Monounsaturated fatty acids, olive oil and blood pressure: epidemiological, clinical and experimental evidence

Association Between Monounsaturated Fatty Acid Intake and Risk of Total Stroke and Its Subtypes: A Systematic Review and Dose-Response Meta-analysis of Prospective Cohort Studies

CONTEXT

There are contradictory results regarding the relationship between dietary intakes of monounsaturated fatty acids (MUFAs) and risk of stroke.

OBJECTIVE

The purpose of this study was to review the existing body of research on the relationship between MUFA consumption and stroke risk through a systematic review and meta-analysis.

DATA SOURCE

PubMed, Scopus, and ISI Web of Science were all systematically searched up to January 2023.

DATA EXTRACTION

A total of 11 prospective cohort studies that investigated MUFA consumption in relation to stroke risk were included.

DATA ANALYSIS

Relative risk (RR) and 95% CIs for the highest vs lowest category of dietary MUFA intake were combined using a random-effects model. Linear and nonlinear dose-response relations were assessed through 1-stage weighted mixed-effects meta-analysis. These studies included 475 207 participants and 8438 cases. In highest vs lowest consumption analysis, MUFA intake was inversely associated with total stroke (RR: 0.80; 95% CI: 0.67, 0.96; I2 =65.2%, Q-test P = .001; n = 11) and hemorrhagic stroke (RR: 0.80; 95% CI: 0.68, 0.95; I2 = 0.0%, Q-test P = .77; n = 5) risk. Conversely, this association was not significant for ischemic stroke (RR: 0.86; 95% CI: 0.69, 1.07; I2 =62.3%, Q-test P = .01; n = 8). An inverse association was observed between each 10-g/d MUFA intake and hemorrhagic stroke (RR: 0.79; 95% CI: 0.65, 0.96) but not total and ischemic stroke. We did not find any evidence for a nonlinear association between MUFA intake and total stroke and its subtypes.

CONCLUSION

This meta-analysis shows that higher MUFA intake could lower the risk of total and hemorrhagic, but not ischemic, stroke. This could be important for public health.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023458555.

Understanding Hypertension: A Metabolomic Perspective

Metabolomics approaches, such as Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS), have emerged as powerful tools for studying cardiovascular diseases (CVD), including hypertension. The use of biological fluids, like plasma and serum, has garnered significant interest due to their accessibility and potential in elucidating disease mechanisms. This review aims to summarize the current literature on the application of metabolomics techniques (FTIR, NMR, and MS) in the study of hypertension, focusing on their contributions to understanding disease pathophysiology, biomarker discovery, and therapeutic advancements. A comprehensive analysis of metabolomic studies was performed, with a particular emphasis on the diversity of altered metabolites associated with systolic blood pressure (SBP), diastolic blood pressure (DBP), and sex-related differences. Metabolomics techniques, including FTIR, NMR, and MS, provide comprehensive insights into the biochemical alterations underlying hypertension, such as amino acid and fatty acid metabolism impairment or inflammation and oxidative stress processes. This review underscores their role in advancing biomarker identification, deepening our understanding of disease mechanisms, and supporting the development of targeted therapeutic strategies. The integration of these tools highlights their potential in personalized medicine and their capacity to improve clinical outcomes.

Gut Microbiota Modulation Through Mediterranean Diet Foods: Implications for Human Health

The Mediterranean diet (MD) is widely recognized for its health benefits, particularly in modulating gut microbiota composition and reducing the risk of metabolic, cardiovascular, and neurodegenerative diseases. Characterized by a high intake of plant-based foods, monounsaturated fats, and polyphenols, primarily from extra virgin olive oil, the MD fosters the growth of beneficial gut bacteria such as Bifidobacterium, Faecalibacterium prausnitzii, and Roseburia, which produce short-chain fatty acids that enhance gut barrier integrity, reduce inflammation, and improve metabolic homeostasis. Clinical and preclinical studies have proved that the MD is associated with increased microbial diversity, reduced pro-inflammatory bacteria, and improved markers of insulin sensitivity, lipid metabolism, and cognitive function. Additionally, the MD positively influences the gut microbiota in various conditions, including obesity, cardiovascular disease, and neurodegeneration, potentially mitigating systemic inflammation and enhancing neuroprotective mechanisms. Emerging evidence suggests that MD variants, such as the Green-MD, and their integration with probiotics can further optimize gut microbiota composition and metabolic parameters. While the beneficial impact of the MD on the gut microbiota and overall health is well supported, further long-term clinical trials are needed to better understand individual variability and improve dietary interventions tailored to different populations.

Associations of erythrocyte membrane fatty acids with blood pressure in children

BACKGROUND & AIMS

Different fatty acids may vary in their effect on blood pressure. We tested whether fatty acid classes measured in erythrocytes are associated with blood pressure.

METHODS

This cross-sectional study included 421 children from Guangzhou, China. Erythrocyte membrane fatty acid concentrations were measured by gas chromatography-mass spectrometry. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured with an electronic sphygmomanometer. Abnormal blood pressure (ABP) was defined as an elevated SBP and/or DBP. Analysis of covariance (ANCOVA) and multivariable logistic regression models were performed to explore the associations of fatty acid subgroups with the risk of blood pressure status. The joint effect of fatty acid subgroups was evaluated using Probit Bayesian Kernel Machine Regression (BKMR).

RESULTS

ANCOVA analysis showed that children in the higher quartiles of odd-chain saturated fatty acids (OSFAs) had significantly lower levels of both SBP (P-trend = 0.020) and DBP (P-trend = 0.008). In contrast, DBP increased significantly across quartiles of monounsaturated fatty acids (MUFAs). In adjusted models of logistic regression analysis, the higher quartiles of MUFAs concentrations were associated with a higher risk of ABP (P-trend = 0.001). BKMR analysis showed that the risk of ABP increased significantly with increasing total MUFAs mixture levels. Similar associations were observed between MUFAs and DBP. Conversely, OSFAs concentrations were negatively correlated with both SBP and DBP. Additionally, children with higher levels of mixture of n-3 polyunsaturated fatty acids (n-3 PUFAs) exhibited lower SBP.

CONCLUSIONS

Fatty acid subclasses may differ in their relationship with abnormal blood pressure in children. MUFAs exhibit a positive association with blood pressure, whereas OSFAs and n-3 PUFAs demonstrate an inverse association with blood pressure.

Formulation, Characterization, and Antioxidant Properties of Chitosan Nanoparticles Containing Phenolic Compounds from Olive Pomace

Olive phenolic compounds like hydroxytyrosol (OH-Tyr), tyrosol (Tyr), and their precursors have different health-promoting properties, mainly based on their strong antioxidant capacity. However, their presence in extra-virgin olive oil (EVOO) is scarce since they are primarily contained in the by-products of oil production, such as olive pomace (OP). The aim of this work was to extract and encapsulate OP phenolic compounds into chitosan-tripolyphosphate nanoparticles (NPs) using an ionotropic gelation lyophilization approach to increase their resistance to environmental and chemical stress. NPs resulted in a monodisperse (PDI: 0.21) population of cationic NPs (ζ-potential: 33 mV, size: 229 nm) with an encapsulation efficiency (EE%), expressed as total phenolic content (TPC) and total OH-Tyr + Tyr content, of 64-65%. Mannitol and maltodextrin DE 19 (MD-19) were evaluated as lyoprotectants to counteract irreversible NP aggregation during lyophilization. The NP powder freeze dried using 0.7% of MD-19 showed the best performance, returning a monodispersed population of particles after rehydration. The antioxidant capacity of the obtained NPs was confirmed both in cell-free assays and in a THP-1 cell model of oxidative stress. This method represents a promising way to deliver health-promoting olive phenols for nutraceutical purposes and, hence, to valorize otherwise wasted by-products.

