Adherence to Mediterranean Diet and Non-Alcoholic Fatty Liver Disease: Effect on Insulin Resistance

The Impact of Dietary Patterns and Nutrition in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has become one of the most common causes of chronic liver disease worldwide. The prevalence of NAFLD has grown proportionally with the rise in obesity, sedentary lifestyle, unhealthy dietary patterns, and metabolic syndrome. Currently, in the absence of approved pharmacologic treatment, the keystone of treatment is lifestyle modification focused on achieving a weight loss of 7%-10%, cardiovascular exercise, and improving insulin sensitivity. The primary aim of this review is to outline the effect of different dietetic approaches against NAFLD and highlight the important micronutrient components in the management of NAFLD.

Mechanisms of Non-Alcoholic Fatty Liver Disease in the Metabolic Syndrome. A Narrative Review

Non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MS) are two different entities sharing common clinical and physio-pathological features, with insulin resistance (IR) as the most relevant. Large evidence leads to consider it as a risk factor for cardiovascular disease, regardless of age, sex, smoking habit, cholesterolemia, and other elements of MS. Therapeutic strategies remain still unclear, but lifestyle modifications (diet, physical exercise, and weight loss) determine an improvement in IR, MS, and both clinical and histologic liver picture. NAFLD and IR are bidirectionally correlated and, consequently, the development of pre-diabetes and diabetes is the most direct consequence at the extrahepatic level. In turn, type 2 diabetes is a well-known risk factor for multiorgan damage, including an involvement of cardiovascular system, kidney and peripheral nervous system. The increased MS incidence worldwide, above all due to changes in diet and lifestyle, is associated with an equally significant increase in NAFLD, with a subsequent rise in both morbidity and mortality due to both metabolic, hepatic and cardiovascular diseases. Therefore, the slowdown in the increase of the "bad company" constituted by MS and NAFLD, with all the consequent direct and indirect costs, represents one of the main challenges for the National Health Systems.

Current Concepts, Opportunities, and Challenges of Gut Microbiome-Based Personalized Medicine in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NALFD) is now a leading cause of chronic liver disease worldwide, in part, as a consequence of rapidly rising levels of obesity and metabolic syndrome and is a major risk factor for cirrhosis, hepatocellular carcinoma, and liver-related mortality. From NAFLD stems a myriad of clinical challenges related to both diagnosis and management. A growing body of evidence suggests an intricate linkage between the gut microbiome and the pathogenesis of NAFLD. We highlight how our current knowledge of the gut-liver axis in NAFLD may be leveraged to develop gut microbiome-based personalized approaches for disease management, including its use as a non-invasive biomarker for diagnosis and staging, as a target for therapeutic modulation, and as a marker of drug response. We will also discuss current limitations of these microbiome-based approaches. Ultimately, a better understanding of microbiota-host interactions in NAFLD will inform the development of novel preventative strategies and precise therapeutic targets.

Dynamics of hepatic steatosis resolution and changes in gut microbiome with weight loss in nonalcoholic fatty liver disease

Background

Weight loss is recommended as the primary treatment for nonalcoholic fatty liver disease (NAFLD). However, the magnitude and velocity of hepatic steatosis resolution with weight loss is unclear, making it difficult to counsel patients seeking weight loss for treatment of NAFLD. The aim of this study was to determine the rate of hepatic steatosis improvement and stool microbiome changes associated with rapid diet‐induced weight loss in NAFLD.

Methods

Fourteen NAFLD patients (mean ± standard deviation, body mass index [BMI] 36.4 ± 4 kg/m²) enrolled in a 12‐week meal replacement program underwent frequent measurement of Fibroscan‐controlled attenuation parameter (CAP). Magnetic resonance imaging (MRI‐Dixon method) for hepatic fat quantitation and stool microbiome analysis (16S rRNA gene sequencing) were completed in 11 subjects at baseline and Week 12.

Results

At Week 12, mean (95% confidence interval) weight loss was −13.4 (−15.2, −11.5)% and CAP score −26.6 (−35.6, −17.6)% (both Ps < 0.001). CAP scores changed at a rate of −4.9 dB/m/kg (−30.1 dB/m per unit BMI) in Weeks 1–4 and −0.6 dB/m/kg (−2.4 dB/m per unit BMI) in Weeks 8–12. MRI‐determined hepatic fat fraction decreased by −74.1% (p < 0.001) at a rate of −0.51%/kg (−3.19% per unit BMI), with complete steatosis resolution in 90% patients. BMI change was associated with decreased stool microbial diversity (coefficient = 0.17; Shannon Index), increased abundance of Prevotella_9 (Bacteroidetes; coefficient = 0.96) and decreased abundance of Phascolarctobacterium (Firmicutes; coefficient = −0.42) (both Ps < 0.05).

Conclusions

Diet‐induced intensive weight loss is associated with rapid improvement and complete resolution of hepatic steatosis and decreased stool microbial diversity. These findings highlight the dynamic nature of hepatic fat and may help clinicians to develop evidence‐based treatment goals for patients with NAFLD and obesity who undertake weight loss interventions. Further research is warranted to understand the effects of intensive weight loss and gut microbiome changes on long‐term NAFLD resolution.

Multidimensional Impact of Mediterranean Diet on IBD Patients

BACKGROUND & AIMS

Malnutrition with the accumulation of fat tissue and nonalcoholic fatty liver disease (NAFLD) are conditions associated with inflammatory bowel disease (IBD). Visceral fat and NAFLD-related liver dysfunction can both worsen intestinal inflammation. Because the Mediterranean diet (Md) has been shown to ameliorate both obesity and NAFLD, the aim of this study was to analyze the impact of Md on the nutritional state, liver steatosis, clinical disease activity, and quality of life (QoL) in IBD patients.

METHODS

Patients with IBD, both Crohn's disease (CD) and ulcerative colitis (UC), followed Md for 6 months. Their body mass index (BMI), body tissue composition, liver steatosis and function, serum lipid profile, clinical disease activity, and inflammatory biomarkers (C-reactive protein and fecal calprotectin) were collected at baseline (T0) and compared with those obtained after 6 months (T180) to evaluate the impact of Md.

RESULTS

One hundred forty-two IBD patients, 84 UC and 58 CD, followed Md for 6 months. At T180, diet-adherent CD and UC improved BMI (UC -0.42, P = 0.002; CD -0.48, P = 0.032) and waist circumference (UC -1.25 cm, P = 0.037; CD -1.37 cm, P = 0.041). Additionally, the number of patients affected by liver steatosis of any grade was significantly reduced in both groups (UC T0 31 of 84 [36.9%] vs T180 18 of 84 [21.4%], P = 0.0016; CD T0 27 of 58 [46.6%] vs T180 18 of 58 [31.0%], P < 0.001) after dietary intervention. Finally, after 6 months of the diet, fewer UC and CD patients with stable therapy had active disease (UC T0 14 of 59 [23.7%] vs T180 4 of 59 [6.8%], P = 0.004; CD T0 9 of 51 [17.6%] vs T180 2 of 51 [3.0%], P = 0.011) and elevated inflammatory biomarkers. Mediterranean diet improved QoL in both UC and CD, but neither serum lipid profile nor liver function were modified by the diet.

