Olive oil consumption and its repercussions on lipid metabolism

In vivo and in silico insights into the antidiabetic efficacy of EVOO and hydroxytyrosol in a rat model

Extra virgin olive oil (EVOO) has a putative antidiabetic activity mostly attributed to its polyphenol Hydroxytyrosol. In this study, we explored the antidiabetic effects of EVOO and Hydroxytyrosol on an in vivo T2D-simulated rat model as well as in in silico study. Wistar rats were divided into four groups. The first group served as a normal control (NC), while type 2 diabetes (T2D) was induced in the remaining groups using a high-fat diet (HFD) for 12 weeks followed by a single dose of streptozotocin (STZ, 30 mg/kg). One diabetic group remained untreated (DC), while the other two groups received an 8-week treatment with either EVOO (90 g/kg of the diet) (DO) or Hydroxytyrosol (17.3 mg/kg of the diet) (DH). The DC group exhibited hallmark features of established T2D, including elevated fasting blood glucose levels, impaired glucose tolerance, increased HOMA-IR, widespread downregulation of insulin receptor expression, heightened oxidative stress, and impaired β-cell function. In contrast, treatments with EVOO and Hydroxytyrosol elicited an antidiabetic response, characterized by improved glucose tolerance, as indicated by accelerated blood glucose clearance. Systematic analysis revealed the underlying antidiabetic mechanisms: both treatments enhanced insulin receptor expression in the liver and skeletal muscles, increased adiponectin levels, and mitigated oxidative stress. Moreover, while EVOO reduced intramyocellular lipids, Hydroxytyrosol restored adipose tissue insulin sensitivity and enhanced β-cell survival. Molecular docking and dynamics confirm Hydroxytyrosol's high affinity binding to PGC-1α, IRE-1α, and PPAR-γ, particularly IRE-1α, highlighting its potential to modulate diabetic signaling pathways. Collectively, these mechanisms highlight the putative antidiabetic role of EVOO and Hydroxytyrosol. Moreover, the favorable docking scores of Hydroxytyrosol with PGC-1α, IRE-1α, and PPAR-γ support the antidiabetic potential and offer promising avenues for further research and the development of novel antidiabetic therapies.

Olive oil protects against cardiac hypertrophy in D-galactose induced aging rats

BACKGROUND

Aged heart is defined via structural and mitochondrial dysfunction of the heart. However, there is still no potent compound to improve cardiac function abnormalities in aged individuals. Olive oil (OLO), as an oil with monounsaturated fatty acids, has diverse protective effects on the cardiovascular system, including anti-inflammatory, anti-diabetic, and mitigating effects on blood pressure. In the present study, we evaluated the protective effects of OLO against aging-related cardiac dysfunction.

METHODS

Male Wistar rats were randomly divided into three groups: Control, D-galactose-induced aging rats (D-GAL group), and aging rats treated with OLO (D-GAL + OLO group). Aging in rats was induced by intraperitoneal injection of D-GAL at 150 mg/kg dose for eight weeks and the D-GAL + OLO group was treated with oral OLO by gavage for eight weeks. The heart tissues were harvested to assay the oxidative stress, molecular parameters, and histological analysis.

RESULTS

The D-GAL given rats indicated increased cardiomyocyte diameter as cardiac hypertrophy marker (21 ± 0.8, p < 0.001), an increased Malondialdehyde (MDA) level (27 ± 3, p < 0.001), a reduced Superoxide dismutase (SOD) (p < 0.001, 18.12 ± 1.3), and reduction in gene expression of Sirtuin 1 (SIRT1) (p < 0.05, 0.37 ± 0.06), Peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1α (p < 0.001, 0.027 ± 0.04), and Transcription Factor A, Mitochondrial (TFAM) (p < 0.001, 0.023 ± 0.01), Bcl2 (p < 0.001, 0.04 ± 0.004) and an increase in gene expression of Bax (p < 0.001, 23.5 ± 5.4) in comparison with the control animals. Treatment with OLO improved cardiac hypertrophy (14 ± 0.4, p < 0.001), MDA (22 ± 2.5, p < 0.01), SOD (p < 0.001, 34.9 ± 2), SIRT1 (p < 0.05, 1.37 ± 0.46), PGC-1α (p < 0.001, 1.11 ± 0.1), TFAM (p < 0.01, 0.23 ± 0.02), Bcl2 (p < 0.05, 0.35 ± 0.05) and Bax genes (p < 0.01, 0.1 ± 0.03).