Assessing Sarcocornia as a Salt Substitute: Effects on Lipid Profile and Gelatinase Activity

Sodium, although essential for life, is a key factor in changes in vascular function and cardiovascular disease when consumed in excess. Sarcocornia spp., a halophyte plant with many nutritional benefits, presents itself as a promising substitute for the consumption of purified salt. Matrix metalloproteinases (MMPs) 2 and 9 are widely studied due to their action in physiological processes and as biomarkers at the diagnostic level due to their increased expression in inflammatory processes. This study aimed to evaluate whether replacing salt with Sarcocornia perennis (S. perennis) powder in healthy young people leads to an improvement in biochemical profiles and the attenuation of MMP-2 and MMP-9 activity. In the present study, 30 participants were randomized into a control group that consumed salt and an intervention group that replaced salt with powdered S. perennis. The evaluation of the biochemical parameters was carried out by the spectrophotometry method, and the evaluation of MMP activity was carried out by zymography. A significant decrease was observed in the intervention group in total cholesterol, high-density lipoprotein cholesterol (HDL-c), and creatinine (p-value ≤ 0.05), along with lower but not significantly different mean values of triglycerides. Regarding MMP activity after the intervention, a lower mean value was observed for MMP-9 activity, with there being higher mean values for MMP-2 activity, both with p-values ≥ 0.05. The results confirmed that the consumption of S. perennis is a beneficial choice for health regarding the lipid profile. The evaluation of MMP activity indicated the potential of S. perennis in the regulation of MMP-9 activity in healthy individuals, along with the need for the further study of these proteases in individuals with pathologies.

Qualitative and quantitative determination of phenols and their metabolites in urine by in-syringe solid-phase extraction and LC-MS/MS analysis for evaluation of virgin olive oil metabolism

To know the bioavailability of virgin olive oil (VOO) phenols and its impact on health, it is necessary to determine the levels of phenols excreted in urine. We present here a novel strategy for in-syringe solid-phase extraction and analysis of the extract by liquid chromatography-tandem mass spectrometry (LC-MS/MS), using ammonium fluoride as ionization agent to enhance sensitivity. This approach allows avoiding additional steps such as solvent evaporation or analytes derivatization. The method can be used with a previous acid hydrolysis for quantitative determination of tyrosol and hydroxytyrosol to estimate metabolized phenols. We tested this application by analysis of a cohort of volunteers (n = 20) after a standardized intake of VOO. Additionally, the method can be used as such for metabolite profiling of phenolic derivatives in urine using LC-MS/MS in high-resolution data-independent acquisition (DIA). Information about the phenolic profile of the consumed VOO and the human metabolism is thus obtained. The proposed approach represents a simple and versatile tool for qualitative and quantitative characterization of VOO phenolic metabolism.

Fatty acids act on vascular endothelial cells and influence the development of cardiovascular disease

Endothelial cells (ECs) maintain the health of blood vessels and prevent the development of cardiovascular disease (CVD). Free saturated fatty acids (FAs) induce EC damage and increase the risk of CVD by promoting arteriosclerosis. Conversely, polyunsaturated FAs (PUFAs), such as docosahexaenoic acid, are thought to suppress EC damage induced during the early stages of CVD. This review describes the effects of multiple dietary FAs on EC disorders involved in the development of CVD. The roles of FAs in atherosclerosis and CVD were analyzed by evaluating articles published in PubMed, Science Direct, and Web of Science. Saturated FAs were found to induce EC damage by reducing the production and action of EC-derived nitric oxide. Oxidative stress, inflammation, and the renin-angiotensin system were found to be involved in EC disorder. Furthermore, n-3 PUFAs were found to reduce EC dysfunction and prevent the development of EC disorder. These results indicate that FAs may affect EC failure induced during the early stages of CVD and reduce the risk of developing the disease.

The Influence of Dietary Interventions on Arterial Stiffness in Overweight and Obese Subjects

Arterial stiffness is often increased in overweight/obese subjects before the development of hypertension. It is also one of the earliest indicators of increased cardiovascular disease risk and can be considered a good predictor of the development of subclinical cardiovascular dysfunction. Arterial stiffness is a significant prognostic factor influencing cardiovascular risk, which dietary habits can modify. Obese patients should use the caloric-restricted diet because it augments aortic distensibility, diminishes pulse wave velocity (PWV), and increases the activity of endothelial nitric oxide synthases. High intake of saturated fatty acids (SFA), trans fats, and cholesterol, typical for the Western diet, impairs endothelial function and raises brachial-ankle PMV. The replacement of SFA with monounsaturated (MUFA) or polyunsaturated fatty acids (PUFA) derived from seafood and plants diminishes the risk of arterial stiffness. The dairy product intake (excluding butter) decreases PWV in the general population. The high-sucrose diet causes toxic hyperglycemia and increases arterial stiffness. Complex carbohydrates with a low glycemic index (including isomaltose) should be recommended to keep vascular health. The high sodium intake (>10 g/day), particularly associated with low potassium consumption, has a deleterious effect on arterial stiffness (↑ baPWV). Since vegetables and fruits are good sources of vitamins and phytochemicals, they should be recommended in patients with high PMV. Thus, the dietary recommendation to prevent arterial stiffness should be similar to the Mediterranean diet, which is rich in dairy products, plant oils, and fish, with a minimal red meat intake and five servings of fruits and vegetables daily.

CLOCK Gene Variation Is Associated with the Incidence of Metabolic Syndrome Modulated by Monounsaturated Fatty Acids

The circadian locomotor output cycles kaput (CLOCK) gene plays a crucial role in regulating circadian rhythms through its transcription factor gene product. The objective of this study was to investigate the association between CLOCK rs1801260 and the incidence of metabolic syndrome modulated by dietary monounsaturated fatty acid (MUFA) intake in Korean adults. Using a dataset from the Ansan-Ansung Cohort Study of the Korean Genome and Epidemiology Study, 3608 Korean adults were included after an average of nine years of follow-up. Men who were minor allele carriers (G allele) of CLOCK rs1801260 had a 18% higher incidence of metabolic syndrome than non-carriers [hazard ratio (HR), 1.18; 95% confidence interval (CI), 1.00-1.40; p Value = 0.047]. By dichotomizing dietary MUFA intake, we observed that men who were minor allele carriers (G allele) of CLOCK rs1801260 had a 42% increased incidence of metabolic syndrome when dietary MUFA intake was ≤3.5% (HR: 1.42, 95% CI 1.23-1.81; p Value = 0.004). No significant association was found between CLOCK rs1801260 and the incidence of metabolic syndrome modulated by dietary MUFA intake in women. CLOCK polymorphisms affected metabolic syndrome, modulated by dietary MUFA intake in men. These results suggest the significance of CLOCK genes in the pathogenesis of metabolic syndrome and the modulating role of dietary MUFA intake and provide new insights into the underlying mechanisms connecting the circadian system, dietary factors, and metabolic syndrome.