CONCLUSIONS

A significant reduction of malnutrition-related parameters and liver steatosis was observed in both CD and UC patients after short-term dietary intervention based on the adoption of Md, and this was associated with a spontaneous improvement of disease activity and inflammatory markers.

Oxidative Stress in NAFLD: Role of Nutrients and Food Contaminants

Non-alcoholic fatty liver disease (NAFLD) is often the hepatic expression of metabolic syndrome and its comorbidities that comprise, among others, obesity and insulin-resistance. NAFLD involves a large spectrum of clinical conditions. These range from steatosis, a benign liver disorder characterized by the accumulation of fat in hepatocytes, to non-alcoholic steatohepatitis (NASH), which is characterized by inflammation, hepatocyte damage, and liver fibrosis. NASH can further progress to cirrhosis and hepatocellular carcinoma. The etiology of NAFLD involves both genetic and environmental factors, including an unhealthy lifestyle. Of note, unhealthy eating is clearly associated with NAFLD development and progression to NASH. Both macronutrients (sugars, lipids, proteins) and micronutrients (vitamins, phytoingredients, antioxidants) affect NAFLD pathogenesis. Furthermore, some evidence indicates disruption of metabolic homeostasis by food contaminants, some of which are risk factor candidates in NAFLD. At the molecular level, several models have been proposed for the pathogenesis of NAFLD. Most importantly, oxidative stress and mitochondrial damage have been reported to be causative in NAFLD initiation and progression. The aim of this review is to provide an overview of the contribution of nutrients and food contaminants, especially pesticides, to oxidative stress and how they may influence NAFLD pathogenesis.

Nutritional Approaches for the Management of Nonalcoholic Fatty Liver Disease: An Evidence-Based Review

Nonalcoholic fatty liver disease (NAFLD) is on the rise worldwide representing a public health issue. Its coexistence with obesity and other metabolic alterations is highly frequent. Therefore, current therapy interventions for NAFLD are mainly focused on progressive weight loss through modulation of overall calorie intake with or without specific macronutrient adjustments. Furthermore, other relevant nutritional interventions are built on food selection and time-restricted eating. Since every strategy might bring different results, choosing the optimal diet therapy for a patient is a complicated task, because NAFLD is a multifactorial complex disease. Importantly, some factors need to be considered, such as nutrition-based evidence in terms of hepatic morphophysiological improvements as well as adherence of the patient to the meal plan and adaptability in their cultural context. Thus, the purpose of this review is to explore and compare the subtleties and nuances of the most relevant clinical practice guidelines and the nutritional approaches for the management of NAFLD with a special attention to tangible outcomes and long-term adherence.

Relationship between triglyceride glucose index and the incidence of non-alcoholic fatty liver disease in the elderly: a retrospective cohort study in China

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is one of the major causes of liver-related diseases but relationship between triglyceride glucose (TyG) and NAFLD in the elderly is not reported yet. In this study, we investigated the role of TyG index for predicting the incidence of NAFLD in the elderly.

DESIGN AND SETTING

This is a prospective cohort study in Henan, China, from 2011 to 2018.

PARTICIPANTS AND METHODS

In total, 46 693 elderly who participated in a routine physical examination programme from 2011 to 2018 were included in this study. TyG index was calculated as ln (fasting triglyceride (mg/dL)×fasting plasma glucose (mg/dL)/2), while NAFLD was defined as hepatic steatosis after excluding other causes based on the results of abdominal ultrasonography; Cox regression model was performed to explore the relationship between TyG index and NAFLD. Also, mediation effect was used to analyse the role of the TyG index in WHtR (waist-to-height ratio) and NAFLD.

RESULTS

During the 149 041 person-years follow-up, a total of 5660 NAFLD events occurred (3.80/100 person-years). After adjusting for potential confounding factors, quartiles 4 of TyG index significantly increased the incidence of NAFLD compared with quartile 1, the HRs and 95% CI were 1.314 (1.234 to 1.457). In addition, TyG index played a partial mediating role in the relationship between WHtR and NAFLD and indirect effect was 1.009 (1.006 to 1.011).

CONCLUSION

Higher TyG index was associated with higher risk of NAFLD in the aged, and therefore, TyG index may be a novel predictor for incidence of NAFLD. Further, regular examination and evaluation of the TyG index might be useful for controlling the occurrence of NAFLD.

Clinical assessment and management of liver fibrosis in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is among the most frequent etiologies of cirrhosis worldwide, and it is associated with features of metabolic syndrome; the key factor influencing its prognosis is the progression of liver fibrosis. This review aimed to propose a practical and stepwise approach to the evaluation and management of liver fibrosis in patients with NAFLD, analyzing the currently available literature. In the assessment of NAFLD patients, it is important to identify clinical, genetic, and environmental determinants of fibrosis development and its progression. To properly detect fibrosis, it is important to take into account the available methods and their supporting scientific evidence to guide the approach and the sequential selection of the best available biochemical scores, followed by a complementary imaging study (transient elastography, magnetic resonance elastography or acoustic radiation force impulse) and finally a liver biopsy, when needed. To help with the selection of the most appropriate method a Fagan′s nomogram analysis is provided in this review, describing the diagnostic yield of each method and their post-test probability of detecting liver fibrosis. Finally, treatment should always include diet and exercise, as well as controlling the components of the metabolic syndrome, +/- vitamin E, considering the presence of sleep apnea, and when available, allocate those patients with advanced fibrosis or high risk of progression into clinical trials. The final end of this approach should be to establish an opportune diagnosis and treatment of liver fibrosis in patients with NAFLD, aiming to decrease/stop its progression and improve their prognosis.

Changes of Branched-Chain Amino Acids and Ectopic Fat in Response to Weight-loss Diets: the POUNDS Lost Trial

CONTEXT

Recent evidence has related circulating branch-chained amino acids (BCAAs) to ectopic fat distribution.

OBJECTIVE

To investigate the associations of changes in plasma BCAAs induced by weight-loss diet interventions with hepatic fat and abdominal fat, and potential modification by different diets.

DESIGN, SETTING, AND PARTICIPANTS

The current study included 184 participants from the 2-year Preventing Overweight and Using Novel Dietary Strategies (POUNDS Lost) trial with repeated measurements on plasma BCAAs, hepatic fat, and abdominal fat over 2 years.

MAIN OUTCOME MEASURES

Repeated measurements of hepatic fat, abdominal fat distribution, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and total adipose tissue (TAT).

RESULTS

Over 2 years, a decrease in total plasma BCAAs was significantly associated with improvement in hepatic density (a marker for hepatic fat; P = 0.02) and reductions in abdominal fat, including VAT, SAT, and TAT (all P < 0.05) in the main analyses. Additionally, we observed that decreases in BCAAs were associated with decreased insulin, homeostasis model assessment of insulin resistance, and triglycerides, independent of weight loss (all P < 0.05). Moreover, we found that dietary protein intake significantly modified the relation between changes in total plasma BCAAs and hepatic density at 6 months (Pinteraction = 0.01). Participants with a larger decrease in total BCAAs showed a greater increase in hepatic density when consuming a high-protein diet, compared with those with a smaller decrease or increase in total BCAAs.

