Substitution of dietary ω-6 polyunsaturated fatty acids for saturated fatty acids decreases LDL apolipoprotein B-100 production rate in men with dyslipidemia associated with insulin resistance: a randomized controlled trial

Crosstalk Between Dietary Fatty Acids and MicroRNAs in the Regulation of Hepatic ApoB-Containing Lipoprotein Synthesis in Humans

Enhanced hepatic synthesis, assembly, and secretion of apolipoprotein B (ApoB)-containing lipoproteins elevate their plasma levels and-like their impaired clearance from the circulation-can increase cardiovascular risk. Both dietary fatty acids and microRNAs contribute to the nutrient-dependent regulation of hepatic gene expression. Together, these factors may modulate lipid and ApoB-containing lipoprotein synthesis in the liver, either exacerbating or mitigating dyslipidemia. Research continues to reveal the complexity of fatty acid-microRNA networks and highlights differences in regulating hepatic ApoB-containing lipoprotein synthesis between humans and rodents. Consequently, this review focuses on studies conducted in humans or human-derived hepatocytes.

Inverse association of dietary consumption of n3 and n6 fatty acids with hyperuricemia among adults

BACKGROUND

The precise link between dietary consumption of n-3 and n-6 fatty acids and hyperuricemia remains equivocal. Accordingly, the purpose of the current investigation is to clarify any possible associations between the consumption of n-3 and n-6 fatty acids and hyperuricemia in the context of American adults.

MATERIALS AND METHODS

The present investigation employed a cross-sectional design, comprising a sample of 21,120 American adults above the age of 20 from the National Health and Nutrition Examination Survey (NHANES) waves between 2007 and 2016. The dietary consumption of n-3 and n-6 fatty acids was measured through two 24-h dietary recall interviews. To assess the relationships of dietary consumption of n3 and n6 fatty acids with hyperuricemia, we applied multivariable logistic regression, t tests, chi-square tests, and restricted cubic spline. To determine the robustness of our findings, sensitivity analyses were also carried out.

RESULTS

The results of the multivariable logistic regression models indicated a significant correlation between dietary consumption of n3 and n6 fatty acids and hyperuricemia. The ORs with 95% CIs of hyperuricemia for the highest tertile versus lowest tertile of dietary consumption of n3 and n6 fatty acids were 0.76 (0.66, 0.88) (p < 0.001) and 0.72 (0.64, 0.82) (p < 0.001), respectively. Moreover, dose‒response analyses revealed a linear relationship between n-3 and n-6 fatty acid consumption and the risk of hyperuricemia.

CONCLUSION

The findings of this study indicate a significant inverse correlation between the dietary consumption of n3 and n6 fatty acids and hyperuricemia in the US adult population. Notably, there was no significant relationship between the n6:n3 ratio and hyperuricemia.

Dietary and circulating omega-6 fatty acids and their impact on cardiovascular disease, cancer risk, and mortality: a global meta-analysis of 150 cohorts and meta-regression

BACKGROUND

Despite the significant increase in omega-6 fatty acid consumption, evidence regarding their health impacts remains inconsistent. This study performs an umbrella review and updated meta-analysis to evaluate the association between dietary and circulating omega-6 levels and the risks of cardiovascular diseases (CVDs), cancer, and mortality.

METHODS

A systematic search was conducted in PubMed, Scopus, and Web of Science until January 2024 to identify eligible meta-analyses of prospective observational studies. The Cochrane risk of bias and GRADE tools were used to assess the risk of bias and certainty of the evidence, respectively.

RESULTS

Analysis of 150 publications revealed that higher dietary intake and circulating levels of omega-6 were associated with lower risks of CVDs, cancer incidence, and all-cause mortality in the general population, particularly for coronary heart disease and stroke. While omega-6 intake was linked to lower risks of lung and prostate cancers, it was associated with higher risks of ovarian and endometrial cancers. Subgroup analyses revealed that these protective associations were more pronounced in cohort studies and absent in populations with pre-existing health conditions.

CONCLUSIONS

Higher dietary intake and circulating levels of omega-6 fatty acids were associated with lower risks of CVDs, cancers, and all-cause mortality. However, the associations vary by cancer type and are less evident in individuals with pre-existing health conditions. These findings highlight the potential benefits of omega-6 fatty acids for public health while underscoring the need for further research to address specific risks and underlying mechanisms.

TRIAL REGISTRATION

Registration number (PROSPERO): CRD42024522842.

Dietary polyunsaturated fatty acids intake is negatively associated with hyperuricemia: The National Health and Nutrition Examination Survey 2003-2015

BACKGROUND AND AIMS

The objective of this research was to explore the associations between dietary PUFAs intake and hyperuricemia risk.

METHODS AND RESULTS

Based on the National Health and Nutrition Examination Survey (NHANES) 2003-2015, all eligible individuals were divided into hyperuricemia and non-hyperuricemia groups based on diagnostic criteria for hyperuricemia (serum uric acid >420 μmol/L for men and >360 μmol/L for women). Multivariate-adjusted logistic regression was employed to explore the relationship between dietary PUFAs intake and hyperuricemia risk. Total PUFAs and their subtypes were modeled to isocalorically replace saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs). Higher intake of n-3 PUFAs, n-6 PUFAs, linoleic acid (LA), alpha-linoleic acid (ALA), and non-marine PUFAs intake correlated with decreased hyperuricemia risk, with adjusted odds ratio (OR) and 95% confidence interval (95%CIs) were 0.77 (0.63, 0.93), 0.75 (0.61, 0.92), 0.75 (0.61, 0.91), 0.69 (0.55, 0.87), and 0.73 (0.59, 0.91), respectively. Replacing 5% of total energy intake from SFAs with isocaloric PUFAs was associated with decreased odds of hyperuricemia in men (0.69 (0.57, 0.84)) and in individuals (0.81 (0.71, 0.92)). Similar trends were observed in the substitution of SFAs with non-marine PUFAs in men (0.87 (0.80, 0.94)) and in all individuals (0.92 (0.88, 0.98)). Sensitivity analyses exhibited consistent results with primary analyses.