CONCLUSIONS

Overall, OLO protects the heart against D-GAL-induced aging via increasing antioxidant effects, and enhancing cardiac expression of SIRT1, PGC-1α, TFAM, Bcl2 and Bax genes.

Recipe for Heart Health: A Randomized Crossover Trial on Cardiometabolic Effects of Extra Virgin Olive Oil Within a Whole-Food Plant-Based Vegan Diet

BACKGROUND

Whole-food, plant-based vegan diets, low in oils, and Mediterranean diets, rich in extra virgin olive oil (EVOO), reduce cardiovascular disease risk factors. Optimal quantity of dietary fat, particularly EVOO, is unclear.

METHODS AND RESULTS

In a randomized crossover trial with weekly cooking classes, adults with ≥5% cardiovascular disease risk followed a high (4 tablespoons/day) to low (<1 teaspoon/day) or low to high EVOO whole-food, plant-based diet for 4 weeks each, separated by a 1-week washout. The primary outcome was difference in low-density lipoprotein cholesterol (LDL-C) from baseline. Secondary measures were changes in additional cardiometabolic markers. Linear mixed models assessed changes from baseline between phases, with age, sex, and body weight change as covariates. In 40 participants, fat intake comprised 48% and 32% of energy during high and low EVOO phases, respectively. Both diets resulted in comparable reductions in LDL-C, total cholesterol, apolipoprotein B, high-density lipoprotein cholesterol, glucose, and high-sensitivity C-reactive protein (all P<0.05). With diet-sequence interactions for LDL-C, differences were detected between diets by diet order (mean±SEM high to low: Δ-12.7[5.9] mg/dL, P=0.04 versus low to high: Δ+15.8[6.8] mg/dL, P=0.02). Similarly, low to high order led to increased glucose, total cholesterol, and high-density lipoprotein cholesterol (all P<0.05). Over period 1, LDL-C reductions were -25.5(5.1) post-low versus -16.7(4.2) mg/dL post-high EVOO, P=0.162, which diminished over period 2.

CONCLUSIONS

Both plant-based diet patterns improved cardiometabolic risk profiles compared with baseline diets, with more pronounced decreases in LDL-C after the low EVOO diet. Addition of EVOO after following a low intake pattern may impede further lipid reductions.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04828447.

Daily olive oil intake is feasible to reduce trigeminal neuralgia facial pain: A pilot study

Extra virgin olive oil (EVOO) is thought to contribute to neuroprotection and, thus, may influence pain symptoms experienced by adults with demyelination-related trigeminal neuralgia (TN). This study aimed to determine the feasibility of daily intake of EVOO and its potential to alleviate facial pain of TN. Adults, self-reporting as female and affected by TN, were enrolled in a 16-week nonblinded, parallel study. After a 4-week baseline, participants were randomized to 60 mL/day EVOO or control (usual diet and no supplemental EVOO) for 12 weeks. Participants completed a daily questionnaire on pain intensity and compliance, the Penn Facial Pain Scale weekly, the 36-Item Short Form Survey monthly, and dietary assessment during baseline and intervention. Participants (n = 52; 53.3 ± 12.9 years) were recruited nationally; 42 completed the study. The EVOO group, with 90% intake compliance, showed significant decreases in the Penn Facial Pain Scale items of interference with general function, interference with orofacial function, and severity of pain from baseline, whereas the control group showed no improvements. EVOO benefit, compared with control, trended for the interference with orofacial function (P = .05). The 36-Item Short Form Survey items of role limitations resulting from emotional problems and role limitations from physical health favored EVOO. The EVOO group significantly improved their Healthy Eating Index 2015 component scores of fatty acids (primarily from increased oleic acid), sodium, and refined grains. EVOO intake of 60 mL/day was feasible for participants experiencing TN and may mitigate pain and improve quality of life. This trial was registered at clinicaltrials.gov (NCT05032573).

