Plasma lipids, erythrocyte membrane lipids and blood pressure of hypertensive women after ingestion of dietary oleic acid from two different sources

Mediterranean diet in the targeted prevention and personalized treatment of chronic diseases: evidence, potential mechanisms, and prospects

The prevalence of chronic diseases is currently a major public health issue worldwide and is exploding with the population growth and aging. Dietary patterns are well known to play a important role in our overall health and well-being, and therefore, poor diet and malnutrition are among the most critical risk factors for chronic disease. Thus, dietary recommendation and nutritional supplementation have significant clinical implications for the targeted treatment of some of these diseases. Multiple dietary patterns have been proposed to prevent chronic disease incidence, like Dietary Approaches to Stop Hypertension (DASH) and Diabetes Risk Reduction Diet (DRRD). Among them, the MedDiet, which is one of the most well-known and studied dietary patterns in the world, has been related to a wide extent of health benefits. Substantial evidence has supported an important reverse association between higher compliance to MedDiet and the risk of chronic disease. Innovative strategies within the healthcare framework of predictive, preventive, and personalized medicine (PPPM/3PM) view personalized dietary customization as a predictive medical approach, cost-effective preventive measures, and the optimal dietary treatment tailored to the characteristics of patients with chronic diseases in primary and secondary care. Through a comprehensive collection and review of available evidence, this review summarizes health benefits of MedDiet in the context of PPPM/3PM for chronic diseases, including cardiovascular disease, hypertension, type 2 diabetes, obesity, metabolic syndrome, osteoporosis, and cancer, thereby a working hypothesis that MedDiet can personalize the prevention and treatment of chronic diseases was derived.

The value of coupling thin-layer chromatography to mass spectrometry in lipid research - a review

Mass spectrometry has emerged as an extremely powerful analytical tool, which is widely used in many fields. This broad application range became possible with the invention of MALDI and ESI as "soft ionization" techniques that keep fragmentation of the analyte to a minimum. However, when these techniques are applied to mixture analysis, less-sensitively detectable compounds may be suppressed by more sensitively detectable compounds, a process called "ion suppression". Thus, previous separation of the mixture into the individual lipid classes is necessary to be able to detect all compounds. This review summarizes the current knowledge in the field of combined TLC/MS and discusses the most important strengths and weaknesses of the different MS (particularly ionization) techniques with respect to phospholipids. This comprises techniques such as MALDI and ESI, but less established approaches such as plasma desorption will be also discussed.

Changes in fatty acid profile of Holothuria forskali muscle following acute mercury exposure

The present study aimed to document the interaction between mercury (Hg), as a model chemical stressor to an aquatic organism, and Fatty acid (FA) profile in the longitudinal muscle of the sea cucumber Holothuria forskali. To assess the sensitivity of this species to the toxic effects of Hg, young H. forskali were exposed to gradual doses of Hg (40, 80 and160 µg·L-1) for 96 h. The results showed that following Hg exposure, the FA profile of H. forskali corresponded to an increase in the level of saturated fatty acids, and the decrease in the level of monounsaturated and polyunsaturated fatty acids. The most prominent changes in the FA composition were recorded at the lowest dose with noticeable decreases in linoleic, arachidonic and eicosapentaenoic acid levels and an increase of docosahexaenoic acid. The occurrence of a state of oxidative stress induced by Hg contamination was evidenced by the enhanced levels of malondialdehyde, hydrogen peroxide and lipid hydroperoxide. Overall, the low concentration of mercury exerted the most obvious effects on lipid metabolism, suggesting that changes in fatty acid composition may be act as an early biomarker to assess mercury toxicity in this ecologically and economically important species.

Extra Virgin Olive Oil Phenols Dilate the Rat Mesenteric Artery by Activation of BKCa2+ Channels in Smooth Muscle Cells

Accumulating evidence has shown the beneficial health effects of extra virgin olive oil (EVOO) consumption in reducing blood pressure and preventing the risk of developing hypertension. Some studies associate the hypotensive activity of EVOO to a minor component—the phenols. This study was designed to investigate the effects of EVOO phenols on the rat resistance mesenteric artery (MA) and to find out the possible vascular pathways involved. The experiments were carried out using a pressurized myograph, which allowed the effects of phenols on isolated MA to be tested under different conditions: (a) with endothelium removed; (b) with inhibition of nitric oxide synthase by N_ω-Nitro-l-arginine methyl ester hydrochloride (l-NAME, 10⁻⁴ M) + N_ω-Nitro-l-arginine (l-NNA, 10⁻⁴ M); (c) with inhibition of cyclooxygenase by indomethacin (10⁻⁵ M); (d) with inhibition of guanylate cyclase by 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ,10⁻⁵ M) or adenylate cyclase by 9-(Tetrahydro-2′-furyl)adenine (SQ, 10⁻⁵ M); (e) with depolarization by high potassium chloride (40 mM); and (f) with inhibition of the large conductance Ca²⁺–potassium channels (BK_Ca2+) with paxilline (10⁻⁵ M). EVOO phenols induce vasodilation of the endothelium, mediated by a direct effect on smooth muscle cells (SMC) by activation of BK_Ca2+ channels, an action by which phenols can regulate the vascular tone of the resistance artery. Phenols can be regarded as bioactive molecules that may contribute to the antihypertensive effects of EVOO.

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

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.

Association Between Nutrient Patterns and Hypertension Among Adults in the United States: A Population-Based Survey

INTRODUCTION

Hypertension (HTN) is a common medical condition associated with many adverse health outcomes. Diet plays a crucial role in the pathology, prevention, and management of HTN.

AIM

To identify nutrient patterns (NPs) and to investigate their association with the risk of HTN among adults in the United States (US).

METHODS

This cross-sectional study used data from the US community-based National Health and Nutrition Examination Survey (NHANES). Participants with data on dietary intake and blood pressure were analyzed. NPs were determined by principal components analysis (PCA). In all the analyses (analysis of covariance and multivariate logistic regression), we accounted for the survey design and sample weights.