CONCLUSIONS

Our findings indicate that weight-loss diet-induced decrease in plasma BCAAs is associated with reductions of hepatic and abdominal fat. In addition, dietary protein intake may modify these associations.

Complex Dietary Topologies in Non-alcoholic Fatty Liver Disease: A Network Science Analysis

Background and Aims: Previous studies have explored the associations between nutrition (food groups, nutrients, and dietary patterns) and the prevalence of non-alcoholic fatty liver disease. However, it remains unclear whether how foods are consumed together is associated with non-alcoholic fatty liver disease. The present study aims to construct dietary networks from network science and to explore the associations between complex dietary networks and non-alcoholic fatty liver disease. Methods: The present case-control study generated 2,043 multivariate matched controls for 2,043 newly diagnosed non-alcoholic fatty liver disease cases. Mutual information, which represents both linear and non-linear dependencies among food groups, was used to construct the network topologies. Results: The dietary topologies in the studied case and control groups were different despite the fact that only few food groups show differences in absolute intake. The dietary structure of the case group focused on two major components with more cohesion among food groups, while contrarily the control group had one major component with higher diversity of food groups. The dietary topology of the case group showed equality in connections among beneficial and detrimental food groups, whereas the control group focused more on healthier food choices. Conclusions: This study suggests how foods are consumed, besides the absolute intake, could be an important determinant of the occurrence of non-alcoholic fatty liver disease. A diverse diet that focuses on whole grain, tubers, and vegetables could yield beneficial effects regarding non-alcoholic fatty liver disease. Network science could offer a complementary tool in nutritional epidemiology.

Non-alcoholic Fatty Liver Disease as a Canonical Example of Metabolic Inflammatory-Based Liver Disease Showing a Sex-Specific Prevalence: Relevance of Estrogen Signaling

There is extensive evidence supporting the interplay between metabolism and immune response, that have evolved in close relationship, sharing regulatory molecules and signaling systems, to support biological functions. Nowadays, the disruption of this interaction in the context of obesity and overnutrition underlies the increasing incidence of many inflammatory-based metabolic diseases, even in a sex-specific fashion. During evolution, the interplay between metabolism and reproduction has reached a degree of complexity particularly high in female mammals, likely to ensure reproduction only under favorable conditions. Several factors may account for differences in the incidence and progression of inflammatory-based metabolic diseases between females and males, thus contributing to age-related disease development and difference in life expectancy between the two sexes. Among these factors, estrogens, acting mainly through Estrogen Receptors (ERs), have been reported to regulate several metabolic pathways and inflammatory processes particularly in the liver, the metabolic organ showing the highest degree of sexual dimorphism. This review aims to investigate on the interaction between metabolism and inflammation in the liver, focusing on the relevance of estrogen signaling in counteracting the development and progression of non-alcoholic fatty liver disease (NAFLD), a canonical example of metabolic inflammatory-based liver disease showing a sex-specific prevalence. Understanding the role of estrogens/ERs in the regulation of hepatic metabolism and inflammation may provide the basis for the development of sex-specific therapeutic strategies for the management of such an inflammatory-based metabolic disease and its cardio-metabolic consequences.

Cross-sectional analysis of the health profile and dietary intake of a sample of Canadian adults diagnosed with non-alcoholic fatty liver disease

Background

Dietary intake is an important factor in the development and management of non-alcoholic fatty liver disease (NAFLD); however, optimal dietary composition remains unclear. Moreover, there is minimal evidence on the relationship between dietary intake and markers of liver health in Canadian adults diagnosed with NAFLD.

Objective

The aim of this study is to characterize the dietary intake of a sample of Canadian adults diagnosed with NAFLD and examine the correlations with markers of liver health.

Design

Forty-two adults recruited from the community and hepatology clinics in Calgary, Canada from 2016 to 2019 completed a 3-day food record. Anthropometrics, blood biomarkers, liver stiffness (FibroScan), and liver fat (magnetic resonance imaging) were measured. Nutrient intake was compared with the data from the 2004 and 2015 Canadian Community Health Surveys. Relationships were assessed using Pearson’s correlation and regression analysis.

Results

Relative to Canadian dietary recommendations, participants consumed lower magnesium, fiber, calcium, vitamin D, and vitamin E, and higher cholesterol, saturated fat, total fat, fructose, iron, vitamin B12, selenium, phosphorus, and sodium. Compared with the national average, participants consumed more energy, fiber, sodium, total fat, and saturated fat. Systolic blood pressure (P = 0.012), serum α-2 macroglobulin (P = 0.008), carbohydrate (P = 0.022), total fat (P = 0.029), and saturated fat intakes (P = 0.029) were associated with FibroScan scores. Liver fat was correlated with serum triglycerides (P < 0.001), trunk fat (P = 0.029), added sugar (P = 0.042), phosphorus (P = 0.017), and magnesium intake (P = 0.013). In females, selenium intake was associated with liver fat (P = 0.015) and FibroScan score (P = 0.05), while in males, liver fat was associated with trunk fat (P = 0.004), body weight (P = 0.004), high-density lipoprotein (P < 0.001), and fructose intake (P = 0.037). Regression analysis showed that increasing magnesium intake corresponds to a decrease in liver fat.

Conclusion

Despite the higher energy intake of participants, overall nutrient intake is low, suggesting lower diet quality. Associations between select micronutrients and liver health markers warrant further investigation.

Serum Soluble Receptor for AGE (sRAGE) Levels Are Associated With Unhealthy Lifestyle and Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has been demonstrated to be positively associated with serum advanced glycation end products (AGEs) and negatively with soluble receptor for AGE (sRAGE) in a few small studies. We aimed to test the association between lifestyle and sRAGE levels and the association between sRAGE levels or AGEs intake and NAFLD, insulin resistance (IR), and elevated alanine aminotransferase (ALT).

Increased Liver Localization of Lipopolysaccharides in Human and Experimental NAFLD

BACKGROUND AND AIMS

Lipopolysaccharides (LPS) is increased in nonalcoholic fatty liver disease (NAFLD), but its relationship with liver inflammation is not defined.

APPROACH AND RESULTS

We studied Escherichia coli LPS in patients with biopsy-proven NAFLD, 25 simple steatosis (nonalcoholic fatty liver) and 25 nonalcoholic steatohepatitis (NASH), and in mice with diet-induced NASH. NASH patients had higher serum LPS and hepatocytes LPS localization than controls, which was correlated with serum zonulin and phosphorylated nuclear factor-κB expression. Toll-like receptor 4 positive (TLR4⁺ ) macrophages were higher in NASH than simple steatosis or controls and correlated with serum LPS. NASH biopsies showed a higher CD61⁺ platelets, and most of them were TLR4⁺ . TLR4⁺ platelets correlated with serum LPS values. In mice with NASH, LPS serum levels and LPS hepatocyte localization were increased compared with control mice and associated with nuclear factor-κB activation. Mice on aspirin developed lower fibrosis and extent compared with untreated ones. Treatment with TLR4 inhibitor resulted in lower liver inflammation in mice with NASH.

