Effects of meals rich in either monounsaturated or saturated fat on lipid concentrations and on insulin secretion and action in subjects with high fasting triglyceride concentrations

Effects of Single Low-Carbohydrate, High-Fat Meal Consumption on Postprandial Lipemia and Markers of Endothelial Dysfunction: A Systematic Review of Current Evidence

CONTEXT

Postprandial lipemia (PPL) is associated with increased risk of endothelial dysfunction (ED), a precursor of atherosclerotic cardiovascular disease (ASCVD). The effects of low-carbohydrate, high-fat (LCHF) diets on ASCVD risk are uncertain; therefore, gaining a greater understanding of LCHF meals on PPL may provide valuable insights.

OBJECTIVE

The current systematic review investigated the effects of single LCHF meal consumption on PPL and markers of ED.

DATA SOURCES

CINAHL Plus, PubMed, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for key terms related to endothelial function, cardiovascular disease, glycemia, lipemia, and the postprandial state with no restriction on date.

DATA EXTRACTION

Full-text articles were independently screened by 2 reviewers, of which 16 studies were eligible to be included in the current review. All trials reported a minimum analysis of postprandial triglycerides (PPTG) following consumption of an LCHF meal (<26% of energy as carbohydrate). Results were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

DATA ANALYSIS

Single-meal macronutrient composition was found to play a key role in determining postprandial lipid and lipoprotein responses up to 8 hours post-meal. Consumption of LCHF meals increased PPTG and may contribute to ED via reduced flow-mediated dilation and increased oxidative stress; however, energy and macronutrient composition varied considerably between studies.

CONCLUSION

Consumption of an LCHF meal had a negative impact on PPL based on some, but not all, single-meal studies; therefore, the contribution of LCHF meals to cardiometabolic health outcomes remains unclear. Further research is needed on specific categories of LCHF diets to establish a causal relationship between postprandial modulation of lipids/lipoproteins and impaired vascular endothelial function.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD 42023398774.

Association between density of food retailers and fitness centers and gestational diabetes mellitus in Eastern Massachusetts, USA: population-based study

Background

Few studies have investigated the relationship between the food and physical activity environment and odds of gestational diabetes mellitus (GDM). This study quantifies the association between densities of several types of food establishments and fitness centers with the odds of having GDM.

Methods

The density of supermarkets, fast-food restaurants, full-service restaurants, convenience stores and fitness centers at 500, 1000 and 1500 m (m) buffers was counted at residential addresses of 68,779 pregnant individuals from Eastern Massachusetts during 2000-2016. The 'healthy food index' assessed the relative availability of healthy (supermarkets) vs unhealthy (fast-food restaurants, convenience stores) food retailers. Multivariable logistic regression quantified the cross-sectional association between exposure variables and the odds of having GDM, adjusting for individual and area-level characteristics. Effect modification by area-level socioeconomic status (SES) was assessed.

Findings

In fully adjusted models, pregnant individuals living in the highest density tertile of fast-food restaurants had higher GDM odds compared to those living in the lowest density tertile (500 m: odds ratio (OR):1.17 95% CI: [1.04, 1.31]; 1000 m: 1.33 95% CI: [1.15, 1.53]); 1500 m: 1.18 95% CI: [1.01, 1.38]). Greater residential density of supermarkets was associated with lower odds of GDM (1000 m: 0.86 95% CI: [0.74, 0.99]; 1500 m: 0.86 95% CI: [0.72, 1.01]). Similarly, living in the highest fitness center density tertile was associated with decreased GDM odds (500 m:0.87 95% CI: [0.76, 0.99]; 1500 m: 0.89 95% CI: [0.79, 1.01]). There was no evidence of effect modification by SES and no association found between the healthy food index and GDM odds.

Interpretation

In Eastern Massachusetts, living near a greater density of fast-food establishments was associated with higher GDM odds. Greater residential access to supermarkets and fitness centers was associated with lower the odds of having GDM.

Funding

NIH.

Comprehensive Strategies for Metabolic Syndrome: How Nutrition, Dietary Polyphenols, Physical Activity, and Lifestyle Modifications Address Diabesity, Cardiovascular Diseases, and Neurodegenerative Conditions

Several hallmarks of metabolic syndrome, such as dysregulation in the glucose and lipid metabolism, endothelial dysfunction, insulin resistance, low-to-medium systemic inflammation, and intestinal microbiota dysbiosis, represent a pathological bridge between metabolic syndrome and diabesity, cardiovascular, and neurodegenerative disorders. This review aims to highlight some therapeutic strategies against metabolic syndrome involving integrative approaches to improve lifestyle and daily diet. The beneficial effects of foods containing antioxidant polyphenols, intestinal microbiota control, and physical activity were also considered. We comprehensively examined a large body of published articles involving basic, animal, and human studie, as well as recent guidelines. As a result, dietary polyphenols from natural plant-based antioxidants and adherence to the Mediterranean diet, along with physical exercise, are promising complementary therapies to delay or prevent the onset of metabolic syndrome and counteract diabesity and cardiovascular diseases, as well as to protect against neurodegenerative disorders and cognitive decline. Modulation of the intestinal microbiota reduces the risks associated with MS, improves diabetes and cardiovascular diseases (CVD), and exerts neuroprotective action. Despite several studies, the estimation of dietary polyphenol intake is inconclusive and requires further evidence. Lifestyle interventions involving physical activity and reduced calorie intake can improve metabolic outcomes.

Comparison of the impact of saturated fat from full-fat yogurt or low-fat yogurt and butter on cardiometabolic factors: a randomized cross-over trial

PURPOSE

Dairy foods are often a major contributor to dietary saturated fatty acids (SFA) intake. However, different SFA-rich foods may not have the same effects on cardiovascular risk factors. We compared full-fat yogurt with low-fat yogurt and butter for their effects on cardiometabolic risk factors in healthy individuals.

METHODS

Randomized, two-period crossover trial conducted from October 2022 to April 2023 among 30 healthy men and women (15 to receive full-fat yogurt first, and 15 to receive low-fat yogurt and butter first). Participants consumed a diet with 1.5-2 servings of full-fat (4%) yogurt or low-fat (< 1.5) yogurt and 10-15 g of butter per day for 4 weeks, with 4 weeks wash-out when they consumed 1.5-2 servings of low-fat milk. At baseline, and the end of each 4 weeks, fasting blood samples were drawn and plasma lipids, glycemic and inflammatory markers as well as expression of some genes in the blood buffy coats fraction were determined.

RESULTS

All 30 participants completed the two periods of the study. Apolipoprotein B was higher for the low-fat yogurt and butter [changes from baseline, + 10.06 (95%CI 4.64 to 15.47)] compared with the full-fat yogurt [-4.27 (95%CI, -11.78 to 3.23)] and the difference between two treatment periods was statistically significant (p = 0.004). Non-high-density lipoprotein increased for the low-fat yogurt and butter [change, + 5.06 (95%CI (-1.56 to 11.69) compared with the full-fat yogurt [change, - 4.90 (95%CI, -11.61 to 1.81), with no significant difference between two periods (p = 0.056). There were no between-period differences in other plasma lipid, insulin, and inflammatory biomarkers or leukocyte gene expression of ATP-binding cassette transporter 1 and CD36.

CONCLUSION

This study suggests that short-term intake of SFAs from full-fat yogurt compared to intake from butter and low-fat yogurt has fewer adverse effects on plasma lipid profile.

CLINICALTRIALS

GOV: NCT05589350, 10/15/2022.

