Effects of Virgin Olive Oil and Phenol-Enriched Virgin Olive Oils on Lipoprotein Atherogenicity

Is the MIND diet useful for polycystic ovary syndrome? A case-control study

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most prevalent cause of ovulatory infertility and endocrine abnormalities in reproductive-age women. Although the MIND diet has been introduced to improve brain function, evidence shows that the MIND diet is rich in beneficial food groups that can have a preventive effect on other metabolic disorders. The present study was conducted to investigate the association between adherence to the MIND diet and PCOS.

METHODS

This age and BMI frequency-matched case-control study was conducted on 216 women between January 2018 and March 2019 in Yazd, Iran. PCOS was diagnosed based on Rotterdam criteria. Participants were selected by convenience sampling method. The validated 178-item food frequency questionnaire was used to assess the usual dietary intake. Logistic regression was used to estimate the association between the MIND diet and PCOS.

RESULTS

The findings of the present study showed a significant inverse association between adherence to the MIND diet and PCOS in the crude model (OR for T3 vs. T1: 0.12 (95% CI: 0.05-0.25), P-value < 0.001) and multivariable-adjusted model including energy intake, age, BMI, waist circumference, marital status, pregnancy history, drug use history, education and physical activity (OR for T3 vs. T1 = 0.08 (95% CI: 0.03-0.19), P-value < 0.001). Adherence to the MIND diet had a protective effect of 92%.

CONCLUSION

Although the results of the present study showed that higher adherence to the MIND diet is associated with a lower risk of PCOS, more studies are needed to confirm these findings in the future.

Wild and cultivated olive trees: Nutraceutical insights of extra virgin olive oils in cardiovascular and ocular diseases

Extra virgin olive oil (EVOO) from Olea europaea (cultivated olive tree) and the oil obtained from the wild olive variety or acebuche (ACE oil from Olea oleaster) contain an extraordinary number of bioactive molecules. These include oleic acid, sterols, tocopherols, triterpene compounds, and polyphenols. Both oils are known for their healthy properties and are considered to be a nutraceutical tool against cardiovascular diseases, including arterial hypertension, preeclampsia, and ocular diseases such as glaucoma or diabetic retinopathy. The benefits of EVOO and ACE oil stem from their anti-inflammatory, antioxidant, and anti-cancer properties. They also have potential as prebiotic compounds. In this update, we synthesise and illustrate the various characteristics and beneficial effects of olive oils from different varieties of olive trees, with special emphasis on Olea oleaster, also known as Olea europaea, L. var. sylvestris.

Improving the functionality of virgin and cold-pressed edible vegetable oils: Oxidative stability, sensory acceptability and safety challenges

In recent years, there has been a growing demand for minimally processed foods that offer health benefits and premium sensory characteristics. This trend has led to increased consumption of virgin (VOs) and cold-pressed (CPOs) oils, which are rich sources of bioactive substances. To meet consumer needs for new oil products conferring multi-functional properties over a longer storage period, the scientific community has been revisiting traditional enrichment practices while exploring novel fortification technologies. In the last four years, the interest has been growing faster; an ascending number of annually published studies are about the addition of different plant materials, agri-food by-products, or wastes (intact or extracts) to VOs and CPOs using traditional or innovative fortification processes. Considering this trend, the present review aims to provide an overview and summarize the key findings from relevant papers that were retrieved from extensively searched databases. Our meta-analysis focuses on exposing the most recent trends regarding the exploitation of VOs and CPOs as substrates, the fortification agents and their form of use, as well as the fortification technologies employed. The review critically discusses possible health claim and labeling issues and highlights some chemical and microbial safety concerns along with authenticity issues and gaps in quality specifications that manufacturers have yet to address. All these aspects are examined from the perspective of developing new oil products with well-balanced techno-, senso- and bio-functional characteristics.