CONCLUSIONS

In NAFLD, Escherichia coli LPS may increase liver damage by inducing macrophage and platelet activation through the TLR4 pathway.

Poor Adherence to Mediterranean Diet and Serum Lipopolysaccharide are Associated with Oxidative Stress in Patients with Non-Alcoholic Fatty Liver Disease

Oxidative stress plays a pivotal role in non-alcoholic fatty liver disease (NAFLD). Factors inducing oxidative stress in NAFLD may be several; however, a relationship with the adherence to Mediterranean Diet (Med-diet) and with serum lipopolysaccharide (LPS) has been poorly investigated in this setting. The aim was to investigate factors associated with impaired oxidative stress in NAFLD, focusing on the potential role of LPS and Med-diet. We enrolled 238 consecutive outpatients from the PLINIO study, in whom we measured the soluble Nox2-derived peptide (sNox2-dp), a marker of systemic oxidative stress, and serum LPS. Adherence to Med-diet was investigated by a nine-item validated dietary questionnaire. Serum sNox2-dp and LPS were higher in patients with NAFLD compared to those without (25.0 vs. 9.0 pg/mL, p < 0.001 and 62.0 vs. 44.9 pg/mL, p < 0.001, respectively). In patients with NAFLD, the highest sNox2-dp tertile was associated with the top serum LPS tertile (Odds Ratio (OR): 4.71; p < 0.001), APRI > 0.7 (OR: 6.96; p = 0.005) and Med-diet-score > 6 (OR: 0.14; p = 0.026). Analyzing individual foods, the daily consumption of wine (OR: 0.29, p = 0.046) and the adequate weekly consumption of fish (OR: 0.32, p = 0.030) inversely correlated with the top sNox2-dp tertile. In conclusion, patients with NAFLD showed impaired oxidative stress. Levels of sNox2 correlated with serum LPS and with low adherence to Med-Diet.

Diet Associations With Nonalcoholic Fatty Liver Disease in an Ethnically Diverse Population: The Multiethnic Cohort

BACKGROUND AND AIMS

Epidemiological data on dietary risk factors for nonalcoholic fatty liver disease (NAFLD) from population-based studies, particularly in an ethnically diverse population, are scarce. We examined dietary factors in relation to NAFLD risk in African Americans, Japanese Americans, Latinos, native Hawaiians, and whites in the Multiethnic Cohort (MEC).

APPROACH AND RESULTS

A nested case-control analysis was conducted within the MEC, a large prospective study with >215,000 older adult participants in Hawaii and California. NAFLD was identified using Medicare claims data, and controls were selected among participants without liver disease and individually matched to cases by birth year, sex, ethnicity, and length of Medicare enrollment. Diet was assessed at baseline through a validated quantitative food frequency questionnaire. Diet-NAFLD associations were quantified by odds ratios and 95% confidence intervals using multivariable conditional logistic regression. The study consisted of 2,974 NAFLD cases (518 with cirrhosis, 2,456 without cirrhosis) and 29,474 matched controls. Red meat (P trend = 0.010), processed red meat (P trend = 0.004), poultry (P trend = 0.005), and cholesterol (P trend = 0.005) intakes were positively associated with NAFLD, while dietary fiber intake (P trend = 0.003) was inversely associated with risk. Stronger associations were observed between red meat and cholesterol and NAFLD with cirrhosis than without cirrhosis (P heterogeneity ≤0.014).

CONCLUSIONS

Dietary factors are independently associated with NAFLD and NAFLD-related cirrhosis in a multiethnic population. Decreasing the consumption of cholesterol, red and processed meat, and poultry and increasing consumption of fiber may reduce the risk for NAFLD and related advanced liver disease.

Association between Non-Alcoholic Fatty Liver Disease and Dietary Habits, Stress, and Health-Related Quality of Life in Korean Adults

Considering the increasing prevalence of non-alcoholic fatty liver disease (NAFLD), this study aimed to evaluate the association between NAFLD and dietary habits, stress, and health-related quality of life (HRQoL) in Korean individuals by using data from the Korea National Health and Nutrition Examination Survey (KNHANES) VI 2013-2015. NAFLD was defined in individuals with a hepatic steatosis index (HSI) value ≥36. Eating habits were assessed based on the frequencies of eating and eating out; stress was assessed through the stress perception rate; and the EuroQol-5D (EQ-5D) questionnaire was used to assess the HRQoL. We performed a complex sample logistic regression analysis and estimated the odds ratios by adjusting for significant factors to evaluate associations between NAFLD and dietary habits, stress, and HRQoL. Occurrence of NAFLD was not significantly associated with meal frequencies over one week. With an increase in stress, based on the stress perception rate, the risk of NAFLD increased 1.316-fold (95% confidence interval (CI): 1.175-1.469, p < 0.05). Additionally, a decrease in the EQ-5D score by 1 increased the risk of NAFLD 3.38-fold (95% CI: 1.893-4.844, p < 0.05). Thus, NAFLD treatment should include stress management, and underlying HRQoL should be considered during treatment.

Monounsaturated fat rapidly induces hepatic gluconeogenesis and whole-body insulin resistance

BACKGROUNDWhile saturated fat intake leads to insulin resistance and nonalcoholic fatty liver, Mediterranean-like diets enriched in monounsaturated fatty acids (MUFA) may have beneficial effects. This study examined effects of MUFA on tissue-specific insulin sensitivity and energy metabolism.METHODSA randomized placebo-controlled cross-over study enrolled 16 glucose-tolerant volunteers to receive either oil (OIL, ~1.18 g/kg), rich in MUFA, or vehicle (VCL, water) on 2 occasions. Insulin sensitivity was assessed during preclamp and hyperinsulinemic-euglycemic clamp conditions. Ingestion of 2H2O/acetaminophen was combined with [6,6-2H2]glucose infusion and in vivo 13C/31P/1H/ex vivo 2H-magnet resonance spectroscopy to quantify hepatic glucose and energy fluxes.RESULTSOIL increased plasma triglycerides and oleic acid concentrations by 44% and 66% compared with VCL. Upon OIL intervention, preclamp hepatic and whole-body insulin sensitivity markedly decreased by 28% and 27%, respectively, along with 61% higher rates of hepatic gluconeogenesis and 32% lower rates of net glycogenolysis, while hepatic triglyceride and ATP concentrations did not differ from VCL. During insulin stimulation hepatic and whole-body insulin sensitivity were reduced by 21% and 25%, respectively, after OIL ingestion compared with that in controls.CONCLUSIONA single MUFA-load suffices to induce insulin resistance but affects neither hepatic triglycerides nor energy-rich phosphates. These data indicate that amount of ingested fat, rather than its composition, primarily determines the development of acute insulin resistance.TRIAL REGISTRATIONClinicalTrials.gov NCT01736202.FUNDINGGerman Diabetes Center, German Federal Ministry of Health, Ministry of Culture and Science of the state of North Rhine-Westphalia, German Federal Ministry of Education and Research, German Diabetes Association, German Center for Diabetes Research, Portugal Foundation for Science and Technology, European Regional Development Fund, and Rede Nacional de Ressonancia Magnética Nuclear.