A randomized, double-blind, placebo-controlled, clinical trial to evaluate the benefits of Nigella sativa seeds oil in reducing cardiovascular risks in hypertensive patients

The efficacy, safety, and utility of Nigella sativa seeds oil as a complementary treatment for hypertension, glucose control, and lipid metabolism were evaluated. Hypertensive patients in the intervention (n = 26) and placebo (n = 29) groups received 2.5 ml of N. sativa seeds oil and sunflower oil twice daily for 8 weeks, respectively. The levels of systolic and diastolic blood pressure (SBP, DBP), blood lipid profile, and fasting blood sugar (FBS), at different stages of the treatment period (0, 3, 6, 8 weeks), and malondialdehyde (MDA) and glutathione reductase (GR), at the baseline and end of the study, were assessed. SBP level in the intervention group was significantly reduced, compared with the baseline values (p < .001) and the placebo group (p < .05). A significant decline was observed in the levels of DBP, total cholesterols, and low density lipoprotein (LDL) (p < .000), MDA, and FBS (p < .001); also, a significant increase was observed in the levels of high density lipoprotein (HDL) and GR (p < .001). The use of N. sativa seeds oil as an adjunct to common medications exhibited additional antihypertensive effects as well as beneficial effects on glucose control and lipid metabolism in hypertensive patients with no renal, hepatic, and patient-reported adverse events.

Reduction in saturated fat intake for cardiovascular disease

BACKGROUND

Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally, it is unclear whether the energy from saturated fats eliminated from the diet are more helpfully replaced by polyunsaturated fats, monounsaturated fats, carbohydrate or protein.

OBJECTIVES

To assess the effect of reducing saturated fat intake and replacing it with carbohydrate (CHO), polyunsaturated (PUFA), monounsaturated fat (MUFA) and/or protein on mortality and cardiovascular morbidity, using all available randomised clinical trials.

SEARCH METHODS

We updated our searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and Embase (Ovid) on 15 October 2019, and searched Clinicaltrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) on 17 October 2019.

SELECTION CRITERIA

Included trials fulfilled the following criteria: 1) randomised; 2) intention to reduce saturated fat intake OR intention to alter dietary fats and achieving a reduction in saturated fat; 3) compared with higher saturated fat intake or usual diet; 4) not multifactorial; 5) in adult humans with or without cardiovascular disease (but not acutely ill, pregnant or breastfeeding); 6) intervention duration at least 24 months; 7) mortality or cardiovascular morbidity data available.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed inclusion, extracted study data and assessed risk of bias. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity analyses, funnel plots and GRADE assessment.

MAIN RESULTS

We included 15 randomised controlled trials (RCTs) (16 comparisons, 56,675 participants), that used a variety of interventions from providing all food to advice on reducing saturated fat. The included long-term trials suggested that reducing dietary saturated fat reduced the risk of combined cardiovascular events by 17% (risk ratio (RR) 0.83; 95% confidence interval (CI) 0.70 to 0.98, 12 trials, 53,758 participants of whom 8% had a cardiovascular event, I² = 67%, GRADE moderate-quality evidence). Meta-regression suggested that greater reductions in saturated fat (reflected in greater reductions in serum cholesterol) resulted in greater reductions in risk of CVD events, explaining most heterogeneity between trials. The number needed to treat for an additional beneficial outcome (NNTB) was 56 in primary prevention trials, so 56 people need to reduce their saturated fat intake for ~four years for one person to avoid experiencing a CVD event. In secondary prevention trials, the NNTB was 53. Subgrouping did not suggest significant differences between replacement of saturated fat calories with polyunsaturated fat or carbohydrate, and data on replacement with monounsaturated fat and protein was very limited. We found little or no effect of reducing saturated fat on all-cause mortality (RR 0.96; 95% CI 0.90 to 1.03; 11 trials, 55,858 participants) or cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 10 trials, 53,421 participants), both with GRADE moderate-quality evidence. There was little or no effect of reducing saturated fats on non-fatal myocardial infarction (RR 0.97, 95% CI 0.87 to 1.07) or CHD mortality (RR 0.97, 95% CI 0.82 to 1.16, both low-quality evidence), but effects on total (fatal or non-fatal) myocardial infarction, stroke and CHD events (fatal or non-fatal) were all unclear as the evidence was of very low quality. There was little or no effect on cancer mortality, cancer diagnoses, diabetes diagnosis, HDL cholesterol, serum triglycerides or blood pressure, and small reductions in weight, serum total cholesterol, LDL cholesterol and BMI. There was no evidence of harmful effects of reducing saturated fat intakes.

AUTHORS' CONCLUSIONS

The findings of this updated review suggest that reducing saturated fat intake for at least two years causes a potentially important reduction in combined cardiovascular events. Replacing the energy from saturated fat with polyunsaturated fat or carbohydrate appear to be useful strategies, while effects of replacement with monounsaturated fat are unclear. The reduction in combined cardiovascular events resulting from reducing saturated fat did not alter by study duration, sex or baseline level of cardiovascular risk, but greater reduction in saturated fat caused greater reductions in cardiovascular events.

Chemical Profiles of Twenty-three Monovarietal Olive Oils Produced in Liangshan Region of China

The main objective of this study was to differentiate twenty-three monovarietal olive oils produced in China (Azappa, Thiaki, Leucocarpa ovoid, manzanillo de labata, etc.) by studying their physicochemical properties, fatty acid profiles and oxidative stability. The majority of analytical indicators had statistically significant differences (p < 0.05). The tested cultivars produced excellent olive oils with an appreciable amount of natural antioxidants and chemical composition within the legal range. Our results demonstrate that Leucocarpa ovoid oil was characterized by high mean levels of total phenols (401.8 mg/kg), oleic acid (79.62%) and oxidative stability (18.64 h). Additionally, five types of olive oil were selected due to their high overall quality. Investigation of virgin olive oils indicates that the differences in the fatty acid profiles, phenols, sterols and tocopherols may be caused by genetic factors. The principal components analysis (PCA) results showed a strong differentiation between various cultivars in regard to their fatty acid composition and phenol, sterol and tocopherol levels. These components can be effective tools for efficient comparison and differentiation of these cultivars. To the best of our knowledge, this is the first work on the differentiation of the chemical constituents of virgin olive oils.

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.

Reduction in saturated fat intake for cardiovascular disease

BACKGROUND

Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally, it is unclear whether the energy from saturated fats eliminated from the diet are more helpfully replaced by polyunsaturated fats, monounsaturated fats, carbohydrate or protein.

OBJECTIVES

To assess the effect of reducing saturated fat intake and replacing it with carbohydrate (CHO), polyunsaturated (PUFA), monounsaturated fat (MUFA) and/or protein on mortality and cardiovascular morbidity, using all available randomised clinical trials.

SEARCH METHODS

We updated our searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and Embase (Ovid) on 15 October 2019, and searched Clinicaltrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) on 17 October 2019.

SELECTION CRITERIA

Included trials fulfilled the following criteria: 1) randomised; 2) intention to reduce saturated fat intake OR intention to alter dietary fats and achieving a reduction in saturated fat; 3) compared with higher saturated fat intake or usual diet; 4) not multifactorial; 5) in adult humans with or without cardiovascular disease (but not acutely ill, pregnant or breastfeeding); 6) intervention duration at least 24 months; 7) mortality or cardiovascular morbidity data available.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed inclusion, extracted study data and assessed risk of bias. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity analyses, funnel plots and GRADE assessment.