Role of Olive Bioactive Compounds in Respiratory Diseases

Respiratory diseases recently became the leading cause of death worldwide, due to the emergence of COVID-19. The pathogenesis of respiratory diseases is centred around inflammation and oxidative stress. Plant-based alongside synthetic drugs were considered as therapeutics due to their proven nutraceutical value. One such example is the olive, which is a traditional symbol of the MedDiet. Olive bioactive compounds are enriched with antioxidant, anti-inflammatory, anticancer and antiviral properties. However, there are few studies relating to the beneficial effect of olive bioactive compounds on respiratory diseases. A vague understanding of its molecular action, dosage and bioavailability limits its usefulness for clinical trials about respiratory infections. Hence, our review aims to explore olive bioactive compound's antioxidant, anti-inflammatory and antiviral properties in respiratory disease defence and treatment. Molecular insight into olive compounds' potential for respiratory system protection against inflammation and ensuing infection is also presented. Olive bioactive compounds mainly protect the respiratory system by subsiding proinflammatory cytokines and oxidative stress.

Therapeutic Properties and Use of Extra Virgin Olive Oil in Clinical Nutrition: A Narrative Review and Literature Update

Extra virgin olive oil (EVOO) is a cornerstone of the Mediterranean diet (MedD). In this narrative review, we synthesize and illustrate the various characteristics and clinical applications of EVOO and its components—such as oleic acid, hydroxytyrosol, and oleuropein—in the field of clinical nutrition and dietetics. The evidence is split into diet therapy, oleic acid-based enteral nutrition formulations and oral supplementation formulations, oleic acid-based parenteral nutrition, and nutraceutical supplementation of minor components of EVOO. EVOO has diverse beneficial health properties, and current evidence supports the use of whole EVOO in diet therapy and the supplementation of its minor components to improve cardiovascular health, lipoprotein metabolism, and diabetes mellitus in clinical nutrition. Nevertheless, more intervention studies in humans are needed to chisel specific recommendations for its therapeutic use through different formulations in other specific diseases and clinical populations.

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

PURPOSE

Olive 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.

METHODS

In 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.

RESULTS

Fourty-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.

CONCLUSIONS

Although 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).

Alleviation of Malathion Toxicity Effect by Coffea arabica L. Oil and Olea europaea L. Oil on Lipid Profile: Physiological and In Silico Study

The community health plans commonly use malathion (MAL), an organophosphate pesticide (OP), to eliminate pathogenic insects. The objective of the present research is to evaluate the consequences of Coffea arabica L. oil and Olea europaea L. oil on MAL-intoxicated male rats. Six equal groups of animals were used for conducting this study (n = 10). Animals in group one were designated as control, animals belonging to group two were exposed to MAL in the measure of hundred mg per kg BW (body weight) for forty-nine days (seven weeks), rats in the third and fourth groups were administered with 400 mg/kg BW of Coffea arabica L. and Olea europaea L. oils, respectively, and the same amount of MAL as given to the second group. Groups five and six were administered with the same amount of Coffea arabica L. oil and Olea europaea L. oil as given to group three. Exposure of rats to 100 mg/kg body weight of MAL resulted in statistical alteration of the serum lipid profile. A marked decline was noticed in the severe changes of these blood parameters when MAL-intoxicated rats were treated with Coffea arabica L. oil and Olea europaea L. oil. Two compounds from Coffea arabica L. oil (Chlorogenic acid) and Olea europaea L. oil (Oleuropein) demonstrated good interaction with xanthine oxidase (XO) and 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR) enzymes that are associated with cholesterol production. The present study indicated that Coffea arabica L. oil and Olea europaea L. oil could be considered prospective and potential healing agents against metabolic conditions induced by MAL.

Extra Virgin Olive Oil Protects the Testis and Blood from the Toxicity of Paracetamol (Overdose) in Adult Male Rats

Extra virgin olive oil (EVOO) is important in people's daily diets. Paracetamol is a widely used analgesic and antipyretic drug. The aim of this study is to investigate the protective effect of EVOO against hematotoxicity and testicular toxicity induced by paracetamol overdose in rats. Forty rats were divided into four groups. Group 1 rats were given water (control), Group 2 rats were given oral EVOO daily (2 mL/kg b.wt.), Group 3 rats were given oral paracetamol daily (650 mg/kg b.wt.), and Group 4 rats were given paracetamol and EVOO daily. After 15 days, blood and testis samples were collected for biochemical, histological, and ultrastructural studies. The results show that paracetamol decreased the PCV, Hb, and RBC counts relative to the control, and significantly increased the WBC counts and stab cells in Group 3. A significant decrease in blood testosterone was found in Group 3 compared to the control, while a significant increase in testosterone levels was observed in Group 4 compared to Group 3. Light and electron microscopy showed disorganized seminiferous tubules in Group 3. The testis in Group 4 appeared in normal shape. In conclusion, the results indicate that EVOO protects the testis and blood from paracetamol toxicity and may also increase fertility in male rats.