CONCLUSION

Higher dietary intake of n-3 PUFAs, n-6 PUFAs, LA, ALA, and non-marine PUFAs was associated with decreased hyperuricemia risk. These results support the recommendation to substitute SFAs with PUFAs in diet.

Dietary, macronutrient, micronutrient, and nutrigenetic factors impacting cardiovascular risk markers apolipoprotein B and apolipoprotein A1: a narrative review

Genetic predisposition and dietary factors can impact cardiovascular disease (CVD) risk. Two important markers in assessing CVD risk are apolipoprotein (apo) B and apolipoprotein A1 plasma levels. These markers are measured as a ratio, with a high apoB:apoA1 ratio associated with increased CVD risk. Dietary and lifestyle recommendations are the cornerstone of managing primary and secondary CVD risk-mitigation strategies. One way to assess the impact of various dietary and lifestyle interventions on CVD risk is to evaluate the changes in CVD risk markers, such as apoB, apoA1, and apoB:apoA1 ratio. Various human studies have demonstrated the impact of dietary, macronutrient, and micronutrient interventions on apoB and apoA1 status. This review aims to elucidate dietary, macronutrient, micronutrient, and nutrigenetic considerations for impacting apoB and apoA1 levels. A low-carbohydrate, high-saturated-fat diet, low fiber intake, low vitamin and mineral intake, and zinc and iron deficiency are associated with an elevated apoB:apoA1 ratio. The Mediterranean diet, vegan diet, fermented dairy products, lower sugar intake, higher protein intake, higher polyunsaturated fat intake, and an omega-3-rich diet are associated with a decreased apoB:apoA1 ratio. Micronutrients associated with a decreased apoB:apoA1 ratio include vitamin D sufficiency, increased serum vitamin C, and magnesium. Variants in the APOE, APOA1, and FADS2 genes may alter the apoB:apoA1 ratio in response to various dietary interventions. When accounting for factors that may favorably alter the apoB:apoA1 ratio, researchers should consider a healthy diet sufficient in polyunsaturated fats, vitamins, minerals, trace minerals, and lower excess sugars.

Substitution of dietary monounsaturated fatty acids from olive oil for saturated fatty acids from lard increases low-density lipoprotein apolipoprotein B-100 fractional catabolic rate in subjects with dyslipidemia associated with insulin resistance: a randomized controlled trial

BACKGROUND

The substitution of monounsaturated acids (MUFAs) for saturated fatty acids (SFAs) is recommended for cardiovascular disease prevention but its impact on lipoprotein metabolism in subjects with dyslipidemia associated with insulin resistance (IR) remains largely unknown.

OBJECTIVES

This study aimed to evaluate the impact of substituting MUFAs for SFAs on the in vivo kinetics of apolipoprotein (apo)B-containing lipoproteins and on the plasma lipidomic profile in adults with IR-induced dyslipidemia.

METHODS

Males and females with dyslipidemia associated with IR (n = 18) were recruited for this crossover double-blind randomized controlled trial. Subjects consumed, in random order, a diet rich in SFAs (SFAs: 13.4%E; MUFAs: 14.4%E) and a diet rich in MUFAs (SFAs: 7.1%E; MUFAs: 20.7%E) in fully controlled feeding conditions for periods of 4 wk each, separated by a 4-wk washout. At the end of each diet, fasting plasma samples were taken together with measurements of the in vivo kinetics of apoB-containing lipoproteins.

RESULTS

Substituting MUFAs for SFAs had no impact on triglyceride-rich lipoprotein apoB-48 fractional catabolic rate (FCR) (Δ = -8.9%, P = 0.4) and production rate (Δ = 0.0%, P = 0.9), although it decreased very low-density lipoprotein apoB-100 pool size (PS) (Δ = -22.5%; P = 0.01). This substitution also reduced low-density lipoprotein cholesterol (LDL-C) (Δ = -7.0%; P = 0.01), non-high-density lipoprotein cholesterol (Δ = -2.5%; P = 0.04), and LDL apoB-100 PS (Δ = -6.0%; P = 0.05). These differences were partially attributed to an increase in LDL apoB-100 FCR (Δ = +1.6%; P = 0.05). The MUFA diet showed reduced sphingolipid concentrations and elevated glycerophospholipid levels compared with the SFA diet.

CONCLUSIONS

This study demonstrated that substituting dietary MUFAs for SFAs decreases LDL-C levels and LDL PS by increasing LDL apoB-100 FCR and results in an overall improved plasma lipidomic profile in individuals with IR-induced lipidemia.

TRIAL REGISTRATION

This trial was registered as clinicaltrials.gov as NCT03872349.