Olive Oil Consumption and Cardiovascular Protection: Mechanism of Action

Cardiovascular diseases (CVDs) are still the leading cause of death and disability worldwide, and they could be prevented by a diet modification and a healthy lifestyle. Dietary modifications include a reduction in the consumption of saturated fatty acids and replacing them with mono or polyunsaturated fatty acids. Olive oil is a monounsaturated fatty acid and its increased consumption has been associated with a significant reduction of CVDs. Its significant cardiovascular benefits have been attributed to its high content of vitamin E, polyphenols, and other ingredients that possess significant anti-inflammatory and antioxidant properties. Several prospective and epidemiological studies have reported an inverse association between olive oil consumption and the incidence of CVD, hypertension, and type 2 diabetes mellitus. Also, a seminal study demonstrated that the use of a Mediterranean diet, which is rich in olive oil, fruits, vegetables, and fish, and low in red meat, was associated with significant reductions in CVD and mortality. However, despite its proven cardiovascular benefits, olive oil is scarcely used in the United States and other Western countries. To determine the current use of olive oil in the United States and other Western countries, a Medline search of the English literature between 2012 and January 2022 was conducted, and 36 pertinent articles were selected. The data from these articles, together with collateral literature, will be discussed in this concise review.

Quality of dietary macronutrients is associated with glycemic outcomes in adults with cystic fibrosis

Objective

Poor diet quality contributes to metabolic dysfunction. This study aimed to gain a greater understanding of the relationship between dietary macronutrient quality and glucose homeostasis in adults with cystic fibrosis (CF).

Design

This was a cross-sectional study of N = 27 adults with CF with glucose tolerance ranging from normal (n = 9) to prediabetes (n = 6) to being classified as having cystic fibrosis-related diabetes (CFRD, n = 12). Fasted blood was collected for analysis of glucose, insulin, and C-peptide. Insulin resistance was assessed by Homeostatic Model Assessment for Insulin Resistance (HOMA2-IR). Subjects without known CFRD also underwent a 2-h oral glucose tolerance test. Three-day food records were used to assess macronutrient sources. Dietary variables were adjusted for energy intake. Statistical analyses included ANOVA, Spearman correlations, and multiple linear regression.

Results

Individuals with CFRD consumed less total fat and monounsaturated fatty acids (MUFA) compared to those with normal glucose tolerance (p < 0.05). In Spearman correlation analyses, dietary glycemic load was inversely associated with C-peptide (rho = -0.28, p = 0.05). Total dietary fat, MUFA, and polyunsaturated fatty acids (PUFA) were positively associated with C-peptide (rho = 0.39-0.41, all p < 0.05). Plant protein intake was inversely related to HOMA2-IR (rho = -0.28, p = 0.048). Associations remained significant after adjustment for age and sex.

Discussion

Improvements in diet quality are needed in people with CF. This study suggests that higher unsaturated dietary fat, higher plant protein, and higher carbohydrate quality were associated with better glucose tolerance indicators in adults with CF. Larger, prospective studies in individuals with CF are needed to determine the impact of diet quality on the development of CFRD.

Stabilized soy protein emulsion enriched with silicon and containing or not methylcellulose as novel technological alternatives to reduce animal fat digestion

During the last decade, the consumption of animal saturated fat has been associated with an increased risk of chronic disease. Experience shows that changing the dietary habits of the population is a complicated and slow process, so technological strategies offer new possibilities for the development of functional foods. The present work is focused on studying the impact of using a food-grade non-ionic hydrocolloid (methylcellulose; MC) and/or the inclusion of silicon (Si) as a bioactive compound in pork lard emulsions stabilized with soy protein concentrate (SPC), on the structure, rheology, lipid digestibility and Si bioaccesibility during in vitro gastrointestinal digestion (GID). Four emulsions (SPC, SPC/Si, SPC/MC and SPC/MC/Si) were prepared with a final biopolymer (SPC and/or MC) concentration of 4% and 0.24% Si. The results showed a lower degree of lipid digestion in SPC/MC compared with SPC, specifically at the end of the intestinal phase. Moreover, Si partially reduced fat digestion only when incorporated into the SPC-stabilized emulsion, while this effect was lost in SPC/MC/Si. This was probably due to its retention inside the matrix emulsion, which resulted in lower bioaccesibility than in SPC/Si. Additionally, the correlation between the flow behavior index (n) and the lipid absorbable fraction was significant, suggesting that n can be a predictive marker of the extent of lipolysis. Concretely, our results revealed that SPC/Si and SPC/MC can be used as pork fat digestion reducers and thus, they can replace pork lard in the reformulation of animal products with potential health benefits.

The Impacts of Animal-Based Diets in Cardiovascular Disease Development: A Cellular and Physiological Overview

Cardiovascular disease (CVD) is the leading cause of death in the United States, and diet plays an instrumental role in CVD development. Plant-based diets have been strongly tied to a reduction in CVD incidence. In contrast, animal food consumption may increase CVD risk. While increased serum low-density lipoprotein (LDL) cholesterol concentrations are an established risk factor which may partially explain the positive association with animal foods and CVD, numerous other biochemical factors are also at play. Thus, the aim of this review is to summarize the major cellular and molecular effects of animal food consumption in relation to CVD development. Animal-food-centered diets may (1) increase cardiovascular toll-like receptor (TLR) signaling, due to increased serum endotoxins and oxidized LDL cholesterol, (2) increase cardiovascular lipotoxicity, (3) increase renin-angiotensin system components and subsequent angiotensin II type-1 receptor (AT1R) signaling and (4) increase serum trimethylamine-N-oxide concentrations. These nutritionally mediated factors independently increase cardiovascular oxidative stress and inflammation and are all independently tied to CVD development. Public policy efforts should continue to advocate for the consumption of a mostly plant-based diet, with the minimization of animal-based foods.

The roles of dietary lipids and lipidomics in gut-brain axis in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM), one of the main types of Noncommunicable diseases (NCDs), is a systemic inflammatory disease characterized by dysfunctional pancreatic β-cells and/or peripheral insulin resistance, resulting in impaired glucose and lipid metabolism. Genetic, metabolic, multiple lifestyle, and sociodemographic factors are known as related to high T2DM risk. Dietary lipids and lipid metabolism are significant metabolic modulators in T2DM and T2DM-related complications. Besides, accumulated evidence suggests that altered gut microbiota which plays an important role in the metabolic health of the host contributes significantly to T2DM involving impaired or improved glucose and lipid metabolism. At this point, dietary lipids may affect host physiology and health via interaction with the gut microbiota. Besides, increasing evidence in the literature suggests that lipidomics as novel parameters detected with holistic analytical techniques have important roles in the pathogenesis and progression of T2DM, through various mechanisms of action including gut-brain axis modulation. A better understanding of the roles of some nutrients and lipidomics in T2DM through gut microbiota interactions will help develop new strategies for the prevention and treatment of T2DM. However, this issue has not yet been entirely discussed in the literature. The present review provides up-to-date knowledge on the roles of dietary lipids and lipidomics in gut-brain axis in T2DM and some nutritional strategies in T2DM considering lipids- lipidomics and gut microbiota interactions are given.

Effects of diets rich in ghee or olive oil on cardiometabolic risk factors in healthy adults: a two-period, crossover, randomised trial

This study aimed to evaluate the cardiovascular health-related effects of consuming ghee in the usual diet. Thirty healthy men and women were studied in a free-living outpatient regimen. The participants were instructed for the isoenergetic inclusion of ghee or olive oil in their diets for 4 weeks using a randomised crossover design. At the end of run-in (baseline), 2-week wash-out and interventions, fasting blood samples were drawn. In addition, 2-h postprandial blood samples were collected after ingestion of a meal containing olive oil or ghee at week 4 of each dietary intervention. Body weight was not different between the two interventions. Compared with the olive oil, the diet with ghee increased fasting plasma apo-B (apo B) (0·09, 95 % CI 0·02, 0·17 g/l, P = 0·018), non-HDL-cholesterol (non-HDL-cholesterol) (0·53, 95 % CI 0·01, 1·05 mmol/l, P = 0·046) and LDL-cholesterol did not differ significantly between diet groups (0·29, 95 % CI -0·05, 0·63 mmol/l, P = 0·092), but had no significant effect on total cholesterol:HDL-cholesterol ratio (0·75, 95 % CI - 0·24 to 1·74 mmol/l, P = 0·118). No significant difference was observed in fasting as well as 2-h postprandial plasma TAG, glucose, insulin and plasminogen activator inhibitor-1 concentrations. This study showed that ghee that is predominantly saturated fats had an increasing effect on plasma apo B and non-HDL-cholesterol compared with olive oil, adding further evidence to the existing recommendations to replace dietary fats high in SFA with dietary fats high in unsaturated fats to reduce CVD risk.