The effects of olive oil and cholesterol enriched diets on aortic fatty streak development and lipid peroxidation in rabbits

BACKGROUND AND AIM

High plasma cholesterol levels, mainly low-density lipoprotein-cholesterol (LDL) is a widely recognized major risk factor for coronary heart disease (CHD). According to epidemiologic studies' findings, people from the Mediterranean countries have lower CHD rates than other countries; in these countries the usual diet is high in olive oil. The present study compares the effects of a cholesterol-enriched diet with or without adding olive oil on serum lipoproteins, lipid peroxidation, and atherosclerosis development.

METHODS

Twenty Dutch male rabbits were categorized into four groups (one group as control, and others as experimental). They received one of control (CON), olive oil-rich (OIL), cholesterol-rich (CHOL), and cholesterol + olive oil (COIL) diet for 12 weeks. Fasting blood samples from the heart were collected at the beginning and the end of the experimental period.

RESULTS

Means of serum lipids were not significantly different at the beginning of the experimental period. After the intervention, significant differences were shown in total cholesterol (TC) (CON: 27.75 ± 4.83, OIL: 19.75 ± 2.62, CHOL: 1757.20 ± 149.62, COIL: 2906.40 ± 421.01; P < 0.001), high-density lipoprotein-cholesterol (HDL-C) (CON: 16 ± 1.47, OIL: 10.25 ± 1.70, CHOL: 22.2 ± 3.83, COIL: 28.60 ± 6.27; P = 0.04), triglyceride (CON: 65 ± 12.21, OIL: 71.75 ± 6.23, CHOL: 244.2 ± 44.45, COIL: 775.6 ± 105.07; P < 0.001), and MDA between groups (CON: 0.57 ± 0.10, OIL: 0.63 ± 0.15, CHOL: 5.62 ± 0.18, COIL: 2.06 ± 0.64; P < 0.001). The comparison of CHOL and the COIL groups showed a higher mean of malondialdehyde (MDA) in group CHOL (4.47 ± 0.28 vs 1.1 ± 0.6; P < 0.001). Aortic lesion was not observed in CON and OIL groups. Aortic lesion degree was significantly lower in the COIL group compared to the CHOL (2.4 ± 0.6 vs 3.66 ± 0.33; P = 0.02).

CONCLUSIONS

These findings showed the preventive effect of olive oil on atherosclerosis development. However, it is independent of the plasma lipoprotein effect, and olive oil probably acts on arteries directly.

Olive Oil Intake and Cardiovascular Disease Prevention: "Seek and You Shall Find"

PURPOSE OF REVIEW

The present narrative review focuses on the up-to-date clinical data on the correlations between olive oil consumption and cardiovascular (CV) diseases (i.e., CHD, stroke, and peripheral artery disease).

RECENT FINDINGS

Olive oil contains monounsaturated fats, several antioxidant phenols, and other micronutrients that mediate CV-protective effects via improvements in oxidative stress, endothelial dysfunction, inflammation, thrombosis, blood pressure, and lipid and carbohydrate metabolism. High consumption of olive oil, and in particular the extra-virgin, which is rich in phenolic antioxidants, has been suggested to prevent against coronary heart disease (CHD). The olive oil-induced cardioprotection was further supported by the findings of a very recent analysis of 2 large US prospective cohort studies showing that a higher olive oil intake was related to a lower risk of CV morbidity and mortality after 24 years of follow-up and that replacement of dairy fat, margarine, butter, or mayonnaise with the equivalent amount of olive oil significantly reduced CV risk. There is evidence for associations between olive oil consumption and lower risk for CV diseases. Both health policy makers and physicians should be aware of these associations and thus promote the intake of olive oil in both primary and secondary prevention settings to minimize individual's CV risk.