MAIN RESULTS

We included 15 randomised controlled trials (RCTs) (16 comparisons, ~59,000 participants), that used a variety of interventions from providing all food to advice on reducing saturated fat. The included long-term trials suggested that reducing dietary saturated fat reduced the risk of combined cardiovascular events by 21% (risk ratio (RR) 0.79; 95% confidence interval (CI) 0.66 to 0.93, 11 trials, 53,300 participants of whom 8% had a cardiovascular event, I² = 65%, GRADE moderate-quality evidence). Meta-regression suggested that greater reductions in saturated fat (reflected in greater reductions in serum cholesterol) resulted in greater reductions in risk of CVD events, explaining most heterogeneity between trials. The number needed to treat for an additional beneficial outcome (NNTB) was 56 in primary prevention trials, so 56 people need to reduce their saturated fat intake for ~four years for one person to avoid experiencing a CVD event. In secondary prevention trials, the NNTB was 32. Subgrouping did not suggest significant differences between replacement of saturated fat calories with polyunsaturated fat or carbohydrate, and data on replacement with monounsaturated fat and protein was very limited. We found little or no effect of reducing saturated fat on all-cause mortality (RR 0.96; 95% CI 0.90 to 1.03; 11 trials, 55,858 participants) or cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 10 trials, 53,421 participants), both with GRADE moderate-quality evidence. There was little or no effect of reducing saturated fats on non-fatal myocardial infarction (RR 0.97, 95% CI 0.87 to 1.07) or CHD mortality (RR 0.97, 95% CI 0.82 to 1.16, both low-quality evidence), but effects on total (fatal or non-fatal) myocardial infarction, stroke and CHD events (fatal or non-fatal) were all unclear as the evidence was of very low quality. There was little or no effect on cancer mortality, cancer diagnoses, diabetes diagnosis, HDL cholesterol, serum triglycerides or blood pressure, and small reductions in weight, serum total cholesterol, LDL cholesterol and BMI. There was no evidence of harmful effects of reducing saturated fat intakes.

AUTHORS' CONCLUSIONS

The findings of this updated review suggest that reducing saturated fat intake for at least two years causes a potentially important reduction in combined cardiovascular events. Replacing the energy from saturated fat with polyunsaturated fat or carbohydrate appear to be useful strategies, while effects of replacement with monounsaturated fat are unclear. The reduction in combined cardiovascular events resulting from reducing saturated fat did not alter by study duration, sex or baseline level of cardiovascular risk, but greater reduction in saturated fat caused greater reductions in cardiovascular events.

Integrated Analysis of Comparative Lipidomics and Proteomics Reveals the Dynamic Changes of Lipid Molecular Species in High-Oleic Acid Peanut Seed

Modern peanut contains fatty acid desaturase 2 (FAD2) mutation, which is capable of producing high oleic acid for human health. However, the dynamic changes of the lipidome regarding fad2 remain elusive in peanut seed. In the present study, 547 lipid features were identified in high- and normal-oleic peanut seeds by utilizing the mass spectrometric approach. The fad2-induced differently expressed lipids (DELs) were polarly distributed at early and maturation stages during high-oleic acid (OA) seed development. Subsequently, integration of previously published proteomic data and lipidomic data revealed that 21 proteins and 149 DELs were annotated into the triacylglycerol assembly map, of which nine enzymes and 31 lipid species shared similar variation tendencies. Additionally, the variation tendencies of 17 acyl fatty acids were described in a hypothetical biosynthetic pathway. Collectively, the understanding of the lipid composition correlated with fad2 established a foundation for future high-OA peanut breeding based on lipidomic data.

Virgin Olive Oil and Health: Summary of the III International Conference on Virgin Olive Oil and Health Consensus Report, JAEN (Spain) 2018

The Mediterranean diet is considered as the foremost dietary regimen and its adoption is associated with the prevention of degenerative diseases and an extended longevity. The preeminent features of the Mediterranean diet have been agreed upon and the consumption of olive oil stands out as the most peculiar one. Indeed, the use of olive oil as the nearly exclusive dietary fat is what mostly characterizes the Mediterranean area. Plenty of epidemiological studies have correlated that the consumption of olive oil was associated with better overall health. Indeed, extra virgin olive oil contains (poly)phenolic compounds that are being actively investigated for their purported biological and pharma-nutritional properties. On 18 and 19 May 2018, several experts convened in Jaen (Spain) to discuss the most recent research on the benefits of olive oil and its components. We reported a summary of that meeting (reviewing several topics related to olive oil, not limited to health) and concluded that substantial evidence is accruing to support the widespread opinion that extra virgin olive oil should, indeed, be the fat of choice when it comes to human health and sustainable agronomy.

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

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

Diet and primary prevention of stroke: Systematic review and dietary recommendations by the ad hoc Working Group of the Italian Society of Human Nutrition

BACKGROUND AND AIMS

To systematically review the latest evidence on established and emerging nutrition-related risk factors for incidence of and mortality from total, ischemic and haemorrhagic strokes. The present review was conducted in the framework of the work carried out through 2015 and 2016 for the preparation of the Italian Guidelines for the Prevention and Treatment of Stroke, 8th Edition, by ISO-SPREAD (Italian Stroke Organization and the Stroke Prevention and Educational Awareness Diffusion).

METHODS AND RESULTS

Systematic review of articles focused on primary prevention of stroke published between January 2013 to May 2016 through an extensive search of the literature using MEDLINE/PUBMED, EMBASE and the Cochrane Library. Articles were ranked according to the SIGN methodology while the GRADE system was used to establish the strength of recommendations. As a result of our literature search, we examined 87 meta-analyses overall (mainly of prospective studies), a few isolated more recent prospective studies not included in the meta-analyses, and a smaller number of available randomized controlled trials and case-control studies. Based on the analysis of the above articles, 36 Syntheses of the available evidence and 36 Recommendations were eventually prepared. The present document was developed by organizing the available evidence into three individual areas (nutrients, food groups and dietary patterns) to provide a systematic and user-friendly overview of the available evidence on the relationship between nutrition and primary prevention of stroke. Yet analysis of foods and food patterns allowed translating the information about nutrients in a tool more amenable to use in daily life also in the light of the argument that people eat foods rather than nutrients.

CONCLUSIONS

The present literature review and dietary recommendations provide healthcare professionals and all interested readers with a useful overview for the reduction of the risk of total, ischemic and haemorrhagic stroke through dietary modifications.

Comparison of Oil Content and Fatty Acids Profile of Western Schley, Wichita, and Native Pecan Nuts Cultured in Chihuahua, Mexico

Two different extraction processes, Soxhlet and ultrasound, were used to obtain the oil extracts of Western Schley, Wichita, and Native pecan nuts cultured in Chihuahua, Mexico. The aspects evaluated in this study were the extraction yield of the processes and fatty acids' profile of the resulting extracts. Gas chromatography coupled with mass spectrometry (GC-MS) was used to identify and determine the composition percentage of fatty acids present in pecan nuts oils extracted. The results obtained show that higher oil extraction yields were obtained by Soxhlet method with hexane (69.90%) in Wichita varieties. Wichita, Western Schley, and Native pecan nuts from Chihuahua are rich in PUFA (polyunsaturated fatty acids) and MUFA (monounsaturated fatty acids) and have low levels of SFA (saturated fatty acids). The predominant fatty acid present in all pecan nuts oils was linoleic acid followed by oleic acid. Myristic acid, palmitic acid, and linolenic acid were also identified in representative quantities. The results from this study suggest that there are statistically significant differences in the chemical composition of the pecan nuts oils extracted from the varieties cultured in Chihuahua, Mexico, and those cultivated in other regions of the world.