RESULTS

Overall, 22,184 (4002 hypertensive and 18,182 normotensive) individuals were included. We identified three NPs which explained 50.8% of the variance of the dietary nutrient consumption. There was a graded decrease in the odds of association with HTN by quartiles of mono-unsaturated fatty acids (MUFA) dietary pattern where the 4th quartile was associated with a 28% (odds ratio [OR] 0.72, 95% confidence interval [CI] 0.63-0.82; p < 0.001) lower odds of HTN compared with the first quartile. The second NP "high in micronutrients and vitamins" presented a decreasing trend in the odds of association with HTN with the 4th quartile having a 20% [OR 0.80, 95% CI 0.63-0.97; p < 0.001] lower odds of HTN compared with the 1st quartile.

CONCLUSION

Our findings provide further evidence on the inverse association between a high intake of minerals, vitamins, and MUFA and the risk of HTN. Further observational studies and clinical trials are needed to better understand the influence of MUFA, vitamins, and mineral consumption on HTN.

Metabolic and Vascular Effect of the Mediterranean Diet

Several studies indicated how dietary patterns that were obtained from nutritional cluster analysis can predict disease risk or mortality. Low-grade chronic inflammation represents a background pathogenetic mechanism linking metabolic risk factors to increased risk of chronic degenerative diseases. A Mediterranean diet (MeDi) style has been reported as associated with a lower degree of inflammation biomarkers and with a protective role on cardiovascular and cerebrovascular events. There is heterogeneity in defining the MedDiet, and it can, owing to its complexity, be considered as an exposome with thousands of nutrients and phytochemicals. Recently, it has been reported a novel positive association between baseline plasma ceramide concentrations and cardiovascular events and how adherence to a Mediterranean Diet-style may influence the potential negative relationship between elevated plasma ceramide concentrations and cardiovascular diseases (CVD). Several randomized controlled trials (RCTs) showed the positive effects of the MeDi diet style on several cardiovascular risk factors, such as body mass index, waist circumference, blood lipids, blood pressure, inflammatory markers and adhesion molecules, and diabetes and how these advantages of the MeDi are maintained in comparison of a low-fat diet. Some studies reported a positive effect of adherence to a Mediterranean Diet and heart failure incidence, whereas some recent studies, such as the PREDIMED study, showed that the incidence of major cardiovascular events was lower among those assigned to MeDi supplemented with extra-virgin olive oil or nuts than among those assigned to a reduced-fat diet. New studies are needed to better understand the molecular mechanisms, whereby the MedDiet may exercise its effects. Here, we present recent advances in understanding the molecular basis of MedDiet effects, mainly focusing on cardiovascular diseases, but also discussing other related diseases. We review MedDiet composition and assessment as well as the latest advances in the genomic, epigenomic (DNA methylation, histone modifications, microRNAs, and other emerging regulators), transcriptomic (selected genes and whole transcriptome), and metabolomic and metagenomic aspects of the MedDiet effects (as a whole and for its most typical food components). We also present a review of the clinical effects of this dietary style underlying the biochemical and molecular effects of the Mediterranean diet. Our purpose is to review the main features of the Mediterranean diet in particular its benefits on human health, underling the anti-inflammatory, anti-oxidant and anti-atherosclerotic effects to which new knowledge about epigenetic and gut-microbiota relationship is recently added.

Phytochemical Constituents, Antioxidant, Cytotoxicity, Antimicrobial, Antitrypanosomal, and Antimalarial Potentials of the Crude Extracts of Callistemon citrinus

Plants are reservoir for potentially useful bioactive compounds, and owing to the rising occurrences of drug resistance to malaria parasites, there is a need to discover and develop new phytochemicals in plant that can be used as antimalarial agents. In this study, we gave a detailed description of the phytochemicals present in both ethyl acetate and methanolic extracts of Callistemon citrinus (C. citrinus) using Gas Chromatography-Mass Spectrometry (GC-MS) analysis; both extracts were also evaluated for their in vitro antimalarial, antitrypanosomal, and cytotoxicity activities against Trypanosoma brucei brucei (T. b brucei) parasites, Plasmodium falciparum (P. falciparum) malaria parasites 3D7 strain, and human cervix adenocarcinoma cells (HeLa cells); in addition, the antimicrobial and antioxidant efficacies were determined using standard methods. Both extracts were characterized by a high amount of fatty acids (52.88 and 62.48%). The ethyl acetate extract exhibited a greater activity with minimum inhibitory concentration (MIC) values ranging from 0.025 to 0.10 mg/mL while the methanol extract ranged from 0.025 to 0.15 mg/mL. Both extracts were bactericidal to Escherichia coli ATCC 35150 (E. coli) and Pseudomonas aeruginosa ACC (P. aeruginosa). Qualitative and quantitative phytochemical screenings conducted for both extracts revealed the presence of alkaloids, glycosides, saponins, steroids, and triterpenoids, fat and oils, flavonoids, phenols, and tannins in varying amounts. Both crude extracts exhibited antitrypanosomal potentials with an IC₅₀ of 6.6/9.7 μg/mL and antiplasmodial activities with an IC₅₀ of 8.4/13.0 μg/mL. Conclusion from this study indicates that apart from the folkloric uses of this plant in traditional settings, the extracts possess a broad spectrum of antimicrobial, antitrypanosomal, and antimalarial activities and some pharmaceutically essential bioactive components with remarkable antioxidant capacities that may be used in the synthesis of novel drugs for the management of different varieties of ailments.