Hydroxytyrosol Induces Dyslipidemia in an ApoB100 Humanized Mouse Model

SCOPE

Extra virgin olive oil has numerous cardiopreventive effects, largely due to its high content of (poly)phenols such as hydroxytyrosol (HT). However, some animal studies suggest that its excessive consumption may alter systemic lipoprotein metabolism. Because human lipoprotein metabolism differs from that of rodents, this study examines the effects of HT in a humanized mouse model that approximates human lipoprotein metabolism.

METHODS AND RESULTS

Mice are treated as follows: control diet or diet enriched with HT. Serum lipids and lipoproteins are determined after 4 and 8 weeks. We also analyzed the regulation of various genes and miRNA by HT, using microarrays and bioinformatic analysis. An increase in body weight is found after supplementation with HT, although food intake was similar in both groups. In addition, HT induced the accumulation of triacylglycerols but not cholesterol in different tissues. Systemic dyslipidemia after HT supplementation and impaired glucose metabolism are observed. Finally, HT modulates the expression of genes related to lipid metabolism, such as Pltp or Lpl.

CONCLUSION

HT supplementation induces systemic dyslipidemia and impaired glucose metabolism in humanized mice. Although the numerous health-promoting effects of HT far outweigh these potential adverse effects, further carefully conducted studies are needed.

Dietary flaxseed oil induces production of adiponectin in visceral fat and prevents obesity in mice

Induction of obesity by dietary fats and oils differs according to the type of fat. Adiponectin is believed to be related to obesity prevention. We hypothesized that flaxseed oil is important for preventing obesity and producing adiponectin. To clarify this hypothesis, we investigated the relationship between obesity and different fat sources in mice fed diets with 6 types of fat and oils. C57BL/6J mice were given a control diet containing 5% corn oil or a high-fat diet containing 20% of either lard, palm oil, rapeseed oil, oleate-rich safflower oil, corn oil, or flaxseed oil for 14 weeks. In another experiment, mice were given a control diet and rosiglitazone (10 mg/kg body weight) by oral gavage for 1 week. At the end of study, plasma adiponectin and expression of fatty acid metabolism-related factors in white and brown adipose tissue and the liver were measured. Dietary flaxseed oil, which is rich in α-linolenic acid, did not induce obesity. Flaxseed oil resulted in increased β-oxidation-related factors in epididymal white adipose tissue, decreased fatty acid synthesis-related factors in the liver, and thermogenesis-related factor in brown adipose tissue following increase of plasma adiponectin. The results suggested that increase in plasma adiponectin after intake of flaxseed oil may be due to altered expression of AdipoQ and peroxisome proliferator-activated receptor γ in epididymal white adipose tissue. Flaxseed oil increased expression of adiponectin in visceral fat and regulated obesity-controlling fatty acid metabolism-related factors in white adipose tissue and liver, and thermogenesis-related factor in brown adipose tissue.

Use of Olives-derived Phytochemicals for Prevention and Treatment of Atherosclerosis: An Update

Mediterranean diet is frequently associated with longevity and a lower incidence of adverse cardiovascular events because of the biological activities and health effects of olives - its key component. Olive oil, olive leaf extract, fruits and different by-products contain many bioactive components that exert anti-oxidant, anti-inflammatory and anti-apoptotic activities. In this review, we focus on the recent studies exploring molecular mechanisms underlying the cardioprotective properties of different olive oils, olive leave extracts, and specific micro-constituents (such as oleuropein, tyrosol, hydroxytyrosol and others) in vitro on rodent models and in clinical trials on human subjects. Particularly, hydroxytyrosol and oleuropein were identified as the major bioactive compounds responsible for the antioxidant, anti-inflammatory, anti-platelet aggregation and anti-atherogenic activities of olive oil. In total, the discussed results demonstrated a positive association between the consumption of olive oil and improvement in outcomes in atherosclerosis, diabetes, myocardial infarction, heart failure, hypertension and obesity.