Oleate restores altered autophagic flux to rescue palmitate lipotoxicity in hypothalamic neurons

Accumulation of excess lipids in non-adipose tissues, such as the hypothalamus, is termed lipotoxicity and causative of free fatty acid-mediated pathology in metabolic disease. This study aimed to elucidate the molecular mechanisms behind oleate (OA)- and palmitate (PA)-mediated changes in hypothalamic neurons. Using the well-characterized hypothalamic neuronal cell model, mHypoE-46, we assessed gene changes through qRT-PCR, cell death with quantitative imaging, PA metabolism using stable isotope labeling, and cellular mechanisms using pharmacological modulation of lipid metabolism and autophagic flux. Palmitate (PA) disrupts gene expression, including Npy, Grp78, and Il-6 mRNA in mHypoE-46 hypothalamic neurons. Blocking PA metabolism using triacsin-C prevented the increase of these genes, implying that these changes depend on PA intracellular metabolism. Co-incubation with oleate (OA) is also potently protective and prevents cell death induced by increasing concentrations of PA. However, OA does not decrease U-¹³C-PA incorporation into diacylglycerol and phospholipids. Remarkably, OA can reverse PA toxicity even after significant PA metabolism and cellular impairment. OA can restore PA-mediated impairment of autophagy to prevent or reverse the accumulation of PA metabolites through lysosomal degradation, and not through other reported mechanisms. The autophagic flux inhibitor chloroquine (CQ) mimics PA toxicity by upregulating autophagy-related genes, Npy, Grp78, and Il-6, an effect partially reversed by OA. CQ also prevented the OA defense against PA toxicity, whereas the autophagy inducer rapamycin provided some protection. Thus, PA impairment of autophagic flux significantly contributes to its lipotoxicity, and OA-mediated protection requires functional autophagy. Overall, our results suggest that impairment of autophagy contributes to hypothalamic lipotoxicity.

Dietary Risk Factors and Eating Behaviors in Peripheral Arterial Disease (PAD)

Dietary risk factors play a fundamental role in the prevention and progression of atherosclerosis and PAD (Peripheral Arterial Disease). The impact of nutrition, however, defined as the process of taking in food and using it for growth, metabolism and repair, remains undefined with regard to PAD. This article describes the interplay between nutrition and the development/progression of PAD. We reviewed 688 articles, including key articles, narrative and systematic reviews, meta-analyses and clinical studies. We analyzed the interaction between nutrition and PAD predictors, and subsequently created four descriptive tables to summarize the relationship between PAD, dietary risk factors and outcomes. We comprehensively reviewed the role of well-studied diets (Mediterranean, vegetarian/vegan, low-carbohydrate ketogenic and intermittent fasting diet) and prevalent eating behaviors (emotional and binge eating, night eating and sleeping disorders, anorexia, bulimia, skipping meals, home cooking and fast/ultra-processed food consumption) on the traditional risk factors of PAD. Moreover, we analyzed the interplay between PAD and nutritional status, nutrients, dietary patterns and eating habits. Dietary patterns and eating disorders affect the development and progression of PAD, as well as its disabling complications including major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Nutrition and dietary risk factor modification are important targets to reduce the risk of PAD as well as the subsequent development of MACE and MALE.

Acute effects of prior dietary fat ingestion on postprandial metabolic responses to protein and carbohydrate co-ingestion in overweight and obese men: A randomised crossover trial

BACKGROUND

Obesity and insulin resistance are associated with an impaired sensitivity to anabolic stimuli such as dietary protein (anabolic resistance). Omega-3 polyunsaturated fatty acids (n-3 PUFA) may be protective against the deleterious effects of saturated fatty acids (SFA) on insulin resistance. However, the contribution of excess fat consumption to anabolic and insulin resistance and the interaction between SFA and n-3 PUFA is not well studied.

AIM

The primary aim of this study was to investigate the effects of an oral fat pre-load, with or without the partial substitution of SFA with fish oil (FO)-derived n-3 PUFA, on indices of insulin and anabolic sensitivity in response to subsequent dietary protein and carbohydrate (dextrose) co-ingestion.

METHODS

Eight middle-aged males with overweight or obesity (52.8 ± 2.0 yr, BMI 31.8 ± 1.4 kg·m^-2) ingested either an SFA, or isoenergetic SFA and FO emulsion (FO), or water/control (Con), 4 h prior to a bolus of milk protein and dextrose.

RESULTS

Lipid ingestion (in particular FO) impaired the early postprandial uptake of branched chain amino acids (BCAA) into the skeletal muscle in response to protein and dextrose, and attenuated the peak glycaemic response, but was not accompanied by differences in whole body (Matsuda Index: Con: 4.66 ± 0.89, SFA: 5.10 ± 0.94 and FO: 4.07 ± 0.59) or peripheral (forearm glucose _netAUC: Con: 521.7 ± 101.7; SFA: 470.2 ± 125.5 and FO: 495.3 ± 101.6 μmol·min^-1·100 g lean mass·min [t = 240-420 min]) insulin sensitivity between visits. Postprandial whole body fat oxidation was affected by visit (P = 0.024) with elevated rates in SFA and FO, relative to Con (1.85 ± 0.55; 2.19 ± 0.21 and 0.65 ± 0.35 kJ·h^-1·kg^-1 lean body mass, respectively), however muscle uptake of free fatty acids (FFA) was unaffected.

CONCLUSION

Oral lipid preloads, consisting of SFA and FO, impair the early postprandial BCAA uptake into skeletal muscle, which occurs independent of changes in insulin sensitivity.

CLINICAL TRIAL REGISTRY NUMBER

ClinicalTrials.gov Identifier NCT03146286.

Impact of Meal Fatty Acid Composition on Postprandial Lipemia in Metabolically Healthy Adults and Individuals with Cardiovascular Disease Risk Factors: A Systematic Review

Consuming fat results in postprandial lipemia, which is defined as an increase in blood triglyceride (TG) concentration. According to current knowledge, an excessively elevated postprandial TG concentration increases the risk of cardiovascular disease (CVD). It is well known that meal-dependent (e.g., nutrient composition) as well as meal-independent factors (e.g., age) determine the magnitude of the lipemic response. However, there is conflicting evidence concerning the influence of fatty acid (FA) composition on postprandial TG concentration. The FA composition of a meal depends on the fat source used; for example, butter and coconut oil are rich in SFAs, while olive oil and canola oil have a high content of unsaturated FAs. To investigate the influence of meals prepared with fat sources rich in either SFAs or unsaturated FAs on postprandial lipemia, we carried out a systematic literature search in PubMed, Scopus, and the Cochrane Library. Randomized crossover studies were analyzed and the AUC of postprandial TG concentration served as the primary outcome measure. To examine the influence of health status, we differentiated between metabolically healthy individuals and those with CVD risk factors. In total, 23 studies were included. The results show that, in metabolically healthy adults, the FA composition of a meal is not a relevant determinant of postprandial lipemia. However, in individuals with CVD risk factors, SFA-rich meals (>32 g SFA/meal) often elicited a stronger lipemic response than meals rich in unsaturated FAs. The results suggest that adults with hypertriglyceridemia, an elevated BMI (≥30 kg/m2), and/or who are older (>40 y) may benefit from replacing SFA sources with unsaturated FAs. These hypotheses need to be verified by further studies in people with CVD risk factors using standardized postprandial protocols. This review was registered in PROSPERO as CRD42021214508 (https://www.crd.york.ac.uk/prospero/).

