasodilation, lowering blood pressure (BP), and supporting vascular integrity. Furthermore, it modulates biomarkers of cardiovascular health, such as C-reactive protein, low-density lipoprotein (LDL) cholesterol, and NT-proBNP, aligning with improved hemostatic balance and reduced arterial vulnerability. Emerging evidence highlights its interaction with gut microbiota, further augmenting its cardioprotective effects. This review synthesizes current evidence, elucidating EVOO’s multifaceted mechanisms of action and therapeutic potential. Future directions emphasize the need for advanced extraction techniques, nutraceutical formulations, and personalized dietary recommendations to maximize its health benefits. EVOO represents a valuable addition to dietary strategies aimed at reducing the global burden of cardiovascular diseases.

Protective effects of oleic acid and polyphenols in extra virgin olive oil on cardiovascular diseases

Type of study: literature review

Number of citations: 44

Year: 2023

Authors: Yan Lu, Jun Zhao, Qiqi Xin, Rong Yuan, Yul Miao, Keji Chen, Weihong Cong

Journal: Food Science and Human Wellness

Journal ranking: Q1

Key takeaways: Extra virgin olive oil's oleic acid and polyphenols may help combat cardiovascular diseases risk factors like oxidative stress, inflammation, blood pressure, endothelial function, and cholesterol.

Abstract: The Mediterranean diet has long been recognized as one of the most effective ways to prevent and improve cardiovascular disease. Extra virgin olive oil (EVOO) is the typical sources of fat in the Mediterranean diet which have been shown to have noteworthy nutritional value and positive impact on human health. It is worth noting that EVOO owes its superior nutritional value to its bioactive composition. The main component of EVOO is monounsaturated fatty acids (MUFAs) in the form of oleic acid. Oleic acid accounts for up to 70%-80% of EVOO. Secondly, EVOO contains approximately more than 30 phenolic compounds, of which HT is essential for the protection against CVDs. In this review, we focused on the potential mechanisms of oleic acid and polyphenols combat cardiovascular diseases risk in terms of oxidative stress, inflammation, blood pressure, endothelial function and cholesterol. This review might provide a reference for the studies on cardiovascular protective effects of EVOO.

A review on management of cardiovascular diseases by olive polyphenols

Type of study: literature review

Number of citations: 41

Year: 2020

Authors: A. Mehmood, Muhammad Usman, P. Patil, Lei Zhao, Chengtao Wang

Journal: Food Science & Nutrition

Journal ranking: Q1

Key takeaways: Olive oil's polyphenols, such as oleuropein and tyrosol, play a crucial role in managing cardiovascular diseases, such as hypercholesterolemia, hypertension, and atherosclerosis.

Abstract: Abstract Noncommunicable diseases have increasingly grown the cause of morbidities and mortalities worldwide. Among them, cardiovascular diseases (CVDs) continue to be the major contributor to deaths. CVDs are common in the urban community population due to the substandard living conditions, which have a significant impact on the healthcare system, and over 23 million human beings are anticipated to suffer from the CVDs before 2030. At the moment, CVD physicians are immediately advancing both primary and secondary prevention modalities in high‐risk populations. The cornerstone of CVD prevention is a healthy lifestyle that is more cost‐effective than the treatments after disease onset. In fact, in the present scenario, comprehensive research conducted on food plant components is potentially efficacious in reducing some highly prevalent CVD risk factors, such as hypercholesterolemia, hypertension, and atherosclerosis. Polyphenols of olive oil (OO), virgin olive oil (VOO), and extra virgin olive oil contribute an essential role for the management of CVDs. Olive oil induces cardioprotective effects due to the presence of a plethora of polyphenolic compounds, for example, oleuropein (OL), tyrosol, and hydroxytyrosol. The present study examines the bioavailability and absorption of major olive bioactive compounds, for instance, oleacein, oleocanthal, OL, and tyrosol. This review also elucidates the snobbish connection of olive polyphenols (OP) and the potential mechanism involved in combating various CVD results taken up from the in vitro and in vivo studies, such as animal and human model studies.

Effects of high phenolic olive oil on cardiovascular risk factors: A systematic review and meta-analysis.

Type of study: meta-analysis

Number of citations: 104

Year: 2015

Authors: Christoph Hohmann, H. Cramer, Andreas Michalsen, C. Kessler, N. Steckhan, K. Choi, G. Dobos

Journal: Phytomedicine : international journal of phytotherapy and phytopharmacology

Journal ranking: Q1

Key takeaways: High phenolic olive oil provides small beneficial effects on systolic blood pressure and serum oxidative status, making it a potential nutraceutical for cardiovascular prevention.

Extra virgin olive oil high in polyphenols improves antioxidant status in adults: a double-blind, randomized, controlled, cross-over study (OLIVAUS)

Type of study: rct

Number of citations: 22

Year: 2021

Authors: K. Sarapis, E. George, W. Marx, H. Mayr, J. Willcox, T. Esmaili, Katie L. Powell, Oladayo S Folasire, A. Lohning, M. Garg, Colleen J. Thomas, C. Itsiopoulos, G. Moschonis

Journal: European Journal of Nutrition

Journal ranking: Q1

Key takeaways: High polyphenol olive oil improves antioxidant status and reduces inflammation in adults, with more pronounced effects in those with high cardiometabolic risk.

Abstract: PurposeOlive oil polyphenols have been associated with cardiovascular health benefits. This study examined the antioxidant and anti-inflammatory effect of extra-virgin high polyphenol olive oil (HPOO) vs. low polyphenol olive oil (LPOO) in healthy Australian adults.MethodsIn a double-blind cross-over trial, 50 participants (aged 38.5 ± 13.9 years, 66% females) were randomized to consume 60 mL/day of HPOO (320 mg/kg polyphenols) or LPOO (86 mg/kg polyphenols) for three weeks. Following a 2-week wash-out period, participants crossed-over to the alternate treatment. Plasma oxidized low-density lipoprotein (ox-LDL), total antioxidant capacity (TAC), high-sensitivity C-reactive protein (hs-CRP) and anthropometrics were measured at baseline and follow-up.ResultsFourty-three participants completed the study. Although there were no significant differences between treatments in the total sample, plasma ox-LDL decreased by 6.5 mU/mL (95%CI − 12.4 to − 0.5) and TAC increased by 0.03 mM (95% CI 0.006–0.05) only in the HPOO arm. Stratified analyses were also performed by cardiovascular disease risk status defined by abdominal obesity (WC > 94 cm in males, > 80 cm in females) or inflammation (hs-CRP > 1 mg/L). In the subgroup with abdominal obesity, ox-LDL decreased by 13.5 mU/mL (95% CI − 23.5 to − 3.6) and TAC increased by 0.04 mM (95% CI 0.006–0.07) only after HPOO consumption. In the subgroup with inflammation, hs-CRP decreased by 1.9 mg/L (95% CI − 3.7 to −0.1) only in the HPOO arm.ConclusionsAlthough there were no significant differences between treatments, the changes observed after HPOO consumption demonstrate the antioxidant and anti-inflammatory effect of this oil, which is more pronounced in adults with high cardiometabolic risk (Clinical Trial Registration: ACTRN12618000706279).

The Effect of High Polyphenol Extra Virgin Olive Oil on Blood Pressure and Arterial Stiffness in Healthy Australian Adults: A Randomized, Controlled, Cross-Over Study

Type of study: rct

Number of citations: 29

Year: 2020

Authors: K. Sarapis, Colleen J. Thomas, Johanna Hoskin, E. George, W. Marx, H. Mayr, Greg Kennedy, A. Pipingas, J. Willcox, L. Prendergast, C. Itsiopoulos, G. Moschonis

Journal: Nutrients

Journal ranking: Q1

Key takeaways: High polyphenol extra virgin olive oil significantly reduces peripheral and central systolic blood pressure in healthy Australian adults, but does not affect diastolic blood pressure or arterial stiffness.

Abstract: Extra virgin olive oil (EVOO) is suggested to be cardioprotective, partly due to its high phenolic content. We investigated the effect of extra virgin high polyphenol olive oil (HPOO) versus low polyphenol olive oil (LPOO) on blood pressure (BP) and arterial stiffness in healthy Australian adults. In a double-blind, randomized, controlled cross-over trial, 50 participants (age 38.5 ± 13.9 years, 66% female) were randomized to consume 60 mL/day of either HPOO (360 mg/kg polyphenols) or LPOO (86 mg/kg polyphenols) for three weeks. Following a two-week washout period, participants crossed over to consume the alternate oil. Anthropometric data, peripheral BP, central BP and arterial stiffness were measured at baseline and follow up. No significant differences were observed in the changes from baseline to follow up between the two treatments. However, a significant decrease in peripheral and central systolic BP (SBP) by 2.5 mmHg (95% CI: −4.7 to −0.3) and 2.7 mmHg (95% CI: −4.7 to −0.6), respectively, was observed after HPOO consumption. Neither olive oil changed diastolic BP (DBP) or measures of arterial stiffness. The reductions in SBP after HPOO consumption provide evidence for a potentially widely accessible dietary intervention to prevent cardiovascular disease in a multiethnic population. Longer intervention studies and/or higher doses of EVOO polyphenols are warranted to elucidate the potential effect on DBP and arterial stiffness.

Cardioprotective Effects of the Polyphenol Hydroxytyrosol from Olive Oil.

Type of study: literature review

Number of citations: 66

Year: 2017

Authors: S. Tejada, S. Pinya, María del Mar Bibiloni, J. Tur, A. Pons, A. Sureda

Journal: Current drug targets

Journal ranking: Q2

Key takeaways: Hydroxytyrosol from olive oil shows potential cardioprotective effects, but further clinical trials are needed for human clinical use.

