Fructose, high-fructose corn syrup, sucrose, and nonalcoholic fatty liver disease or indexes of liver health: a systematic review and meta-analysis

Responses of the Serum Lipid Profile to Exercise and Diet Interventions in Nonalcoholic Fatty Liver Disease

BACKGROUND

This study aimed to assess the response patterns of circulating lipids to exercise and diet interventions in nonalcoholic fatty liver disease (NAFLD).

METHODS

The 8.6-month four-arm randomized controlled study comprised 115 NAFLD patients with prediabetes who were assigned to aerobic exercise (AEx; n = 29), low-carbohydrate diet (Diet; n = 28), AEx plus low-carbohydrate diet (AED; n = 29), and nonintervention (NI, n = 29) groups. Hepatic fat content (HFC) was quantified by proton magnetic resonance spectroscopy. Serum lipidomic analytes were measured using liquid chromatography-mass spectrometry.

RESULTS

After intervention, the total level of phosphatidylcholine (PC) increased significantly in the AEx group ( P = 0.043), whereas phosphatidylethanolamine (PE) and triacylglycerol decreased significantly in the AED group ( P = 0.046 and P = 0.036, respectively), and phosphatidylserine decreased in the NI group ( P = 0.002). Changes of 21 lipid metabolites were significantly associated with changes of HFC, among which half belonged to PC. Most of the molecules related to insulin sensitivity belonged to sphingomyelin (40 of 79). Controlling for the change of visceral fat, the significant associations between lipid metabolites and HFC remained. In addition, baseline serum lipids could predict the response of HFC to exercise and/or diet interventions (PE15:0/18:0 for AED, area under the curve (AUC) = 0.97; PE22:6(4Z,7Z,10Z,13Z,16Z,19Z)/0:0 for AEx, AUC = 0.90; and PC14:1(9Z)/19:1(9Z) for Diet, AUC = 0.92).

CONCLUSIONS

Changes of lipidome after exercise and/or diet interventions were associated with HFC reductions, which are independent of visceral fat reduction, particularly in metabolites belonging to PC. Importantly, baseline PE could predict the HFC response to exercise, and PC predicted the response to diet. These results indicate that a circulating metabolomics panel can be used to facilitate clinical implementation of lifestyle interventions for NAFLD management.

Effect of various dietary fructose concentrations on the gallstone formation process in mice

Introduction

Background: little information is availaible on the effect of fructose on bile lipids. The first stage in the formation of gallstones corresponds to biliary cholesterol crystallization, derived from the vesicular transporters. The aim of this study was to investigate the influence of consuming diets with different fructose concentrations on serum lipids and their implications on gallstones formation. Methods: BALB/c mice divided into a control group as well as groups were treated with different fructose concentrations (10 %, 30 %, 50 % or 70 %) for different periods (1, 2 or 5 months). Blood, liver and bile samples were obtained. In bile samples, cholesterol and phospholipids levels were analyzed, and cholesterol transporters (vesicles and micelles) were separated by gel filtration chromatography. Results: treated animals showed: 1) increases in body weight similar to the control group; 2) a significant increase in plasma triglycerides only at very high fructose concentrations; 3) a significant increase in total serum cholesterol in the treatment for 1 month; 4) no variations in HDL-cholesterol; 5) a significant increase in serum glucose only at very high fructose concentrations in the second month of treatment; 6) no differences in the plasma alanine-aminotransferase activity; 7) a significant increase in liver triglyceride levels only at very high fructose concentrations; 8) no change in biliary lipid concentrations or in micellar and vesicular phospholipids. Conclusion: changes in plasma, liver and bile lipids were only observed at very high fructose concentrations diets. We conclude that fructose apparently does not alter the gallstone formation process in our experimental model.

Fructose corn syrup induces inflammatory injury and obesity by altering gut microbiota and gut microbiota-related arachidonic acid metabolism

Excessive fructose corn syrup (FCS) intake brings a series of health problems. The aim of the present study was to explore the mechanism of FCS-induced metabolic disorders from the perspective of gut microbiota. Mice were fed for 16 weeks with normal or 30% FCS drinking water. Compared to the control group, FCS caused significantly higher fat deposition, hepatic steatosis, liver and intestinal inflammatory damages (P<.05). FCS increased the abundance of Muribaculaceae in vivo and in vitro, which was positively correlated with the indices of metabolic disorders (P<.05). In vivo and in vitro data indicated that FCS enhanced the microbial function involved in pentose phosphate pathway and arachidonic acid metabolism, metabolomics further demonstrated that FCS led to an increase in prostaglandins (the catabolites of arachidonic acid) (P<.05). Our study confirmed that FCS can directly promote gut microbiota to synthesize inflammatory factor prostaglandins, which provides new insights and directions for the treatment of FCS-induced metabolic disorders and inflammation.

Dietary intake of pregnant women with non-alcoholic fatty liver disease: A case-control study

BACKGROUND AND AIMS

Findings on the role of diet in non-alcoholic fatty liver disease (NAFLD) pathogenesis are inconsistent. There are few studies on the dietary habits of pregnant women with NAFLD. Our primary aim was to compare the dietary intakes of pregnant women with and without NAFLD.

METHODS

This case-control study recruited 60 women (26-34 weeks' gestation) with recently diagnosed gestational diabetes (GDM) before any treatment was implemented. At recruitment, all participants underwent B-mode hepatic ultrasound. We included 30 women with sonographic NAFLD (cases) and 30 women without NAFLD (controls) matched for age, skin color, and pre-pregnancy body mass index. We assessed participants' dietary intakes in the last six months using a validated food frequency questionnaire. Mann-Whitney´s test was used to compare differences in median macro and micronutrient intakes between cases and controls.