Utility of Liver Function Tests and Fatty Liver Index to Categorize Metabolic Phenotypes in a Mediterranean Population

The aim of this study was to analyze the utility of liver function tests (LFT) and fatty liver index (FLI), a surrogate marker of non-alcoholic fatty liver disease, in the categorization of metabolic phenotypes in a Mediterranean population. A cross-sectional study was performed on a random representative sample of 2233 adults assigned to a health center in Málaga, Spain. The metabolic phenotypes were determined based on body mass index (BMI) categorization and the presence or absence of two or more cardiometabolic abnormalities (high blood pressure, low high-density lipoprotein (HDL) cholesterol, hypertriglyceridemia, pre-diabetes) or type 2 diabetes. No difference was observed between metabolically healthy and metabolically abnormal phenotypes on LFT. The mean FLI of the population was 41.1 ± 28.6. FLI was significantly higher (p < 0.001) in the metabolically abnormal phenotypes in all BMI categories. The proportion of individuals with pathological FLI (≥60) was significantly higher in the metabolically abnormal overweight and obese phenotypes (p < 0.001). On a multivariate model adjusted for sex, age, and waist circumference, a significant correlation was found between pathological FLI and metabolically abnormal phenotypes in the overweight and obese BMI categories. Area under the curve (AUC) of FLI as a biomarker was 0.76, 0.74, and 0.72 for the metabolically abnormal normal-weight, overweight, and obese groups, respectively. Liver biochemistry is poorly correlated with metabolic phenotypes. Conversely, a good correlation between FLI, as a marker of non-alcoholic fatty liver disease (NAFLD), and metabolically abnormal phenotypes in all BMI ranges was found. Our study suggests that FLI may be a useful marker for characterizing metabolically abnormal phenotypes in individuals who are overweight or obese.

Association between dietary patterns with insulin resistance in an Iranian population

AIM

To assess the association between dietary patterns no single food or group, and risk of insulin resistance (Fasting blood sugar (FBS), Fasting insulin, 2h-glucose, 2h-insulin and HOMA-IR).

METHODS

In a cross-sectional, population-based study in Tehran, Iran, 2016-2017. Adults (n = 1500, 38% men) mean age 43.72 ± 14.9 years. Dietary intake was collected by semi-quantitative food frequency questionnaire and insulin resistance was evaluated by Fasting blood sugar (FBS), Fasting insulin, 2h glucose, 2h insulin and HOMA-IR. Associations were assessed by using correlation and multivariable linear regression.

RESULTS

After controlling of the confounding factor or possible underlying such as gender, age, menopausal, BMI, physical activity and the amount of daily energy intake, unhealthy dietary pattern had a positive relationship with all indexes of insulin resistance except 2h glucose and HOMA-IR, healthy dietary pattern had negative and significant relationship with indexes of insulin resistance but apart from 2h glucose.

CONCLUSIONS

It can be figured out that receiving diet rich in healthy foods might reduce the risk of creating insulin resistance.

Food groups and the likelihood of non-alcoholic fatty liver disease: a systematic review and meta-analysis

Dietary habits have been implicated in the development and severity of non-alcoholic fatty liver disease (NAFLD). Several epidemiological studies attempted to assess the relationship between food groups and the likelihood of NAFLD, but these results were conflicting. The present meta-analysis was conducted to assess the association between food groups and the likelihood of NAFLD. Published literature was retrieved and screened from MEDLINE, Embase and Web of Science. Out of 7892 retrieved articles, twenty-four observational studies (fifteen cross-sectional studies and nine case–control studies) met our eligibility criteria and were finally included in this systematic review and meta-analysis. Consumption of both red meat and soft drinks contributed to a positive association with NAFLD. Inversely, nut consumption was negatively associated with NAFLD. There were no significant influences on the likelihood of NAFLD about consuming whole grains, refined grains, fish, fruits, vegetables, eggs, dairy products and legumes. This meta-analysis suggests that individuals who consumed more red meat and soft drinks may have a significantly increased likelihood of NAFLD, whereas higher nut intake may be negatively associated with NAFLD. Further prospective studies are required to assess the association between food patterns and NAFLD.

Nonalcoholic Fatty Liver Disease: A Silent Epidemic

Nonalcoholic fatty liver disease is a growing condition among adolescent and adult populations, present in around 20%-30% of people in the United Kingdom. Nonalcoholic fatty liver disease is known as a silent disease and over many years may go on to cause nonalcoholic steatohepatitis. In the future it may become a leading contributor to cirrhosis, liver transplantation, and mortality. In recent years, programs have been set up to raise awareness of this condition with the first International NASH (nonalcoholic steatohepatitis) Day taking place in 2018; nevertheless, nonalcoholic fatty liver disease and nonalcoholic steatohepatitis is still not clearly understood by many. An extensive review has shown a lack of nursing literature on this topic, and effective specialist nurse input for this patient group should be a key component in tackling this growing epidemic in the years to come.

Beneficial effects of Chinese herbs in the treatment of fatty liver diseases

Eating habits and lifestyle directly impact general health. Consumption of fat- and sugar-rich foods and alcohol increase the risk of developing fatty liver disease. The prevalence of fatty liver disease is markedly critical, and its pathogenesis and progression are complicated. Chinese herbal medicine has been used to treat and prevent human diseases through-out history, and is a rich source of biologically active substances with unique curative properties. More recently, Chinese herbs and their extracts have been identified as a novel source of potential therapeutic agents in the prevention and treatment of fatty liver disease. Beneficial effects of these herbal medicines mean that they can be classified as novel candidates for the treatment and prevention of both alcoholic fatty liver disease (AFLD) and non-alcoholic fatty liver disease (NAFLD), in place of conventional allopathic treatments. In this review, we explore the current literature related to herbal medicines used for the treatment of or protection against fatty liver diseases and describe their mechanisms of action.

Mediterranean diet for patients with non-alcoholic fatty liver disease, a systematic review and meta-analysis of observational and clinical investigations

Aim

Mediterranean diet (MD) is a healthful dietary pattern with benefits for prevention of metabolic diseases including non-alcoholic fatty liver disease (NAFLD). In the current meta-analysis, we assessed the association between MD and liver steatosis and cardiometabolic risk factors in patients with NAFLD.

Methods

PubMed, Scopus, and Embase were searched to find observational and clinical studies on the issue. No restriction on date and language was made. Outcomes included body mass index (BMI), waist circumference, blood pressure, triglycerides (TG), cholesterol fractions, glucose, insulin, insulin resistance, and liver transaminases.

Results

Seven observational reports and 6 trials met our inclusion criteria and entered in the meta-analysis. In observational studies, there was an inverse association between MD and NAFLD (effect size (ES) = 0.95; 95% CI: 0.90, 1.00; P = 0.05). In trials, subgroup analysis based on the method of liver examination showed effectiveness of MD on steatosis examined by magnetic resonance spectroscopy (P < 0.002; n = 2) but not by ultrasound (P = 0.08; n = 2). MD also showed a significant decreasing effect on BMI (ES = -1.23 kg/m²; 95% CI: -2.38, -0.09), plasma triglycerides (ES = -33.01 mg/dL; 95% CI: -52.84, -13.18), and HOMA-IR (ES = -0.94; 95% CI: -1.29, -0.58) but no significant effect was observed in waist circumference, cholesterol fractions, glucose and insulin, and liver transferases.