Abstract: BACKGROUND The Mediterranean diet includes olive oil as its primary source of fat. This diet is frequently associated to longevity and a lower incidence of chronic diseases due to its biological activities and health effects. Apart from oleic acid, olive oil contains many bioactive components including polyphenols that have been reported to exert antioxidant and anti-inflammatory activities. Polyphenols may almost in part be responsible for the protective effects against cardiovascular diseases associated with olive oil. OBJECTIVE To review and discuss the available literature on hydroxytyrosol effects as a cardioprotective agent. Moreover, we also discuss the chemistry, nutritional aspects and bioavailability of hydroxytyrosol. RESULTS Hydroxytyrosol is one of the major phenolic compounds in olive oil and has demonstrated strong radical-scavenging properties. Several studies have been performed in order to look further into the effects of the polyphenol hydroxytyrosol in relation to cardiovascular events and illnesses in animal trials and in vitro. However, no clinical trials have focused on the specific action of hydroxytyrosol and cardiovascular diseases, although some are being undertaken to look at olive oil or olive leaf extract properties. CONCLUSION Hydroxytyrosol from olive oil exerts antioxidant, anti-inflammatory, anti-platelet aggregation and ati-atherogenic activities in in vitro and animal models. However, its possible therapeutic use in humans requires additional clinical trials.

Effect of polyphenol-rich extra-virgin olive oil on lipid profile and inflammatory biomarkers in patients undergoing coronary angiography: a randomised, controlled, clinical trial

Type of study: rct

Number of citations: 22

Year: 2020

Authors: Nafiseh Khandouzi, A. Zahedmehr, J. Nasrollahzadeh

Journal: International Journal of Food Sciences and Nutrition

Journal ranking: Q1

Key takeaways: Daily consumption of polyphenol-rich extra-virgin olive oil can improve LDL-C and selected inflammatory markers in patients undergoing coronary angiography.

Abstract: Abstract The present study was conducted to compare the effects of high polyphenol extra-virgin olive oil (EVOO) with low polyphenol refined olive oil (ROO) on some cardiovascular risk factors in patients undergoing coronary angiography. In a randomised, controlled, parallel-arm, clinical trial, 40 patients with at least one classic cardiovascular risk factor who referred to coronary angiography were randomly allocated to two groups and receied 25 mL EVOO or ROO daily for 6 weeks. Plasma LDL-cholesterol significantly reduced in EVOO group (–9.52 ± 20.44 vs 8.68 ± 18.77 mg/dL, p = .007 for EVOO and ROO respectively). EVOO resulted in a significant reduction in plasma CRP (–0.40 ± 0.52 vs 0.007 ± 0.42 mg/L, p = .01 for EVOO and ROO respectively) and increased ex-vivo whole blood LPS-stimulated IL-10 production (12.13 ± 33.64 vs −17.47 ± 49.04 pg/mL, p = .035 for EVOO and ROO respectively). Daily consumption of polyphenol-rich EVOO in subjects who have been under medical treatment with risk-reducing agents could additionally improve LDL-C and selected inflammatory markers. Trial Registration Number: NCT03796780

The Fluid Aspect of the Mediterranean Diet in the Prevention and Management of Cardiovascular Disease and Diabetes: The Role of Polyphenol Content in Moderate Consumption of Wine and Olive Oil

Type of study: literature review

Number of citations: 160

Year: 2019

Authors: P. Ditano-Vázquez, J. Torres-Peña, F. Galeano-Valle, Ana I. Perez-Caballero, P. Demelo-Rodríguez, J. López-Miranda, N. Katsiki, J. Delgado-Lista, L. Alvarez-Sala-Walther

Journal: Nutrients

Journal ranking: Q1

Key takeaways: The Mediterranean diet, including red wine and olive oil, is beneficial for cardiovascular health due to their polyphenol content, which improves lipid profile, insulin sensitivity, and endothelial function.

Abstract: A growing interest has emerged in the beneficial effects of plant-based diets for the prevention of cardiovascular disease, diabetes and obesity. The Mediterranean diet, one of the most widely evaluated dietary patterns in scientific literature, includes in its nutrients two fluid foods: olive oil, as the main source of fats, and a low-to-moderate consumption of wine, mainly red, particularly during meals. Current mechanisms underlying the beneficial effects of the Mediterranean diet include a reduction in inflammatory and oxidative stress markers, improvement in lipid profile, insulin sensitivity and endothelial function, as well as antithrombotic properties. Most of these effects are attributable to bioactive ingredients including polyphenols, mono- and poly-unsaturated fatty acids. Polyphenols are a heterogeneous group of phytochemicals containing phenol rings. The principal classes of red wine polyphenols include flavonols (quercetin and myricetin), flavanols (catechin and epicatechin), anthocyanin and stilbenes (resveratrol). Olive oil has at least 30 phenolic compounds. Among them, the main are simple phenols (tyrosol and hydroxytyrosol), secoroids and lignans. The present narrative review focuses on phenols, part of red wine and virgin olive oil, discussing the evidence of their effects on lipids, blood pressure, atheromatous plaque and glucose metabolism.

Effect of high polyphenol extra virgin olive oil on markers of cardiovascular disease risk in healthy Australian adults (OLIVAUS): A protocol for a double-blind randomised, controlled, cross-over study.

Type of study: rct

Number of citations: 9

Year: 2020

Authors: W. Marx, E. George, H. Mayr, Colleen J. Thomas, K. Sarapis, G. Moschonis, Greg Kennedy, A. Pipingas, J. Willcox, L. Prendergast, C. Itsiopoulos

Journal: Nutrition & dietetics: the journal of the Dietitians Association of Australia

Journal ranking: Q2

Key takeaways: High polyphenol extra virgin olive oil may provide a superior cardioprotective effect compared to low polyphenol olive oil in healthy non-Mediterranean Australian adults.

Abstract: BACKGROUND Previous clinical studies have suggested that high polyphenol extra virgin olive oil (EVOO) provides a superior cardioprotective effect compared to low polyphenol olive oil. However, further studies are required to replicate these results in non-Mediterranean populations. AIM To investigate the effect of high polyphenol EVOO versus low polyphenol olive oil with known polyphenol composition on markers of cardiovascular disease risk in a healthy non-Mediterranean cohort. METHODS In a double-blind randomised cross-over trial, the present study will examine the effect of high polyphenol EVOO versus low polyphenol olive oil in 50 healthy participants. Each intervention phase will be 3 weeks long with a 2-week washout period between each phase. Outcomes to be assessed include HDL cholesterol efflux, oxidised LDL, blood lipids, C-reactive protein, arterial stiffness, blood pressure and cognitive function. Dietary intake, physical activity levels and anthropometry will also be collected. DISCUSSION Because of the rigorous trial design, novel and clinically relevant outcomes, the use of a well-characterised EVOO, and, in contrast to the current literature, the non-Mediterranean study population, the present study will provide a significant contribution to the understanding of the clinical importance of polyphenol intake in the Australian sociocultural context.

The Effect of Polyphenols in Olive Oil on Heart Disease Risk Factors

Type of study: rct

Number of citations: 507

Year: 2006

Authors: M. Covas, Kristiina Nyyssnen, H. Poulsen, J. Kaikkonen, H. Zunft, H. Kiesewetter, A. Gaddi, R. de la Torre, J. Mursu, Hans Bumler, S. Nascetti, J. Salonen, Montserrat Fit, J. Virtanen, J. Marrugat

Journal: Annals of Internal Medicine

Journal ranking: Q1

Key takeaways: Virgin olive oil has greater polyphenol content, which may have greater health benefits than refined olive oil, but the increase in HDL cholesterol level was small.