Fatty acids and their role in type-2 diabetes (Review)

Age, lifestyle and diet are major risk factors for the onset of type 2 diabetes mellitus (T2DM). Insulin resistance (IR) and β-cell dysfunction underlie the pathophysiology of T2DM. Diabetic populations are also prone to lipid and lipoprotein abnormalities as an indirect effect of IR on key metabolic enzymes. However, recent studies suggested that lipid changes may not only be a consequence of impaired glucose metabolism but also a causative factor. Fatty acids (FAs) influence translocation of glucose transporters and insulin receptor binding and signalling, in addition to cell membrane fluidity and permeability. It is thus suggested that FAs may have an essential role in the development of IR and T2DM. Specific combinations of FAs within phospholipids and triglycerides were indicated to exhibit the strongest associations with the risk of T2DM. The aim of the present review was to investigate the role of FAs in the pathogenesis of T2DM, as it has yet to be fully elucidated.

Effects of cashew nut consumption on body composition and glycemic indices: A meta-analysis and systematic review of randomized controlled trials

BACKGROUND AND AIMS

Present meta-analysis and systematic review was conducted to synthesis a definitive conclusion from previous randomized controlled clinical trials (RCTs).

METHODS

A comprehensive search was done up to July 2020, in order to extract RCTs which investigated the effect of cashew nut on weight, body mass index (BMI), waist circumference (WC), fasting blood sugar (FBS), insulin, and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). Weighted mean difference (WMD) and 95% confidence interval (CI) were used to estimate effect size. Meta regression analysis was done to identify probable sources of heterogeneity.

RESULTS

Six clinical trials with 521 participants were included. Combined effect sizes demonstrated no effect of cashew consumption on weight (WMD): 0.02, 95% CI: -1.04, 1.09, P > 0.05), BMI (WMD: 0.1, 95% CI: -0.72, 0.74, P > 0.05), and WC (WMD: -0.13, 95% CI: -1.97, 1.70, P > 0.05). Results were also not significant for FBS (WMD: 3.58, 95% CI: -3.92, 11.08, P > 0.05), insulin (WMD: -0.19, 95% CI: -1.63, 1.25, P > 0.05), and HOMA-IR (WMD: 0.25, 95% CI: -0.55, 1.06, P > 0.05).

CONCLUSION

The sum up, incorporating cashew into the diet has no significant effect on body composition or modifying glycemic indices.

Dietary Fatty Acids in Postprandial Triglyceride-Rich Lipoproteins Modulate Human Monocyte-Derived Dendritic Cell Maturation and Activation

Dietary fatty acids have been demonstrated to modulate systemic inflammation and induce the postprandial inflammatory response of circulating immune cells. We hypothesized that postprandial triglyceride-rich lipoproteins (TRLs) may have acute effects on immunometabolic homeostasis by modulating dendritic cells (DCs), sentinels of the immunity that link innate and adaptive immune systems. In healthy volunteers, saturated fatty acid (SFA)-enriched meal raised serum levels of granulocyte/macrophage colony-stimulating factor GM-CSF (SFAs > monounsaturated fatty acids (MUFAs) = polyunsaturated fatty acids (PUFAs)) in the postprandial period. Autologous TRL-SFAs upregulated the gene expression of DC maturation (CD123 and CCR7) and DC pro-inflammatory activation (CD80 and CD86) genes while downregulating tolerogenic genes (PD-L1 and PD-L2) in human monocyte-derived DCs (moDCs). These effects were reversed with oleic acid-enriched TRLs. Moreover, postprandial SFAs raised IL-12p70 levels, while TRL-MUFAs and TRL-PUFAs increased IL-10 levels in serum of healthy volunteers and in the medium of TRL-treated moDCs. In conclusion, postprandial TRLs are metabolic entities with DC-related tolerogenic activity, and this function is linked to the type of dietary fat in the meal. This study shows that the intake of meals enriched in MUFAs from olive oil, when compared with meals enriched in SFAs, prevents the postprandial production and priming of circulating pro-inflammatory DCs, and promotes tolerogenic response in healthy subjects. However, functional assays with moDCs generated in the presence of different fatty acids and T cells could increase the knowledge of postprandial TRLs’ effects on DC differentiation and function.

ω-6/ω-3 fatty acid ratio as an essential predictive biomarker in the management of type 2 diabetes mellitus

OBJECTIVES

Intake of dietary fatty acid may play a major role in the prevention and management of lifestyle-related diseases such as type 2 diabetes mellitus (T2DM). Therefore, the aim of this study was to find an association between ω-6 to ω-3 fatty acid ratio and T2DM.

METHODS

Fasting plasma glucose, glycated hemoglobin, and insulin were measured using commercially available kits. Fatty acid methyl esters were prepared using standard protocols. Delta-5 desaturase (D5D) and delta-6 desaturase (D6D) activities were determined from product-to-precursor ratios of individual fatty acids in plasma. Statistical analysis was performed using SPSS version 20.

RESULTS

The ratio of ω-6 to ω-3 was higher in the group with diabetes (13:1) when compared with the group without diabetes (4:1) and was statistically significant (P < 0.0001). Further association studies showed that univariate model with the ω-6 to ω-3 ratio and a multivariate model with D5D, D6D, and ω-6 to ω-3 ratio could serve as predictive polyunsaturated fatty acid pathway models for T2DM.

CONCLUSIONS

From the study results, it is evident that ω-6 to ω-3 fatty acid ratios can serve as essential predictive biomarkers in the management of patients with T2DM. This would not only help in management but would also aid in prevention of increased T2DM incidence in India. These results potentiate the need to maintain an ideal balance of ω-6 to ω-3, as prevention is always better than cure.

The Influence of Different Foods and Food Ingredients on Acute Postprandial Triglyceride Response: A Systematic Literature Review and Meta-Analysis of Randomized Controlled Trials

The use of postprandial triglyceride (ppTG) as a cardiovascular disease risk indicator has gained recent popularity. However, the influence of different foods or food ingredients on the ppTG response has not been comprehensively characterized. A systematic literature review and meta-analysis was conducted to assess the effects of foods or food ingredients on the ppTG response. PubMed, MEDLINE, Cochrane, and CINAHL databases were searched for relevant acute (<24-h) randomized controlled trials published up to September 2018. Based on our selection criteria, 179 relevant trials (366 comparisons) were identified and systematically compiled into distinct food or food ingredient categories. A ppTG-lowering effect was noted for soluble fiber (Hedges' giAUC = -0.72; 95% CI: -1.33, -0.11), sodium bicarbonate mineral water (Hedges' gAUC = -0.42; 95% CI: -0.79, -0.04), diacylglycerol oil (Hedges' giAUC = -0.38; 95% CI: -0.75, -0.00), and whey protein when it was contrasted with other proteins. The fats group showed significant but opposite effects depending on the outcome measure used (Hedges' giAUC = -0.32; 95% CI: -0.61, -0.03; and Hedges' gAUC = 0.16; 95% CI: 0.06, 0.26). Data for other important food groups (nuts, vegetables, and polyphenols) were also assessed but of limited availability. Assessing for oral fat tolerance test (OFTT) recommendation compliance, most trials were ≥4 h long but lacked a sufficiently high fat challenge. iAUC and AUC were more common measures of ppTG. Overall, our analyses indicate that the effects on ppTG by different food groups are diverse, largely influenced by the type of food or food ingredient within the same group. The type of ppTG measurement can also influence the response.

Acute Effects of Three Different Meal Patterns on Postprandial Metabolism in Older Individuals with a Risk Phenotype for Cardiometabolic Diseases: A Randomized Controlled Crossover Trial

SCOPE

The aim of this study is to investigate acute postprandial responses to intake of meals typical for Mediterranean and Western diets.

METHODS

In a randomized crossover design, overweight and obese participants with a risk phenotype for cardiometabolic diseases consumed three different isoenergetic meals: Western diet-like high-fat (WDHF), Western diet-like high-carbohydrate (WDHC), and Mediterranean diet (MED) meal. Blood samples are collected at fasting and 1, 2, 3, 4, 5 h postprandially and analyzed for parameters of lipid and glucose metabolism, inflammation, oxidation, and antioxidant status.