Conclusion

Overall, available data from observational and clinical studies indicated a trend for the relationship between MD and hepatic steatosis. Improvement in the most important risk factors of NAFLD, i.e. BMI, serum triglycerides, and insulin resistance, may be involved in such relationship.

Nonalcoholic Fatty Liver Disease in Adults: Current Concepts in Etiology, Outcomes, and Management

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of disease, extending from simple steatosis to inflammation and fibrosis with a significant risk for the development of cirrhosis. It is highly prevalent and is associated with significant adverse outcomes both through liver-specific morbidity and mortality but, perhaps more important, through adverse cardiovascular and metabolic outcomes. It is closely associated with type 2 diabetes and obesity, and both of these conditions drive progressive disease toward the more advanced stages. The mechanisms that govern hepatic lipid accumulation and the predisposition to inflammation and fibrosis are still not fully understood but reflect a complex interplay between metabolic target tissues including adipose and skeletal muscle, and immune and inflammatory cells. The ability to make an accurate assessment of disease stage (that relates to clinical outcome) can also be challenging. While liver biopsy is still regarded as the gold-standard investigative tool, there is an extensive literature on the search for novel noninvasive biomarkers and imaging modalities that aim to accurately reflect the stage of underlying disease. Finally, although no therapies are currently licensed for the treatment of NAFLD, there are interventions that appear to have proven efficacy in randomized controlled trials as well as an extensive emerging therapeutic landscape of new agents that target many of the fundamental pathophysiological processes that drive NAFLD. It is highly likely that over the next few years, new treatments with a specific license for the treatment of NAFLD will become available.

The Effectiveness of Mediterranean Diet in Nonalcoholic Fatty Liver Disease Clinical Course: An Intervention Study

Diet is a modifiable key factor targeted in prevention and management of nonalcoholic fatty liver disease (NAFLD). The aim was to study the effect of Mediterranean Diet (MedDiet) on clinical, biochemical, and inflammatory profile in NAFLD patients with simple steatosis. Potential associations of signal transducer and activator of transcription 3 (STAT3) rs2293152 genotype to diet composition and patients' profile were investigated. In this nonrandomized, open-label, 24-week prospective intervention study, 44 untreated NAFLD patients with nonsignificant fibrosis received nutritional counsel to increase adherence to MedDiet. Adherence to MedDiet was estimated with MedDietScore. Furthermore, we genotyped STAT3 rs2293152 single nucleotide polymorphism and performed clinical and inflammatory measurements. In all patients, MedDietScore increased and anthropometric indices improved, whereas liver imaging, liver fibrosis score, blood pressure, fasting glucose, glycated hemoglobin (HbA1c), C-reactive protein (CRP), visfatin, and oxidized low-density lipoprotein levels were also significantly ameliorated compared with baseline (P < .05). No association of STAT3 polymorphism with diet composition was found. Comparisons of mean differences between G- and C-carriers at the end point of the trial showed that only visfatin was significantly associated with the STAT3 genotype (-0.0 ± 4.6 vs. -4.2 ± 3.9, P = .04, respectively). Carrying the G-allele was associated with an increase of the visfatin levels (3.4 ± 1.5 ng/mL, P = .028). Our results show amelioration of clinical, biochemical, and inflammatory biomarkers in NAFLD patients in response to MedDiet. STAT3 rs2293152 G-carriers experienced more beneficial changes at the end of the intervention compared with baseline. An association between visfatin levels and STAT3 genotype has been shown for the first time.

Lysosomal acid lipase activity and liver fibrosis in the clinical continuum of non-alcoholic fatty liver disease

BACKGROUND AND AIMS

Recent evidence showed a reduced activity of the lysosomal acid lipase (LAL) in patients with non-alcoholic fatty liver disease (NAFLD) and cryptogenic cirrhosis (CC). However, the relationship between LAL activity and liver fibrosis has never been investigated.

METHODS

Cross-sectional study including 575 outpatients referred for the management of cardio-metabolic and liver disease. The absence of liver fibrosis was defined by a FIB-4 < 1.30 and NAFLD fibrosis score (NFS) <-1.455. LAL activity was measured with dried blood spot technique.

RESULTS

Overall, 515 patients had a diagnosis of NAFLD (454 NAFL and 61 biopsy-proven NASH) and 60 of CC. The value of LAL activity progressively decreased from healthy subjects to NAFL/NASH patients to CC (P < .001). LAL activity was reduced by 10% in patients with NAFL, by 20% in NASH and by 50% in CC. The prevalence of CC decreased across the tertiles of LAL activity: 22.2% in the lowest, 4.6% in the intermediate and 0.5% in the highest tertile. In NAFLD patients, 69.9% had a FIB4 < 1.30, and 43.1% a NFS <-1.455. Multivariate logistic regression analysis showed that Log (LAL activity) was associated with FIB-4 < 1.30 (Odds ratio [OR] 2.19 95% confidence interval [CI] 1.33-3.62, P = .002) and NFS < -1.455 (OR 2.43, 95% CI 1.51-3.91, P < .001) after adjustment for confounding factors.

CONCLUSIONS

We found a progressive reduction of LAL activity according to liver disease severity. LAL activity was inversely associated with markers of liver fibrosis in patients with NAFLD.

Characterizing specific subgroups in patients with NAFLD: overweight vs obese phenotype

Non-alcoholic fatty liver disease (NAFLD) is increasingly recognized as the most common cause of chronic liver disease worldwide, with a global prevalence of 25.2%. The high burden of NAFLD extends beyond liver diseases, as patients are at risk of developing not only liver related conditions, including cirrhosis and hepatocellular carcinoma, but also cardiovascular complications associated to metabolic syndrome. The present special issue of The Spanish Journal of Gastroenterology (Revista Española de Enfermedades Digestivas) focusses on diverse key aspects of NAFLD, including characterization of fecal microbiota profiles, the role of bariatric endoscopy, evaluation of suitable pre-clinical models for NAFLD or differential epidemiological risk factors associated to NASH and fibrosis.

Diet and Non-Alcoholic Fatty Liver Disease: The Mediterranean Way

Lifestyle interventions remain the first-line treatment for non-alcoholic fatty liver disease (NAFLD), even if the optimal alimentary regimen is still controversial. The interest in antioxidants has increased over time, and literature reports an inverse association between nutrients rich in antioxidants and the risk of mortality due to non-communicable diseases, including NAFLD. Mediterranean diet (MD) is a model characterized by main consumption of plant-based foods and fish and reduced consumption of meat and dairy products. MD represents the gold standard in preventive medicine, probably due to the harmonic combination of many foods with antioxidant and anti-inflammatory properties. This regimen contributes substantially to the reduction of the onset of many chronic diseases as cardiovascular diseases, hypertension, type 2 diabetes mellitus, obesity, cancer, and NAFLD. The present review aims to clarify the intake of antioxidants typical of the MD and evaluate their effect on NAFLD.