Abstract: Context Olive oil, the main fat in the Mediterranean diet, contains polyphenols, which have antioxidant properties and may affect serum lipid levels. Contribution The authors studied virgin olive oil (high in polyphenols), refined olive oil (low in polyphenols), and a mixture of the 2 oils in equal parts. Two hundred healthy young men consumed 25 mL of an olive oil daily for 3 weeks followed by the other olive oils in a randomly assigned sequence. Olive oils with greater polyphenol content increased high-density lipoprotein (HDL) cholesterol levels and decreased serum markers of oxidation. Cautions The increase in HDL cholesterol level was small. Implications Virgin olive oil might have greater health benefits than refined olive oil. The Editors Polyphenol intake has been associated with low cancer and coronary heart disease (CHD) mortality rates (1). Antioxidant and anti-inflammatory properties and improvements in endothelial dysfunction and the lipid profile have been reported for dietary polyphenols (2). Studies have recently suggested that Mediterranean health benefits may be due to a synergistic combination of phytochemicals and fatty acids (3). Olive oil, rich in oleic acid (a monounsaturated fatty acid), is the main fat of the Mediterranean diet (4). To date, most of the protective effect of olive oil within the Mediterranean diet has been attributed to its high monounsaturated fatty acid content (5). However, if the effect of olive oil can be attributed solely to its monounsaturated fatty acid content, any type of olive oil, rapeseed or canola oil, or monounsaturated fatty acidenriched fat would provide similar health benefits. Whether the beneficial effects of olive oil on the cardiovascular system are exclusively due to oleic acid remains to be elucidated. The minor components, particularly the phenolic compounds, in olive oil may contribute to the health benefits derived from the Mediterranean diet. Among olive oils usually present on the market, virgin olive oils produced by direct-press or centrifugation methods have higher phenolic content (150 to 350 mg/kg of olive oil) (6). In experimental studies, phenolic compounds in olive oil showed strong antioxidant properties (7, 8). Oxidized low-density lipoprotein (LDL) is currently thought to be more damaging to the arterial wall than native LDL cholesterol (9). Results of randomized, crossover, controlled clinical trials on the antioxidant effect of polyphenols from real-life daily doses of olive oil in humans are, however, conflicting (10). Growing evidence suggests that dietary phenols (1115) and plant-based diets (16) can modulate lipid and lipoprotein metabolism. The Effect of Olive Oil on Oxidative Damage in European Populations (EUROLIVE) Study is a multicenter, randomized, crossover, clinical intervention trial that aims to assess the effect of sustained daily doses of olive oil, as a function of its phenolic content, on the oxidative damage to lipid and LDL cholesterol levels and the lipid profile as cardiovascular risk factors. Methods Participants We recruited healthy men, 20 to 60 years of age, from 6 European cities through newspaper and university advertisements. Of the 344 persons who agreed to be screened, 200 persons were eligible (32 men from Barcelona, Spain; 33 men from Copenhagen, Denmark; 30 men from Kuopio, Finland; 31 men from Bologna, Italy; 40 men from Postdam, Germany; and 34 men from Berlin, Germany) and were enrolled from September 2002 through June 2003 (Figure 1). Participants were eligible for study inclusion if they provided written informed consent, were willing to adhere to the protocol, and were in good health. We preselected volunteers when clinical record, physical examination, and blood pressure were strictly normal and the candidate was a nonsmoker. Next, we performed a complete blood count, biochemical laboratory analyses, and urinary dipstick tests to measure levels of serum glucose, total cholesterol, creatinine, alanine aminotransferase, and triglycerides. We included candidates with values within the reference range. Exclusion criteria were smoking; use of antioxidant supplements, aspirin, or drugs with established antioxidant properties; hyperlipidemia; obesity; diabetes; hypertension; intestinal disease; or any other disease or condition that would impair adherence. We excluded women to avoid the possible interference of estrogens, which are considered to be potential antioxidants (17). All participants provided written informed consent, and the local institutional ethics committees approved the protocol. Figure 1. Study flow diagram. Sequence of olive oil administration: 1) high-, medium-, and low-polyphenol olive oil; 2) medium-, low-, and high-polyphenol olive oil; and 3) low-, high-, and medium-polyphenol olive oil. Design and Study Procedure The trial was a randomized, crossover, controlled study. We randomly assigned participants consecutively to 1 of 3 sequences of olive oil administration. Participants received a daily dose of 25 mL (22 g) of 3 olive oils with high (366 mg/kg), medium (164 mg/kg), and low (2.7 mg/kg) polyphenol content (Figure 1) in replacement of other raw fats. Sequences were high-, medium-, and low-polyphenol olive oil (sequence 1); medium-, low-, and high-polyphenol olive oil (sequence 2); and low-, high-, and medium-polyphenol olive oil (sequence 3). In the coordinating center, we prepared random allocation to each sequence, taken from a Latin square, for each center by blocks of 42 participants (14 persons in each sequence), using specific software that was developed at the Municipal Institute for Medical Research, Barcelona, Spain (Aleator, Municipal Institute for Medical Research). The random allocation was faxed to the participating centers upon request for each individual included in the study. Treatment containers were assigned a code number that was concealed from participants and investigators, and the coordinating center disclosed the code number only after completion of statistical analyses. Olive oils were specially prepared for the trial. We selected a virgin olive oil with high natural phenolic content (366 mg/kg) and measured its fatty acid and vitamin E composition. We tested refined olive oil harvested from the same cultivar and soil to find an olive oil with similar quantities of fatty acid and a similar micronutrient profile. Vitamin E was adjusted to values similar to those of the selected virgin olive oil. Because phenolic compounds are lost in the refinement process, the refined olive oil had a low phenolic content (2.7 mg/kg). By mixing virgin and refined olive oil, we obtained an olive oil with an intermediate phenolic content (164 mg/kg). Olive oils did not differ in fat and micronutrient composition (that is, vitamin E, triterpenes, and sitosterols), with the exception of phenolic content. Three-week interventions were preceded by 2-week washout periods, in which we requested that participants avoid olive and olive oil consumption. We chose the 2-week washout period to reach the equilibrium in the plasma lipid profile because longer intervention periods with fat-rich diets did not modify the lipid concentrations (18). Daily doses of 25 mL of olive oil were blindly prepared in containers delivered to the participants at the beginning of each intervention period. We instructed participants to return the 21 containers at the end of each intervention period so that the daily amount of unconsumed olive oil could be registered. Dietary Adherence We measured tyrosol and hydroxytyrosol, the 2 major phenolic compounds in olive oil as simple forms or conjugates (7), by gas chromatography and mass spectrometry in 24-hour urine before and after each intervention period as biomarkers of adherence to the type of olive oil ingested. We asked participants to keep a 3-day dietary record at baseline and after each intervention period. We requested that participants in all centers avoid a high intake of foods that contain antioxidants (that is, vegetables, legumes, fruits, tea, coffee, chocolate, wine, and beer). A nutritionist also personally advised participants to replace all types of habitually consumed raw fats with the olive oils (for example, spread the assigned olive oil on bread instead of butter, put the assigned olive oil on boiled vegetables instead of margarine, and use the assigned olive oil on salads instead of other vegetable oils or standard salad dressings). Data Collection Main outcome measures were changes in biomarkers of oxidative damage to lipids. Secondary outcomes were changes in lipid levels and in biomarkers of the antioxidant status of the participants. We assessed outcome measures at the beginning of the study (baseline) and before (preintervention) and after (postintervention) each olive oil intervention period. We collected blood samples at fasting state together with 24-hour urine and recorded anthropometric variables. We measured blood pressure with a mercury sphygmomanometer after at least a 10-minute rest in the seated position. We recorded physical activity at baseline and at the end of the study and assessed it by using the Minnesota Leisure Time Physical Activity Questionnaire (19). We measured 1) glucose and lipid profile, including serum glucose, total cholesterol, high-density lipoprotein (HDL) cholesterol, and triglyceride levels determined by enzymatic methods (2023) and LDL cholesterol levels calculated by the Friedewald formula; 2) oxidative damage to lipids, including plasma-circulating oxidized LDL measured by enzyme immunoassay, plasma total F2-isoprostanes determined by using high-performance liquid chromatography and stable isotope-dilution and mass spectrometry, plasma C18 hydroxy fatty acids measured by gas chromatography and mass spectrometry, and serum LDL cholesterol uninduced conjugated dienes measured by spectrophotometry and adjusted for the cholesterol concentration in LDL cholesterol levels; 3) antioxidant sta

Olive Oil Consumption and Cardiovascular Protection: Mechanism of Action

Type of study: systematic review

Number of citations: 6

Year: 2022

Authors: S. Chrysant, G. Chrysant

Journal: Cardiology in Review

Journal ranking: Q2

Key takeaways: Increased olive oil consumption, along with a Mediterranean diet rich in vitamin E, polyphenols, and other ingredients, is associated with a significant reduction in cardiovascular diseases and mortality.

Abstract: Cardiovascular diseases (CVDs) are still the leading cause of death and disability worldwide, and they could be prevented by a diet modification and a healthy lifestyle. Dietary modifications include a reduction in the consumption of saturated fatty acids and replacing them with mono or polyunsaturated fatty acids. Olive oil is a monounsaturated fatty acid and its increased consumption has been associated with a significant reduction of CVDs. Its significant cardiovascular benefits have been attributed to its high content of vitamin E, polyphenols, and other ingredients that possess significant anti-inflammatory and antioxidant properties. Several prospective and epidemiological studies have reported an inverse association between olive oil consumption and the incidence of CVD, hypertension, and type 2 diabetes mellitus. Also, a seminal study demonstrated that the use of a Mediterranean diet, which is rich in olive oil, fruits, vegetables, and fish, and low in red meat, was associated with significant reductions in CVD and mortality. However, despite its proven cardiovascular benefits, olive oil is scarcely used in the United States and other Western countries. To determine the current use of olive oil in the United States and other Western countries, a Medline search of the English literature between 2012 and January 2022 was conducted, and 36 pertinent articles were selected. The data from these articles, together with collateral literature, will be discussed in this concise review.

Olive Oil Polyphenols Enhance High-Density Lipoprotein Function in Humans: A Randomized Controlled Trial

Type of study: rct

Number of citations: 136

Year: 2014

Authors: Á. Hernáez, S. Fernández-Castillejo, M. Farràs, Úrsula Catalán, I. Subirana, R. Montes, R. Solà, D. Muñoz-Aguayo, Anna Gelabert-Gorgues, Óscar Díaz-Gil, K. Nyyssönen, H. Zunft, R. de la Torre, S. Martín-Peláez, A. Pedret, A. Remaley, M. Covas, M. Fitó

Journal: Arteriosclerosis, Thrombosis, and Vascular Biology

Journal ranking: Q1

Key takeaways: Polyphenol-rich olive oil consumption enhances HDL function, including cholesterol efflux capacity, size, stability, and oxidative status, providing first-level evidence for its beneficial effects against cardiovascular risk factors.

Abstract: Objective— Olive oil polyphenols have shown beneficial properties against cardiovascular risk factors. Their consumption has been associated with higher cholesterol content in high-density lipoproteins (HDL). However, data on polyphenol effects on HDL quality are scarce. We, therefore, assessed whether polyphenol-rich olive oil consumption could enhance the HDL main function, its cholesterol efflux capacity, and some of its quality-related properties, such HDL polyphenol content, size, and composition. Approach and Results— A randomized, crossover, controlled trial with 47 healthy European male volunteers was performed. Participants ingested 25 mL/d of polyphenol-poor (2.7 mg/kg) or polyphenol-rich (366 mg/kg) raw olive oil in 3-week intervention periods, preceded by 2-week washout periods. HDL cholesterol efflux capacity significantly improved after polyphenol-rich intervention versus the polyphenol-poor one (+3.05% and −2.34%, respectively; P=0.042). Incorporation of olive oil polyphenol biological metabolites to HDL, as well as large HDL (HDL2) levels, was higher after the polyphenol-rich olive oil intervention, compared with the polyphenol-poor one. Small HDL (HDL3) levels decreased, the HDL core became triglyceride-poor, and HDL fluidity increased after the polyphenol-rich intervention. Conclusions— Olive oil polyphenols promote the main HDL antiatherogenic function, its cholesterol efflux capacity. These polyphenols increased HDL size, promoted a greater HDL stability reflected as a triglyceride-poor core, and enhanced the HDL oxidative status, through an increase in the olive oil polyphenol metabolites content in the lipoprotein. Our results provide for the first time a first-level evidence of an enhancement in HDL function by polyphenol-rich olive oil.