RESULTS

Compared to MED and WDHF meals, intake of a WDHC meal results in prolonged and elevated increases in glucose and insulin. Elevations for triglycerides are enhanced after the WDHF meal compared to the MED and the WDHC meal. Glucagon-like peptide-1 and interleukin-6 increase postprandially without meal differences. Apart from vitamin C showing an increase after the MED meal and a decrease after WDHF and WDHC meals, antioxidant markers decrease postprandially without meal differences. Plasma interleukin-1β is not affected by meal intake.

CONCLUSIONS

Energy-rich meals induce hyperglycemia, hyperlipemia, an inflammatory response, and a decrease in antioxidant markers. A meal typical for the Mediterranean diet results in favorable effects on glycemic, insulinemic, and lipemic responses.

Effects of fatty acids composition in a breakfast meal on the postprandial lipid responses: a systematic review and meta-analysis of randomised controlled trials

Replacement of food rich in saturated fatty acids (SFAs) with unsaturated fatty acids (UFAs) is a well-known dietary strategy to reduce the risk of cardiovascular disease while its impact on postprandial blood lipids is less examined. This study assessed the effects of fatty acids composition on the postprandial triglycerides and cholesterol responses. Seventeen randomised controlled trials were identified and pooled analysis results revealed that consumption of a UFAs-rich or an SFAs-rich breakfast meal did not acutely affect postprandial triglycerides and cholesterol responses. However, subgroup analysis observed that triglycerides incremental area under the curve was lower with an SFAs-rich meal (SMD: -0.36; 95% CI: -0.57, -0.15) over a less than 8 h duration, while was higher (SMD: 0.59; 95% CI: 0.05, 1.23) over a longer postprandial duration. It suggests that the postprandial duration is of importance when evaluating the effects of fatty acids composition on blood lipid responses.

Relationship Between the Consumption of Milk-Based Oils Including Butter and Kermanshah Ghee with Metabolic Syndrome: Ravansar Non-Communicable Disease Cohort Study

BACKGROUND

The prevalence of metabolic syndrome (MetS) in recent years has been growing in different societies, which may be due to lifestyle changes including changes in diet, in particular the consumption pattern of edible oils. The purpose of this study was to investigate the relationship between the consumption of animal oils including butter and Kermanshah ghee with MetS and its components in the adult population of Ravansar Non-Communicable Disease (RaNCD) cohort study.

METHODS

This cross-sectional study was carried out on 5550 adults aged 35-65 years using baseline data of Ravansar's prospective study center in Iran. MetS was defined according to the criteria of modified NCEP ATP III for Iranian adults. Relationship between the consumption of butter and Kermanshah ghee and MetS was analyzed by logistic regression model using STATA software.

RESULTS

In our study, the frequency of MetS was 31.40%. The mean body mass index and mean age were 27.1±4.6 kg/m² and 47.6±8.2 years. The mean values of consumed butter and Kermanshah ghee were 3.3±1.8 and 5.1±2.3 g/day, respectively. After adjusting the confounding variables, the highest to the lowest quintile of butter and Kermanshah ghee consumption showed a reverse correlation with the MetS (OR = 0.7, 95% CI = 0.5-0.9) and (OR= 0.7, 95% CI=0.6-0.9), respectively.

CONCLUSION

This study revealed a reverse relationship between milk and Kermanshah ghee consumption with MetS and its components. Therefore, consumption of milk-based oils may be associated with lower cardiovascular risk factors.

Microstructure of starch-based meals with either palm or soybean oils alter in vitro starch digestibility with no major effects on glycaemic responses

Glycaemic response (GR) to starch-based meals depends on their food composition and microstructure. We studied the effect of palm and soybean oils on the microstructure of a solid starch-oil-gluten matrix, on the starch gelatinisation and in vitro digestibility. Additionally, a pilot cross-over study was carried out to assess GR after eating gelatinised starch/gluten-based foods with the addition of either palm or soybean oil in 8 young non-diabetic female volunteers (ISRCTN39636850). Both types of foods generated similar starch gelatinisation temperature. Starch/gluten-based food with soybean oil had rougher microstructure compared to food with palm oil, showing a higher initial and lower final in vitro digestion. Administration of starch/gluten-based meals with either palm or soybean oils to volunteers show very similar postprandial glucose or insulin responses. In conclusion, differences in fatty acid composition changes food microstructure and in vitro starch digestibility, with no major effects on glycaemic responses in female volunteers.

Macronutrient intake and physical activity levels in individuals with and without metabolic syndrome: An observational study in an urban population

BACKGROUND

We aimed to compare dietary macronutrient intake and physical activity level (PAL) between community-based samples of Iranian adults with metabolic syndrome (MetS+) and without metabolic syndrome (MetS-).

METHODS

This cross-sectional study was conducted among 3800 men and women aged 35-65 years. The International Diabetes Federation (IDF) criteria were used to define MetS. A 24-hour recall was used to evaluate dietary intake. The James and Schofield human energy requirements equations were used to calculate PAL and questions were categorized into time spent on activities during work (including housework), during non-work time, and in bed.

RESULTS

The mean ± standard deviation (SD)age of the MetS+ and MetS- subjects was, respectively, 48.8 ± 7.8 years (521 men and 1178 women) and 47.6 ± 7.5 years (714 men and 1222 women) (P = 0.930). The mean energy intake was higher in the MetS+ men compared with MetS- men (1977.4 ± 26.6 vs. 1812.7 ± 21.7 Kcal; P < 0.001). Crude and energy-adjusted intake from total fat was lower in MetS+ women compared with MetS- women (both P < 0.010). PALs were lower in MetS+ compared with MetS- participants (P < 0.001). After adjusting for confounders, no significant association was observed between the intake of individual macronutrients and MetS. In contrast, PAL was inversely associated with the incidence of MetS [OR = 0.34 (95% CI: 0.17-0.57); P < 0.001].

CONCLUSION

In the current study, there was an inverse relationship between PAL and the risk of MetS, but no association between individual dietary macronutrients intake and the incidence of MetS.

Mediterranean diet and health status: Active ingredients and pharmacological mechanisms

The Mediterranean diet (MedDiet) is one of the most widely described and evaluated dietary patterns in scientific literature. It is characterized by high intakes of vegetables, legumes, fruits, nuts, grains, fish, seafood, extra virgin olive oil, and a moderate intake of red wine. A large body of observational and experimental evidence suggests that higher adherence to the MedDiet is associated with lower risk of mortality, cardiovascular disease, metabolic disease, and cancer. Current mechanisms underlying the beneficial effects of the MedDiet include reduction of blood lipids, inflammatory and oxidative stress markers, improvement of insulin sensitivity, enhancement of endothelial function, and antithrombotic function. Most likely, these effects are attributable to bioactive ingredients such as polyphenols, monounsaturated and polyunsaturated fatty acids, or fibre. This review will focus on both established and less established mechanisms of action of biochemical compounds contained in a MedDiet. LINKED ARTICLES: This article is part of a themed section on The Pharmacology of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.6/issuetoc.

Determination of glycemic index of enteral formulas used in clinical practice

Glycemic Index (GI) is a measure of carbohydrate quality and is recognised as a valid and reproducible method of classifying carbohydrate foods according to its effects on postprandial glycaemia. In this randomised crossover trial (RBR-7rjx3k) we determined the GI of nine enteral formulas, following the Food and Agriculture Organisation/World Health Organisation method. Forty healthy participants were included in the study (85% female mean age 27.1 ± 6.7 years). GI of the enteral formulas ranged from 40.5 to 85.2; four formulas had high GI (Nutrienteral 1.5^®, Novasource GI Control^®, Diamax^®, Isosource Soya^®), two intermediate GI (Fresubin 1.2 HP Fibre^®, Nutrison Energy Multifiber 1.5^®) and three low GI (Trophic 1.5^®, Glucerna^®, Novasource GC HP^®). The GI coefficient of variation ranged from 22.9% to 83.6%. The effect of the enteral formulas with low GI in glycemic control of patients with enteral nutrition prescription needs to be test in future studies.