Real-world comorbidities and treatment patterns among patients with non-alcoholic fatty liver disease receiving phosphatidylcholine as adjunctive therapy in Russia

Objective

Previous research conducted in Russia showed that the number of patients with non-alcoholic fatty liver disease (NAFLD) and associated metabolic comorbidities is large. We conducted an observational study to describe the management of NAFLD in patients with metabolic syndrome in Russia.

Design

A total of 2843 adult patients from 174 medical sites across 6 federal districts of Russia with newly diagnosed NAFLD, who had at least one of four comorbidities, namely overweight/obesity, hypertension, type 2 diabetes mellitus, and hypercholesterolaemia, and who received phosphatidylcholine (PPC) as an adjunctive treatment to standard care, were enrolled during 2015-2016.

Results

Overall, 2263 patients (79.6%) had at least two metabolic comorbidities associated with NAFLD; overweight/obesity was the most common comorbidity reported in 2298 patients (80.8%). Simple steatosis was the most frequently identified clinical form of NAFLD, diagnosed in 2128 patients (74.9%). Among hypertensive patients, ACE inhibitors, statins, and sartans were most commonly prescribed. Biguanides were administered in more than half of diabetic patients. In patients with overweight/obesity and hypercholesterolaemia, statins were the most frequently prescribed medications. Almost all patients (2837/2843; 99.8%) were treated with 1.8 g of PPC three times per day. PPC therapy was associated with a 90.5% 6-month compliance rate, high treatment satisfaction, and a favourable safety profile. However, almost 15% of diabetic patients and 40% of overweight/obese patients received no further treatment.

Conclusions

In Russia, patients with newly diagnosed NAFLD represent a population heavily burdened by comorbidities, mainly overweight/obesity and hypercholesterolaemia. A significant part of these patients did not receive a comprehensive pharmacotherapy, highlighting the existing unmet need in the current management of NAFLD patients with metabolic syndrome in Russia.

The influence of dietary fatty acids on liver fat content and metabolism

Non-alcoholic fatty liver disease encompasses a spectrum of conditions from hepatic steatosis through to cirrhosis; obesity is a known risk factor. The liver plays a major role in regulating fatty acid metabolism and perturbations in intrahepatic processes have potential to impact on metabolic health. It remains unclear why intra-hepatocellular fat starts to accumulate, but it likely involves an imbalance between fatty acid delivery to the liver, fatty acid synthesis and oxidation within the liver and TAG export from the liver. As man spends the majority of the day in a postprandial rather than postabsorptive state, dietary fatty acid intake should be taken into consideration when investigating why intra-hepatic fat starts to accumulate. This review will discuss the impact of the quantity and quality of dietary fatty acids on liver fat accumulation and metabolism, along with some of the potential mechanisms involved. Studies investigating the role of dietary fat in liver fat accumulation, although surprisingly limited, have clearly demonstrated that it is total energy intake, rather than fat intake per se, that is a key mediator of liver fat content; hyperenergetic diets increase liver fat whilst hypoenergetic diets decrease liver fat content irrespective of total fat content. Moreover, there is now, albeit limited evidence emerging to suggest the composition of dietary fat may also play a role in liver fat accumulation, with diets enriched in saturated fat appearing to increase liver fat content to a greater extent when compared with diets enriched in unsaturated fats.

The Epidemiology, Risk Profiling and Diagnostic Challenges of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) encompasses a wide spectrum of liver damage from the more prevalent (75%⁻80%) and nonprogressive nonalcoholic fatty liver (NAFL) category to its less common and more ominous subset, nonalcoholic steatohepatitis (NASH). NAFLD is now the most common cause of chronic liver disease in the developed world and is a leading indication for liver transplantation in United States (US). The global prevalence of NAFLD is estimated to be 25%, with the lowest prevalence in Africa (13.5%) and highest in the Middle East (31.8%) and South America (30.4%). The increasing incidence of NAFLD has been associated with the global obesity epidemic and manifestation of metabolic complications, including hypertension, diabetes, and dyslipidemia. The rapidly rising healthcare and economic burdens of NAFLD warrant institution of preventative and treatment measures in the high-risk sub-populations in an effort to reduce the morbidity and mortality associated with NAFLD. Genetic, demographic, clinical, and environmental factors may play a role in the pathogenesis of NAFLD. While NAFLD has been linked with various genetic variants, including PNPLA-3, TM6SF2, and FDFT1, environmental factors may predispose individuals to NAFLD as well. NAFLD is more common in older age groups and in men. With regards to ethnicity, in the US, Hispanics have the highest prevalence of NAFLD, followed by Caucasians and then African-Americans. NAFLD is frequently associated with the components of metabolic syndrome, such as type 2 diabetes mellitus (T2DM), obesity, hypertension, and dyslipidemia. Several studies have shown that the adoption of a healthy lifestyle, weight loss, and pro-active management of individual components of metabolic syndrome can help to prevent, retard or reverse NAFLD-related liver damage. Independently, NAFLD increases the risk of premature cardiovascular disease and associated mortality. For this reason, a case can be made for screening of NAFLD to facilitate early diagnosis and to prevent the hepatic and extra-hepatic complications in high risk sub-populations with morbid obesity, diabetes, and other metabolic risk factors.

Adherence to the Mediterranean diet is positively associated with sperm motility: A cross-sectional analysis

The aim of this cross-sectional analysis is to investigate the associations between the adherence to the Mediterranean Diet (MD) and semen quality parameters. To assess the adherence to the MD, the Trichopoulou score was used. Semen parameters were assessed as described in the 2010 WHO's report and the results are showed across tertiles of MD adherence. A total of 106 participants were included. Compared to those in the lowest MD adherence tertile, participants in the top tertile had statistically significant higher BMI and waist circumference and consumed more energy, and also had statistically significant higher semen pH, and total sperm motility and progressive sperm motility percentages, and lower sperm immotility percentages. Moreover, percentage of total and progressive motility were significantly higher among those subjects in the higher adherence to MD in comparison with those in low-medium adherence category. The multivariable linear regression models evaluating the relationship between the sperm quality parameters and tertiles of MD adherence adjusted by age, energy and BMI showed that compared with the lowest tertile, men in the highest tertile had a higher percentage of total sperm motility [β non-standardized coefficient = 12.785]. These findings suggest that adherence to the MD was positively associated with sperm motility.

Glucose Lowering Strategies for Cardiac Benefits: Pathophysiological Mechanisms

Recent trials in Type 2 diabetes (T2D) have shown cardiovascular benefits with specific GLP-1 receptor agonists and SGLT2 inhibitors. We discuss the landscape of outcome trials in T2D from a pathophysiology viewpoint, review current knowledge gaps in underlying mechanisms, propose a caloric fuel routing hypothesis, and highlight areas of future research.