Effects of Olive Oil on Blood Pressure: Epidemiological, Clinical, and Mechanistic Evidence

Type of study: literature review

Number of citations: 45

Year: 2020

Authors: M. Massaro, E. Scoditti, M. Carluccio, N. Calabriso, G. Santarpino, T. Verri, R. de Caterina

Journal: Nutrients

Journal ranking: Q1

Key takeaways: Olive oil, due to its high oleic acid and antioxidant polyphenol content, shows anti-hypertensive effects, making it an optimal fat choice for managing hypertension in both healthy and cardiovascular disease patients.

Abstract: The increasing access to antihypertensive medications has improved longevity and quality of life in hypertensive patients. Nevertheless, hypertension still remains a major risk factor for stroke and myocardial infarction, suggesting the need to implement management of pre- and hypertensive patients. In addition to antihypertensive medications, lifestyle changes, including healthier dietary patterns, such as the Dietary Approaches to Stop Hypertension (DASH) and the Mediterranean diet, have been shown to favorably affect blood pressure and are now recommended as integrative tools in hypertension management. An analysis of the effects of nutritional components of the Mediterranean diet(s) on blood pressure has therefore become mandatory. After a literature review of the impact of Mediterranean diet(s) on cardiovascular risk factors, we here analyze the effects of olive oil and its major components on blood pressure in healthy and cardiovascular disease individuals and examine underlying mechanisms of action. Both experimental and human studies agree in showing anti-hypertensive effects of olive oil. We conclude that due to its high oleic acid and antioxidant polyphenol content, the consumption of olive oil may be advised as the optimal fat choice in the management protocols for hypertension in both healthy and cardiovascular disease patients.

Beneficial Effects of Polyphenol-Rich Food Oils in Cardiovascular Health and Disease

Type of study:

Number of citations: 4

Year: 2023

Authors: L. Kindernay, K. Ferenczyová, V. Farkašová, Ulrika Duľová, Jakub Strapec, M. Barteková

Journal: Reviews in Cardiovascular Medicine

Journal ranking: Q2

Key takeaways: Polyphenol-rich food oils, such as olive, flaxseed, soybean, sesame, and coconut oils, have positive cardiovascular effects, likely due to their antioxidant, anti-inflammatory, and anti-proliferative properties.

Abstract: A variety of vegetable and fruit derived food oils are considered beneficial for human health due to their content of functional components including their positive effects in cardiovascular system. In addition to the favorable ratio of unsaturated versus saturated fatty acids, some of these oils include also other health beneficial compounds such as vitamins, minerals, pigments, enzymes and phenolic compounds. Particularly polyphenols have been documented to exert numerous positive effects in cardiovascular system including their anti-hypertensive, anti-atherogenic as well as cardio- and vasculo- protective effects in subjects suffering from various cardiovascular and cardiometabolic diseases, likely via their antioxidant, anti-inflammatory, anti-coagulant, anti-proliferative and anti-diabetic properties. However, it has not been proven so far whether the positive cardiovascular effects of polyphenol-rich food oils are, and to what measure, attributed to their phenolic content. Thus, the current review aims to summarize the main cardiovascular effects of major polyphenol-rich food oils including olive, flaxseed, soybean, sesame and coconut oils, and to uncover the role of their phenolic compounds in these effects.

Olive oil polyphenols decrease blood pressure and improve endothelial function in young women with mild hypertension.

Type of study: rct

Number of citations: 231

Year: 2012

Authors: R. Moreno-Luna, R. Muñoz-Hernández, M. Miranda, Alzenira F. Costa, L. Jiménez-Jiménez, A. Vallejo-Vaz, Francisco J. G. Muriana, J. Villar, P. Stiefel

Journal: American journal of hypertension

Journal ranking: Q2

Key takeaways: A diet containing polyphenol-rich olive oil can decrease blood pressure and improve endothelial function in young women with high-normal blood pressure or stage 1 essential hypertension.

`Post-prandial effects of high-polyphenolic extra virgin olive oil on endothelial function in adults at risk for type 2 diabetes: A randomized controlled crossover trial.

Type of study: rct

Number of citations: 20

Year: 2020

Authors: V. Njike, R. Ayettey, J. Treu, K. Doughty, D. Katz

Journal: International journal of cardiology

Journal ranking: Q1

Key takeaways: High-polyphenolic extra virgin olive oil improves endothelial function in adults at risk for type 2 diabetes, while refined olive oil does not, without affecting blood pressure.

Abstract: BACKGROUND Effects of olive oil on cardiovascular risk have been controversial. We compared the effects of high-polyphenolic extra virgin olive oil (EVOO) and refined olive oil without polyphenols on endothelial function (EF) in adults at risk for Type 2 diabetes mellitus (T2DM). METHODS Randomized, controlled, double-blind, crossover trial of 20 adults (mean age 56.1 years; 10 women, 10 men) at risk for T2DM (i.e., as defined by either prediabetes or metabolic syndrome) assigned to one of two possible sequence permutations of two different single dose treatments (50 mL of high-polyphenolic EVOO or 50 mL of refined olive oil without polyphenols), with 1-week washout. Participants received their olive oils in a smoothie consisting of ½ cup frozen blueberries and 1 cup (8 oz) low-fat vanilla yogurt blended together. Primary outcome measure was EF measured as flow-mediated dilatation. Participants were evaluated before and 2 h after ingestion of their assigned olive oil treatment. RESULTS EVOO acutely improved EF as compared to refined olive oil (1.2 ± 6.5% versus -3.6 ± 3.8%; p = 0.0086). No significant effects on systolic or diastolic blood pressure were observed. CONCLUSIONS High-polyphenolic EVOO acutely enhanced EF in the study cohort, whereas refined olive oil did not. Blood pressure effects were not observed. Reports on the vascular effects of olive oil ingestion should specify the characteristics of the oil. CLINICAL TRIAL REGISTRATION NUMBER NCT04025281.

Olive oil polyphenols enhance the expression of cholesterol efflux related genes in vivo in humans. A randomized controlled trial.

Type of study: rct

Number of citations: 105

Year: 2013

Authors: M. Farràs, R. Valls, S. Fernández-Castillejo, M. Giralt, R. Solà, I. Subirana, M. Motilva, V. Konstantinidou, M. Covas, M. Fitó

Journal: The Journal of nutritional biochemistry

Journal ranking: Q1

Key takeaways: Olive oil polyphenols significantly enhance the expression of genes related to cholesterol efflux from cells to HDL in humans, potentially reducing cardiovascular risk through an in vivo nutrigenomic effect.

Potential Health Benefits of Olive Oil and Plant Polyphenols

Type of study:

Number of citations: 514

Year: 2018

Authors: Monika Gorzynik-Debicka, Paulina Przychodzeń, F. Cappello, Alicja Kuban-Jankowska, A. Marino Gammazza, N. Knap, M. Wozniak, Magdalena Górska-Ponikowska

Journal: International Journal of Molecular Sciences

Journal ranking: Q1

Key takeaways: Olive oil's polyphenols show potential health benefits, including antioxidant, anti-inflammatory, and immune system modulation.

Abstract: Beneficial effects of natural plant polyphenols on the human body have been evaluated in a number of scientific research projects. Bioactive polyphenols are natural compounds of various chemical structures. Their sources are mostly fruits, vegetables, nuts and seeds, roots, bark, leaves of different plants, herbs, whole grain products, processed foods (dark chocolate), as well as tea, coffee, and red wine. Polyphenols are believed to reduce morbidity and/or slow down the development of cardiovascular and neurodegenerative diseases as well as cancer. Biological activity of polyphenols is strongly related to their antioxidant properties. They tend to reduce the pool of reactive oxygen species as well as to neutralize potentially carcinogenic metabolites. A broad spectrum of health-promoting properties of plant polyphenols comprises antioxidant, anti-inflammatory, anti-allergic, anti-atherogenic, anti-thrombotic, and anti-mutagenic effects. Scientific studies present the ability of polyphenols to modulate the human immune system by affecting the proliferation of white blood cells, and also the production of cytokines or other factors that participate in the immunological defense. The aim of the review is to focus on polyphenols of olive oil in context of their biological activities.

High Polyphenol Extra Virgin Olive Oil and Metabolically Unhealthy Obesity: A Scoping Review of Preclinical Data and Clinical Trials

Type of study: systematic review

Number of citations: 1

Year: 2025

Authors: Konstantina Liva, Athanasios A. Panagiotopoulos, Alexandra Foscolou, C. Amerikanou, Alkistis Vitali, Stavros Zioulis, Konstantina Argyri, Georgios I. Panoutsopoulos, A. Kaliora, A. Gioxari

Journal: Clinics and Practice

Journal ranking: Q3

Key takeaways: High phenolic extra virgin olive oil (HP-EVOO) effectively reduces inflammation, glycemic control, oxidative stress, and endothelial function, potentially protecting against metabolic syndrome, hypertension, and type 2 diabetes.

Abstract: Background/Objectives: During the last decade, there has been an increased interest in phenolic compound-rich natural products as natural therapies for regulating the molecular pathways behind central obesity and associated metabolic disorders. The present scoping review presents the outcomes of clinical and preclinical studies examining the anti-obesity effects of high phenolic extra virgin olive oil (HP-EVOO) and its possible underlying molecular mechanisms. Methods: Studies published between 2014 and 2024 were searched via MEDLINE, Scopus, Cochrane, the Web of Science, Semantic Scholar, Google Scholar, Science.gov, and Clinicaltrials.gov databases. A combination of keywords and Boolean logic was used to search throughout the last decade in all databases, including “hyperglycemia” or “hypertension” or “metabolic syndrome” or “dyslipidemia” or “hyperlipidemia” or “hypoglycemia” or “obesity” or “macrovascular diabetic complications” or “microvascular diabetic complications” or “cardiovascular disease” or “overweight” or “insulin sensitivity” or “insulin resistance” and “extra virgin olive oil” or “high phenolic olive oil” and “human” or “animal model”. Results: The 10-year literature survey identified 21 studies in both animal models and humans, indicating that HP-EVOO improves inflammation, glycemic control, oxidative stress and endothelial function, potentially protecting against metabolic syndrome, hypertension and type 2 diabetes, even compared to EVOO. Moreover, HP-EVOO’s antiplatelet effect and improvement in HDL functionality reduce cardiovascular risk. Conclusions: The evidence presented in this study demonstrates that HP-EVOO represents an effective preventive and therapeutic dietary approach to cardiometabolic diseases.