Supplementary nutrients for prevention of vascular calcification in patients with chronic kidney disease

Vascular calcification (VC) and malnutrition associated with cardiovascular disease are common in patients with chronic kidney disease (CKD) treated with dialysis. VC, which reflects vascular aging, and malnutrition are also encountered in the non-CKD elderly population. This similarity of clinical findings suggests that the progression of CKD is related to aging and the existence of a causal relationship between VC and malnutrition. To retard renal progression, a low- or very-low-protein diet is usually recommended for CKD patients. Dietary education may induce malnutrition and deficiency of important nutrients, such as vitamins K and D. Menaquinone-7, a type of vitamin K2, is under investigation for inhibiting VC in elderly patients without CKD, as well as for prevention of VC in patients with CKD. Nutritional vitamin D, such as cholecalciferol, may be considered to decrease the required dose of active vitamin D, which increases the risk of VC due to increased calcium and phosphate loads. Omega-3 fatty acids are important nutrients and their ability to inhibit VC needs to be evaluated in clinical trials. This review focuses on the ability of supplementary nutrients to prevent VC in patients with CKD, in whom dietary restriction is essential.

Biomarkers of food intake for nuts and vegetable oils: an extensive literature search

Nuts and vegetable oils are important sources of fat and of a wide variety of micronutrients and phytochemicals. Following their intake, several of their constituents, as well as their derived metabolites, are found in blood circulation and in urine. As a consequence, these could be used to assess the compliance to a dietary intervention or to determine habitual intake of nuts and vegetable oils. However, before these metabolites can be widely used as biomarkers of food intake (BFIs), several characteristics have to be considered, including specificity, dose response, time response, stability, and analytical performance. We have, therefore, conducted an extensive literature search to evaluate current knowledge about potential BFIs of nuts and vegetable oils. Once identified, the strengths and weaknesses of the most promising candidate BFIs have been summarized. Results from selected studies have provided a variety of compounds mainly derived from the fatty fraction of these foods, but also other components and derived metabolites related to their nutritional composition. In particular, α-linolenic acid, urolithins, and 5-hydroxyindole-3-acetic acid seem to be the most plausible candidate BFIs for walnuts, whereas for almonds they could be α-tocopherol and some catechin-derived metabolites. Similarly, several studies have reported a strong association between selenium levels and consumption of Brazil nuts. Intake of vegetable oils has been mainly assessed through the measurement of specific fatty acids in different blood fractions, such as oleic acid for olive oil, α-linolenic acid for flaxseed (linseed) and rapeseed (canola) oils, and linoleic acid for sunflower oil. Additionally, hydroxytyrosol and its metabolites were the most promising distinctive BFIs for (extra) virgin olive oil. However, most of these components lack sufficient specificity to serve as BFIs. Therefore, additional studies are necessary to discover new candidate BFIs, as well as to further evaluate the specificity, sensitivity, dose-response relationships, and reproducibility of these candidate biomarkers and to eventually validate them in other populations. For the discovery of new candidate BFIs, an untargeted metabolomics approach may be the most effective strategy, whereas for increasing the specificity of the evaluation of food consumption, this could be a combination of different metabolites.

Impact of ultrasonication techniques on the preparation of novel Amiloride-nanoemulsion used for intranasal delivery in the treatment of epilepsy

AIM

To develop a nanoemulsion-nanoformulation in order to enhance brain bioavailability for Amiloride (Amilo) via intranasal (i.n.) drug delivery in the brain.

MATERIAL AND METHODS

Oleic Acid, Tween-20 and Carbitol were selected as oil, surfactant and co-surfactant, respectively. For nanoemulsion preparation, an aqueous micro titration method followed by a high energy ultra-sonication method was used whereas three-factor three-level central composite design was employed to get the best formulation. The independent variables selected for the optimization were %oil, % Surfactant and co-surfactant (S_mix) and sonication time (seconds).

RESULTS

Based on the constraints applied for independent and dependent variables, the optimized formulation was selected with 2.5% oil, 10% S_mix and a sonication time of 45 s. The experimental values observed for dependent variables such as hydrodynamic diameter (nm), % transmittance and % cumulative drug release were found to be 89.36 ± 11.18 nm, 99.23 ± 0.84% and 80.36 ± 5.48%, respectively. Results showed; a spherical shape (transmission electron microscopy and scanning electron microscopy - assisted morphological characterization), polydispersity index (0.231 ± 0.018), zeta potential (-9.83 ± 0.12 mV), refractive index (1.38 ± 0.042), viscosity (41 ± 5 cp), pH (6.4 ± 0.18) and drug content of 98.28 ± 0.29%, for optimized Amiloride-loaded-Nanoemulsion (Amilo-NE). For bioavailability evaluation, ultra-performance liquid chromatography-mass spectroscopy based bioanalytical method was developed and validated for pharmacokinetics, biodistribution, brain-targeting efficiency (1992.67 ± 45.63%) and nose-to-brain transport (586.18 ± 11.63%) whereby an enhanced Amilo-brain bioavailability was observed as compared to intravenous administration (i.v.). Furthermore, Amilo-NE enhanced the treatment in seizure threshold i.e. both rodent models of epilepsy (increasing current electroshock and pentylenetetrazole) induced seizures in mice.

CONCLUSION

A significant role of Amilo-NE as observed after high targeting potential and efficiency of the formulation supports the easy brain targeting for Amilo-NE.

Membrane lipid alterations in the metabolic syndrome and the role of dietary oils

The metabolic syndrome is a cluster of pathological conditions, including hypertension, hyperglycemia, hypertriglyceridemia, obesity and low HDL levels that is of great concern worldwide, as individuals with metabolic syndrome have an increased risk of type-2 diabetes and cardiovascular disease. Insulin resistance, the key feature of the metabolic syndrome, might be at the same time cause and consequence of impaired lipid composition in plasma membranes of insulin-sensitive tissues like liver, muscle and adipose tissue. Diet intervention has been proposed as a powerful tool to prevent the development of the metabolic syndrome, since healthy diets have been shown to have a protective role against the components of the metabolic syndrome. Particularly, dietary fatty acids are capable of modulating the deleterious effects of these conditions, among other mechanisms, by modifications of the lipid composition of the membranes in insulin-sensitive tissues. However, there is still scarce data based of high-level evidence on the effects of dietary oils on the effects of the metabolic syndrome and its components. This review summarizes the current knowledge on the effects of dietary oils on improving alterations of the components of the metabolic syndrome. It also examines their influence in the modulation of plasma membrane lipid composition and in the functionality of membrane proteins involved in insulin activity, like the insulin receptor, GLUT-4, CD36/FAT and ABCA-1, and their effect in the metabolism of glucose, fatty acids and cholesterol, and, in turn, the key features of the metabolic syndrome. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.