Nutritional Supplements for the Treatment of Hypertension: A Practical Guide for Clinicians

Nutraceuticals are dietary components with pharmacologic properties that can be used to treat various disease states. There is growing interest among patients in the use of nutraceuticals for the management of hypertension; as such, it is important that clinicians are prepared to engage in meaningful discussions with their patients about these substances. Flavonoids, beetroot, garlic, and unsaturated fats have garnered significant attention for their blood pressure lowering properties. We review the clinical evidence and reported mechanisms of action for these substances in an attempt to offer a practical guide for clinicians to engage with patients who are highly motivated to seek out nutraceutical therapies to manage their hypertension.

Lipotoxicity in Obesity: Benefit of Olive Oil

The clinical implication of Lipotoxicity in obesity derives primarily from its potential to progress to insulin resistance, endothelial dysfunction and atherosclerosis. Olive oil rich diet decrease accumulation of triglyceride in the liver, improved postprandial triglyceride levels, improve glucose and GLP-1 response in insulin resistant subjects, and up regulate GLUT-2 expression in the liver. The exact molecular mechanism is unknown but, decreasing NFkB activation, decreasing LDL oxidation and improving insulin resistance by less production of inflammatory cytokines (TNF-a, IL-6) and improvement of kinases JNK-mediated phosphorylation of IRS-1 are the principle mechanisms. The beneficial effect of the Mediterranean diet derived from monounsaturated fatty acids (MUFA), mainly from olive oil. In this review we document lipotoxicity in obesity and the benefit of olive oil.

Discovery and fine-mapping of loci associated with MUFAs through trans-ethnic meta-analysis in Chinese and European populations

MUFAs are unsaturated FAs with one double bond and are derived from endogenous synthesis and dietary intake. Accumulating evidence has suggested that plasma and erythrocyte MUFA levels are associated with cardiometabolic disorders, including CVD, T2D, and metabolic syndrome (MS). Previous genome-wide association studies (GWASs) have identified seven loci for plasma and erythrocyte palmitoleic and oleic acid levels in populations of European origin. To identify additional MUFA-associated loci and the potential functional variant at each locus, we performed ethnic-specific GWAS meta-analyses and trans-ethnic meta-analyses in more than 15,000 participants of Chinese and European ancestry. We identified novel genome-wide significant associations for vaccenic acid at FADS1/2 and PKD2L1 [log10(Bayes factor) ≥ 8.07] and for gondoic acid at FADS1/2 and GCKR [log10(Bayes factor) ≥ 6.22], and also observed improved fine-mapping resolutions at FADS1/2 and GCKR loci. The greatest improvement was observed at GCKR, where the number of variants in the 99% credible set was reduced from 16 (covering 94.8 kb) to 5 (covering 19.6 kb, including a missense variant rs1260326) after trans-ethnic meta-analysis. We also confirmed the previously reported associations of PKD2L1, FADS1/2, GCKR, and HIF1AN with palmitoleic acid and of FADS1/2 and LPCAT3 with oleic acid in the Chinese-specific GWAS and the trans-ethnic meta-analyses. Pathway-based analyses suggested that the identified loci were in unsaturated FA metabolism and signaling pathways. Our findings provide novel insight into the genetic basis relevant to MUFA metabolism and biology.

The Health Potential of Fruits and Vegetables Phytochemicals: Notable Examples

Fruit and vegetables are essential components of a healthy diet. The World Health Organization (WHO) recommends an intake of five to eight portions (400-600 g) daily of fruits and vegetables to reduce risk of cardiovascular disease, cancer, poor cognitive performance, and other diet-related diseases, as well as for the prevention of micronutrient deficiencies. Much of their potential for disease prevention is thought to be provided by phytochemicals, among which the preventive activity of antioxidants is most well documented. Since numerous meta-studies published indicate variable and often contradictory results about the impact of isolated phytochemicals on health, their consumption as supplements must be carried out with care, because doses may exceed the recommended nutritional intake. Nonetheless, there is a general consensus that whole fruit and vegetable intake is more important in providing health benefits than that of only one of their constituent, because of additive and synergistic effects. This review describes the most recent literature regarding the health benefits of some selected fruits and vegetables. Importantly, since some phytochemicals regulate the same genes and pathways targeted by drugs, diets rich in fruits and vegetables in combination with medical therapies are being considered as novel approaches to treatment. Therefore, phytochemicals in fruits and vegetable might be a promising tool for the prevention and/or amelioration of a wide range of diseases.

The mountainous Cretan dietary patterns and their relationship with cardiovascular risk factors: the Hellenic Isolated Cohorts MANOLIS study

OBJECTIVE

We carried out de novo recruitment of a population-based cohort (MANOLIS study) and describe the specific population, which displays interesting characteristics in terms of diet and health in old age, through deep phenotyping.

DESIGN

Cross-sectional study where anthropometric, biochemical and clinical measurements were taken in addition to interview-based completion of an extensive questionnaire on health and lifestyle parameters. Dietary patterns were derived through principal component analysis based on a validated FFQ.

SETTING

Geographically isolated Mylopotamos villages on Mount Idi, Crete, Greece.

SUBJECTS

Adults (n 1553).

RESULTS

Mean age of the participants was 61·6 years and 55·8 % were women. Of the population, 82·7 % were overweight or obese with a significantly different prevalence between overweight men and women (43·4 v. 34·7 %, P=0·002). The majority (70·6 %) of participants were married, while a larger proportion of women were widowed than men (27·8 v. 3·5 %, P<0·001). Smoking was more prevalent in men (38·7 v. 8·2 %, P<0·001), as 88·8% of women had never smoked. Four dietary patterns emerged as characteristic of the population; these were termed 'local', 'high fat and sugar, 'Greek café/tavern' and 'olive oil, fruits and vegetables'. Individuals more adherent to the local dietary pattern presented higher blood glucose (β=4·026, P<0·001). Similarly, individuals with higher compliance with the Greek café/tavern pattern had higher waist-to-hip ratio (β=0·012, P<0·001), blood pressure (β=1·015, P=0·005) and cholesterol (β=5·398, P<0·001).

CONCLUSIONS

Profiling of the MANOLIS elderly population identifies unique unhealthy dietary patterns that are associated with cardiometabolic indices.

Metabolic Effects of Monounsaturated Fatty Acid-Enriched Diets Compared With Carbohydrate or Polyunsaturated Fatty Acid-Enriched Diets in Patients With Type 2 Diabetes: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

Dietary interventions in patients with type 2 diabetes (T2D) are important for preventing long-term complications. Although a healthy diet is crucial, there is still uncertainty about the optimal macronutrient composition. We performed a meta-analysis comparing diets high in cis-monounsaturated fatty acids (MUFA) to diets high in carbohydrates (CHO) or in polyunsaturated fatty acids (PUFA) on metabolic risk factors in patients with T2D.

RESEARCH DESIGN AND METHODS

We systematically reviewed PubMed, MEDLINE, and Cochrane databases and prior systematic reviews and meta-analyses to identify interventions assessing HbA1c, fasting plasma glucose and insulin, LDL and HDL cholesterol, triglycerides, body weight, or systolic/diastolic blood pressure. Meta-analyses were conducted using both fixed- and random-effects models to calculate the weighted mean difference (WMD) and 95% CI.

RESULTS

We identified 24 studies totaling 1,460 participants comparing high-MUFA to high-CHO diets and 4 studies totaling 44 participants comparing high-MUFA to high-PUFA diets. When comparing high-MUFA to high-CHO diets, there were significant reductions in fasting plasma glucose (WMD -0.57 mmol/L [95% CI -0.76, -0.39]), triglycerides (-0.31 mmol/L [-0.44, -0.18]), body weight (-1.56 kg [-2.89, -0.23]), and systolic blood pressure (-2.31 mmHg [-4.13, -0.49]) along with significant increases in HDL cholesterol (0.06 mmol/L [0.02, 0.10]). When high-MUFA diets were compared with high-PUFA diets, there was a significant reduction in fasting plasma glucose (-0.87 mmol/L [-1.67, -0.07]). All of the outcomes had low to medium levels of heterogeneity, ranging from 0.0 to 69.5% for diastolic blood pressure (Phet = 0.011).