Network Meta-Analysis of Metabolic Effects of Olive-Oil in Humans Shows the Importance of Olive Oil Consumption With Moderate Polyphenol Levels as Part of the Mediterranean Diet

Type of study: meta-analysis

Number of citations: 64

Year: 2019

Authors: Evangelia Tsartsou, N. Proutsos, E. Castanas, M. Kampa

Journal: Frontiers in Nutrition

Journal ranking: Q1

Key takeaways: Olive oil consumption with moderate polyphenol levels as part of the Mediterranean diet improves metabolic factors and antioxidant and inflammatory status, with more pronounced benefits in individuals with metabolic syndrome or chronic conditions.

Abstract: The beneficial role of olive oil consumption is nowadays widely recognized. However, it is not clear whether its health effects are due to the presence of monounsaturated lipids and/or to the antioxidant fraction of microconstituents present in olive oil. The aim of the present study was to analyze the exact role of olive oil in the modification of metabolic factors (glucose and circulating lipids) and explore the role of its antioxidant polyphenols. In the present work, we have performed a network meta-analysis of 30 human intervention studies, considering direct and indirect interactions and impact of each constituent. Interestingly, we show that the impact of olive oil on glucose, triglycerides, and LDL-cholesterol is mediated through an adherence to the Mediterranean diet, with the only notable effect of olive oil polyphenols being the increase of HDL-cholesterol, and the amelioration of the antioxidant and inflammatory status of the subjects. Additionally, we report for the first time that lower antioxidant polyphenol levels may be sufficient for the beneficial effects of olive oil, while we show that the lipid fraction of olive oil may be responsible for some of its beneficial actions. In all parameters examined the beneficial effect of olive oil was more pronounced in subjects with an established metabolic syndrome or other chronic conditions/diseases. In conclusion, all these findings provide new knowledge that could lead to re-establishment of the role of olive oil in human nutrition.

Olive Polyphenols and the Metabolic Syndrome

Type of study: systematic review

Number of citations: 84

Year: 2017

Authors: B. Saibandith, J. Spencer, I. Rowland, D. Commane

Journal: Molecules : A Journal of Synthetic Chemistry and Natural Product Chemistry

Journal ranking: Q1

Key takeaways: Consuming olive polyphenols, particularly from olive leaves and extra virgin olive oil, can reduce risk factors for metabolic syndrome by improving blood sugar, blood pressure, and reducing low density lipoprotein oxidation.

Abstract: Here, the effects of consuming polyphenol-rich olive products, including olive leaves, their crude extract, and extra virgin olive oil, on aspects of the metabolic syndrome are reviewed. We have sought to summarize the available scientific evidence from dietary intervention trials demonstrating a role for these phytochemicals in ameliorating aberrant glucose metabolism, high blood pressure and elevated blood lipids, and we discuss the potential mechanisms underpinning these observations. Searches for relevant literature published in English were conducted via PubMed and Science Direct. Based on published dietary intervention studies, there is convincing evidence to show that olive polyphenols, independently of olive lipids, reduce risk factors for metabolic syndrome, in particular by improving blood sugar and blood pressure control, and in reducing low density lipoprotein oxidation. There is more limited evidence to suggest that the consumption of olive polyphenols or related products can reduce body weight and visceral fat or impede weight gain, and similarly there are some limited data suggesting improved lipid profiles. There is some mechanistic data to support observations made in human volunteers, but further work is needed in this area. The consumption of olive polyphenols within the context of a healthy pattern of food intake may, in part, explain the reduced risk of metabolic disease associated with adherence to the Mediterranean diet.

Hydroxytyrosol in the Prevention of the Metabolic Syndrome and Related Disorders

Type of study: literature review

Number of citations: 112

Year: 2017

Authors: Julien Peyrol, C. Riva, M. Amiot

Journal: Nutrients

Journal ranking: Q1

Key takeaways: Hydroxytyrosol, the main polyphenol in olive oil, can improve lipid profile, glycaemia, and insulin sensitivity, and counteract oxidative stress and inflammation, potentially preventing Metabolic Syndrome and related disorders.

Abstract: Virgin olive oil (VOO) constitutes the main source of fat in the Mediterranean diet. VOO is rich in oleic acid, displaying health-promoting properties, but also contains minor bioactive components, especially phenolic compounds. Hydroxytyrosol (HT), the main polyphenol of olive oil, has been reported to be the most bioactive component. This review aims to compile the results of clinical, animal and cell culture studies evaluating the effects of HT on the features of Metabolic Syndrome (MetS) (body weight/adiposity, dyslipidemia, hypertension, and hyperglycemia/insulin resistance) and associated complications (oxidative stress and inflammation). HT was able to improve the lipid profile, glycaemia, and insulin sensitivity, and counteract oxidative and inflammatory processes. Experimental studies identified multiple molecular targets for HT conferring its beneficial effect on health in spite of its low bioavailability. However, rodent experiments and clinical trials with pure HT at biologically relevant concentrations are still lacking. Moreover, the roles of intestine and its gut microbiota have not been elucidated.

Potential Health Benefits of Olive Oil Polyphenols in Metabolic Disorders Management

Type of study: systematic review

Number of citations: 1

Year: 2024

Authors: Kaoutar Boumezough, Mehdi Alami, Jamal Oubaouz, Mojgan Morvaridzadeh, Nada Zoubdane, A. Khalil, M’hamed Ramchoun, Ilham Zahir, C. Ramassamy, Tamas Fulop, H. Berrougui

Journal: PharmaNutrition

Journal ranking: Q2

Key takeaways: Olive oil, rich in phenolic compounds, can help prevent atherosclerosis by enhancing lipid profile and providing antioxidant, anti-inflammatory, and hypoglycemic benefits.

Biological Relevance of Extra Virgin Olive Oil Polyphenols Metabolites

Type of study: literature review

Number of citations: 137

Year: 2018

Authors: G. Serreli, M. Deiana

Journal: Antioxidants

Journal ranking: Q1

Key takeaways: Extra virgin olive oil polyphenols metabolites, not just their parent compounds, have beneficial effects on human health by modulating intracellular signaling and improving cellular response to oxidative stress and pro-inflammatory stimuli.

Abstract: Extra virgin olive oil (EVOO) polyphenols beneficial effects have widely been debated throughout the last three decades, with greater attention to hydroxytyrosol and tyrosol, which are by far the most studied. The main concern about the evaluation of EVOO phenols activities in vitro and in vivo is that the absorption and metabolism of these compounds once ingested lead to the production of different metabolites in the human body. EVOO phenols in the ingested forms are less concentrated in human tissues than their glucuronide, sulfate and methyl metabolites; on the other hand, metabolites may undergo deconjugation before entering the cells and thus act as free forms or may be reformed inside the cells so acting as conjugated forms. In most in vitro studies the presence of methyl/sulfate/glucuronide functional groups does not seem to inhibit biological activity. Parent compounds and metabolites have been shown to reach tissue concentrations useful to exert beneficial effects others than antioxidant and scavenging properties, by modulating intracellular signaling and improving cellular response to oxidative stress and pro-inflammatory stimuli. This review aims to give an overview on the reported evidence of the positive effects exerted by the main EVOO polyphenols metabolites in comparison with the parent compounds.

Olive Oil Polyphenols Improve HDL Cholesterol and Promote Maintenance of Lipid Metabolism: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Type of study: meta-analysis

Number of citations: 12

Year: 2023

Authors: R. Zupo, F. Castellana, P. Crupi, Addolorata Desantis, M. Rondanelli, F. Corbo, M. L. Clodoveo

Journal: Metabolites

Journal ranking: Q2

Key takeaways: Daily consumption of olive oil polyphenols improves HDL cholesterol and contributes to maintaining lipid metabolism, suggesting that food labeling should emphasize this health feature.

Abstract: In 2011, the European Food Safety Authority (EFSA) accorded a health claim to olive oil polyphenols in that they protected LDL particles from oxidative damage. However, limited scientific evidence has so far failed to confer any claim of function on the maintenance of normal lipid metabolism. We performed a systematic review and meta-analysis of human RCTs, evaluating the effect of olive oil polyphenol administration on lipid profiles. Previous literature was acquired from six electronic databases until June 2023. A total of 75 articles were retrieved and screened for inclusion criteria, which resulted in the selection of 10 RCTs that evaluated the effect of daily exposure to olive oil polyphenols on serum lipids in adults. Meta-analyses were built by tertiles of outcomes, as follows: low (0–68 mg/kg), medium (68–320 mg/kg), and high (320–600 mg/kg) polyphenols for HDL and LDL cholesterol (HDL-C and LDL-C, respectively), and low (0–59.3 mg/kg), medium (59.3–268 mg/kg), and high (268–600 mg/kg) polyphenols for total cholesterol (TC). The study protocol was registered on PROSPERO (registration code: CRD42023403383). The study design was predominantly cross-over (n = 8 of 10) but also included parallel (n = 2 of 10). The study population was predominantly European and healthy. Daily consumption of olive oil polyphenols did not affect TC levels and only slightly significantly reduced LDL-C, with WMD statistically significant only for high daily consumption of olive oil polyphenols (WMD −4.28, 95%CI −5.78 to −2.77). Instead, our data found a statistically significant HDL-C enhancing effect (WMD pooled effect model: 1.13, 95%CI 0.45; 1.80, heterogeneity 38%, p = 0.04) with WMD by daily exposure level showing a statistically significant improvement effect for low (WMD 0.66, 95%CI 0.10–1.23), medium (WMD 1.36, 95%CI 0.76–1.95), and high (WMD 1.13, 95%CI 0.45–1.80) olive oil polyphenol consumptions. Olive oil polyphenols contribute toward maintaining lipid metabolism. Thus, food labeling regulations should stress this health feature of olive oil, whereby a declaration of the olive oil polyphenol content should be added to products on the market. Consumers need to be aware of the quality and possible health effects of any products they consume, and enforcement of nutrition labels offers the best way of providing this information.