Hydroxytyrosol in the Prevention of the Metabolic Syndrome and Related Disorders

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.

Effects of postoperative parenteral nutrition with different lipid emulsions in patients undergoing major abdominal surgery

PURPOSE

This study was designed to investigate the effects of total parenteral nutrition (PN) using different lipid emulsions in patients undergoing major abdominal surgery.

METHODS

Fifty-two patients were randomized to receive soybean oil + medium chain triglycerides (MCT) (group I), soybean oil + olive oil (group II), soybean oil + olive oil + fish oil (group III) as a lipid source. PN was started on postoperative day 1 and patients were maintained on PN for a minimum period of 4 days. Laboratory variables (CRP, prealbumin, transferrin) were measured before surgery and on postoperative days.

RESULTS

Three treatment groups were included in the study. Patients in group I received long chain triglycerides (LCT) + LCT/MCT emulsion (%75 LCT + %25 LCT/MCT); Patients in group II received olive oil based emulsion (80% olive oil + 20% soybean oil, ClinOleic); Patients in group III received fish oil in addition to olive oil based emulsion (%85 ClinOleic + %15 Omegaven; Fresenius Kabi). The following 14 parameters were assessed: body weight, CRP, prealbumin, transferrin, tumor necrosis factor-α, interleukin-6, total antioxidant status, thiobarbituric acid reactive substances, oxidized low density lipoprotein-2, complete blood cell, international normalized ratio, D-dimer, activated partially thromboplastin time, prothrombin time. All other parameters showed no differences among the groups.

CONCLUSION

The results of our trial demonstrate a potential beneficial effect of soybean oil/olive oil based lipid emulsions for use in PN regarding inflammatory response and oxidant capacity in the treatment of patients.

Effect of olive oil phenolic compounds on the expression of blood pressure-related genes in healthy individuals

PURPOSE

To investigate whether the ingestion of olive oil having different phenolic contents influences the expression of blood pressure-related genes, involved in the renin-angiotensin-aldosterone system, in healthy humans.

METHODS

A randomized, double-blind, crossover human trial with 18 healthy subjects, who ingested 25 mL/day of olive oils (1) high (366 mg/kg, HPC) and (2) low (2.7 mg/kg, LPC) in phenolic compounds for 3 weeks, preceded by 2-week washout periods. Determination of selected blood pressure-related gene expression in peripheral blood mononuclear cells (PBMNC) by qPCR, blood pressure and systemic biomarkers.

RESULTS

HPC decreased systolic blood pressure compared to pre-intervention values and to LPC, and maintained diastolic blood pressure values compared to LPC. HPC decreased ACE and NR1H2 gene expressions compared with pre-intervention values, and IL8RA gene expression compared with LPC.

CONCLUSIONS

The introduction to the diet of an extra-virgin olive oil rich in phenolic compounds modulates the expression of some of the genes related to the renin-angiotensin-aldosterone system. These changes could underlie the decrease in systolic blood pressure observed.

Virgin olive oil: a key food for cardiovascular risk protection

Olive oil is considered to be one of the most healthy dietary fats. However, several types of olive oils are present in the market. A key question for the consumer is: What of the olive oils is the best when concerning nutritional purposes? With the data available at present, the answer is: the Virgin Olive Oil (VOO), rich in phenolic compounds. On November 2011, the European Food Safety Authority released a claim concerning the benefits of daily ingestion of olive oil rich in phenolic compounds, such as VOO. In this review, we summarised the key work that has provided the evidence of the benefits of VOO consumption on other types of edible oils, even olive oils. We focused on data from randomised, controlled human studies, which are capable of providing the evidence of Level I that is required for performing nutritional recommendations at population level.

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

BACKGROUND

Cardiovascular diseases are the world's leading cause of death. Prevention by nutrition is an easy and effective approach especially by advising foods with nutraceutic properties like high phenolic olive oil (HPOO).

AIM

The aim of this review was to systematically access and meta-analyse the effects of HPOO on risk factors of the cardiovascular system and thusly to evaluate its use as a nutraceutical in prevention.

DATA SYNTHESIS

Medline/PubMed, EMBase, the Cochrane Library, CAMbase and CAM-QUEST were searched through July 2013. Randomized controlled trials (RCTs) comparing high vs. low (resp. non) phenolic olive oils in either healthy participants or patients with cardiovascular diseases were included. For study appraisal the Cochrane Collaboration's risk of bias tool was used. Main outcomes were blood pressure, serum lipoproteins and oxidation markers. Standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated and analysed by the generic inverse variance methods using a random effects model. Eight cross over RCTs comparing ingestion (21-90 d) of high vs. low (resp. non) phenolic olive oils with a total of 355 subjects were included.

RESULTS

There were medium effects for lowering systolic blood pressure (n = 69; SMD -0.52; CI -0.77/-0.27; p < 0.01) and small effects for lowering oxLDL (n = 300; SMD -0.25; CI [-0.50/0.00]; p = 0.05). No effects were found for diastolic blood pressure (n = 69; SMD -0.20; CI -1.01/0.62; p = 0.64); malondialdehyde (n = 71; SMD -0.02; CI [-0.20/0.15]; p = 0.79), total cholesterol (n = 400; SMD -0.05; CI [-0.16/0.05]; p = 0.33); HDL (n = 400; SMD -0.03; CI [-0.14/0.08]; p = 0.62); LDL (n = 400; SMD -0.03; CI [-0.15/0.09]; p = 0.61); and triglycerides (n = 360; SMD 0.02; CI [-0.22/0.25]; p = 0.90).