A complementary method with PFBBr-derivatization based on a GC-EI-MS platform for the simultaneous quantitation of short-, medium- and long-chain fatty acids in murine plasma and feces samples

Fatty acids (FAs) are essential molecules in all organisms and are involved in various physiological and pathophysiological processes. Pentafluorobenzyl bromide (PFBBr) is commonly used for FA derivatization for gas chromatography-mass spectrometry (GC-MS) quantification by chemical ionization (CI). While CI is the conventional ionization mode for PFBBr derivatization, the electron ionization (EI) source has also demonstrated efficacy in achieving satisfactory analytical performance for the analysis of PFB esters. In this study, we present a novel approach utilizing PFBBr-derivatization on a GC-EI-MS platform to quantitatively analyze a comprehensive range of 44 fatty acids (FAs) spanning from C2 to C24. The method's sensitivity, precision, accuracy, linearity, recovery, and matrix effect were rigorously validated against predetermined acceptance criteria. In comparison to the conventional CI ionization mode, the utilization of PFBBr-derivatization in GC-EI-MS exhibits a wider range of applications and achieves comparable sensitivity levels to the conventional CI platform. By using this method, we successfully quantified 44 FAs in plasma and feces samples from the mice with deoxynivalenol (DON)-induced kidney injury. Among these, the levels of most FA species were increased in the DON-exposure group compared with the control group. The orthogonal partial least squares discriminant analysis (OPLS-DA) of all the tested FAs showed a visual separation of the two groups, indicating DON exposure resulted in a disturbance of the FA profile in mice. These results indicate that the established method by integration of GC-MS with PFBBr derivatization is an efficient approach to quantify the comprehensive FA profile, which includes short-, medium- and long-chain FAs. In addition, our study provides new insights into the mechanism underlying DON exposure-induced kidney injury.

Dietary saturated fatty acids increased all-cause and cardiovascular disease mortality in an elderly population: The National Health and Nutrition Examination Survey

The influence of dietary saturated fatty acids intake on human health and cardiovascular disease (CVD) remains debated. The aim of this study was to explore the association between dietary saturated fatty acid consumption and all-cause and CVD mortality among the elderly population. Data for the participants in this study were obtained from the National Health and Nutrition Examination Survey dataset spanning the years 2003 through 2008. Information regarding mortality and the follow-up duration were extracted from the 2019 public-use linked mortality files provided by the National Center for Health Statistics. A total of 3404 participants were included in this study. The ratio of dietary saturated fatty acids to total fat was associated with the mortality from all-cause, heart disease, and cerebrovascular disease after adjusting confounding factors (P < .05). For every 10% increase in the saturated fatty acids to total fat ratio, all-cause mortality increased by 24% (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.13-1.37), the heart disease mortality increased by 26% (HR, 1.26; 95% CI, 1.05-1.52), and the cerebrovascular disease mortality increased by 67% (HR, 1.67; 95% CI, 1.14-2.45) at 10 years' follow-up. In addition, low dietary saturated fatty acids intake was associated with reduced mortality because of all-cause and heart disease after adjusting confounding factors (P < .05). In conclusion, in this elderly population, dietary saturated fatty acid intake was associated with all-cause mortality, heart disease mortality, and cerebrovascular disease mortality. Reducing saturated fatty acid intake in the diet may extend the survival rate for the elderly population. However, the difference of the effects of specific dietary saturated fatty acids with different chain lengths on mortality needs further study.

Impact of saturated compared with unsaturated dietary fat on insulin sensitivity, pancreatic β-cell function and glucose tolerance: a systematic review and meta-analysis of randomized, controlled trials

BACKGROUND

The impact of the dietary fat type on type 2 diabetes (T2D) remains unclear.

OBJECTIVES

We aimed to evaluate the effects of replacing dietary saturated fatty acids (SFA) with mono- or poly-unsaturated fatty acids (MUFA and PUFA, respectively) on insulin sensitivity, pancreatic β-cell function, and glucose tolerance, as surrogate endpoints for T2D.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials that replaced ≥5% of total energy intake provided by SFA with MUFA or PUFA and reported indexes of insulin sensitivity, β-cell function, and/or glucose tolerance. We searched MEDLINE, Scopus, and the Cochrane Library (CENTRAL) up to 9 January, 2023. Eligible interventions had to be isocaloric, with no significant difference in other macronutrients. Data were synthesized using random-effects model meta-analysis.

RESULTS

Of 6355 records identified, 10 parallel and 20 crossover trials with 1586 participants were included. The mean age of the participants was 42 years, 47% were male, mean body mass index (BMI; in kg/m2) was 26.8, median baseline fasting glucose was 5.13 mmol/L, and the median duration of interventions was 5 weeks. Replacing SFA with MUFA or PUFA had no significant effects on insulin sensitivity [standardized mean difference (SMD) SFA compared with MUFA: 0.01, 95% confidence interval (CI): -0.06 to 0.09, I2 = 0% and SMD SFA compared with PUFA: 0, 95% CI: -0.15 to 0.14, I2 = 0%]. Replacing SFA with MUFA did not significantly impact the β-cell function, evaluated by the disposition index (mean difference: -12, 95% CI: -158 to 133, I2=0%). Evidence on glucose tolerance (SFA compared with MUFA or PUFA) and on β-cell function when SFA were replaced with PUFA was scant.

CONCLUSIONS

Short-term substitution of saturated with unsaturated fat does not significantly affect insulin sensitivity nor β-cell function (the latter in the SFA compared with MUFA comparison). Future studies are needed to elucidate longer term effects of dietary fat saturation on glucose homeostasis. This trial was registered at PROSPERO as CRD42020178382.