Beneficial effects of dietary supplementation with olive oil, oleic acid, or hydroxytyrosol in metabolic syndrome: systematic review and meta-analysis.

Type of study: meta-analysis

Number of citations: 80

Year: 2021

Authors: Rosario Pastor, Cristina Bouzas, J. Tur

Journal: Free radical biology & medicine

Journal ranking: Q1

Key takeaways: Olive oil or oleic acid consumption is as effective as other strategies for managing metabolic syndrome, with no significant effect on MetS.

Consumption of extra-virgin olive oil rich in phenolic compounds improves metabolic control in patients with type 2 diabetes mellitus: a possible involvement of reduced levels of circulating visfatin

Type of study: non-rct experimental

Number of citations: 102

Year: 2016

Authors: C. Santangelo, C. Filesi, R. Varì, Beatrice Scazzocchio, T. Filardi, Vincenzo Fogliano, M. D'Archivio, C. Giovannini, Andrea Lenzi, Susanna Morano, R. Masella

Journal: Journal of Endocrinological Investigation

Journal ranking: Q2

Key takeaways: Daily consumption of polyphenol-rich extra-virgin olive oil improves metabolic control and reduces circulating inflammatory adipokines in overweight type 2 diabetes patients.

Abstract: Aim Phenolic compounds naturally contained in extra-virgin olive oil (EVOO) have demonstrated anti-inflammatory and antioxidant properties. The present study aimed at evaluating the effects of a polyphenol-rich extra-virgin olive oil (EVOO) (high-polyphenol EVOO, HP-EVOO) on the metabolic control and the production of specific pro-/anti-inflammatory adipokines in overweight patients with type 2 diabetes mellitus (T2D).MethodsEleven overweight T2D patients not in treatment with insulin were invited to follow their habitual diet for a total of 8 weeks. During the first 4 weeks (wash-out period), they were asked to consume refined olive oil (ROO, polyphenols not detectable) and then to replace ROO with HP-EVOO (25 mL/day, 577 mg of phenolic compounds/kg) for the remaining 4 weeks. Anthropometric parameters, fasting glycaemia, glycated haemoglobin (HbA1c), high-sensitive C-reactive protein, plasma lipid profile, liver function and serum levels of TNF-α, IL-6, adiponectin, visfatin and apelin were assessed at the end of each 4-week period.ResultsHP-EVOO consumption significantly reduced fasting plasma glucose (P = 0.023) and HbA1c (P = 0.039) levels as well as BMI (P = 0.012) and body weight (P = 0.012). HP-EVOO ingestion determined a reduction in serum level of aspartate aminotransferase (AST, P = 0.0056) and alanine aminotransferase (ALT, P = 0.024). Serum visfatin levels strongly decreased after HP-EVOO ingestion (P = 0.0021).ConclusionsDaily consumption of polyphenol-rich EVOO might improve metabolic control and circulating inflammatory adipokines profile in overweight T2D patients.

Genes and miRNA expression signatures in peripheral blood mononuclear cells in healthy subjects and patients with metabolic syndrome after acute intake of extra virgin olive oil.

Type of study: non-rct experimental

Number of citations: 89

Year: 2016

Authors: S. D'Amore, M. Vacca, M. Cariello, G. Graziano, A. D'orazio, R. Salvia, R. C. Sasso, C. Sabbà, G. Palasciano, A. Moschetta

Journal: Biochimica et biophysica acta

Journal ranking: brak

Key takeaways: Acute high-polyphenol extra virgin olive oil intake can improve metabolism, inflammation, and cancer risk by modulating gene and miRNA expression in peripheral blood mononuclear cells.

Polyphenol‐rich virgin olive oil reduces insulin resistance and liver inflammation and improves mitochondrial dysfunction in high‐fat diet fed rats

Type of study: non-rct experimental

Number of citations: 67

Year: 2017

Authors: A. Lama, C. Pirozzi, M. Mollica, G. Trinchese, Francesca Di Guida, G. Cavaliere, A. Calignano, G. M. Raso, R. B. Canani, R. Meli

Journal: Molecular Nutrition & Food Research

Journal ranking: Q1

Key takeaways: Polyphenol-rich virgin olive oil reduces insulin resistance, inflammation, and hepatic oxidative stress in high-fat diet-fed rats, potentially preventing nonalcoholic fatty liver disease progression.

Abstract: Scope: Virgin olive oil is an essential component of the Mediterranean diet. Its antioxidant and anti‐inflammatory properties are mainly linked to phenolic contents. This study aims to evaluate the beneficial effects of a polyphenol‐rich virgin olive oil (HPCOO) or olive oil without polyphenols (WPOO) in rats fed high‐fat diet (HFD). Methods and results: Male Sprague‐Dawley rats were divided into four groups based on the different types of diet: (I) standard diet (STD); (II) HFD; (III) HFD containing WPOO, and (IV) HFD containing HPCOO. HPCOO and WPOO induced a significant improvement of HFD‐induced impaired glucose homeostasis (by hyperglycemia, altered oral glucose tolerance, and HOMA‐IR) and inflammatory status modulating pro‐ and anti‐inflammatory cytokines (TNF‐α, IL‐1, and IL‐10) and adipokines. Moreover, HPCOO and less extensively WPOO, limited HFD‐induced liver oxidative and nitrosative stress and increased hepatic fatty acid oxidation. To study mitochondrial performance, oxidative capacity and energy efficiency were also evaluated in isolated liver mitochondria. HPCOO, but not WPOO, reduced H2O2 release and aconitase activity by decreasing degree of coupling, which plays a major role in the control of mitochondrial reactive oxygen species emission. Conclusion: HPCOO limits HFD‐induced insulin resistance, inflammation, and hepatic oxidative stress, preventing nonalcoholic fatty liver disease progression.

Nutraceutical Properties of Olive Oil Polyphenols. An Itinerary from Cultured Cells through Animal Models to Humans

Type of study:

Number of citations: 228

Year: 2016

Authors: S. Rigacci, M. Stefani

Journal: International Journal of Molecular Sciences

Journal ranking: Q1

Key takeaways: Olive oil polyphenols, found in the Mediterranean diet, have been shown to have beneficial properties for longevity and against age-related diseases like cancer, cardiovascular, metabolic, and neurodegenerative diseases.

Abstract: The increasing interest in the Mediterranean diet hinges on its healthy and anti-ageing properties. The composition of fatty acids, vitamins and polyphenols in olive oil, a key component of this diet, is considered a key feature of its healthy properties. Therefore, it is of significance that the Rod of Asclepius lying on a world map surrounded by olive tree branches has been chosen by the World Health Organization as a symbol of both peace and well-being. This review travels through most of the current and past research, recapitulating the biochemical and physiological correlations of the beneficial properties of olive tree (Olea europaea) polyphenols and their derivatives found in olive oil. The factors influencing the content and beneficial properties of olive oil polyphenols will also be taken into account together with their bioavailability. Finally, the data on the clinical and epidemiological relevance of olive oil and its polyphenols for longevity and against age- and lifestyle-associated pathologies such as cancer, cardiovascular, metabolic and neurodegenerative diseases are reviewed.

Gene Expression Study in Gilthead Seabream (Sparus aurata): Effects of Dietary Supplementation with Olive Oil Polyphenols on Immunity, Metabolic, and Oxidative Stress Pathways

Type of study: non-rct experimental

Number of citations: 4

Year: 2024

Authors: Martina Torricelli, A. Felici, R. Branciari, M. Trabalza-Marinucci, R. Galarini, M. Biagetti, Amedeo Manfrin, Laura Boriani, Eleonora Radicchi, C. Sebastiani, M. Ciullo, D. Ranucci, Francesco Agnetti

Journal: International Journal of Molecular Sciences

Journal ranking: Q1

Key takeaways: Dietary supplementation with olive oil polyphenols from wastewater enhances growth performance and positively impacts immune, metabolic, and oxidative stress pathways in farmed gilthead seabream.

Abstract: In an era with an ever-growing population, sustainability and green transition are the main milestones to be considered within the current European Green Deal program, and the recovery of by-products for the integration of feed with bioactive molecules, that are sustainable and with high nutritional value, is an ambitious mission to be explored also in aquaculture. Olive oil extraction produces a range of solid and liquid by-products, in varying proportions depending on the utilized production techniques, all of which are considered as possible pollutants. However, these products are also rich of polyphenols, bioactive molecules with several and well-known beneficial properties (antimicrobic, anti-inflammatory, antioxidant, and immune-modulating). On this basis, this work aimed at evaluating the effects of dietary supplementation with polyphenols derived from olive mill wastewater on growth performance and on gene expression modulation, by means of RT-qPCR assays, in farmed Sparus aurata. Particularly, some target genes of metabolic, immunity, and oxidative stress pathways have been investigated in breeding gilthead seabream. Differential gene expression analysis was carried out, and differences between the control group (n = 9) and the treated one (n = 9) were computed with Student’s t test. The results have highlighted that supplemented feed enhanced fish growth, with a significant feed conversion ratio between the two groups. Furthermore, the polyphenol diet had a beneficial impact on gene expression fold with a level of significance for fatty acid binding protein 2, superoxide dismutase 1, and interleukin-12 genes at hepatic or intestinal district. These significant and promising preliminary findings promote, in the future, other investigations on polyphenolic by-products and on their putative or possible re-utilization in fish feeding.