LIMITATIONS

The small number of studies/participants limits this review.

CONCLUSIONS

HPOO provides small beneficial effects on systolic blood pressure and serum oxidative status (oxLDL). HPOO should be considered as a nutraceutical in cardiovascular prevention.

Membrane composition and dynamics: a target of bioactive virgin olive oil constituents

The endogenous synthesis of lipids, which requires suitable dietary raw materials, is critical for the formation of membrane bilayers. In eukaryotic cells, phospholipids are the predominant membrane lipids and consist of hydrophobic acyl chains attached to a hydrophilic head group. The relative balance between saturated, monounsaturated, and polyunsaturated acyl chains is required for the organization and normal function of membranes. Virgin olive oil is the richest natural dietary source of the monounsaturated lipid oleic acid and is one of the key components of the healthy Mediterranean diet. Virgin olive oil also contains a unique constellation of many other lipophilic and amphipathic constituents whose health benefits are still being discovered. The focus of this review is the latest evidence regarding the impact of oleic acid and the minor constituents of virgin olive oil on the arrangement and behavior of lipid bilayers. We highlight the relevance of these interactions to the potential use of virgin olive oil in preserving the functional properties of membranes to maintain health and in modulating membrane functions that can be altered in several pathologies. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.

Relationship of dietary monounsaturated fatty acids to blood pressure: the International Study of Macro/Micronutrients and Blood Pressure

OBJECTIVE

In short-term feeding trials, replacement of other macronutrients with monounsaturated fatty acid reduces blood pressure. However, observational studies have not clearly demonstrated a relationship between monounsaturated fatty acid intake and blood pressure. We report associations of monounsaturated fatty acid intake of individuals with blood pressure in a cross-sectional study.

METHODS

The International Study of Macro/Micronutrients and Blood Pressure is a cross-sectional epidemiologic study of 4680 men and women ages 40-59 years from 17 population samples in China, Japan, UK and USA. Nutrient intake data were based on four in-depth multipass 24-h dietary recalls/person and two-timed 24-h urine collections/person. Blood pressure was measured eight times at four visits.

RESULTS

Mean monounsaturated fatty acid intake ranged from 8.1%kcal (China) to 12.2%kcal (USA). With sequential models to control for possible confounders (dietary, other), linear regression analyses showed significant inverse relationship of total monounsaturated fatty acid intake with DBP for all participants; for 2238 'nonintervened' individuals, the relationship was stronger. Estimated DBP differences with 2-SD higher monounsaturated fatty acids (5.35%kcal) were -0.82 mmHg (P < 0.05) for all participants and -1.70 mmHg (P < 0.01) for nonintervened individuals. Inverse associations of dietary total oleic acid (main monounsaturated) with blood pressure in nonintervened individuals were not significant, but those of oleic acid from vegetable sources were stronger and significant (P < 0.05).

CONCLUSION

Dietary monounsaturated fatty acid intake, especially oleic acid from vegetable sources, may contribute to prevention and control of adverse blood pressure levels in general populations.

Extra-virgin olive oil consumption reduces the age-related decrease in HDL and paraoxonase 1 anti-inflammatory activities

Paraoxonase 1 (PON1) is associated with HDL and modulates the antioxidant and anti-inflammatory role of HDL. The goals of the present study were to investigate the effect of ageing and the role of PON1 on the anti-inflammatory activity of HDL, and to determine whether extra-virgin olive oil (EVOO) consumption could improve the atheroprotective activity of HDL. HDL and PON1 were isolated from the plasma of ten young (Y-HDL and Y-PON1) and ten elderly (E-HDL and E-PON1) healthy volunteers before and after 12 weeks of EVOO consumption. Inflammation was assessed by measuring intracellular adhesion molecule 1 (ICAM-1) expression. THP-1 (human acute monocytic leukaemia cell line) monocyte chemotaxis was measured using a Boyden chamber. Oxidative damage to HDL was assessed by measuring conjugated diene formation and changes in electrophoretic migration. Y-HDL had more anti-inflammatory activity than E-HDL. The conjugated diene content and the electrophoretic mobility of E-HDL were higher than those of Y-HDL. Y-PON1 had significant anti-inflammatory activity, reducing ICAM-1 expression by 32·64 (SD 2·63)%, while E-PON1 had no significant effect. THP-1 chemotaxis measurements confirmed the ICAM-1 expression results. The 12 weeks of EVOO consumption significantly increased the anti-inflammatory activities of both HDL and PON1. The anti-inflammatory activity of HDL was modulated by PON1 and was lower in the elderly volunteers. EVOO consumption increased the anti-inflammatory effect of HDL and reduced the age-related decrease in anti-atherogenic activity.

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

BACKGROUND

Olive oil polyphenols have been associated with several cardiovascular health benefits. This study aims to examine the influence of a polyphenol-rich olive oil on blood pressure (BP) and endothelial function in 24 young women with high-normal BP or stage 1 essential hypertension.

METHODS

We conducted a double-blind, randomized, crossover dietary-intervention study. After a run-in period of 4 months (baseline values), two diets were used, one with polyphenol-rich olive oil (∼30 mg/day), the other with polyphenol-free olive oil. Each dietary period lasted 2 months with a 4-week washout between diets. Systolic and diastolic BP, serum or plasma biomarkers of endothelial function, oxidative stress, and inflammation, and ischemia-induced hyperemia in the forearm were measured.

RESULTS

When compared to baseline values, only the polyphenol-rich olive oil diet led to a significant (P < 0.01) decrease of 7.91 mm Hg in systolic and 6.65 mm Hg of diastolic BP. A similar finding was found for serum asymmetric dimethylarginine (ADMA) (-0.09 ± 0.01 µmol/l, P < 0.01), oxidized low-density lipoprotein (ox-LDL) (-28.2 ± 28.5 µg/l, P < 0.01), and plasma C-reactive protein (CRP) (-1.9 ± 1.3 mg/l, P < 0.001). The polyphenol-rich olive oil diet also elicited an increase in plasma nitrites/nitrates (+4.7 ± 6.6 µmol/l, P < 0.001) and hyperemic area after ischemia (+345 ± 386 perfusion units (PU)/sec, P < 0.001).

