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Purpose: Previous studies have shown the anti-inflammatory and antioxidant properties of phenolic compounds of virgin olive oil (VOO). However, the effect of bioavailable phenolic compounds on the vascular endothelium is unknown. We aimed to evaluate the effect of the consumption of virgin olive oil rich in phenolic compounds on the vascular endothelium., Methods: We treated HUVEC with human serum obtained in fasting state and after the intake of a breakfast prepared with VOO with a high or low content of phenolic compounds., Results: Treatment of HUVEC with serum obtained 2 h after the intake of the high-phenol VOO-based breakfast decreased p65 and MCP-1 gene expression (p < 0.001 and p = 0.002, respectively) and increased MT-CYB, SDHA and SOD1 gene expression (p = 0.004, p = 0.012 and p = 0.001, respectively), as compared with the treatment of HUVEC with the serum obtained 2 h after the intake of the low-phenol VOO-based breakfast. The treatment with serum obtained 4 h after the intake of the high-phenol VOO-based breakfast decreased MCP-1 and CAT gene expression (p < 0.001 and p = 0.003, respectively) and increased MT-CYB gene expression (p < 0.001), as compared to the treatment with serum obtained 4 h after the intake of the low-phenol VOO-based breakfast., Conclusion: Our results suggest that the consumption of virgin olive oil rich in phenolic compounds may reduce the risk of atherosclerosis development by decreasing inflammation and improving the antioxidant profile in the vascular endothelium.

Background: Glu298Asp polymorphism of the endothelial nitric oxide synthase (eNOS) gene (NOS3) has been characterized as a risk factor of hypertension and coronary artery disease. Previous studies suggest that the higher risk observed in T allele carriers is due to endothelial dysfunction associated with a lower eNOS activity and that acute consumption of phenol-rich olive oil ameliorates postprandial endothelial dysfunction by reducing oxidative stress and increasing nitric oxide bioavailability. Nevertheless, how these facts may interact in a population with altered endothelial function such as metabolic syndrome patients remains unknown., Objective: The objective of the study was to evaluate whether the presence of NOS3 Glu298Asp polymorphism interacts with the phenol content of virgin olive oil (VOO) to influence postprandial endothelial function., Design: Fifty-seven subjects with metabolic syndrome received three breakfasts based on VOO with different phenolic content. Baseline, incremental area under the curve, peak, and maximum parameters of postocclusive skin reactive hyperemia (PORH) were evaluated by laser Doppler, and the nitrate/nitrite [NO((x))] and eNOS concentrations were obtained during fasting and postprandially., Results: A gene-diet interaction was found on maximum PORH and NO((x)) (P = 0.039 and P = 0.043, respectively). TT subjects showed lower values of eNOS, NO((x)), and maximum PORH as compared with GG and GT subjects, especially in the postprandial measurements (all P < 0.05). However, most of these differences were attenuated when high-phenol VOO was consumed., Conclusion: In a population with a compromised endothelial function, concentrations of phenols in dietary VOO interact with NOS3 Glu298Asp to ameliorate the endothelial dysfunction associated to the TT genotype.

Background: Dietary inorganic nitrate (NO3−) is a polyatomic ion, which is present in large quantities in green leafy vegetables and beetroot, and has attracted considerable attention in recent years as a potential health-promoting dietary compound. Numerous small, well-controlled laboratory studies have reported beneficial health effects of inorganic NO3− consumption on blood pressure, endothelial function, cerebrovascular blood flow, cognitive function, and exercise performance. Translating the findings from small laboratory studies into 'real-world' applications requires careful consideration. Main body: This article provides a brief overview of the existing empirical evidence basis for the purported health-promoting effects of dietary NO3− consumption. Key areas for future research are then proposed to evaluate whether promising findings observed in small animal and human laboratory studies can effectively translate into clinically relevant improvements in population health. These proposals include: 1) conducting large-scale, longer duration trials with hard clinical endpoints (e.g. cardiovascular disease incidence); 2) exploring the feasibility and acceptability of different strategies to facilitate a prolonged increase in dietary NO3− intake; 3) exploitation of existing cohort studies to explore associations between NO3− intake and health outcomes, a research approach allowing larger samples sizes and longer duration follow up than is feasible in randomised controlled trials; 4) identifying factors which might account for individual differences in the response to inorganic NO3− (e.g. sex, genetics, habitual diet) and could assist with targeted/personalised nutritional interventions; 5) exploring the influence of oral health and medication on the therapeutic potential of NO3− supplementation; and 6) examining potential risk of adverse events with long term high- NO3− diets. Conclusion: The salutary effects of dietary NO3− are well established in small, well-controlled laboratory studies. Much less is known about the feasibility and efficacy of long-term dietary NO3− enrichment for promoting health, and the factors which might explain the variable responsiveness to dietary NO3− supplementation between individuals. Future research focussing on the translation of laboratory data will provide valuable insight into the potential applications of dietary NO3− supplementation to improve population health. [ABSTRACT FROM AUTHOR]

Background: Circulating nitric oxide (NO) and lipid levels are closely associated with coronary artery disease (CAD). It is unclear whether the rs1799983 polymorphism in endothelial nitric oxide synthase (NOS3) gene is associated with plasma levels of NO and lipids. This systematic review and meta-analysis (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) aimed to clarify the relationships between the rs1799983 polymorphism and plasma levels of NO and lipids.Methods: Sixteen studies (2702 subjects) and 59 studies (14 148 subjects) were identified for the association analyses for NO and lipids, respectively. Mean difference (MD) and 95% CI were used to estimate the effects of the rs1799983 polymorphism on plasma NO and lipid levels. The primary outcome variable was NO, and the secondary outcomes included triglycerides, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C).Results: Carriers of the T allele had lower levels of NO (MD -0.27 μmol/L, 95% CI -0.42 to -0.12 μmol/L, p<0.001) and HDL-C (MD -0.07 mmol/L, 95% CI -0.14 to -0.00 mmol/L, p=0.04), and higher levels of TC (MD 0.13 mmol/L, 95% CI 0.06 to 0.20 mmol/L, p<0.001) and LDL-C (MD 0.14 mmol/L, 95% CI 0.05 to 0.22 mmol/L, p=0.002) than the non-carriers. Triglyceride levels were comparable between the genotypes.Conclusion: The association between the NOS3 rs1799983 polymorphism and CAD may be partly mediated by abnormal NO and lipid levels caused by the T allele. [ABSTRACT FROM AUTHOR]