Intestinal microbiota modulation at the strain level by the olive oil polyphenols in the diet

Type of study: non-rct experimental

Number of citations: 5

Year: 2023

Authors: Natalia Andújar-Tenorio, A. Cobo, Ana Mª Martínez-Rodríguez, M. Hidalgo, I. Prieto, Antonio Gálvez, M. Martínez-Cañamero

Journal: Frontiers in Nutrition

Journal ranking: Q1

Key takeaways: Olive oil polyphenols can modulate intestinal microbiota, allowing it to adapt to changing environments and potentially impact gut physiology.

Abstract: Introduction Previously we have reported a r16S gene next generation sequencing study on the effect of high fat diets in the intestinal microbiota using a murine model. However, many important microbial traits occur at strain level and, in order to detect these population changes, culture-dependent approaches need to be applied. With this goal, we decided to study a very well-known commensal genus, Enterococcus, and therefore, intestinal enterococci methodically isolated during the above-mentioned experiment were analyzed. Materials and methods A collection of 75 distinct enterococcal strains isolated from feces of mice fed a standard diet or high-fat diets enriched with butter, refined olive oil, or extra virgin olive oil and after 0, 6 or 12 weeks of diet, were genetically and phenotypically characterized in search of virulence factors, biogenic amine production and antibiotic resistance. All strains were tested for the susceptibility in vitro to two virgin olive oil polyphenols, oleuropein (the bitter principle of olives) and hydroxytyrosol (derived from oleuropein by enzymatic hydrolysis and responsible for the high stability of olive oil). Results No drastic polyphenol effect was found except at high concentrations. However, when carrying out a comparative statistical study in the 75 strains of the collection according to the different diets, we have detected significant differences between the strains isolated from mice fed with a diet enriched with virgin olive oil and the rest of the diets. EVOO strains also presented less resistance to antibiotics and a more beneficial profile overall. Discussion These results support the prebiotic role of polyphenols, showing how they are able to modulate the set of strains that comprises a genus in the gut, allowing them to adapt to a changing environment in the host’s intestine and possibly exerting effects on its physiology.

Olive Polyphenols: Antioxidant and Anti-Inflammatory Properties

Type of study: literature review

Number of citations: 165

Year: 2021

Authors: M. Bucciantini, M. Leri, P. Nardiello, F. Casamenti, M. Stefani

Journal: Antioxidants

Journal ranking: Q1

Key takeaways: Olive polyphenols show potential anti-inflammatory and antioxidant properties, potentially benefiting chronic diseases like cardiovascular diseases, diabetes, neurodegenerative disorders, and cancer.

Abstract: Oxidative stress and inflammation triggered by increased oxidative stress are the cause of many chronic diseases. The lack of anti-inflammatory drugs without side-effects has stimulated the search for new active substances. Plant-derived compounds provide new potential anti-inflammatory and antioxidant molecules. Natural products are structurally optimized by evolution to serve particular biological functions, including the regulation of endogenous defense mechanisms and interaction with other organisms. This property explains their relevance for infectious diseases and cancer. Recently, among the various natural substances, polyphenols from extra virgin olive oil (EVOO), an important element of the Mediterranean diet, have aroused growing interest. Extensive studies have shown the potent therapeutic effects of these bioactive molecules against a series of chronic diseases, such as cardiovascular diseases, diabetes, neurodegenerative disorders and cancer. This review begins from the chemical structure, abundance and bioavailability of the main EVOO polyphenols to highlight the effects and the possible molecular mechanism(s) of action of these compounds against inflammation and oxidation, in vitro and in vivo. In addition, the mechanisms of inhibition of molecular signaling pathways activated by oxidative stress by EVOO polyphenols are discussed, together with their possible roles in inflammation-mediated chronic disorders, also taking into account meta-analysis of population studies and clinical trials.

Anti-inflammatory Activity of Extra Virgin Olive Oil Polyphenols: Which Role in the Prevention and Treatment of Immune-Mediated Inflammatory Diseases?

Type of study: systematic review

Number of citations: 120

Year: 2018

Authors: C. Santangelo, R. Varì, Beatrice Scazzocchio, Patrizia De Sanctis, C. Giovannini, M. D'Archivio, R. Masella

Journal: Endocrine, metabolic & immune disorders drug targets

Journal ranking: Q3

Key takeaways: Extra virgin olive oil and its phenolic compounds may improve symptoms in immune-mediated inflammatory diseases, but further research is needed to develop appropriate nutritional guidelines.

Abstract: BACKGROUND AND OBJECTIVE Altered inflammatory response characterizes chronic immunemediated inflammatory diseases (IMID) such as rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, systemic lupus erythematosus, and psoriasis. Accumulating evidence indicates that regular consumption of extra virgin olive oil (EVOO), the main source of fat in the Mediterranean diet, is associated with a reduced risk of developing chronic degenerative disorders such as cardiovascular diseases, type 2 diabetes and cancer. The beneficial effects on health of EVOO have been attributed, besides to the monounsaturated fats content, to the presence of phenolic compounds that have antioxidant, anti-inflammatory and immunomodulatory properties. The purpose of this review is to provide an overview of the effects of EVOO polyphenols on IMID highlighting the potential mechanisms of action. METHODS Scientific papers were found by searching in PubMed up to May 2017 using the following key words: rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, systemic lupus erythematosus, and psoriasis also in combination with EVOO, phenolic compounds, oleuropein, oleocantal, hydroxytyrosol,tyrosol and oleochantal. RESULTS In vitro and in vivo studies indicate that EVOO and its polyphenols can improve diseases symptoms in IMID, by acting both at local and systemic levels and by modulating several molecular pathways. Nevertheless, there are not sufficient data to achieve specific nutritional guidelines. CONCLUSION Further research is needed to evaluate the real contribution of EVOO and its phenolic compounds in modulating the IMID-associated inflammatory perturbations, in order to develop appropriate nutritional recommendations.

Influence of Phenol-Enriched Olive Oils on Human Intestinal Immune Function

Type of study: rct

Number of citations: 49

Year: 2016

Authors: S. Martín-Peláez, O. Castañer, R. Solà, M. Motilva, M. Castell, F. Pérez-Cano, M. Fitó

Journal: Nutrients

Journal ranking: Q1

Key takeaways: High doses of phenolic compounds in olive oil may stimulate the immune system, but lower doses and a combination of two sources show no significant effects.

Abstract: Olive oil (OO) phenolic compounds (PC) are able to influence gut microbial populations and metabolic output. Our aim was to investigate whether these compounds and changes affect the mucosal immune system. In a randomized, controlled, double blind cross-over human trial, for three weeks, preceded by two-week washout periods, 10 hypercholesterolemic participants ingested 25 mL/day of three raw virgin OO differing in their PC concentration and origin: (1) an OO containing 80 mg PC/kg (VOO); (2) a PC-enriched OO containing 500 mg PC/kg from OO (FVOO); and (3) a PC-enriched OO containing a mixture of 500 mg PC/kg from OO and thyme (1:1, FVOOT). Intestinal immunity (fecal immunoglobulin A (IgA) and IgA-coated bacteria) and inflammation markers (C-reactive protein (CRP) and fecal interleukin 6 (IL-6), tumor necrosis factor α (TNFα) and calprotectin) was analyzed. The ingestion of high amounts of OO PC, as contained in FVOO, tended to increase the proportions of IgA-coated bacteria and increased plasma levels of CRP. However, lower amounts of OO PC (VOO) and the combination of two PC sources (FVOOT) did not show significant effects on the variables investigated. Results indicate a potential stimulation of the immune system with very high doses of OO PC, which should be further investigated.

Extra Virgin Olive Oil Polyphenols: Modulation of Cellular Pathways Related to Oxidant Species and Inflammation in Aging

Type of study: literature review

Number of citations: 97

Year: 2020

Authors: G. Serreli, M. Deiana

Journal: Cells

Journal ranking: Q1

Key takeaways: Extra virgin olive oil polyphenols may help modulate the aging process by reducing oxidative stress and chronic inflammation.

Abstract: The olive-oil-centered Mediterranean diet has been associated with extended life expectancy and a reduction in the risk of age-related degenerative diseases. Extra virgin olive oil (EVOO) itself has been proposed to promote a “successful aging”, being able to virtually modulate all the features of the aging process, because of its great monounsaturated fatty acids content and its minor bioactive compounds, the polyphenols above all. Polyphenols are mostly antioxidant and anti-inflammatory compounds, able to modulate abnormal cellular signaling induced by pro-inflammatory stimuli and oxidative stress, as that related to NF-E2-related factor 2 (Nrf-2) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), which have been identified as important modulators of age-related disorders and aging itself. This review summarizes existing literature about the interaction between EVOO polyphenols and NF-κB and Nrf-2 signaling pathways. Reported studies show the ability of EVOO phenolics, mainly hydroxytyrosol and tyrosol, to activate Nrf-2 signaling, inducing a cellular defense response and to prevent NF-κB activation, thus suppressing the induction of a pro-inflammatory phenotype. Literature data, although not exhaustive, indicate as a whole that EVOO polyphenols may significantly help to modulate the aging process, so tightly connected to oxidative stress and chronic inflammation.

Update on Anti-Inflammatory Molecular Mechanisms Induced by Oleic Acid

Type of study:

Number of citations: 101

Year: 2023

Authors: C. Santa-María, Soledad López-Enríquez, S. Montserrat-de la Paz, Isabel Geniz, M. E. Reyes-Quiróz, Manuela Moreno, Francisca Palomares, F. Sobrino, Gonzalo Alba

Journal: Nutrients

Journal ranking: Q1

Key takeaways: Olive oil's oleic acid content contributes to its health benefits by inhibiting proinflammatory cytokines and activating anti-inflammatory ones, influencing cell membrane fluidity, receptors, and gene expression.