Effects of Dietary Linoleic Acid on Blood Lipid Profiles: A Systematic Review and Meta-Analysis of 40 Randomized Controlled Trials

Th aim of this meta-analysis was to elucidate whether dietary linoleic acid (LA) supplementation affected blood lipid profiles, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), compared with other fatty acids. Embase, PubMed, Web of Science and the Cochrane Library databases, updated to December 2022, were searched. The present study employed weighted mean difference (WMD) and a 95% confidence interval (CI) to examine the efficacy of the intervention. Out of the 3700 studies identified, a total of 40 randomized controlled trials (RCTs), comprising 2175 participants, met the eligibility criteria. Compared with the control group, the dietary intake of LA significantly decreased the concentrations of LDL-C (WMD: -3.26 mg/dL, 95% CI: -5.78, -0.74, I² = 68.8%, p = 0.01), and HDL-C (WMD: -0.64 mg/dL, 95% CI: -1.23, -0.06, I² = 30.3%, p = 0.03). There was no significant change in the TG and TC concentrations. Subgroup analysis showed that the LA intake was significantly reduced in blood lipid profiles compared with saturated fatty acids. The effect of LA on lipids was not found to be dependent on the timing of supplementation. LA supplementation in an excess of 20 g/d could be an effective dose for lowering lipid profiles. The research results provide further evidence that LA intake may play a role in reducing LDL-C and HDL-C, but not TG and TC.

Dietary Fatty Acids and Inflammation: Focus on the n-6 Series

Among the polyunsaturated fatty acids (PUFAs), those belonging to the n-3 (or ω3) series, i.e., alpha-linolenic (ALA), eicosapentaenoic (EPA), and docosahexaenoic (DHA) acids have been studied for decades from a pharma-nutritional viewpoint, namely in relation to cardiovascular health. More recent research is focusing on n-6 PUFAs, e.g., linoleic acid (LA), whose levels of consumption are much higher than those of n-3 and that cannot be used "pharmacologically". Perhaps because of this, the biological actions of n-6 PUFAs have not been investigated in details as those of their n-3 counterparts. However, an increasing body of evidence underscores their healthful actions on the cardiovascular system. Among the critiques to n-6 PUFAs and, particularly, LA there is the fact that they are precursors of pro-inflammatory eicosanoids. Hence, the hypothesis posits that we should reduce their intakes precisely to avoid increasing systemic, low-grade inflammation, i.e., one of the major etiological agents in degenerative diseases. In this narrative review, we address the issue of whether n-6 PUFAs are indeed pro-inflammatory, we discuss the most recent evidence of their role(s) in human health and prognosis, and we conclude that adequate intakes of n-6 fatty acids are associated with better cardiovascular health and child development.

Lactic acid bacteria-derived γ-linolenic acid metabolites are PPARδ ligands that reduce lipid accumulation in human intestinal organoids

Gut microbiota regulate physiological functions in various hosts, such as energy metabolism and immunity. Lactic acid bacteria, including Lactobacillus plantarum, have a specific polyunsaturated fatty acid saturation metabolism that generates multiple fatty acid species, such as hydroxy fatty acids, oxo fatty acids, conjugated fatty acids, and trans-fatty acids. How these bacterial metabolites impact host physiology is not fully understood. Here, we investigated the ligand activity of lactic acid bacteria–produced fatty acids in relation to nuclear hormone receptors expressed in the small intestine. Our reporter assays revealed two bacterial metabolites of γ-linolenic acid (GLA), 13-hydroxy-cis-6,cis-9-octadecadienoic acid (γHYD), and 13-oxo-cis-6,cis-9-octadecadienoic acid (γKetoD) activated peroxisome proliferator-activated receptor delta (PPARδ) more potently than GLA. We demonstrate that both γHYD and γKetoD bound directly to the ligand-binding domain of human PPARδ. A docking simulation indicated that four polar residues (T289, H323, H449, and Y473) of PPARδ donate hydrogen bonds to these fatty acids. Interestingly, T289 does not donate a hydrogen bond to GLA, suggesting that bacterial modification of GLA introducing hydroxy and oxo group determines ligand selectivity. In human intestinal organoids, we determined γHYD and γKetoD increased the expression of PPARδ target genes, enhanced fatty acid β-oxidation, and reduced intracellular triglyceride accumulation. These findings suggest that γHYD and γKetoD, which gut lactic acid bacteria could generate, are naturally occurring PPARδ ligands in the intestinal tract and may improve lipid metabolism in the human intestine.

Associations between Insulin-Like Growth Factor Binding Protein-2 and lipoprotein kinetics in men

Low circulating concentrations of insulin-like growth factor binding protein-2 (IGFBP-2) have been associated with dyslipidemia, notably with high triglyceride (TG) levels. However, the determinants by which IGFBP-2 influences lipoprotein metabolism, especially that of TG-rich lipoproteins (TRLs), are poorly understood. Here, we aimed to assess the relationships between IGFBP-2 levels and lipoprotein production and catabolism in human subjects. Fasting IGFBP-2 concentrations were measured in the plasma of 219 men pooled from previous lipoprotein kinetics studies. We analyzed production rate and fractional catabolic rates of TRLapoB-48, and LDL-, IDL-, and VLDLapoB-100 by multicompartmental modeling of l-[5,5,5-D3] leucine enrichment data after a 12 h primed constant infusion in individuals kept in a constant nutritional steady state. Subjects had an average BMI of 30 kg/m², plasma IGFBP-2 levels of 157 ng/ml, and TG of 2.2 mmol/l. After adjustments for age and BMI, IGFBP-2 levels were negatively associated with plasma TG (r = −0.29; P < 0.0001) and positively associated with HDL-cholesterol (r = 0.26; P < 0.0001). In addition, IGFBP-2 levels were positively associated with the fractional catabolic rate of VLDLapoB-100 (r = 0.20; P < 0.01) and IDLapoB-100 (r = 0.19; P < 0.05) and inversely with the production rate of TRLapoB-48 (r = −0.28; P < 0.001). These correlations remained statistically significant after adjustments for age, BMI, and the amount of fat given during the tracer infusion. These findings show that the association between low plasma IGFBP-2 and high TG concentrations could be due to both an impaired clearance of apoB-100-containing VLDL and IDL particles and an increased production of apoB-48-containing chylomicrons. Additional studies are necessary to investigate whether and how IGFBP-2 directly impacts the kinetics of TRL.