CONCLUSIONS

We concluded that the consumption of a diet containing polyphenol-rich olive oil can decrease BP and improve endothelial function in young women with high-normal BP or stage 1 essential hypertension.

Valuable nutrients and functional bioactives in different parts of olive (Olea europaea L.)-a review

The Olive tree (Olea europaea L.), a native of the Mediterranean basin and parts of Asia, is now widely cultivated in many other parts of the world for production of olive oil and table olives. Olive is a rich source of valuable nutrients and bioactives of medicinal and therapeutic interest. Olive fruit contains appreciable concentration, 1-3% of fresh pulp weight, of hydrophilic (phenolic acids, phenolic alchohols, flavonoids and secoiridoids) and lipophilic (cresols) phenolic compounds that are known to possess multiple biological activities such as antioxidant, anticarcinogenic, antiinflammatory, antimicrobial, antihypertensive, antidyslipidemic, cardiotonic, laxative, and antiplatelet. Other important compounds present in olive fruit are pectin, organic acids, and pigments. Virgin olive oil (VOO), extracted mechanically from the fruit, is also very popular for its nutritive and health-promoting potential, especially against cardiovascular disorders due to the presence of high levels of monounsaturates and other valuable minor components such as phenolics, phytosterols, tocopherols, carotenoids, chlorophyll and squalene. The cultivar, area of production, harvest time, and the processing techniques employed are some of the factors shown to influence the composition of olive fruit and olive oil. This review focuses comprehensively on the nutrients and high-value bioactives profile as well as medicinal and functional aspects of different parts of olives and its byproducts. Various factors affecting the composition of this food commodity of medicinal value are also discussed.

Association between vascular calcification scores on plain radiographs and fatty acid contents of erythrocyte membrane in hemodialysis patients

OBJECTIVE

Vascular calcification (VC) scores determined by using simple plain radiographic films are known to be associated with coronary artery disease and mortality in patients undergoing hemodialysis (HD). Omega-3 fatty acid (FA) has been shown to reduce ectopic calcifications in an animal model, and it has also been shown that erythrocyte membrane omega-3 FA content is an independent discriminator of coronary artery disease. The present study was designed to demonstrate relations between VC scores and erythrocyte membrane FA contents in patients undergoing HD.

DESIGN

A cross-sectional study was carried out.

SETTING

The study was carried out at an outpatient hemodialysis unit at Dong-A University Hospital, Busan, Republic of Korea.

PATIENTS

A total of 31 patients undergoing HD were recruited. Patients with significant malnutrition, a short duration of dialysis (<12 months), a history of recent infection, malignancy, or liver disease were excluded.

MAIN OUTCOME MEASURES

Plain radiographic films of the feet, hands, pelvis, and lateral lumbar spine were examined and VC scores were determined using previously reported methods. Erythrocyte membrane FA contents were analyzed by gas chromatography.

RESULTS

The erythrocyte membrane contents of eicosapentaenoic acid and docosahexaenoic acid were not found to be related with VC on simple plain radiographic films. However, erythrocyte membrane contents of oleic acid and total monounsaturated FA (MUFA) were significantly higher in patients with significant VC scores. Furthermore, erythrocyte membrane contents of MUFA and oleic acid were found to be negatively associated with high-density lipoprotein cholesterol level and positively associated with triglyceride level.

CONCLUSION

Erythrocyte membrane contents of MUFA and oleic acid were found to be associated with VC scores determined using plain radiographs and with dyslipidemia in patients undergoing HD.

Hydroxytyrosol: from laboratory investigations to future clinical trials

Mediterranean countries have lower rates of mortality from cardiovascular disease and cancer than Northern European or other Western countries. This has been attributed, at least in part, to the so-called Mediterranean diet, which is composed of specific local foods, including olive oil. Traditionally, many beneficial properties associated with this oil have been ascribed to its high oleic acid content. Today, it is clear that many of the beneficial effects of ingesting virgin olive oil are due to its minor compounds. This review summarizes the existing knowledge concerning the chemistry, pharmacokinetics, and toxicology of hydroxytyrosol, a minor compound of virgin olive oil, as well as this compound's importance for health. The main findings in terms of its beneficial effects in cardiovascular disease and cancer, including its properties against inflammation and platelet aggregation, are emphasized. New evidence and strategies regarding the use of hydroxytyrosol as a natural drug for the prevention and treatment of diseases with high incidences in Western countries are also presented.

Effects of pomace olive oil-enriched diets on endothelial function of small mesenteric arteries from spontaneously hypertensive rats

Pomace olive oil (POM), an olive oil subproduct traditionally used in Spain, is a good source of minor components from the unsaponifiable fraction such as triterpenoids, mainly in the form of oleanolic acid, which induces vascular protection and vasodilatation. Our aim was to evaluate the effects of long-term intake of diets enriched in POM with high concentration in oleanolic acid on endothelial dysfunction associated to hypertension in small mesenteric arteries (SMA) from spontaneously hypertensive rats (SHR). During 12 weeks, rats (six rats per group) were fed either a control 2 % maize oil diet (BD), or high-fat diets containing 15 % refined olive oil (OL), pomace olive oil (POM), or pomace olive oil supplemented in oleanolic acid (POMO; up to 800 parts per million). Endothelial and vascular functions were assessed by relaxing or contracting responses to acetylcholine (ACh) or phenylephrine, respectively. The involvement of endothelium-derived relaxing factors in these responses was evaluated. In contrast to BD, SHR fed high-fat diets showed a biphasic response to ACh related to changes in eicosanoid metabolism. POM enhanced the endothelial function in SMA from SHR by increasing the endothelium-derived hyperpolarising factor (EDHF)-type component, whereas administration of POMO resulted in a similar contribution of NO/EDHF in the endothelial response to ACh. The present study shows that despite the lack of changes in blood pressure, consumption of POM improves endothelial function in SMA from SHR by improving the agonist-mediated EDHF/NO response. Thus, triterpenoids confer a protective role to POM against endothelial dysfunction in hypertension.