A 7-day high-PUFA diet reduces angiopoietin-like protein 3 and 8 responses and postprandial triglyceride levels in healthy females but not males: a randomized control trial

BACKGROUND

Polyunsaturated fatty acids (PUFAs) have beneficial effects on hypertriglyceridemia although their effect on angiopoietin-like proteins (ANGPTLs), specifically ANGPTL3, ANGPTL4 and ANGPTL8 is unknown.

OBJECTIVE

To determine whether a high-PUFA diet improves postprandial triglyceride (TG) levels through reducing ANGPTL responses following high saturated fat (SFA) meals.

METHODS

Twenty-six adults were randomized into a PUFA diet (n = 16) or a control diet group (n = 10). Participants completed a pre-diet visit (v1) where they were given two SFA-rich, high-fat meals. Blood draws were taken at fasting and every 2 h postprandially for a total of 8 h. After v1, participants completed a 7d diet of the same macronutrient proportions (50% carbohydrate, 35% fat, 15% protein) but with different fatty acid (FA) compositions (PUFA = 21% of total energy from PUFAs vs. Control = 7% of total energy from PUFA). All participants then completed the post-diet visit (v2) identical to v1.

RESULTS

In the PUFA group, females, but not males, reduced TG concentrations (Area under the curve (AUC): 141.2 ± 18.7 vs. 80.7 ± 6.5 mg/dL/h, p = 0.01, for v1 vs. v2, respectively). Fasting and postprandial AUC levels of ANGPTL3 and 8, but not ANGPTL4, also decreased from v1 to v2 in PUFA females, but not males. No changes from v1 to v2 were seen in either sex in the control group.

CONCLUSIONS

A PUFA-rich diet improves TG levels in response to high-SFA meals with reductions in ANGPTL3 and ANGPTL8. PUFAs may be more protective against hypertriglyceridemia in females, compared to males since no diet effect was observed in males.

TRIAL REGISTRATION

NCT02246933.

Ectopic Fat Accumulation in Distinct Insulin Resistant Phenotypes; Targets for Personalized Nutritional Interventions

Cardiometabolic diseases are one of the leading causes for disability and mortality in the Western world. The prevalence of these chronic diseases is expected to rise even further in the next decades. Insulin resistance (IR) and related metabolic disturbances are linked to ectopic fat deposition, which is the storage of excess lipids in metabolic organs such as liver and muscle. Notably, a vicious circle exists between IR and ectopic fat, together increasing the risk for the development of cardiometabolic diseases. Nutrition is a key-determining factor for both IR and ectopic fat deposition. The macronutrient composition of the diet may impact metabolic processes related to ectopic fat accumulation and IR. Interestingly, however, the metabolic phenotype of an individual may determine the response to a certain diet. Therefore, population-based nutritional interventions may not always lead to the most optimal (cardiometabolic) outcomes at the individual level, and differences in the metabolic phenotype may underlie conflicting findings related to IR and ectopic fat in dietary intervention studies. Detailed metabolic phenotyping will help to better understand the complex relationship between diet and metabolic regulation, and to optimize intervention outcomes. A subgroup-based approach that integrates, among others, tissue-specific IR, cardiometabolic parameters, anthropometrics, gut microbiota, age, sex, ethnicity, and psychological factors may thereby increase the efficacy of dietary interventions. Nevertheless, the implementation of more personalized nutrition may be complex, costly, and time consuming. Future studies are urgently warranted to obtain insight into a more personalized approach to nutritional interventions, taking into account the metabolic phenotype to ultimately improve insulin sensitivity and reduce the risk for cardiometabolic diseases.

Transcriptome Analyses Reveal Adult Metabolic Syndrome With Intrauterine Growth Restriction in Pig Models

Epidemiological data have indicated that intrauterine growth retardation (IUGR) is a risk factor for the adult metabolic syndrome in pigs. However, the causative genetic mechanism leading to the phenotype in adulthood has not been well characterized. In the present study, both normal and IUGR adult pigs were used as models to survey the differences in global gene expression in livers through transcriptome sequencing. The transcriptome libraries generated 104.54 gb of data. In normal and IUGR pigs, 16,948 and 17,078 genes were expressed, respectively. A total of 1,322 differentially expressed genes (DEGs) were identified. Enrichment analysis of the DEGs revealed that the top overrepresented gene ontology (GO) terms and pathways were related to oxidoreductase activity, ATPase activity, amino catabolic process, glucose metabolism, and insulin signaling pathway. The increased gluconeogenesis (GNG) and decreased glycogen synthesis in the liver contributed to the glucose intolerance observed in IUGR. The reduced expression of insulin signaling genes (such as PI3K and AKT) indicated an elevated risk of diabetes in adulthood. Together, these findings provide a comprehensive understanding of the molecular mechanisms of adult IUGR pigs and valuable information for future studies of therapeutic intervention in IUGR metabolic syndrome.

Association of Fast-Food and Full-Service Restaurant Densities With Mortality From Cardiovascular Disease and Stroke, and the Prevalence of Diabetes Mellitus

BACKGROUND

We explored whether higher densities of fast-food restaurants (FFRs) and full-service restaurants are associated with mortality from cardiovascular disease (CVD) and stroke and the prevalence of type 2 diabetes mellitus (T2D) across the mainland United States.

METHODS AND RESULTS

In this cross-sectional study county-level data for CVD and stroke mortality, and prevalence of T2D, were combined with per capita densities of FFRs and full-service restaurants and analyzed using regression. Mortality and diabetes mellitus prevalence were corrected for poverty, ethnicity, education, physical inactivity, and smoking. After adjustment, FFR density was positively associated with CVD (β=1.104, R²=2.3%), stroke (β=0.841, R²=1.4%), and T2D (β=0.578, R²=0.6%) and full-service restaurant density was positively associated with CVD mortality (β=0.19, R²=0.1%) and negatively related to T2D prevalence (β=-0.25, R²=0.3%). In a multiple regression analysis (FFRs and full-service restaurants together in same model), only the densities of FFRs were significant (and positive). If we assume these relationships are causal, an impact analysis suggested that opening 10 new FFRs in a county would lead to 1 extra death from CVD every 42 years and 1 extra death from stroke every 55 years. Repeated nationally across all counties, that would be an extra 748 CVD deaths and 567 stroke deaths (and 390 new cases of T2D) over the next 10 years.

CONCLUSIONS

These results suggest that an increased density of FFRs is associated with increased risk of death from CVD and stroke and increased T2D prevalence, but the maximal impact (assuming the correlations reflect causality) of each individual FFR is small.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT03243253.

Adherence to the Qatar dietary guidelines: a cross-sectional study of the gaps, determinants and association with cardiometabolic risk amongst adults

Background

The Qatar Dietary Guidelines (QDGs) were developed as part of the national strategy to prevent chronic diseases. This study aims at characterizing gaps between the QDGs and usual dietary and lifestyle patterns in Qatar, identifying demographic and socioeconomic determinants of adherence to the QDGs and investigating the association between adherence and cardiometabolic risk.

Methods

This study is based on the Qatar National STEPwise cross-sectional survey which was conducted on a nationally representative sample of Qatari adults, aged 18 to 64 years (n = 1109). Data collection included socio-demographic characteristics, lifestyle factors, anthropometric (weight, height and waist circumference (WC)), and blood pressure measurements. The dietary intake of participants was evaluated using a non-quantitative food frequency questionnaire (FFQ). Biochemical assessment was performed to measure the fasting levels of blood sugar, triglycerides (TG) and HDL cholesterol. The metabolic syndrome (MetS) was defined as the presence of three or more cardiometabolic risk factors. To examine adherence to the guidelines, each specifc recommendation was matched to corresponding data drawn from the survey. To investigate the association of sociodemographic, lifestyle and cardiometabolic characteristics with adherence to the QDGs, an adherence score was calculated.