Effects of glycemic traits on left ventricular structure and function: a mendelian randomization study

BACKGROUND

Adverse ventricular structure and function is a key pathogenic mechanism of heart failure. Observational studies have shown that both insulin resistance (IR) and glycemic level are associated with adverse ventricular structure and function. However, whether IR and glycemic level are causally associated with cardiac structure and function remains unclear.

METHODS

Genetic variants for IR, fasting insulin, HbA1c, and fasting glucose were selected based on published genome-wide association studies, which included 188,577, 108,557, 123,665, and 133,010 individuals of European ancestry, respectively. Outcome datasets for left ventricular (LV) parameters were obtained from UK Biobank Cardiovascular Magnetic Resonance sub-study (n = 16,923). Mendelian randomization (MR) analyses with the inverse-variance weighted (IVW) method were used for the primary analyses, while weighted median, MR-Egger, and MR-PRESSO were used for sensitivity analyses. Multivariable MR analyses were also conducted to examine the independent effects of glycemic traits on LV parameters.

RESULTS

In the primary IVW MR analyses, per 1-standard deviation (SD) higher IR was significantly associated with lower LV end-diastolic volume (β = - 0.31 ml, 95% confidence interval [CI] - 0.48 to - 0.14 ml; P = 4.20 × 10^-4), lower LV end-systolic volume (β = - 0.34 ml, 95% CI - 0.51 to - 0.16 ml; P = 1.43 × 10^-4), and higher LV mass to end-diastolic volume ratio (β = 0.50 g/ml, 95% CI 0.32 to 0.67 g/ml; P = 6.24 × 10^-8) after Bonferroni adjustment. However, no associations of HbA1c and fasting glucose were observed with any LV parameters. Results from sensitivity analyses were consistent with the main findings, but with a slightly attenuated estimate. Multivariable MR analyses provided further evidence for an independent effect of IR on the adverse changes in LV parameters after controlling for HbA1c.

CONCLUSIONS

Our study suggests that genetic liability to IR rather than those of glycemic levels are associated with adverse changes in LV structure and function, which may strengthen our understanding of IR as a risk factor for heart failure by providing evidence of direct impact on cardiac morphology.

Host Metabolic Disorders Induced by Alterations in Intestinal Flora under Dietary Pesticide Exposure

A dietary pesticide residue causes underestimated influences on body health. In this work, experimental mice were exposed to commonly used pesticides that cause insulin resistance, inflammation, and non-alcoholic fatty liver diseases. Alterations in intestinal flora were detected in the exposure groups. The abundance of the flora causing high endotoxin production was intensively increased and led to body inflammation. High Firmicutes/Bacteroidetes and obesity-related flora characteristics were also found. The metabolisms of intestinal flora and host circulation were investigated through metabolomics. The associations of flora with their metabolites and host circulation were also established. Association analysis can determine the influences of pesticide exposure on such a complex system. The affected metabolic pathways in the liver were also determined to clarify the mechanism underlying the effect of pesticide exposure on host physiology. Interventions with fructooligosaccharides and fecal microbiota transplantation alleviated the metabolic disorders, thus directly confirming that the intestinal flora mediates the effects of pesticide exposure on host circulation. This work elucidated the intestinal-flora-mediated effects of dietary pollutant exposure on body health and provided potential measures for regulating flora and host circulation.

Dyslipidemia Management in 2020: An Update on Diagnosis and Therapeutic Perspectives

Cardiovascular diseases are the leading cause of death in the modern world and dyslipidemia is one of the major risk factors. The current therapeutic strategies for cardiovascular diseases involve the management of risk factors, especially dyslipidemia and hypertension. Recently, the updated guidelines of dyslipidemia management were presented, and the newest data were included in terms of diagnosis, imaging, and treatment. In this targeted literature review, the researchers presented the most recent evidence on dyslipidemia management by including the current therapeutic goals for it. In addition, the novel diagnostic tools based on theranostics are shown. Finally, the future perspectives on treatment based on novel drug delivery systems and their potential to be used in clinical trials were also analyzed. It should be noted that dyslipidemia management can be achieved by the strict lifestyle change, i.e., by adopting a healthy life, and choosing the most suitable medication. This review can help medical professionals as well as specialists of other sciences to update their knowledge on dyslipidemia management, which can lead to better therapeutic outcomes and newer drug developments.

Changes in lipoprotein particle subclasses, standard lipids, and apolipoproteins after supplementation with n-3 or n-6 PUFAs in abdominal obesity: A randomized double-blind crossover study

BACKGROUND & AIMS

Marine-derived omega-3 (n-3) polyunsaturated fatty acids (PUFAs), mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), lower circulating levels of triacylglycerols (TAGs), and the plant-derived omega-6 (n-6) PUFA linoleic acid (LA) may reduce cholesterol levels. Clinical studies on effects of these dietary or supplemental PUFAs on other blood fat fractions are few and have shown conflicting results. This study aimed to determine effects of high-dose supplemental n-3 (EPA + DHA) and n-6 (LA) PUFAs from high-quality oils on circulating lipoprotein subfractions and standard lipids (primary outcomes), as well as apolipoproteins, fatty acids, and glycemic control (secondary outcomes), in females and males with abdominal obesity.