Laminarin Induces Defense Responses and Efficiently Controls Olive Leaf Spot Disease in Olive

Olive leaf spot (OLS) caused by Fusicladiumoleagineum is mainly controlled using copper fungicides. However, the replacement of copper-based products with eco-friendly alternatives is a priority. The use of plant resistance-inducers (PRIs) or biological control agents (BCAs) could contribute in this direction. In this study we investigated the potential use of three PRIs (laminarin, acibenzolar-S-methyl, harpin) and a BCA (Bacillus amyloliquefaciens FZB24) for the management of OLS. The tested products provided control efficacy higher than 68%. In most cases, dual applications provided higher (p < 0.05) control efficacies compared to that achieved by single applications. The highest control efficacy of 100% was achieved by laminarin. Expression analysis of the selected genes by RT-qPCR revealed different kinetics of induction. In laminarin-treated plants, for most of the tested genes a higher induction rate (p < 0.05) was observed at 3 days post application. Pal, Lox, Cuao and Mpol were the genes with the higher inductions in laminarin-treated and artificially inoculated plants. The results of this study are expected to contribute towards a better understanding of PRIs in olive culture and the optimization of OLS control, while they provide evidence for potential contributions in the reduction of copper accumulation in the environment.

Associations between adherence to MIND diet and metabolic syndrome and general and abdominal obesity: a cross-sectional study

BACKGROUND

There is a lack of studies examining the association between Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) and metabolic syndrome (MetS) and obesity. Thus, this study aimed to investigate the association of adherence to the MIND diet with MetS and general and abdominal obesity.

METHODS

This cross-sectional study was performed on 836 Iranian adults, 18-75 years old. A 167-item food frequency questionnaire (FFQ) was used to assess dietary intakes of participants. Anthropometric measurements, blood pressure, fasting blood glucose and lipid profile of each participant were recorded. The guidelines of the National Cholesterol Education Program Adult Treatment Panel III (ATP III) was used to define MetS.

RESULTS

Mean age of study participants was 47.7 ± 10.7 years. The prevalence of MetS was 36.1% and mean body mass index (BMI) and waist circumference (WC) was 27.7 ± 4.69 kg/m² and 92.0 ± 12.4 cm respectively. Those who were in the third tertile of the MIND diet score compared to the first tertile had 12% lower odds of having the MetS (ORs: 0.88; 95% CI 0.62-1.24) but the association was not significant (P = 0.77). There was a significant inverse association between the MIND diet score and odds of reduced high-density lipoprotein cholesterol (HDL-C) (ORs: 0.59; 95% CI 0.41-0.85; P = 0.008) and general obesity (ORs: 1.190.80-1.78; 95% CI 0.80-1.78; P = 0.02) in crude model and after controlling for confounders.

CONCLUSIONS

We found that the MIND diet score is inversely associated with odds of reduced HDL and general obesity in Iranian adults.

The effect of olive leaf extract on cardiovascular health markers: a randomized placebo-controlled clinical trial

Purpose

Overweight and obesity are associated with many health problems, including cardiovascular disease (CVD). Evidence from previous studies has shown that extracts from olive leaves rich in olive phenolics are able to positively affect CVD risk factors, such as high blood pressure and dyslipidemia. The aim of this study was to investigate the effect of 8-week olive leaf extract (OLE) administration on blood lipid profiles in overweight/obese subjects with mildly elevated cholesterol levels.

Methods

In this randomized, double-blind, placebo-controlled study, 77 healthy adult overweight/obese subjects (aged 56 ± 10 years and BMI 29.0 ± 2.7 kg/m²) with total cholesterol levels of 5.0–8.0 mmol/L (5.9 ± 0.7 mmol/L) were randomly assigned to receive 500 mg of OLE (n = 39) or placebo (n = 38) for 8 weeks. In total, 74 subjects completed the entire study protocol. At baseline, after 4 weeks, and after 8 weeks of supplementation, blood lipid profiles, oxidized low-density lipoprotein (oxLDL), blood pressure, glucose, and insulin levels were assessed. In addition, liver function parameters were measured at baseline and after 8 weeks.

Results

OLE supplementation did not significantly affect blood lipid levels after 4 weeks or after 8 weeks compared to placebo (all p > 0.05). For oxLDL, blood pressure, glucose, and insulin levels and liver function parameters, also no statistically significant differences were found between the two intervention groups (all p > 0.05).

Conclusions

Blood lipid profiles were not significantly affected by 8 weeks OLE supplementation in overweight/obese subjects with mildly elevated cholesterol levels.

Trial registered

The trial has been registered at ClinicalTrials.gov (NCT02990637).

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02397-9) contains supplementary material, which is available to authorized users.