CONCLUSIONS

Our meta-analysis provides evidence that consuming diets high in MUFA can improve metabolic risk factors among patients with T2D.

Different consumed oils and metabolic parameters in type 2 diabetes patients in diabetes society of Natanz

AIMS

This study, for the first time, has investigated the effect of highly consumed oils in Iran on type 2 diabetic patient's blood pressure.

MATERIALS AND METHODS

After measuring height, weight and blood pressure and calculating Body Mass Index (BMI) of 200 patients (30-65 years old) with type 2 diabetes (26.7% men, 73.3% women) in diabetes center of Natanz, their consumed oil was obtained by questionnaire, and their blood lipid and glucose were also measured. Data analyzed by SPSS 16 software, one-way ANOVA, independent T test, and Means procedure statistic tests.

RESULTS

In mean procedure test, the highest average of systolic and diastolic blood pressure was in patients consumed solid and semi-solid oils; and the lowest was in patients consumed vegetable liquid oils. However, women consumed solid vegetable oils have lower systolic and mean arterial pressures. In one-way ANOVA test, there was a significant relation between consumed oil and hemoglobin A1C (p=0.049) and diastolic blood pressure (p=0.032).

CONCLUSION

Consumption of solid and semi-solid oils, especially animal fat, cause increasing in blood pressure of diabetic type 2 patients; but consumption of olive oil, and to a lesser extent liquid vegetable oils, related to lesser increasing in their blood pressure.

An Update on Nutrients and Blood Pressure

Adverse blood pressure (BP) is a major independent risk factor for epidemic cardiovascular diseases affecting almost one-quarter of the adult population worldwide. Dietary intake is a major determinant in the development and progression of high BP. Lifestyle modifications, including recommended dietary guidelines, are advocated by the American Society of Hypertension, the International Society of Hypertension, the Japanese Society of Hypertension, and many other organisations for treating all hypertensive people, prior to initiating drug therapy and as an adjunct to medication in persons already on drug therapy. Lifestyle modification can also reduce high BP and prevent development of hypertension. This review synthesizes results from the International Study of Macro/Micronutrients and Blood Pressure (INTERMAP), a cross-sectional epidemiological study of 4,680 men and women aged 40-59 years from Japan, the People's Republic of China, the United Kingdom, and the United States, published over the past few years on cross cultural BP differences. INTERMAP has previously reported that intakes of vegetable protein, glutamic acid, total and insoluble fibre, total polyunsaturated fatty acid and linoleic acid, total n-3 fatty acid and linolenic acid, phosphorus, calcium, magnesium, and non-heme iron were inversely related to BP. Direct associations of sugars (fructose, glucose, and sucrose) and sugar-sweetened beverages (especially combined with high sodium intake), cholesterol, glycine, alanine, and oleic acid from animal sources with BP were also reported by the INTERMAP Study.

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.

Effect of consuming novel foods consisting high oleic canola oil, barley β-glucan, and DHA on cardiovascular disease risk in humans: the CONFIDENCE (Canola Oil and Fibre with DHA Enhanced) study - protocol for a randomized controlled trial

Background

Metabolic syndrome (MetS) has been identified as a major contributor to the development of cardiovascular disease (CVD). Current recommendations for dietary management of people with MetS involve quantitative and qualitative modifications of food intake, such as high consumption of vegetables, fruits, and whole grain foods. The results from our previous human trials revealed the potential of the dietary components high-oleic acid canola oil (HOCO)-docosahexaenoic acid (DHA) and high molecular weight barley β-glucan individually in managing CVD risk factors. Foods with a combination of HOCO-DHA and barley β-glucan have never been tested for their effects on CVD risk. The objective is to determine the effects of consuming novel foods HOCO-DHA, and barley β-glucan on managing CVD risk factors in people with MetS.

Methods/Design

We are conducting a randomized, single-blind crossover trial with four treatment phases of 28 days each separated by a 4-week washout interval. Participants (n=35) will be provided with weight-maintaining, healthy balanced diet recommendations according to their energy requirements during the intervention periods. Participants will receive muffins and cookies as treatment foods in a random order and will consume at least one meal per day at the research center under supervision. The four treatments include muffins and cookies consisting of (1) all-purpose flour and HOCO-DHA (50 g/day); (2) barley flour (4.36 g/day of β-glucan) and a blend of sunflower oil, safflower oil, and butter as control oil (50 g/day); (3) barley flour (4.36 g/day of β-glucan) and HOCO-DHA (50 g/day; dosage of DHA would be 3 g/day); and (4) all-purpose flour and control oil (50 g/day). At the beginning and end of each phase, we will evaluate anthropometrics; systolic and diastolic blood pressure; blood lipid profile; low-density lipoprotein subfractions and particle size; 10-year Framingham CVD risk score; inflammatory status; and plasma and red blood cell fatty acid profiles, fecal microbiome, and body composition by dual-energy X-ray absorptiometry.

Conclusion

Cholesterol synthesis will also be studied, using a stable isotope approach. The proposed study will lead to innovation of novel food products, which may result in improvement in the overall cardiovascular health of humans.

Trial registration

Clinical trials.gov identifier: NCT02091583. Date of registration: 12 March 2014.

Reduction in saturated fat intake for cardiovascular disease

BACKGROUND

Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally it is unclear whether the energy from saturated fats that are lost in the diet are more helpfully replaced by polyunsaturated fats, monounsaturated fats, carbohydrate or protein. This review is part of a series split from and updating an overarching review.

OBJECTIVES

To assess the effect of reducing saturated fat intake and replacing it with carbohydrate (CHO), polyunsaturated (PUFA) or monounsaturated fat (MUFA) and/or protein on mortality and cardiovascular morbidity, using all available randomised clinical trials.

SEARCH METHODS

We updated our searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and EMBASE (Ovid) on 5 March 2014. We also checked references of included studies and reviews.

SELECTION CRITERIA

Trials fulfilled the following criteria: 1) randomised with appropriate control group; 2) intention to reduce saturated fat intake OR intention to alter dietary fats and achieving a reduction in saturated fat; 3) not multifactorial; 4) adult humans with or without cardiovascular disease (but not acutely ill, pregnant or breastfeeding); 5) intervention at least 24 months; 6) mortality or cardiovascular morbidity data available.

DATA COLLECTION AND ANALYSIS

Two review authors working independently extracted participant numbers experiencing health outcomes in each arm, and we performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity analyses and funnel plots.