METHODS

This was a randomized double-blind crossover study with two 7-wk intervention periods separated by a 9-wk washout phase. Females (n = 16) were supplemented with 3 g/d of EPA + DHA (TAG fish oil) or 15 g/d of LA (safflower oil), while males (n = 23) received a dose of 4 g/d of EPA + DHA or 20 g/d of LA. In fasting blood samples, we investigated lipoprotein particle subclasses by nuclear magnetic resonance spectroscopy, as well as standard lipids, apolipoproteins, fatty acid profiles, and glucose and insulin. Data were analyzed by linear mixed-effects modeling with 'subjects' as the random factor.

RESULTS

The difference between interventions in relative change scores was among the lipoprotein subfractions significant for total very-low-density lipoproteins (VLDLs) (n-3 vs. n-6: -38%∗ vs. +16%, p < 0.001; ∗: significant within-treatment change score), large VLDLs (-58%∗ vs. -0.91%, p < 0.001), small VLDLs (-57%∗ vs. +41%∗, p < 0.001), total low-density lipoproteins (LDLs) (+5.8%∗ vs. -4.3%∗, p = 0.002), large LDLs (+23%∗ vs. -2.1%, p = 0.004), total high-density lipoproteins (HDLs) (-6.0%∗ vs. +3.7%, p < 0.001), large HDLs (+11%∗ vs. -5.3%, p = 0.001), medium HDLs (-24%∗ vs. +6.2%, p = 0.030), and small HDLs (-9.9%∗ vs. +9.6%∗, p = 0.002), and among standard lipids for TAGs (-16%∗ vs. -2.6%, p = 0.014), non-esterified fatty acids (-19%∗ vs. +5.5%, p = 0.033), and total cholesterol (-0.28% vs. -4.4%∗, p = 0.042). A differential response in relative change scores was also found for apolipoprotein (apo)B (+0.40% vs. -6.0%∗, p = 0.008), apoA-II (-6.0%∗ vs. +1.5%, p = 0.001), apoC-II (-11%∗ vs. -1.7%, p = 0.025), and apoE (+3.3% vs. -3.8%, p = 0.028).

CONCLUSIONS

High-dose supplementation of high-quality oils with n-3 (EPA + DHA) or n-6 (LA) PUFAs was followed by reductions in primarily TAG- or cholesterol-related markers, respectively. The responses after both interventions point to changes in the lipoprotein-lipid-apolipoprotein profile that have been associated with reduced cardiometabolic risk, also among people with TAG or LDL-C levels within the normal range.

REGISTRATION

Registered under ClinicalTrials.gov Identifier: NCT02647333.

CLINICAL TRIAL REGISTRATION

Registered at https://clinicaltrials.gov/ct2/show/NCT02647333.

Effects of Nutrition Education Program for the Japan Diet on Serum LDL-Cholesterol Concentration in Patients with Dyslipidemia: A Randomized Controlled Trial

Aim: The Japan Diet (JD) recommended by the Japan Atherosclerosis Society based on the traditional Japanese diet is presumably favorable for preventing atherosclerotic cardiovascular diseases, but few high-quality controlled clinical trials have examined its benefits as compared with other diets. We studied effects of nutrition education for JD intake as compared with partial JD (PJD) intake on serum lipids and inflammatory parameters in subjects with dyslipidemia.

Methods: A randomized parallel controlled clinical trial was conducted on outpatients with dyslipidemia. Participants were randomly divided into the JD or the PJD group. Face-to-face nutrition education based on each diet at baseline and at 3 months, as well as monthly counseling by mail during the intervening 3-month period, were provided and participants practiced up to 6 months. Both groups were advised to reduce consumptions of animal fat/ fatty meat/poultry, confections, and alcoholic drinks. Additionally, the JD group participants were recommended to consume more fish, soybean products especially natto, vegetables, and seaweed/mushrooms/konjak, and to switch from refined to unrefined cereals or barley.

Results: Mean LDL-cholesterol was 125 +/- 29 mg/dL at baseline, and the JD group ( n =49) showed a greater mean LDL-cholesterol decrease than the PJD group ( n =49) [- 8 mg/dL in JD vs 1 mg/dL in PJD, difference, -9 mg/dL (95%CI, -17 to 0) p =0.043)], and triglyceride ( p =0.023) and insulin ( p =0.033) reductions were larger in the JD group than in the PJD group at 6 months.

Conclusion: Nutrition education for JD intake was suggested to improve serum lipid and metabolic parameters in patients with dyslipidemia.