Reviewing the cardiovascular and other health effects of olive oil: Limitations and future directions of current supplement formulations

AIMS

We reviewed the literature to date for high-level evidence on the cardiovascular and other health effects of olive oil with a focus on the amount, frequency of use and type of olive oil consumed in prior studies. A total of twelve prospective cohort studies with sample sizes of at least 4000 individuals and one meta-analysis were identified.

DATA SYNTHESIS

The majority of cohorts followed individuals aged ≥55 years old, free of cardiovascular disease (CVD) at baseline but at high risk, over periods of 4-10 years and with daily consumption amounts of 10-35 g/day. With the exception of the PREDIMED cohort that employed extra virgin olive oil, most remaining studies did not differentiate between different types of olive oil. Taken together, the data suggests an association between greater olive oil consumption and a lower CVD incidence/mortality and stroke risk. We use this information to evaluate the use of commercially available, capsule-based olive oil dietary supplements and suggest future directions. Notably, achieving minimum total daily doses described in the aforementioned studies would be challenging with current market formulations of olive oil supplements dosed at 1-1.25 g/capsule.

CONCLUSIONS

Outside of mechanistic studies, little progress has been made in determining the olive oil component(s) underlying the observed health effects given the lack of compositional reporting and consistency across large scale human studies. We propose the use of supplements of varying composition, such as varying total phenolic content, in pragmatic trial designs focused on low-cost methodologies to address this question.

The Association between Dietary Habits and Rapid Postoperative Recovery of Rotator Cuff Repair

Some nutritional factors have been suggested to improve postoperative outcomes in rotator cuff (RC) repair, but dietary effects on the recovery speed after the surgery remain undefined. To investigate the potential roles of dietary habits in this context, we analyzed the 12-month follow-up data of 55 patients with RC repair and found that these patients could be categorized into a rapid recovery group (n = 35) and slow recovery group (n = 20) according to their postoperative recovery patterns. Group-based logistic analysis revealed that habitual intakes of meat (OR = 1.84, 95%CI, 1.22-2.76, p = 0.003), fruits (OR = 2.33, 95%CI, 1.26-5.67, p = 0.01), and wheat-flour foods (OR = 1.62, 95%CI, 1.2-2.25, p = 0.002) were significantly associated with rapid recovery. Moreover, among all intakes of wheat-flour foods, intakes of steamed and boiled flour products were also associated with rapid recovery. Further mediation analysis showed that eosinophilic granulocytes (EOs) significantly mediated the association between rapid RC recovery and the habitual intakes of meat (mediation proportion = 17.5%, P-mediation < 0.0001), fruits (17.9%, p < 0.0001), and wheat-flour foods (11.4%, p < 0.0001). Thus, our study suggests that certain dietary habits play beneficial roles in the context of postoperative recovery for RC repair.

Extra-virgin olive oil ameliorates high-fat diet-induced seminal and testicular disorders by modulating the cholesterol pathway

BACKGROUND

Rabbits are sensitive to dietary cholesterol and rapidly develop hypercholesterolemia, leading to prominent subfertility. Sterol regulatory element-binding protein isoform 2 drives the intracellular cholesterol pathway in many tissues, including the testicles. Its abnormal regulation could be the mainly responsible for the failure of suppressing cholesterol synthesis in a cholesterol-enriched environment, ultimately leading to testicular and seminal alterations. However, extra-virgin olive oil consumption has beneficial properties that promote lowering of cholesterol levels, including the recovery of seminal parameters altered under a high-fat diet.