Results

More than 83% of adults did not meet the recommendations for vegetables, fruits, whole grains, legumes and high fibre intakes, 70% were overweight or obese, 50–72% reported frequent consumption of sweetened beverages and sweets, and 47% reported frequent consumption of fast foods. Younger adults, the unemployed, the least educated and those not married had lower adherence to the QDGs. Adherence was inversely associated with elevated WC (OR: 0.88, 95% CI:0.82–0.95) and the MetS (OR:0.84,95% CI:0.74–0.96).

Conclusions

Building on the identified gaps and vulnerable population groups, the study findings should provide a road map for the prioritization of interventions and the development of culture- specific programs aiming at promoting adherence to dietary guidelines in Qatar, while serving as a model to other countries in the region.

Effects of immediate-release niacin and dietary fatty acids on acute insulin and lipid status in individuals with metabolic syndrome

BACKGROUND

The nature of dietary fats profoundly affects postprandial hypertriglyceridemia and glucose homeostasis. Niacin is a potent lipid-lowering agent. However, limited data exist on postprandial triglycerides and glycemic control following co-administration of high-fat meals with a single dose of niacin in subjects with metabolic syndrome (MetS). The aim of the study was to explore whether a fat challenge containing predominantly saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) or MUFAs plus omega-3 long-chain polyunsaturated (LCPUFAs) fatty acids together with a single dose of immediate-release niacin have a relevant role in postprandial insulin and lipid status in subjects with MetS.

RESULTS

In a randomized crossover within-subject design, 16 men with MetS were given a single dose of immediate-release niacin (2 g) and ∼15 cal kg^-1 body weight meals containing either SFAs, MUFAs, MUFAs plus omega-3 LCPUFAs or no fat. At baseline and hourly over 6 h, plasma glucose, insulin, C-peptide, triglycerides, free fatty acids (FFAs), total cholesterol, and both high- and low-density lipoprotein cholesterol were assessed. Co-administered with niacin, high-fat meals significantly increased the postprandial concentrations of glucose, insulin, C-peptide, triglycerides, FFAs and postprandial indices of β-cell function. However, postprandial indices of insulin sensitivity were significantly decreased. These effects were significantly attenuated with MUFAs or MUFAs plus omega-3 LCPUFAs when compared with SFAs.

CONCLUSION

In the setting of niacin co-administration and compared to dietary SFAs, MUFAs limit the postprandial insulin, triglyceride and FFA excursions, and improve postprandial glucose homeostasis in MetS. © 2017 Society of Chemical Industry.

Reducing Cholesterol and Fat Intake Improves Glucose Tolerance by Enhancing β Cell Function in Nondiabetic Subjects

CONTEXT

A diet low in cholesterol and fat is commonly recommended to prevent metabolic and cardiovascular diseases; however, its effect on glucose tolerance is largely unknown.

OBJECTIVE

We examined whether and by which mechanisms a chronic reduction of cholesterol and fat intake affects glucose tolerance in nondiabetic individuals, independently of weight changes.

DESIGN AND PARTICIPANTS

In this crossover, randomized clinical trial, 30 healthy subjects, including 15 with family history of type 2 diabetes (T2D) (T2D offspring), underwent a 75-g oral glucose tolerance test (OGTT) after two 14-day isocaloric high-cholesterol, high-fat (HChF) or low-cholesterol, and low-fat (LChF) diets.

MAIN OUTCOME MEASURES

We evaluated changes in glucose tolerance, β cell function, insulin clearance, and insulin sensitivity by modeling plasma glucose, insulin, and C-peptide levels during the OGTT.

RESULTS

The shift from the HChF to the LChF diet was neutral on body weight but increased glucose tolerance (mean glucose -5%, P = 0.01) and three components of β cell function: glucose sensitivity (+17%, P = 0.01), insulin secretion at fasting glucose (+20%, P = 0.02), and potentiation (+19%, P = 0.03). The LChF diet improved insulin sensitivity (+7%, P = 0.048) only in T2D offspring, who tended to be more susceptible to the positive effect of the diet on glucose tolerance.

CONCLUSIONS

A chronic and isocaloric decrease in dietary cholesterol and fat intake improves glucose tolerance by diffusely ameliorating β cell function in nondiabetic subjects. Individuals genetically predisposed to develop T2D tend to be more susceptible to the positive effect of this dietary intervention on glucose tolerance and insulin sensitivity.

Association of Dietary Patterns with Components of Metabolic Syndrome and Inflammation among Middle-Aged and Older Adults with Metabolic Syndrome in Taiwan

This study examined the correlation of dietary patterns with components of metabolic syndrome (MetS) and inflammation among middle-aged and older adults with MetS in Taiwan. This cross-sectional study used data from the Mei Jau International Health Management Institution in Taiwan between 2004 and 2013. A total of 26,016 subjects aged 35 years and above were selected for analysis. MetS was defined according to the International Diabetes Federation. Three dietary patterns were identified by principal component analysis. High intake of a meat–instant food dietary pattern (rich in animal protein, saturated fat, sweets, sodium, and food additives) was positively associated with components of MetS and C-reactive protein (CRP), while high intake of a vege–seafood dietary pattern (rich in dietary fiber, vitamins, minerals, and unsaturated fat) or a cereal–dairy dietary pattern (rich in dietary fiber, antioxidants, phytochemicals, complex carbohydrate, prebiotics, and probiotics) was inversely associated with components of MetS and CRP. Our findings suggested that intake of a vege–seafood dietary pattern or a cereal–dairy dietary pattern decreased the risk of developing MetS and inflammation among middle-aged and older adults with MetS.

Olive oil and postprandial hyperlipidemia: implications for atherosclerosis and metabolic syndrome

Olive oil is the primary source of fat in the Mediterranean diet, which is associated with a significant improvement in health status, as measured by reduced mortality from several chronic diseases. The current pandemic of obesity, metabolic syndrome, and type 2 diabetes is intimately associated with an atherogenic dyslipidemic phenotype. The core components of the dyslipidemia of the metabolic syndrome, which most likely initiate atherosclerosis, are the "lipid triad" consisting of high plasma triglycerides, low levels of high-density lipoproteins, and a preponderance of small, dense low-density lipoproteins at fasting. However, postprandial (non-fasting) TGs (postprandial hyperlipidemia) are also recognized as an important component for atherosclerosis. Herein, the purpose of this review was to provide an update on the effects and mechanisms related to olive oil on postprandial hyperlipidemia and its implications for the onset and progression of atherosclerosis and metabolic syndrome.

High Fat Diet with a High Monounsaturated Fatty Acid and Polyunsaturated/Saturated Fatty Acid Ratio Suppresses Body Fat Accumulation and Weight Gain in Obese Hamsters

The aim of this study was to investigate the effect of a high fat diet with experimental oil consisting of 60% MUFAs (monounsaturated fatty acids) with a P/S ratio of 5 on fat deposition and lipid metabolism in obese hamsters. Hamsters were randomly assigned to a control group and a diet-induced obesity group for nine weeks. Then an additional eight-week experimental period began, during which obese hamsters were randomly divided into three groups and fed different amounts of the experimental oil mixture in their diets as follows: 5%, 15%, and 20% w/w (OB-M5, OB-M15, and OB-M20 groups, respectively). The results showed that the OB-M15 and OB-M20 groups had significantly lower blood cholesterol and higher insulin levels. Compared to the control group, the three obese groups exhibited higher hepatic fatty acid synthase activity; however, the acyl-CoA oxidase activities were also enhanced. Although dietary fat content differed, there were no differences in energy intake, final body weights, and epididymal fat weights among the four groups. These results suggest that regardless of whether the specimens had a high fat intake or not, dietary fat containing high MUFAs with a high P/S ratio had beneficial effects on maintaining blood lipid profiles and may not result in body fat accumulation in obese hamsters, possibly by promoting lipolytic enzyme activities.

A minimally processed dietary pattern is associated with lower odds of metabolic syndrome among Lebanese adults

OBJECTIVE

To (i) estimate the consumption of minimally processed, processed and ultra-processed foods in a sample of Lebanese adults; (ii) explore patterns of intakes of these food groups; and (iii) investigate the association of the derived patterns with cardiometabolic risk.