MAIN RESULTS

We include 15 randomised controlled trials (RCTs) (17 comparisons, ˜59,000 participants), which used a variety of interventions from providing all food to advice on how to reduce saturated fat. The included long-term trials suggested that reducing dietary saturated fat reduced the risk of cardiovascular events by 17% (risk ratio (RR) 0.83; 95% confidence interval (CI) 0.72 to 0.96, 13 comparisons, 53,300 participants of whom 8% had a cardiovascular event, I² 65%, GRADE moderate quality of evidence), but effects on all-cause mortality (RR 0.97; 95% CI 0.90 to 1.05; 12 trials, 55,858 participants) and cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 12 trials, 53,421 participants) were less clear (both GRADE moderate quality of evidence). There was some evidence that reducing saturated fats reduced the risk of myocardial infarction (fatal and non-fatal, RR 0.90; 95% CI 0.80 to 1.01; 11 trials, 53,167 participants), but evidence for non-fatal myocardial infarction (RR 0.95; 95% CI 0.80 to 1.13; 9 trials, 52,834 participants) was unclear and there were no clear effects on stroke (any stroke, RR 1.00; 95% CI 0.89 to 1.12; 8 trials, 50,952 participants). These relationships did not alter with sensitivity analysis. Subgrouping suggested that the reduction in cardiovascular events was seen in studies that primarily replaced saturated fat calories with polyunsaturated fat, and no effects were seen in studies replacing saturated fat with carbohydrate or protein, but effects in studies replacing with monounsaturated fats were unclear (as we located only one small trial). Subgrouping and meta-regression suggested that the degree of reduction in cardiovascular events was related to the degree of reduction of serum total cholesterol, and there were suggestions of greater protection with greater saturated fat reduction or greater increase in polyunsaturated and monounsaturated fats. There was no evidence of harmful effects of reducing saturated fat intakes on cancer mortality, cancer diagnoses or blood pressure, while there was some evidence of improvements in weight and BMI.

AUTHORS' CONCLUSIONS

The findings of this updated review are suggestive of a small but potentially important reduction in cardiovascular risk on reduction of saturated fat intake. Replacing the energy from saturated fat with polyunsaturated fat appears to be a useful strategy, and replacement with carbohydrate appears less useful, but effects of replacement with monounsaturated fat were unclear due to inclusion of only one small trial. This effect did not appear to alter by study duration, sex or baseline level of cardiovascular risk. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturated fats. The ideal type of unsaturated fat is unclear.

Reprint of: A parallel randomized trial on the effect of a healthful diet on inflammageing and its consequences in European elderly people: design of the NU-AGE dietary intervention study

BACKGROUND

The proportion of European elderly is expected to increase to 30% in 2060. Combining dietary components may modulate many processes involved in ageing. So, it is likely that a healthful diet approach might have greater favourable impact on age-related decline than individual dietary components. This paper describes the design of a healthful diet intervention on inflammageing and its consequences in the elderly.

METHODS

The NU-AGE study is a parallel randomized one-year trial in 1250 apparently healthy, independently living European participants aged 65-80 years. Participants are randomised into either the diet group or control group. Participants in the diet group received dietary advice aimed at meeting the nutritional requirements of the ageing population. Special attention was paid to nutrients that may be inadequate or limiting in diets of elderly, such as vitamin D, vitamin B12, and calcium. C-reactive protein is measured as primary outcome.

DISCUSSION

The NU-AGE study is the first dietary intervention investigating the effect of a healthful diet providing targeted nutritional recommendations for optimal health and quality of life in apparently healthy European elderly. Results of this intervention will provide evidence on the effect of a healthful diet on the prevention of age related decline.

A parallel randomized trial on the effect of a healthful diet on inflammageing and its consequences in European elderly people: design of the NU-AGE dietary intervention study

BACKGROUND

The proportion of European elderly is expected to increase to 30% in 2060. Combining dietary components may modulate many processes involved in ageing. So, it is likely that a healthful diet approach might have greater favourable impact on age-related decline than individual dietary components. This paper describes the design of a healthful diet intervention on inflammageing and its consequences in the elderly.

METHODS

The NU-AGE study is a parallel randomized one-year trial in 1250 apparently healthy, independently living European participants aged 65-80 years. Participants are randomised into either the diet group or control group. Participants in the diet group received dietary advice aimed at meeting the nutritional requirements of the ageing population. Special attention was paid to nutrients that may be inadequate or limiting in diets of elderly, such as vitamin D, vitamin B12, and calcium. C-reactive protein is measured as primary outcome.

DISCUSSION

The NU-AGE study is the first dietary intervention investigating the effect of a healthful diet providing targeted nutritional recommendations for optimal health and quality of life in apparently healthy European elderly. Results of this intervention will provide evidence on the effect of a healthful diet on the prevention of age related decline.

Nutrition and nutraceutical supplements for the treatment of hypertension: part II

Vascular biology, endothelial and vascular smooth muscle, and cardiac dysfunction play a primary role in the initiation and perpetuation of hypertension, cardiovascular disease, and target organ damage. Nutrient-gene interactions and epigenetics are predominant factors in promoting beneficial or detrimental effects in cardiovascular health and hypertension. Macronutrients and micronutrients can prevent, control, and treat hypertension through numerous mechanisms related to vascular biology. Oxidative stress, inflammation, and autoimmune dysfunction initiate and propagate hypertension and cardiovascular disease. There is a role for the select use of single and component nutraceutical supplements, vitamins, antioxidants, and minerals in the treatment of hypertension based on scientifically controlled studies, which complement optimal nutrition, coupled with other lifestyle modifications.

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.

Blood pressure lowering effect of Nigella sativa L. seed oil in healthy volunteers: a randomized, double-blind, placebo-controlled clinical trial

Nigella sativa L. seeds (N. sativa) have been used as a traditional remedy for a wide range of diseases including hypertension. The present study was performed to explore the effects of N. sativa oil on blood pressure (BP) in healthy volunteers. In a double-blind, randomized study, 70 healthy volunteers aged 34 to 63 years with systolic BP from 110 to 140 mmHg and diastolic BP from 60 to 90 mmHg were randomly allocated to receive 2.5 mL N. sativa oil or placebo two times a day for 8 weeks. The systolic and diastolic BPs, body mass index and blood levels of aspartate transaminase, alanine transaminase, alkaline phosphatase, creatinine and blood urea nitrogen were determined at baseline and endpoint. Results showed that in N. sativa oil treated group the systolic and diastolic BPs decreased significantly compared with baseline and placebo group at the endpoint. Other parameters did not significantly change in both groups at the endpoint. No adverse effects were reported. In conclusion, oral daily administration of 5 mL N. sativa oil to healthy volunteers for 8 weeks lowers systolic and diastolic BPs without any adverse effects.

The role of repeatedly heated soybean oil in the development of hypertension in rats: association with vascular inflammation

Thermally oxidized oil generates reactive oxygen species that have been implicated in several pathological processes including hypertension. This study was to ascertain the role of inflammation in the blood pressure raising effect of heated soybean oil in rats. Male Sprague-Dawley rats were divided into four groups and were fed with the following diets, respectively, for 6 months: basal diet (control); fresh soybean oil (FSO); five-time-heated soybean oil (5HSO); or 10-time-heated soybean oil (10HSO). Blood pressure was measured at baseline and monthly using tail-cuff method. Plasma prostacyclin (PGI(2) ) and thromboxane A(2) (TXA(2) ) were measured prior to treatment and at the end of the study. After six months, the rats were sacrificed, and the aortic arches were dissected for morphometric and immunohistochemical analyses. Blood pressure was increased significantly in the 5HSO and 10HSO groups. The blood pressure was maintained throughout the study in rats fed FSO. The aortae in the 5HSO and 10HSO groups showed significantly increased aortic wall thickness, area and circumferential wall tension. 5HSO and 10HSO diets significantly increased plasma TXA(2) /PGI(2) ratio. Endothelial VCAM-1 and ICAM-1 were significantly increased in 5HSO, as well as LOX-1 in 10HSO groups. In conclusion, prolonged consumption of repeatedly heated soybean oil causes blood pressure elevation, which may be attributed to inflammation.