OBJECTIVES

Our goal was to investigate the effects of high-fat diet supplementation with extra-virgin olive oil at the molecular level on rabbit testes, by analyzing sterol regulatory element-binding protein isoform 2 protein and its corresponding downstream effectors.

MATERIALS AND METHODS

During 12 months, male rabbits were fed a control diet, high-fat diet, or 6-month high-fat diet followed by 6-month high-fat diet plus extra-virgin olive oil. Serum lipids, testosterone levels, bodyweight, and seminal parameters were tested. The mRNA and protein levels of sterol regulatory element-binding protein isoform 2, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, and low-density lipoprotein receptor were determined by semi-quantitative polymerase chain reaction and Western blotting techniques. The expression pattern of sterol regulatory element-binding protein isoform 2 protein in the rabbit testicles was studied by indirect immunofluorescence. In addition, testicular cholesterol was detected and quantified by filipin staining and gas chromatography.

RESULTS

The data showed that the addition of extra-virgin olive oil to high-fat diet reduced testicular cholesterol levels and recovered the expression of sterol regulatory element-binding protein isoform 2, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, and low-density lipoprotein receptor initially altered by the high-fat diet.

DISCUSSION AND CONCLUSIONS

The combination of high-fat diet with extra-virgin olive oil encourages testicular recovery by modifying the expression of the enzymes related to intracellular cholesterol management.

Is There More to Olive Oil than Healthy Lipids?

The Mediterranean diet is a healthy dietary pattern whose main characteristic is olive oil consumption. The potential health benefits of olive oil have been extensively investigated and the present review provides the more recent clinical evidence supporting the positive impact of olive oil intake on human health. PubMed (n = 227) and Scopus (n = 308) databases were searched for published clinical studies in English over the past six years (October 2016 to December 2022), following key word searches of "olive oil" and "health". Major findings associated olive oil with antioxidant and anti-inflammatory effects, improvement in endothelial function and lipid profile, prevention of obesity, diabetes, cardiovascular and neurodegenerative diseases, and modulation of the gut microbiota. These benefits are attributed to the nutritional composition of olive oil, which has a high content of monounsaturated fatty acids (MUFA) (oleic acid in particular) and minor compounds such as polyphenols (oleuropein and hydroxytyrosol). Although additional research continues to be required, the more recently generated evidence supports the potential of olive oil to contribute beneficially to health and to the prevention and management of a variety of non-communicable diseases, as a consequence of the synergism between its components' complexity.

Is Extra Virgin Olive Oil the Critical Ingredient Driving the Health Benefits of a Mediterranean Diet? A Narrative Review

Most chronic diseases are preventable with a healthy diet, although there is debate about the optimal dietary approach. Increasingly more countries are focusing on food-based guidelines rather than the traditional nutrient-based approach. Although there is good agreement on plant foods, controversy remains about the types and amounts of fats and oils. This narrative review aims to systematically summarize and evaluate the latest evidence on the protective effects of extra virgin olive oil (EVOO) on disease risk factors. A systematic search of the relevant literature using PubMed, Cochrane Library, and Embase databases was conducted for the years 2000 through December 2022. A narrative synthesis was then undertaken. Of 281 retrieved articles, 34 articles fulfilled our inclusion criteria and were included. Compared with other dietary fats and low-fat diets, EVOO is superior in the management of clinical biomarkers including lowering blood pressure and LDL-c, increasing protective HDL-c, improving glycemic control, and weight management. The protective effects of EVOO are likely due to its polyphenol content rather than the monounsaturated fat content. It is therefore important to promote the regular use of EVOO in the context of healthy dietary patterns such as the Mediterranean diet for maximal health benefit.