DESIGN

Cross-sectional survey. Data collection included dietary assessment using an FFQ and biochemical, anthropometric and blood pressure measurements. Food items were categorized into twenty-five groups based on the NOVA food classification. The contribution of each food group to total energy intake (TEI) was estimated. Patterns of intakes of these food groups were examined using exploratory factor analysis. Multivariate logistic regression analysis was used to evaluate the associations of derived patterns with cardiometabolic risk factors.

SETTING

Greater Beirut area, Lebanon.

SUBJECTS

Adults ≥18 years (n 302) with no prior history of chronic diseases.

RESULTS

Of TEI, 36·53 and 27·10 % were contributed by ultra-processed and minimally processed foods, respectively. Two dietary patterns were identified: the 'ultra-processed' and the 'minimally processed/processed'. The 'ultra-processed' consisted mainly of fast foods, snacks, meat, nuts, sweets and liquor, while the 'minimally processed/processed' consisted mostly of fruits, vegetables, legumes, breads, cheeses, sugar and fats. Participants in the highest quartile of the 'minimally processed/processed' pattern had significantly lower odds for metabolic syndrome (OR=0·18, 95 % CI 0·04, 0·77), hyperglycaemia (OR=0·25, 95 % CI 0·07, 0·98) and low HDL cholesterol (OR=0·17, 95 % CI 0·05, 0·60).

CONCLUSIONS

The study findings may be used for the development of evidence-based interventions aimed at encouraging the consumption of minimally processed foods.

The impact of triglycerides on glucose tolerance: Lipotoxicity revisited

Elevated plasma triglycerides (TGs) are early key features of conditions associated with a dysregulation in glucose metabolism and may predict the development of type 2 diabetes (T2D) over time. Although the acute ingestion of lipid, either mixed with or shortly before the meal, is neutral or slightly beneficial on glucose tolerance, a short-term increase in plasma TGs induced by either an i.v. lipid infusion or a high-fat diet produces a deterioration of glucose control. Accordingly, chronic lowering of plasma TGs by fibrates improves glucose homeostasis and may also prevent T2D. The chronic effects of the elevation of dietary lipid intake are less clear, particularly in humans, being the quality of fat probably more important than total fat intake. Although on the bases of the available experimental and clinical evidence it cannot be easily disentangled, with respect to elevated non-esterified fatty acids (NEFA) the relative contribution of elevated TGs to glucose homeostasis disregulation seems to be greater and also more plausible. In conclusion, although the association between elevated plasma TGs and impaired glucose tolerance is commonly considered not causative or merely a consequence of NEFA-mediated lipotoxicity, the available data suggest that TGs per se may directly contribute to disorders of glucose metabolism.

Lipids as central modulators of sensory TRP channels

The transient receptor potential (TRP) ion channel family is involved in a diversity of physiological processes including sensory and homeostatic functions, as well as muscle contraction and vasomotor control. Their dysfunction contributes to the etiology of several diseases, being validated as therapeutic targets. These ion channels may be activated by physical or chemical stimuli and their function is highly influenced by signaling molecules activated by extracellular signals. Notably, as integral membrane proteins, lipid molecules also modulate their membrane location and function either by direct interaction with the channel structure or by modulating the physico-chemical properties of the cellular membrane. This lipid-based modulatory effect is being considered an alternative and promising approach to regulate TRP channel dysfunction in diseases. Here, we review the current progress in this exciting field highlighting a complex channel regulation by a large diversity of lipid molecules and suggesting some diseases that may benefit from a membrane lipid therapy. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.

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

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

Impact of the Content of Fatty Acids of Oral Fat Tolerance Tests on Postprandial Triglyceridemia: Systematic Review and Meta-Analysis

Whether the content of saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA) could differently influence postprandial triglycerides (TG) is unknown. We examined possible differences in the postprandial TG response to fat tolerance tests (FTTs), in which SFA or unsaturated fatty acids were used. Crossover clinical trials investigating the effects of FTTs containing SFA and unsaturated fats on postprandial triglyceridemia in databases from 1994 until 2016 were searched. Of 356 studies, 338 were excluded and 18 were considered. TG net incremental areas under the curve were calculated using time-points or changes from baseline. Pooled effects of standardized mean differences and I² test were used.

RESULTS

In 12 studies, responses to SFA versus PUFA meals, and in 16 studies versus MUFA meals were compared. Over 4 hours, no differences between SFA and unsaturated fats were observed. Over 8 hours a lower response to PUFA (SMD -2.28; 95%CI -4.16, -0.41) and a trend to lower response to MUFA (SMD -0.89, 95%CI -1.82, 0.04) were detected. FTTs shorter than 8 hours may not be sufficient to differentiate postprandial TG after challenges with distinct fatty acids. Clinical significance of different postprandial TG responses on cardiovascular risk in the long-term deserves investigation.

The amount and types of fatty acids acutely affect insulin, glycemic and gastrointestinal peptide responses but not satiety in metabolic syndrome subjects

PURPOSE

Limited clinical evidence is available on the effects of amount and types of dietary fats on postprandial insulinemic and gastrointestinal peptide responses in metabolic syndrome subjects. We hypothesized that meals enriched with designated: (1) amount of fats (50 vs 20 g), (2) fats with differing fatty acid composition (saturated, SFA; monounsaturated, MUFA or n-6 polyunsaturated fatty acids, PUFA) would affect insulinemic and gastrointestinal peptide releases in metabolic syndrome subjects.

METHODS

Using a randomized, crossover and double-blinded design, 15 men and 15 women with metabolic syndrome consumed high-fat meals enriched with SFA, MUFA or n-6 PUFA, or a low-fat/high-sucrose (SUCR) meal. C-peptide, insulin, glucose, gastrointestinal peptides and satiety were measured up to 6 h.

RESULTS

As expected, SUCR meal induced higher C-peptide (45 %), insulin (45 %) and glucose (49 %) responses compared with high-fat meals regardless of types of fatty acids (P < 0.001). Interestingly, incremental area under the curve (AUC_0-120min) for glucagon-like peptide-1 was higher after SUCR meal compared with MUFA (27 %) and n-6 PUFA meals (23 %) (P = 0.01). AUC_0-120min for glucose-dependent insulinotropic polypeptide was higher after SFA meal compared with MUFA (23 %) and n-6 PUFA meals (20 %) (P = 0.004). Significant meal x time interaction (P = 0.007) was observed for ghrelin, but not cholecystokinin and satiety.

CONCLUSIONS

The amount of fat regardless of the types of fatty acids affects insulin and glycemic responses. Both the amount and types of fatty acids acutely affect the gastrointestinal peptide release in metabolic syndrome subjects, but not satiety.

Metabolically Healthy Overweight and Obesity Is Associated with Higher Adherence to a Traditional Dietary Pattern: A Cross-Sectional Study among Adults in Lebanon

This study aimed to examine the proportion and socio-demographic correlates of Metabolically Healthy Overweight and Obesity (MHOv/O) among Lebanese adults and to investigate the independent effect of previously identified dietary patterns on odds of MHOv/O. Data were drawn from the National Nutrition and Non-Communicable Disease Risk Factor Survey (Lebanon 2008-2009). Out of the 337 adult participants who had complete socio-demographic, lifestyle, dietary as well as anthropometric and biochemical data, 196 had a BMI ≥ 25 kg/m² and their data were included in this study. MHOv/O was identified using the Adult Treatment Panel criteria. Dietary patterns previously derived in this study population were: Fast Food/Dessert, Traditional-Lebanese and High-Protein. The proportion of MHOv/O in the study sample was 37.2%. Females, higher education and high level of physical activity were positively associated with odds of MHOv/O. Subjects with higher adherence to the Traditional-Lebanese pattern had higher odds of MHOv/O (OR: 1.83, 95% CI: 1.09-3.91). No significant associations were observed between the Fast Food/Dessert and the high-protein patterns with MHOv/O. Follow-up studies are needed to confirm those findings and understand the mechanisms by which the Traditional-Lebanese pattern may exert a protective effect in this subgroup of overweight and obese adults.