Western and heart healthy dietary patterns differentially affect the expression of genes associated with lipid metabolism, interferon signaling and inflammation in the jejunum of Ossabaw pigs

Diet quality and statin therapy are established modulators of coronary artery disease (CAD) progression, but their effect on the gastrointestinal tract and subsequent sequelae that could affect CAD progression are relatively unexplored. To address this gap, Ossabaw pigs (N = 32) were randomly assigned to receive isocaloric amounts of a Western-type diet (WD; high in saturated fat, refined carbohydrate, and cholesterol, and low in fiber) or a heart healthy-type diet (HHD; high in unsaturated fat, whole grains, fruits and vegetables, supplemented with fish oil, and low in cholesterol), with or without atorvastatin, for 6 months. At the end of the study, RNA sequencing with 100 base pair single end reads on NextSeq 500 platform was conducted in isolated pig jejunal mucosa. A two-factor edgeR analysis revealed that the dietary patterns resulted in three differentially expressed genes related to lipid metabolism (SCD, FADS1, and SQLE). The expression of these genes was associated with cardiometabolic risk factors and atherosclerotic lesion severity. Subsequent gene enrichment analysis indicated the WD, compared to the HHD, resulted in higher interferon signaling and inflammation, with some of these genes being significantly associated with serum TNF-α and/or hsCRP concentrations, but not atherosclerotic lesion severity. No significant effect of atorvastatin therapy on gene expression, nor its interaction with dietary patterns, was identified. In conclusion, Western and heart healthy-type dietary patterns differentially affect the expression of genes associated with lipid metabolism, interferon signaling, and inflammation in the jejunum of Ossabaw pigs.

Plasma linoleic acid levels and cardiovascular risk factors: results from the Norwegian ACE 1950 Study

BACKGROUND

A high intake of linoleic acid (LA), the major dietary polyunsaturated fatty acid (PUFA), has previously been associated with reduced cardiovascular (CV) morbidity and mortality in observational studies. However, recent secondary analyses from clinical trials of LA-rich diet suggest harmful effects of LA on CV health.

METHODS

A total of 3706 participants, all born in 1950, were included in this cross-sectional study. We investigated associations between plasma phospholipid levels of LA and CV risk factors in a Norwegian general population, characterized by a relative low LA and high marine n-3 PUFA intake. The main statistical approach was multivariable linear regression.

RESULTS

Plasma phospholipid LA levels ranged from 11.4 to 32.0 wt%, with a median level of 20.8 wt% (interquartile range 16.8-24.8 wt%). High plasma LA levels were associated with lower serum low-density lipoprotein cholesterol levels (standardized regression coefficient [Std. β-coeff.] -0.04, p = 0.02), serum triglycerides (Std. β-coeff. -0.10, p < 0.001), fasting plasma glucose (Std. β-coeff. -0.10, p < 0.001), body mass index (Std. β-coeff. -0.13, p < 0.001), systolic and diastolic blood pressure (Std. β-coeff. -0.04, p = 0.03 and Std. β-coeff. -0.02, p = 0.02, respectively) and estimated glomerular filtration rate (Std. β-coeff. -0.09, p < 0.001). We found no association between plasma LA levels and high-density lipoprotein cholesterol levels, glycated hemoglobin, carotid intima-media thickness, or C-reactive protein.

CONCLUSION

High plasma LA levels were favorably associated with several CV risk factors in this study of a Norwegian general population.

Dietary linoleic acid and human health: Focus on cardiovascular and cardiometabolic effects

This narrative review aims to discuss the more relevant evidence on the role of linoleic acid (LA), a n-6 essential fatty acid that constitutes the predominant proportion of dietary polyunsaturated fatty acids (PUFA), in cardiovascular health. Although LA can be metabolized into Arachidonic Acid (AA), a 20 carbon PUFA which is the precursor of eicosanoids, including some with proinflammatory or prothrombotic-vasoconstrictor action, the large majority of experimental and clinical studies have assessed the potential benefit of increasing dietary intake of LA. Overall, data from clinical studies and meta-analyses suggest an association between high dietary intakes or tissue levels of n-6 PUFA, and specifically LA, and the improvement of cardiovascular risk (mainly of the plasma lipid profile), as well as long-term glycaemic control and insulin resistance. Most observational data show that elevated/increased dietary intake or tissue levels of LA is associated with a reduced incidence of cardiovascular diseases (mainly coronary artery diseases) and of new onset metabolic syndrome or type 2 diabetes. The effects of LA (or n-6 PUFA) in other physio-pathological areas are less clear. High quality clinical trials are needed to assess both the actual amplitude and the underlying mechanisms of the health effects related to dietary intake of this essential fatty acid.

Fatty acid composition and quality properties of chicken sausage formulated with pre-emulsified perilla-canola oil as an animal fat replacer

The potential use of an oil in water (o/w) emulsion made from perilla and canola oil in chicken sausage as an animal fat replacer was assessed. The (o/w) emulsion was made from 50% (wt/wt) perilla-canola oil mixture in a 30:70 ratio, 3.20% (wt/wt) polyglycerol polyricinoleate, 4.48% (wt/wt) soy protein isolate, 14% (wt/wt) inulin, and 28.32% (wt/wt) water. The sausages were manufactured with 60% (wt/wt) ground chicken breast, 20% (wt/wt) fat (beef tallow as a control), and 20% (wt/wt) ice water. Full replacement of animal fat with a perilla-canola oil (o/w) emulsion reduced the fat content and estimated calories but increased the moisture, protein, ash, and carbohydrate content. The proportion of α-linolenic acid (C18:3n3) was increased when animal fat was replaced with either a perilla-canola oil mixture or pre-emulsified perilla-canola oil, resulting in a lower n6 to n3 polyunsaturated fatty acid ratio than the control. The perilla-canola oil (o/w) emulsion improved emulsion stability and minimized cooking loss during sausage manufacturing. Higher L* value (lightness) and whiteness were observed in the sausages formulated with the perilla-canola oil mixture, followed by the pre-emulsified perilla-canola oil and the control. The perilla-canola oil (o/w) emulsion also increased the hardness but maintained an acceptable appearance, flavor, and overall impression similar to the control. The shelf life could be extended by vacuum packing and storing the cooked sausages formulated with a perilla-canola oil (o/w) emulsion for 30 D at 2 ± 1°C. Pre-emulsified perilla-canola oil could be used to replace animal fat in reduced-fat chicken sausage manufacture.