Olive juice dry extract containing hydroxytyrosol, as a nontoxic and safe substance: Results from pre-clinical studies and review of toxicological studies

Products derived from olives, such as the raw fruit and oils, are widely consumed due to their taste, and purported nutritional/health benefits. Phenolic compounds, especially hydroxytyrosol (HT), have been proposed as one of the key substances involved in these effects. An olive juice extract, standardized to contain 20% HT ("OE20HT"), was produced to investigate its health benefits. The aim of this study was to demonstrate the genotoxic safety of this ingredient based on in vitro Ames assay and in vitro micronucleus assay. Results indicated that OE20HT was not mutagenic at concentrations of up to 5000 µg/plate, with or without metabolic activation, and was neither aneugenic nor clastogenic after 3-hour exposure at concentrations of up to 60 µg/mL with or without metabolic activation, or after 24-hour exposure at concentrations of up to 40 µg/mL. To further substantiate the safety of OE20HT following ingestion without conducting additional animal studies, a comprehensive literature review was conducted. No safety concerns were identified based on acute or sub-chronic studies in animals, including reproductive and developmental studies. These results were supported by clinical studies demonstrating the absence of adverse effects after oral supplementation with olive extracts or HT. Based on in vitro data and the literature review, the OE20HT extract is therefore considered as safe for human consumption at doses up to 2.5 mg/kg body weight/day.

The effects of olive oil consumption on blood lipids: a systematic review and dose-response meta-analysis of randomised controlled trials

We performed a systematic review and dose-response meta-analysis of randomised trials on the effects of olive oil consumption on blood lipids in adults. A systematic search was performed in PubMed, Scopus and Web of Science databases until May 2021. Randomised controlled trials (RCT) evaluating the effect of olive oil intake on serum total cholesterol (TC), TAG, LDL-cholesterol and HDL-cholesterol in adults were included. The mean difference (MD) and 95 % CI were calculated for each 10 g/d increment in olive oil intake using a random-effects model. A total of thirty-four RCT with 1730 participants were included. Each 10 g/d increase in olive oil consumption had minimal effects on blood lipids including TC (MD: 0·79 mg/dl; 95 % CI (-0·08, 1·66); I² = 57 %; n 31, GRADE = low certainty), LDL-cholesterol (MD: 0·04 mg/dl, 95 % CI (-1·01, 0·94); I² = 80 %; n 31, GRADE = very low certainty), HDL-cholesterol (MD: 0·22 mg/dl; 95 % CI (-0·01, 0·45); I² = 38 %; n 33, GRADE = low certainty) and TAG (MD: 0·39 mg/dl; 95 % CI (-0·33, 1·11); I² = 7 %; n 32, GRADE = low certainty). Levels of TC increased slightly with the increase in olive oil consumption up to 30 g/d (MD_{30 g/d}: 2·76 mg/dl, 95 % CI (0·01, 5·51)) and then appeared to plateau with a slight downward curve. A trivial non-linear dose-dependent increment was seen for HDL-cholesterol, with the greatest increment at 20 g/d (MD_{20 g/d}: 1·03 mg/dl, 95 % CI (-1·23, 3·29)). Based on existing evidence, olive oil consumption had trivial effects on levels of serum lipids in adults. More large-scale randomized trials are needed to present more reliable results.