Oleic acid content is responsible for the reduction in blood pressure induced by olive oil

Numerous studies have shown that high olive oil intake reduces blood pressure (BP). These positive effects of olive oil have frequently been ascribed to its minor components, such as alpha-tocopherol, polyphenols, and other phenolic compounds that are not present in other oils. However, in this study we demonstrate that the hypotensive effect of olive oil is caused by its high oleic acid (OA) content (approximately 70-80%). We propose that olive oil intake increases OA levels in membranes, which regulates membrane lipid structure (H(II) phase propensity) in such a way as to control G protein-mediated signaling, causing a reduction in BP. This effect is in part caused by its regulatory action on G protein-associated cascades that regulate adenylyl cyclase and phospholipase C. In turn, the OA analogues, elaidic and stearic acids, had no hypotensive activity, indicating that the molecular mechanisms that link membrane lipid structure and BP regulation are very specific. Similarly, soybean oil (with low OA content) did not reduce BP. This study demonstrates that olive oil induces its hypotensive effects through the action of OA.

Effects of 2-hydroxyoleic acid on the structural properties of biological and model plasma membranes

Genetic hypertension is associated with alterations in lipid metabolism, membrane lipid composition and membrane-protein function. 2-Hydroxyoleic acid (2OHOA) is a new antihypertensive molecule that regulates the structure of model membranes and their interaction with certain peripheral signalling proteins in vitro. While the effect of 2OHOA on elevated blood pressure is thought to arise through its influence on signalling proteins, its effects on membrane lipid composition remain to be assessed. 2OHOA administration altered the lipid membrane composition of hypertensive and normotensive rat plasma membranes, and increased the fluidity of reconstituted liver membranes from hypertensive rats. In spontaneously hypertensive rats (SHR), treatment with 2OHOA increased the cholesterol and sphingomyelin content while decreasing that of phosphatidylserine-phosphatidylinositol lipids. In addition, monounsaturated fatty acid levels increased as well as the propensity of reconstituted membranes to form HII-phases. These data suggest that 2OHOA regulates lipid metabolism that is altered in hypertensive animals, and that it affects the structural properties of liver plasma membranes in SHR. These changes in the structural properties of the plasma membrane may modulate the activity of signalling proteins that associate with the cell membrane such as the Galphaq/11 protein and hence, signal transduction.

Mediterranean diet and prevention of coronary heart disease in the elderly

There are now several scientific studies that relate this traditional dietary pattern with the incidence of coronary heart disease, various types of cancer, and other diseases. The past years have several observational and clinical studies suggested the mechanisms by which this traditional diet may affect coronary risk. This review underlines the importance of the Mediterranean dietary patterns in the prevention of coronary heart disease.

The influence of olive oil on human health: not a question of fat alone

Olive oil is the most representative food in the traditional Mediterranean diet and its most important source of MUFA. The healthy benefits of MUFA-rich diets on plasma cholesterol levels, were the first to generate interest in this dietary model. In addition to the benefits conferred by its lipids, olive oil has other biological effects, some of them also related to MUFA. However, most recent studies have shown that there are a number of properties that depend on, or are potentiated by, the consumption of olive oil, such as virgin olive oil, that is rich in microcomponents. This foodstuff, thanks to its double set of benefits, thus tends to produce a better lipid profile and a less prothrombotic environment, promoting antioxidant and anti-inflammatory effects, with a greater endothelial protective capacity. In view of these effects, it would appear that when olive oil is the basic source of dietary alimentary fat it has a major antiatherogenic capacity, which is not shared to the same extent by other oils that are rich in oleic acid but lack its characteristic micronutrients.

Vasculoprotective potential of olive oil components

Epidemiological and clinical studies found that the traditional Mediterranean-style diet is associated with significantly lower mortality from coronary artery disease. Although it is difficult to isolate individual dietary factors, cumulative evidence suggests that olive oil, used as primary source of fat by Mediterranean populations, may play a key role in the observed cardiovascular benefit. Olive oil is a priceless source of vitamins and polyphenolic antioxidants, and has a balanced ratio of monounsaturated and polyunsaturated fatty acids. There are multiple mechanisms by which olive oil might impact the development of atherosclerosis. Olive oil decreases LDL-cholesterol and increases HDL-cholesterol, and also reduces oxidative stress due to polyphenols, which are able to scavenge free radicals and protect LDL from oxidation. In addition, olive oil components may interfere with the inflammatory response within atherosclerotic lesion, by inhibiting endothelial activation involved in monocyte recruitment during early atherogenesis and macrophage production of inflammatory cytokines and matrix degrading enzymes, thus improving vascular stability. Other vasculoprotective mechanisms by olive oil components derive from anti-thrombotic and anti-hypertensive actions. The available data support the need to preserve certain dietary traditions, such as olive oil consumption, to counteract the burden of cardiovascular disease.

Effects of stereospecific positioning of fatty acids in triacylglycerol structures in native and randomized fats: a review of their nutritional implications

Most studies on lipid lowering diets have focused on the total content of saturated, polyunsaturated and monounsaturated fatty acids. However, the distribution of these fatty acids on the triacylglycerol (TAG) molecule and the molecular TAG species generated by this stereospecificity are characteristic for various native dietary TAGs. Fat randomization or interesterification is a process involving the positional redistribution of fatty acids, which leads to the generation of new TAG molecular species. A comparison between native and randomized TAGs is the subject of this review with regards to the role of stereospecificity of fatty acids in metabolic processing and effects on fasting lipids and postprandial lipemia. The positioning of unsaturated versus saturated fatty acids in the sn-2 position of TAGs indicate differences in early metabolic processing and postprandial clearance, which may explain modulatory effects on atherogenecity and thrombogenecity. Both human and animal studies are discussed with implications for human health.