Childhood serum cholesterol ester fatty acids are associated with blood pressure 27 y later in the Cardiovascular Risk in Young Finns Study

BACKGROUND

In adults, dietary fatty acids (FAs) modify blood pressure (BP), but it is not known whether childhood FA quality is associated with adulthood BP.

OBJECTIVE

The purpose of the study was to investigate links between childhood serum cholesterol ester fatty acid (CEFA) proportions and adulthood systolic blood pressure (SBP) and diastolic blood pressure (DBP).

DESIGN

We examined a cohort of 803 boys and girls (aged 3-18 y at baseline in 1980 and followed for 27 y) by using regression models adjusted for the known risk factors of BP. CEFAs were analyzed as markers of dietary FA intake.

RESULTS

In men, serum SFA (B = 2.97, P < 0.001 for SBP; B = 1.48, P = 0.015 for DBP), MUFA (B = 0.61, P = 0.001 for SBP; B = 0.27, P = 0.078 for DBP), and omega-3 (n-3) PUFA (B = 5.50, P < 0.001 for SBP; B = 2.47, P = 0.015 for DBP) proportions, which were derived mainly from animal fats in this population, were positively associated with BP, whereas the omega-6 (n-6) PUFA proportion, which was derived mainly from vegetable oils and margarines, was negatively associated with BP (B = -0.56, P < 0.001 for SBP; B = -0.27, P < 0.018 for DBP). Serum cholesterol ester SFA and PUFA associations were supported by dietary intake data. In women, the associations between CEFA proportions and BP were weaker [for SBP: B = 0.36, P = 0.638 (NS) for SFA; B = 0.44, P = 0.019 for MUFA; B = 1.18, P = 0.376 (NS) for n-3 PUFA; and B = -0.33, P = 0.023 for n-6 PUFA].

CONCLUSION

Our findings suggest that fat quality as reflected in the serum cholesterol ester fraction in childhood is independently associated with adulthood BP particularly in men but also, to some extent, in women.

The role of diet and nutrient composition in nonalcoholic Fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the developed world. NAFLD is tightly linked to insulin resistance and considered to be the hepatic manifestation of the metabolic syndrome. The cornerstone of any treatment regimen for patients with NAFLD is lifestyle modification focused on weight loss, exercise, and improving insulin sensitivity. Here we review the literature and discuss the role of diet and nutrient composition in the management of NAFLD. Because there are currently no specific dietary guidelines for NAFLD, this review proposes a dietary framework for patients with NAFLD based on the available evidence and extrapolates from dietary guidelines aimed at reducing insulin resistance and cardiovascular risk.

Monounsaturated fatty acid, carbohydrate intake, and diabetes status are associated with arterial pulse pressure

BACKGROUND

Diabetes is a global epidemic. Cardiovascular disease (CVD) is one of the most prevalent consequences of diabetes. Nutrition is considered a modifiable risk factor for CVD, particularly for individuals with diabetes; albeit, there is little consensus on the role of carbohydrates, proteins and fats for arterial health for persons with or without diabetes. In this study, we examined the association of macronutrients with arterial pulse pressure (APP), a surrogate measure of arterial health by diabetes status and race.

METHODS

Participants were 892 Mexican Americans (MA), 1059 Black, non-Hispanics (BNH) and 2473 White, non-Hispanics (WNH) with and without diabetes of a weighted sample from the National Nutrition and Health Examination Survey (NHANES) 2007-2008. The cross-sectional analysis was performed with IBM-SPSS version 18 with the complex sample analysis module. The two-year sample weight for the sub-sample with laboratory values was applied to reduce bias and approximate a nationally, representative sample. Arterial stiffness was assessed by arterial pulse pressure (APP).

RESULTS

APP was higher for MA [B = 0.063 (95% CI 0.015 to 0.111), p = 0.013] and BNH [B = 0.044 (95% CI 0.006 to 0.082), p = 0.018] than WNH, controlling for diabetes, age, gender, body mass index (BMI), fiber intake, energy intake (Kcal) and smoking. A two-way interaction of diabetes by carbohydrate intake (grams) was inversely associated with APP [B = -1.18 (95% CI -0.178 to -0.058), p = 0.001], controlling for race, age, gender, BMI, Kcal and smoking. BNH with diabetes who consumed more mono-unsaturated fatty acids (MUFA) than WNH with diabetes had lower APP [B = -0.112 (95%CI-0.179 to -0.045), p = 0.003] adjusting for saturated fatty acids, Kcal, age, gender, BMI and smoking.

CONCLUSION

Higher MUFA and carbohydrate intake for persons with diabetes reflecting lower APP may be due to replacement of saturated fats with CHO and MUFA. The associations of APP with diabetes, race and dietary intake need to be confirmed with intervention and prospective studies. Confirmation of these results would suggest that dietary interventions for minorities with diabetes may improve arterial health.

Dairy components and risk factors for cardiometabolic syndrome: recent evidence and opportunities for future research

Cardiometabolic syndrome (CMS), a cluster of metabolic abnormalities that increases the risk of cardiovascular disease (CVD) and type 2 diabetes, affects over one-third of American adults and accounts for billions of dollars in health care costs annually. Current evidence indicates an inverse association between consumption of dairy foods and risk of CMS and its related disease outcomes. Although the specific mechanism(s) underlying the beneficial effects of dairy consumption on the development of CMS, CVD, and type 2 diabetes have not been fully elucidated, there is evidence that specific components within dairy such as milkfat, vitamin D, calcium, magnesium, potassium, and whey proteins may be individually or collectively involved. Specifically, each of these dairy components has been implicated as having a neutral or beneficial effect on one or more elements of CMS, including the serum lipid profile, blood pressure, fasting glucose, and body composition. Although several mechanisms have been identified by which components in dairy may beneficially affect symptoms associated with CMS, further research is required to better understand how dairy and its components may contribute to metabolic health. The purpose of this review is to present the mechanisms by which specific dairy components modulate risk factors for CMS and identify opportunities for future research.

Determination of lipid oxidation products in vegetable oils and marine omega-3 supplements

Background

There is convincing evidence that replacing dietary saturated fats with polyunsaturated fats (PUFA) decreases risk of cardiovascular diseases. Therefore, PUFA rich foods such as vegetable oils, fatty fish, and marine omega-3 supplements are recommended. However, PUFA are easily oxidizable and there is concern about possible negative health effects from intake of oxidized lipids. Little is known about the degree of lipid oxidation in such products.

Objective

To assess the content of lipid oxidation products in a large selection of vegetable oils and marine omega-3 supplements available in Norway. Both fresh and heated vegetable oils were studied.

Design

A large selection of commercially available vegetable oils and marine omega-3 supplements was purchased from grocery stores, pharmacies, and health food stores in Norway. The content of lipid oxidation products were measured as peroxide value and alkenal concentration. Twelve different vegetable oils were heated for a temperature (225°C) and time (25 minutes) resembling conditions typically used during cooking.

Results

The peroxide values were in the range 1.04–10.38 meq/kg for omega-3 supplements and in the range 0.60–5.33 meq/kg for fresh vegetable oils. The concentration range of alkenals was 158.23–932.19 nmol/mL for omega-3 supplements and 33.24–119.04 nmol/mL for vegetable oils. After heating, a 2.9–11.2 fold increase in alkenal concentration was observed for vegetable oils.

Conclusions

The contents of hydroperoxides and alkenals in omega-3 supplements are higher than in vegetable oils. After heating vegetable oils, a large increase in alkenal concentration was observed.