Dietary Fats and Cardio-Metabolic Outcomes in a Cohort of Italian Adults

Background: Dietary fats, and especially saturated fatty acid (SFA), have been blamed for being the culprit in the dramatic increase in obesity and its associated diseases. However multiple systematic reviews and recent meta-analyses do not support the association between SFA and cardiovascular diseases. Thus, the objective of this study was to test whether specific types and subtypes of dietary fats are associated with metabolic outcomes in a cohort of Italian adults. Methods: Nutritional and demographic data of 1936 adults living in the south of Italy were examined. Food frequency questionnaires (FFQs) were administered to assess the intake of total dietary fat and each specific class of dietary fat, such as SFA, monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA). The intake of fatty acids was also examined according to the carbon-chain length of each individual class. Cases of hypertension, type-2 diabetes and dyslipidemias were collected from previous doctor-confirmed diagnosis records (or direct measurement of blood pressure). Results: After adjustment for potential confounding factors, individuals reporting higher intakes of total and saturated fats were associated with lower likelihood of having hypertension (odds ratio (OR) = 0.57, 95% CI: 0.35, 0.91 and OR = 0.55, 95% CI: 0.34, 0.89, respectively). Moreover, higher intake of short-chain saturated fatty acids (SCSFAs) and medium-chain saturated fatty acids (MCSFAs) was inversely associated with dyslipidemia and diabetes (OR = 0.43, 95% CI: 0.23, 0.82 and OR = 0.25, 95% CI: 0.09, 0.72, respectively). Among MUFAs, C18:1 was inversely associated with hypertension and diabetes (OR = 0.52, 95% CI: 0.30, 0.92 and OR = 0.21, 95% CI: 0.07, 0.67, respectively), while C14:1 intake was inversely associated only with hypertension (OR = 0.57, 95% CI: 0.37, 0.88). In contrast, C20:1 intake was associated with dyslipidemia (OR = 3.35, 95% CI: 1.33, 8.42). Regarding PUFA, C18:2 and 20:5 were inversely associated with hypertension (OR = 0.33, 95% CI: 0.18, 0.60 and OR = 0.30, 95% CI: 0.10, 0.89, respectively). Conclusions: The consumption of SFA does not seem to be harmful to cardio-metabolic health and, on the contrary, SCSFA may exert beneficial effects. Further studies are needed to clearly validate the results of the present study.

A comparative study between olive oil and corn oil on oxidative metabolism

Fats are an important part of diet, but not all lipids have the same structure and chemical properties. Unsaturated fatty acids have one or more double bonds in their structure and can be monounsaturated or polyunsaturated, respectively. Most vegetable oils, such as olive oil and corn oil, contain significant amounts of these fatty acids. The presence of double bonds in the molecule of a fatty acid constitutes vulnerable sites for oxidation reactions generating lipid peroxides, potentially toxic compounds that can cause cellular damage. In response to this oxidative damage, aerobic organisms have intracellular enzymatic antioxidant defense mechanisms. The aim of the present investigation was to study comparatively the effects of control liquid diets, of a defined composition, containing olive oil or corn oil as a lipid source respectively of monounsaturated and polyunsaturated fatty acids, on the oxidative metabolism of rats. Rats were divided into three groups which received a control animal feed diet (A.F.), olive oil liquid diet (O.O) and corn oil liquid diet (C.O) for 30 days. It was observed that the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), increased in the liver and white fat tissue of rats fed with olive oil when compared to the corn oil group. However, in brown fat tissue and blood cells, the enzyme activities showed a tendency to decrease in the olive oil group. In addition, the effect of olive oil and corn oil on several glucose metabolism parameters (pyruvate, lactate, LDH, acetoacetate and beta-hydroxybutyrate) showed that corn oil impairs to a greater extent the cellular metabolism. All these results helped in concluding that some body tissues are more adversely affected than others by the administration of corn oil or olive oil, and their antioxidant defenses and cellular metabolism respond differently too.

Molecular and metabolic effects of extra-virgin olive oil on the cardiovascular gene signature in rodents

BACKGROUND AND AIMS

Overweight and obesity are major risk factors for degenerative diseases, including cardiometabolic disorders and cancer. Research on fat and fatty acids' type is attracting less attention than that on carbohydrates. High adherence to a Mediterranean diet is associated with a better prognosis. One characteristic of the Mediterranean diet is extra-virgin olive oil (EVOO) as the foremost source of dietary fat. EVOO is different from other vegetable oils because it contains peculiar "minor" components, mainly phenolic in nature. Even though olive oil is highly caloric, unrestricted use of olive oil in the PREDIMED trial did not result in weight gain. We sought to study the effects of EVOO in an appropriate mouse model of increased body weight. Furthermore, we explored the biochemical and metabolomic responses to EVOO consumption.