The Association between Food Patterns and the Metabolic Syndrome Using Principal Components Analysis: The ATTICA Study

BACKGROUND

Dietary habits have been associated with the prevalence of the metabolic syndrome.

OBJECTIVE

The associations between foods or food patterns and the characteristics of the metabolic syndrome were evaluated.

DESIGN

Cross-sectional survey.

SUBJECTS

During 2001 to 2002, 1,514 men (aged 18 to 87 years) and 1,528 women (aged 18 to 89 years) without any clinical evidence of cardiovascular disease were randomly enrolled, from the Attica region in Greece.

MAIN OUTCOME MEASURES

Dietary habits were evaluated using a semiquantitative, food frequency questionnaire. Characteristics of the metabolic syndrome (ie, blood pressure, waist circumference, glucose, triglycerides, and high-density lipoprotein cholesterol) were also measured.

STATISTICAL ANALYSIS

Principal components analysis was applied to extract dietary patterns from 22 foods or food groups. Multivariate regression analysis evaluated the associations between the extracted dietary patterns and characteristics of the metabolic syndrome.

RESULTS

Six components were derived explaining 56% of the total variation in intake. Component 1 was characterized by the consumption of cereals, fish, legumes, vegetables, and fruits (explained variation 19.7%); component 2 was characterized by the intake of potatoes and meat (explained variation 11.7%), component 6 was characterized by alcohol intake (explained variation 4.8%), whereas the other components were mainly characterized by consumption of dairy and sweets. After adjusting for various confounders, component 1 was inversely associated with waist circumference, systolic blood pressure, triglycerides, positively associated with high-density lipoprotein cholesterol levels, and inversely with the likelihood of the metabolic syndrome (odds ratio [OR] 0.87, 95% confidence interval [CI] 0.79 to 0.97), whereas components 2 and 6 were positively correlated with the previous indexes, and the likelihood of having the metabolic syndrome (OR 1.13, 95% CI 1.05 to 1.21 and OR 1.26, 95% CI 1.21 to 1.33).

CONCLUSIONS

A dietary pattern that includes cereals, fish, legumes, vegetables, and fruits was independently associated with reduced levels of clinical and biological markers linked to the metabolic syndrome, whereas meat and alcohol intake showed the opposite results.

Olive oil preparation determines the atherosclerotic protection in apolipoprotein E knockout mice

Oils enriched in monounsaturated fatty acids do not seem to behave similarly in protecting against the development of atherosclerosis in animal models, which has been attributed to the presence of soluble phenolic compounds. To test the relevance of other components of oils in the prevention of atherosclerosis, two olive oils from the same cultivar devoid of soluble phenolic compounds were prepared using different procedures (pressure or centrifugation), characterized and fed to apolipoprotein E-deficient mice as 10% (w/w) of their diet. The 2 olive oils had similar levels of monounsaturated fatty acids and squalene, but they differed in their content of linoleic, phytosterols, tocopherols, triterpenes and waxes, which were particularly enriched in the test olive oil obtained by centrifugation. In mice that received a diet enriched in the olive oil derived through centrifugation, the progression of atherosclerosis was delayed compared to the mice that received standard olive oil. That effect was associated with decreases in plasma triglycerides, total and non-high-density lipoprotein cholesterol and isoprostane 8-iso-prostaglandin F(2alpha). Our results clearly indicate that the preparation of olive oil is crucial in determining its antiatherosclerotic effect, which extends beyond the presence of phenolic compounds. The test olive oil exerted its antiatherosclerotic effects by modifying plasma lipids and oxidative stress, and it might be a good candidate to replace other fats in functional foods.

Consumption of virgin olive oil influences membrane lipid composition and regulates intracellular signaling in elderly adults with type 2 diabetes mellitus

We aimed to define changes in membrane fatty acids and signaling proteins induced by virgin olive oil (VOO) consumption in elderly persons with type 2 diabetes (n = 16) compared to a control group (n = 28). The fatty acid composition was determined by gas chromatography and G-protein subunits and protein kinase C alpha (PKCalpha) by immunoblotting. VOO consumption increased the monounsaturated fatty acid content in phospholipids and cholesterol esters in both groups. In contrast, saturated fatty acids were decreased only in phospholipids. The levels of Galphao, Gbeta, and PKCalpha were significantly lower in diabetics than in controls. However, whereas VOO consumption reduced Galphas, Gbeta, and PKCalpha in both groups, reduction in Galphai was observed only in diabetics. These results indicate that long-term VOO consumption modifies the fatty acid composition of plasma membrane, which influences the association of G proteins and PKCalpha with the lipid bilayer. These combined effects probably account for the positive effects of VOO on glycemic homeostasis.

Lipid–protein interactions in GPCR-associated signaling

Signal transduction via G-protein-coupled receptors (GPCRs) is a fundamental pathway through which the functions of an individual cell can be integrated within the demands of a multicellular organism. Since this family of receptors first discovered, the proteins that constitute this signaling cascade and their interactions with one another have been studied intensely. In parallel, the pivotal role of lipids in the correct and efficient propagation of extracellular signals has attracted ever increasing attention. This is not surprising given that most of the signal transduction machinery is membrane-associated and therefore lipid-related. Hence, lipid-protein interactions exert a considerable influence on the activity of these proteins. This review focuses on the post-translational lipid modifications of GPCRs and G proteins (palmitoylation, myristoylation, and isoprenylation) and their significance for membrane binding, trafficking and signaling. Moreover, we address how the particular biophysical properties of different membrane structures may regulate the localization of these proteins and the potential functional consequences of this phenomenon in signal transduction. Finally, the interactions that occur between membrane lipids and GPCR effector enzymes such as PLC and PKC are also considered.