French and Mediterranean-style diets: Contradictions, misconceptions and scientific facts-A review

The determination of appropriate dietary strategies for the prevention of chronic degenerative diseases, cancer, diabetes, and cardiovascular diseases remains a challenging and highly relevant issue worldwide. Epidemiological dietary interventions have been studied for decades with contrasting impacts on human health. Moreover, research scientists and physicians have long debated diets encouraging alcohol intake, such as the Mediterranean and French-style diets, with regard to their impact on human health. Understanding the effects of these diets may help to improve in the treatment and prevention of diseases. However, further studies are warranted to determine which individual food components, or combinations thereof, have a beneficial impact on different diseases, since a large number of different compounds may occur in a single food, and their fate in vivo is difficult to measure. Most explanations for the positive effects of Mediterranean-style diet, and of the French paradox, have focused largely on the beneficial properties of antioxidants, among other compounds/metabolites, in foods and red wine. Wine is a traditional alcoholic beverage that has been associated with both healthy and harmful effects. Not withstanding some doubts, there is reasonable unanimity among researchers as to the beneficial effects of moderate wine consumption on cardiovascular disease, diabetes, osteoporosis, and longevity, which have been ascribed to polyphenolic compounds present in wine. Despite this, conflicting findings regarding the impact of alcohol consumption on human health, and contradictory findings concerning the effects of non-alcoholic wine components such as resveratrol, have led to confusion among consumers. In addition to these contradictions and misconceptions, there is a paucity of human research studies confirming known positive effects of polyphenols in vivo. Furthermore, studies balancing both known and unknown prognostic factors have mostly been conducted in vitro or using animal models. Moreover, current studies have shifted focus from red wine to dairy products, such as cheese, to explain the French paradox. The aim of this review is to highlight the contradictions, misconceptions, and scientific facts about wines and diets, giving special focus to the Mediterranean and French diets in disease prevention and human health improvement. To answer the multiplicity of questions regarding the effects of diet and specific diet components on health, and to relieve consumer uncertainty and promote health, comprehensive cross-demographic studies using the latest technologies, which include foodomics and integrated omics approaches, are warranted.

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.

Health benefits of Mediterranean diet in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. Insulin resistance and obesity-related inflammatory status, associated with genetic, dietary, and lifestyle factors, are involved in its pathogenesis. There is no consensus concerning the pharmacological treatment of NAFLD. However, the international guidelines agree to define a dietetic nutritional management to achieve weight loss, as an essential component of any therapeutic strategy. Areas covered: An overview on the beneficial effects of the Mediterranean diet in the prevention and treatment of NAFLD. Expert commentary: On the basis of its components, the literature reports the beneficial effects of the Mediterranean diet in preventing major chronic diseases, including obesity, diabetes, cardiovascular diseases, and some forms of cancers. In recent years, a growing body of evidence has supported the idea that the Mediterranean diet, associated with physical activity and cognitive behavior therapy, may be the reference nutritional profile for the prevention and the treatment of NAFLD patients.

High red and processed meat consumption is associated with non-alcoholic fatty liver disease and insulin resistance

BACKGROUND & AIMS

High red and processed meat consumption is related to type 2 diabetes. In addition, cooking meat at high temperatures for a long duration forms heterocyclic amines (HCAs), which are related to oxidative stress. However, the association between meat consumption and non-alcoholic fatty liver disease (NAFLD) is yet to be thoroughly tested. Therefore, we aimed to test the association of meat type and cooking method with NAFLD and insulin resistance (IR).

METHODS

This was a cross-sectional study in individuals who were 40-70 years old and underwent screening colonoscopy between 2013 and 2015 in a single center in Israel. NAFLD and IR were evaluated by ultrasonography and homeostasis model assessment. Meat type and cooking method were measured by a food frequency questionnaire (FFQ) and a detailed meat questionnaire. Unhealthy cooking methods were considered as frying and grilling to a level of well done and very well done. Dietary HCA intake was calculated.

RESULTS

A total of 789 individuals had a valid FFQ and 357 had a valid meat questionnaire. High consumption of total meat (portions/day above the median) (odds ratio [OR] 1.49; 95% CI 1.05-2.13; p = 0.028; OR 1.63; 1.12-2.37; p = 0.011), red and/or processed meat (OR1.47; 95% CI 1.04-2.09; p = 0.031; OR1.55; 1.07-2.23; p = 0.020) was independently associated with higher odds of NAFLD and IR, respectively, when adjusted for: body mass index, physical activity, smoking, alcohol, energy, saturated fat and cholesterol intake. High intake of meat cooked using unhealthy methods (OR1.92; 95% CI 1.12-3.30; p = 0.018) and HCAs (OR2.22; 95% CI 1.28-3.86; p = 0.005) were independently associated with higher odds of IR.

CONCLUSION

High consumption of red and/or processed meat is associated with both NAFLD and IR. High HCA intake is associated with IR. If confirmed in prospective studies, limiting the consumption of unhealthy meat types and improving preparation methods may be considered as part of NAFLD lifestyle treatment.

LAY SUMMARY

High red and processed meat consumption is related to several diseases. In addition, cooking meat at high temperatures for a long duration forms heterocyclic amines, which have harmful health effects. Non-alcoholic fatty liver disease is a significant public health burden and its formation is strongly related to insulin resistance. In this study, both were found to be more frequent in people who consume relatively high quantities of red and processed meat. In addition, a high intake of heterocyclic amines was associated with insulin resistance.

Mediterranean diet and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is emerging as the most common chronic liver disease, and is characterized by a wide spectrum of fat-liver disorders that can result in severe liver disease and cirrhosis. Inflammation and oxidative stress are the major risk factors involved in the pathogenesis of NAFLD. Currently, there is no consensus concerning the pharmacological treatment of NAFLD. However, lifestyle interventions based on exercise and a balanced diet for quality and quantity, are considered the cornerstone of NAFLD management. Mediterranean diet (MD), rich in polyunsaturated fats, polyphenols, vitamins and carotenoids, with their anti-inflammatory and anti-oxidant effects, has been suggested to be effective in preventing cardiovascular risk factors. In adults, MD has also been demonstrated to be efficacious in reducing the risk of metabolic syndrome. However, few studies are available on the effects of the MD in both adult and pediatric subjects with NAFLD. Thus, the aims of the present narrative review are to analyze the current clinical evidence on the impact of MD in patients with NAFLD, and to summarize the main mechanisms of action of MD components on this condition.

Waist circumference is a mediator of dietary pattern in Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is an example of pathological fat accumulation in the liver and one of the major health conditions in the world. This study aimed to examine the independent role of dietary patterns in the development of NAFLD. In a cross-sectional study, 1500 individuals referred to a nutrition clinic were randomly selected, their demographic, anthropometric and blood metabolic indices were obtained, and food frequency questionnaires were completed for them. Liver stiffness was calculated using the NAFLD score formula and fibroscan. The two dominant dietary patterns identified were the “healthy” and “unhealthy dietary patterns”. A significant percentage of those with NAFLD (45%) were in the upper quartile of the unhealthy model; however, only 10% had the healthy pattern (p < 0.001). In this study, 32.9 and 13.9% of the healthy and unhealthy participants were in the upper quartile of the healthy diet pattern. Also, it was shown that waist circumference is a strong mediator of dietary patterns and NAFLD relationship, and the indirect effect of diet through abdominal circumference is 28 times greater than the direct effect on NAFLD. The results suggested that healthy and unhealthy dietary patterns are respectively associated with lower- and higher-risk of NAFLD but the role of waist circumference as a mediator deserves more consideration.