Differential associations between plasma concentrations of insulin and glucose and intestinal expression of key genes involved in chylomicron metabolism

The mechanisms underlying the oversecretion of apolipoprotein (apo)B-48-containing triglyceride-rich lipoproteins (TRL) in insulin-resistance (IR) states in humans remain to be fully understood. The objective of this study was to evaluate the association between the plasma levels of insulin and glucose and the intestinal expression of key genes involved in chylomicron metabolism in a large sample of nondiabetic men displaying various degrees of IR. Duodenal biopsies were obtained by gastroduodenoscopy in 127 men free of intestinal disease. Gene expression was measured using quantitative PCR in duodenal samples. Plasma insulin and glucose concentrations were measured in the fasting state. Postprandial TRL apoB-48 kinetics were measured using a primed-constant infusion of l-[5,5,5-D₃]leucine for 12 h in a subgroup of 75 subjects maintained in a constant fed state. Plasma insulin levels were negatively associated with intestinal expression of ACS1 (standard β = -0.20, P = 0.007), DGAT1 (β = -0.18, P = 0.001), DGAT2 (β = -0.20, P = 0.02), and MTP (β = -0.27, P = 0.0005), whereas glucose levels were positively associated with MTP expression (β = 0.15, P = 0.04) independent of age, BMI, waist circumference, dietary intake, and duodenal expression of SREBP1c. Insulin levels, but not glucose concentrations, were positively correlated with postprandial TRL apoB-48 production rate ( r = 0.24, P = 0.04) and pool size ( r = 0.27, P = 0.03). In conclusion, plasma insulin and glucose levels are differentially associated with the expression of key genes involved in chylomicron metabolism. These results suggest that alterations in intestinal lipoprotein metabolism associated with IR may be regulated by plasma levels of both insulin and glucose concurrently and are therefore likely modified by the onset of insulin insufficiency. NEW & NOTEWORTHY We demonstrate that plasma insulin and glucose levels are differentially associated with the expression of key genes involved in chylomicron metabolism in men. For instance, intestinal expression of MTP is negatively associated with plasma insulin concentrations and positively associated with plasma glucose concentrations. Alterations in intestinal lipoprotein metabolism associated with insulin resistance may be regulated by plasma levels of both insulin and glucose concurrently and are therefore likely modified by the onset of insulin insufficiency.

Formula Optimization of a Perilla-canola Oil (O/W) Emulsion and Its Potential Application as an Animal Fat Replacer in Meat Emulsion

The formulation of an oil/water (o/w) emulsion made up of a mixture of perilla oil and canola oil (30/70 w/w) was optimized using a response surface methodology to find a replacement for animal fat in an emulsion-type meat product. A 12 run Plackett-Burman design (PBD) was applied to screen the effect of potential ingredients in the (o/w) emulsion, including polyglycerol polyricinoleate (PGPR), fish gelatin, soy protein isolate (SPI), sodium caseinate, carrageenan (CR), inulin (IN) and sodium tripolyphosphate. The PBD showed that SPI, CR and IN showed promise but required further optimization, and other ingredients did not affect the technological properties of the (o/w) emulsion. The PBD also showed that PGPR played a critical role in inhibiting an emulsion break. The level of PGPR was then fixed at 3.2% (w/w total emulsion) for an optimization study. A central composite design (CCD) was applied to optimize the addition levels of SPI, CR or IN in an (o/w) emulsion and to observe their effects on emulsion stability, cooking loss and the textural properties of a cooked meat emulsion. Significant interactions between SPI and CR increased the cooking loss in the meat emulsion. In contrast, IN showed interactions with SPI leading to a reduction in cooking loss. Thus, CR was also removed from the formulation. After optimization, the level of SPI (4.48% w/w) and IN (14% w/w) was validated, leading to a perilla-canola oil (o/w) emulsion with the ability to replace animal fat in an emulsion-type meat products.

Plasma PCSK9 correlates with apoB-48-containing triglyceride-rich lipoprotein production in men with insulin resistance

Intestinal triglyceride (TG)-rich lipoproteins (TRLs) are important in the pathogenesis of atherosclerosis in insulin resistance (IR). We investigated the association of plasma proprotein convertase subtilisin/kexin type 9 (PCSK9) concentrations with apoB-48-containing TRL metabolism in 148 men displaying various degrees of IR by measuring in vivo kinetics of TRL apoB-48 during a constant-fed state after a primed-constant infusion of L-[5,5,5-D3]leucine. Plasma PCSK9 concentrations positively correlated with TRL apoB-48 pool size (r = 0.31, P = 0.0002) and production rate (r = 0.24, P = 0.008) but not the fractional catabolic rate (r = -0.04, P = 0.6). Backward stepwise multiple linear regression analysis identified PCSK9 concentrations as a positive predictor of TRL apoB-48 production rate (standard β = +0.20, P = 0.007) independent of BMI, age, T2D/metformin use, dietary fat intake during the kinetic study, and fasting concentrations of TGs, insulin, glucose, LDL cholesterol, or C-reactive protein. We also assessed intestinal expression of key genes involved in chylomicron processing from duodenal samples of 71 men. Expression of PCSK9 and HMG-CoAR genes was positively associated (r = 0.43, P = 0.002). These results support PCSK9 association with intestinal secretion and plasma overaccumulation of TRL apoB-48 in men with IR.