METHODS AND RESULTS

C57BL/6N male mice were weight-matched and fed ad libitum with the following diets, for 16 weeks: 1) saturated fatty acid diet (SFA) or 2) extra-virgin olive oil diet (EVOO), a custom-prepared diet, isocaloric compared to SFA, in which 82% of fat was replaced by high (poly)phenol EVOO. We evaluated glucose homeostasis, serum biochemistry and plasma metabolomics, in addition to cardiac and hepatic gene profile, and mitochondrial respiration rate.

CONCLUSION

Replacing saturated fatty acids (e.g. lard) with EVOO translates into moderate yet beneficial cardiometabolic and hepatic effects. Future research will further clarify the mechanisms of action of EVOO (poly)phenols and their role in a balanced diet.

Type does matter. Use VIRGIN olive oil as your preferred fat to reduce your risk of breast cancer: case-control EpiGEICAM study

The Epi-GEICAM study comprises 1017 invasive BC cases matched with controls of similar age (49 ± 9 years) and residence. Diet and OO consumption were collected through a validated food frequency questionnaire. 75% of women referred OO, common (refined) or virgin, as the main fat source. Using conditional logistic regression models, we compared different scenarios of type and frequency of OO consumption, using as reference those women not always using OO for the three culinary practices (seasoning, cooking, and frying) and adding <2 tablespoons (tbsps.) per day during the meal to bread, salad, or dishes. A substantial inverse association was observed in those women always using VOO for the three culinary practices and consuming ≥2 tbsps. of OO per day during meals (adjusted OR, 0.72; 95% CI: 0.51, 1.03; P = 0.07). Potential benefits from OO consumption, at least as regards the protection provided for BC, could be mostly conferred with VOO, and when its consumption is high.

Fatty Acids and Cardiovascular Risk. Evidence, Lack of Evidence, and Diligence

One of the most controversial areas of nutrition research relates to fats, particularly essential fatty acids, in the context of cardiovascular disease risk. A critical feature of dietary fatty acids is that they incorporate into the plasma membrane, modifying fluidity and key physiological functions. Importantly, they can reshape the bioavailability of eicosanoids and other lipid mediators, which direct cellular responses to external stimuli, such as inflammation and chronic stress conditions. This paper provides an overview of the most recent evidence, as well as historical controversies, linking fat consumption with human health and disease. We underscore current pitfalls in the area of fatty acid research and critically frame fatty acid intake in the larger context of diet and behavior. We conclude that fundamental research on fatty acids and lipids is appropriate in certain areas, but the rigor and reproducibility are lacking in others. The pros and cons are highlighted throughout the review, seeking to guide future research on the important area of nutrition, fat intake, and cardiovascular disease risk.

Current Knowledge on Interspecific Hybrid Palm Oils as Food and Food Ingredient

The consumers' opinion concerning conventional palm (Elaeis guineensis) oil is negatively affected by environmental and nutritional issues. However, oils extracted from drupes of interspecific hybrids Elaeis oleifera × E. guineensis are getting more and more interest, due to their chemical and nutritional properties. Unsaturated fatty acids (oleic and linoleic) are the most abundant constituents (60%-80% of total fatty acids) of hybrid palm oil (HPO) and are mainly acylated in position sn-2 of the glycerol backbone. Carotenes and tocotrienols are the most interesting components of the unsaponifiable matter, even if their amount in crude oils varies greatly. The Codex Committee on Fats and Oils recently provided HPO the "dignity" of codified fat substance for human consumption and defined the physical and chemical parameters for genuine crude oils. However, only few researches have been conducted to date on the functional and technological properties of HPO, thus limiting its utilization in food industry. Recent studies on the nutritional effects of HPO softened the initial enthusiasm about the "tropical equivalent of olive oil", suggesting that the overconsumption of HPO in the most-consumed processed foods should be carefully monitored.