Abstract: In 2010, the Mediterranean diet was recognized by UNESCO as an Intangible Cultural Heritage of Humanity. Olive oil is the most characteristic food of this diet due to its high nutraceutical value. The positive effects of olive oil have often been attributed to its minor components; however, its oleic acid (OA) content (70–80%) is responsible for its many health properties. OA is an effective biomolecule, although the mechanism by which OA mediates beneficial physiological effects is not fully understood. OA influences cell membrane fluidity, receptors, intracellular signaling pathways, and gene expression. OA may directly regulate both the synthesis and activities of antioxidant enzymes. The anti-inflammatory effect may be related to the inhibition of proinflammatory cytokines and the activation of anti-inflammatory ones. The best-characterized mechanism highlights OA as a natural activator of sirtuin 1 (SIRT1). Oleoylethanolamide (OEA), derived from OA, is an endogenous ligand of the peroxisome proliferator-activated receptor alpha (PPARα) nuclear receptor. OEA regulates dietary fat intake and energy homeostasis and has therefore been suggested to be a potential therapeutic agent for the treatment of obesity. OEA has anti-inflammatory and antioxidant effects. The beneficial effects of olive oil may be related to the actions of OEA. New evidence suggests that oleic acid may influence epigenetic mechanisms, opening a new avenue in the exploration of therapies based on these mechanisms. OA can exert beneficial anti-inflammatory effects by regulating microRNA expression. In this review, we examine the cellular reactions and intracellular processes triggered by OA in T cells, macrophages, and neutrophils in order to better understand the immune modulation exerted by OA.

Olive Oil Phenolics Prevent Oxysterol‐Induced Proinflammatory Cytokine Secretion and Reactive Oxygen Species Production in Human Peripheral Blood Mononuclear Cells, Through Modulation of p38 and JNK Pathways

Type of study: non-rct in vitro

Number of citations: 31

Year: 2017

Authors: G. Serra, M. Deiana, J. Spencer, G. Corona

Journal: Molecular Nutrition & Food Research

Journal ranking: Q1

Key takeaways: Extra virgin olive oil polyphenols can counteract the proinflammatory effects of dietary and endogenous oxysterols in human immune cells, potentially benefiting chronic immune and inflammatory processes.

Abstract: Scope The aim of the present study was to investigate the ability of extra virgin olive oil (EVOO) polyphenols to counteract the proinflammatory effects induced by dietary and endogenous oxysterols in ex vivo immune cells. Methods and results Peripheral blood mononuclear cells (PBMCs), separated from the whole blood of healthy donors, were utilized and were stimulated with an oxysterols mixture, in the presence of physiologically relevant concentrations of the EVOO polyphenols, hydroxytyrosol, tyrosol, and homovanillic alcohol. Oxysterols significantly increased the production of proinflammatory cytokines, interleukin‐1β, regulated on activation, normal T‐cell expressed and secreted and macrophage migration inhibitory factor in ex vivo cultured PBMCs. Increased levels of reactive oxygen species (ROS) were also detected along with increased phosphorylation of the p38 and JNK. All phenolic compounds significantly reduced cytokine secretion induced by the oxysterols and inhibited ROS production and mitogen activated protein kinase phosphorylation. Conclusions These results suggest that extra virgin olive oil polyphenols modulate the immune response induced by dietary and endogenous cholesterol oxidation products in human immune cells and may hold benefit in controlling chronic immune and/or inflammatory processes.

The Secrets of the Mediterranean Diet. Does [Only] Olive Oil Matter?

Type of study:

Number of citations: 195

Year: 2019

Authors: A. Mazzocchi, L. Leone, C. Agostoni, I. Pali-Schöll

Journal: Nutrients

Journal ranking: Q1

Key takeaways: The Mediterranean diet, with its high consumption of fruits, vegetables, and olive oil, helps protect against chronic and inflammatory diseases by promoting immune system function and reducing inflammation.

Abstract: Diet plays a key role in the maintenance and optimal functioning of immune cells. The Mediterranean dietary pattern is an example of a prudent choice of lifestyle and scientifically accepted to help preserve human health by protecting against major chronic and inflammatory diseases. Mediterranean diets (MedDiets) are characteristically high in the consumption of fruits, vegetables and salad, bread and whole grain cereals, potatoes, legumes/beans, nuts, and seeds. Their common central feature is the usage of olive oil as the main source of fat. The health benefits attributed to olive oil are specifically related to extra virgin olive oil (EVOO) intake with its high nutritional quality and multiple positive effects on health. Overall, MedDiets have direct (mono-unsaturated fatty acids (MUFAs), tocopherols, polyphenols) and indirect (low saturated fats, well-balanced linoleic/alpha linolenic acid) effects on the immune system and inflammatory responses. In the present paper, we summarize the current knowledge on the effect of olive oil per se and MedDiets generally on immune-mediated and inflammatory diseases, such as coronary heart disease (CHD)/cardiovascular diseases (CVD), obesity, type-2 diabetes, cancer, asthma, and allergies.

Buccopharyngeal route administered high polyphenolic olive oil and COVID‐19: A pilot clinical trial

Type of study:

Number of citations: 2

Year: 2023

Authors: F. Rodríguez-Argente, María Alba‐Domínguez, María P. Díaz‐Martínez, Cristian Díaz‐Vergara, Belén Díaz‐Márques, Paloma Ferrero‐Ortega, A. Gil‐Adrados, Lorena Gómez‐Bernardo, Laura Gordo‐Murillo, Elsa Humanes‐de la Fuente, Jesús Jurado-Palomo, Ángel Ortega-González, J. Machado-Gallas, Álvaro Moreno-Ancillo, Gerardo Ávila‐Martín, A. Marín-Guerrero, Joaquín Álvarez‐Gregori

Journal: Immunity, Inflammation and Disease

Journal ranking: Q2

Key takeaways: High polyphenolic olive oil administered through an oropharyngeal route may activate mucosal immunity and potentially improve COVID-19 outcomes.

Abstract: Waning immunity after vaccination justifies the need for additional effective COVID‐19 treatments. Immunomodulation of local immune response at the oropharyngeal mucosa could hypothetically activate mucosal immunity, which can prevent SARS‐CoV‐2 main immune evasion mechanisms in early stages of the disease and send an effective warning to other components of immune system. Olive polyphenols are biologically active compounds with immunomodulatory activity. There are previous studies based on immunomodulation with olive polyphenols and respiratory infections using an enteral route, which point to potential effects on time to resolution of symptoms. The investigators sought to determine whether participants following immunomodulation with tiny quantities of high polyphenolic olive oil administered through an oromucosal route could have a better outcome in COVID‐19.

Olive Oil: Nutritional Applications, Beneficial Health Aspects and its Prospective Application in Poultry Production

Type of study:

Number of citations: 49

Year: 2021

Authors: R. M. Bilal, Chunjie Liu, Haohan Zhao, Yanzhou Wang, M. Farag, M. Alagawany, F. Hassan, S. Elnesr, H. Elwan, Huajiao Qiu, Q. Lin

Journal: Frontiers in Pharmacology

Journal ranking: Q1

Key takeaways: Olive oil has nutritional benefits and potential for improving poultry performance and product quality due to its polyphenolic content and antioxidant properties.

Abstract: Plant polyphenols have promoting health features, including anti-mutagenic, anti-inflammatory, anti-thrombotic, anti-atherogenic, and anti-allergic effects. These polyphenols improve the immune system by affecting the white blood cell proliferation, as well as by the synthesis of cytokines and other factors, which contribute to immunological resistance. Olive trees are one of the most famous trees in the world. Whereas, olive olive oil and derivatives represent a large group of feeding resource for farm animals. In recent years, remarkable studies have been carried out to show the possible use of olive oil and derivatives for improvement of both animal performance and product quality. In vivo application of olive oil and its derived products has shown to maintain oxidative balance owing to its polyphenolic content. Consumption of extra virgin olive oil reduces the inflammation, limits the risk of liver damage, and prevents the progression of steatohepatitis through its potent antioxidant activities. Also, the monounsaturated fatty acids content of olive oil (particularly oleic acid), might have positive impacts on lipid peroxidation and hepatic protection. Therefore, this review article aims to highlight the nutritional applications and beneficial health aspects of olive oil and its effect on poultry production.

The effect of olive oil polyphenols on antibodies against oxidized LDL. A randomized clinical trial.

Type of study: rct

Number of citations: 76

Year: 2011

Authors: O. Castañer, M. Fitó, M. López-Sabater, H. Poulsen, K. Nyyssönen, H. Schröder, J. Salonen, Karina de la Torre-Carbot, H. Zunft, R. de la Torre, H. Bäumler, A. Gaddi, G. Sáez, M. Tomás, M. Covas

Journal: Clinical nutrition

Journal ranking: Q1

Key takeaways: Olive oil polyphenols promote the generation of autoantibodies against oxidized LDL, with stronger effects at higher concentrations of lipid oxidative damage.

Modulation of Nrf2 by Olive Oil and Wine Polyphenols and Neuroprotection

Type of study: literature review

Number of citations: 84

Year: 2017

Authors: M. Martínez-Huélamo, J. Rodríguez-Morató, A. Boronat, R. de la Torre

Journal: Antioxidants

Journal ranking: Q1

Key takeaways: Olive oil and red wine polyphenols, rich in antioxidants, contribute to improved cognitive function and neuroprotection by modulating Nrf2 expression and promoting endogenous antioxidant defense mechanisms.

Abstract: Strong adherence to a Mediterranean diet is associated with improved cognitive function and a lower prevalence of mild cognitive impairment. Olive oil and red wine are rich sources of polyphenols which are responsible in part for the beneficial effects on cognitive functioning. Polyphenols induce endogenous antioxidant defense mechanisms by modulating transcription factors such as the nuclear factor (erythroid-derived 2)-like 2 (Nrf2). This review discusses the scientific data supporting the modulating effect of olive oil and red wine polyphenols on Nrf2 expression, and the potential health benefits associated with cognitive functioning.