RESULTS

Total median daily energy (1965.1 × 1949.2 calories) and lipid (25.1% × 28.3%) intakes were similar in women with and without NAFLD and fell within recommended ranges. Participants with NAFLD reported significantly higher median daily intakes of carbohydrates (59.4% × 53.1% p = 0.003), and significantly lower protein (15.6% × 17.0% p = 0.005), fiber (10.7 × 13.3 g/day p = 0.010), and vitamin C (151.8 × 192.6 mg/day p = 0.008) intakes than those without NAFLD.

CONCLUSIONS

Pregnant women with NAFLD ingest more carbohydrates and less protein, fiber, and vitamin C than those without NAFLD. Our findings contribute to understanding the role of diet in the development of NAFLD in pregnant women.

Unraveling the mechanisms of trans-cinnamic acid in ameliorating non-alcoholic fatty liver disease

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing significantly due to high amounts of fat and fructose in the diet. Phytochemicals present in herbal plants and nutrients present in food play vital roles in the management of NAFLD. One of these is trans-cinnamic acid (TCA). We are evaluate the role of TCA in NAFLD induced by a high-fat, high-fructose diet.

METHODOLOGY

Rats fed a high-fat, high-fructose (HFHF) diet for ten weeks exhibited distinct signs of NAFLD. Rats were given TCA (10 mg/kg, 20 mg/kg, and 40 mg/kg) and pioglitazone (10 mg/kg) for four weeks along with a HFHF diet. At the end, body weight, food intake, liver, lipid measurements, TNF-α, antioxidants, and histopathology were evaluated.

RESULTS

TCA significantly decreased serum glutamic-oxaloacetic transaminase and glutamic pyruvic transaminase in rats. Serum cholesterol, triglyceride, and low-density lipid levels were substantially decreased in TCA-treated rats compared to diseased controls. Superoxide dismutase, glutathione, and malondialdehyde were significantly decreased in rats treated with a high dose of TCA (40 mg/kg) compared to HFFD-fed rats. HFFD-fed rats exhibited fatty liver alterations, whereas rats treated with TCA exhibited significantly fewer morphologic changes associated with fatty liver disease. TCA at a high dose exhibited decreased TNF-α levels, thereby decreasing hepatic inflammation.

CONCLUSION

TCA proved its role in the treatment of NAFLD by substantially reducing liver enzymes, pro-inflammatory markers (TNF-α), and lipid markers. Inclusion of TCA as a therapeutic regimen alongside diet-based treatment undoubtedly has therapeutic potential in NAFLD and related diseases.

Uncovering the Gut-Liver Axis Biomarkers for Predicting Metabolic Burden in Mice

Western diet (WD) intake, aging, and inactivation of farnesoid X receptor (FXR) are risk factors for metabolic and chronic inflammation-related health issues ranging from metabolic dysfunction-associated steatotic liver disease (MASLD) to dementia. The progression of MASLD can be escalated when those risks are combined. Inactivation of FXR, the receptor for bile acid (BA), is cancer prone in both humans and mice. The current study used multi-omics including hepatic transcripts, liver, serum, and urine metabolites, hepatic BAs, as well as gut microbiota from mouse models to classify those risks using machine learning. A linear support vector machine with K-fold cross-validation was used for classification and feature selection. We have identified that increased urine sucrose alone achieved 91% accuracy in predicting WD intake. Hepatic lithocholic acid and serum pyruvate had 100% and 95% accuracy, respectively, to classify age. Urine metabolites (decreased creatinine and taurine as well as increased succinate) or increased gut bacteria (Dorea, Dehalobacterium, and Oscillospira) could predict FXR deactivation with greater than 90% accuracy. Human disease relevance is partly revealed using the metabolite-disease interaction network. Transcriptomics data were also compared with the human liver disease datasets. WD-reduced hepatic Cyp39a1 (cytochrome P450 family 39 subfamily a member 1) and increased Gramd1b (GRAM domain containing 1B) were also changed in human liver cancer and metabolic liver disease, respectively. Together, our data contribute to the identification of noninvasive biomarkers within the gut-liver axis to predict metabolic status.

Glucose versus fructose metabolism in the liver measured with deuterium metabolic imaging

Chronic intake of high amounts of fructose has been linked to the development of metabolic disorders, which has been attributed to the almost complete clearance of fructose by the liver. However, direct measurement of hepatic fructose uptake is complicated by the fact that the portal vein is difficult to access. Here we present a new, non-invasive method to measure hepatic fructose uptake and metabolism with the use of deuterium metabolic imaging (DMI) upon administration of [6,6'-²H₂]fructose. Using both [6,6'-²H₂]glucose and [6,6'-²H₂]fructose, we determined differences in the uptake and metabolism of glucose and fructose in the mouse liver with dynamic DMI. The deuterated compounds were administered either by fast intravenous (IV) bolus injection or by slow IV infusion. Directly after IV bolus injection of [6,6'-²H₂]fructose, a more than two-fold higher initial uptake and subsequent 2.5-fold faster decay of fructose was observed in the mouse liver as compared to that of glucose after bolus injection of [6,6'-²H₂]glucose. In contrast, after slow IV infusion of fructose, the ²H fructose/glucose signal maximum in liver spectra was lower compared to the ²H glucose signal maximum after slow infusion of glucose. With both bolus injection and slow infusion protocols, deuterium labeling of water was faster with fructose than with glucose. These observations are in line with a higher extraction and faster turnover of fructose in the liver, as compared with glucose. DMI with [6,6'-²H₂]glucose and [6,6'-²H₂]fructose could potentially contribute to a better understanding of healthy human liver metabolism and aberrations in metabolic diseases.

Circulating chemerin level and the risk of nonalcoholic fatty liver disease: a systematic review and meta-analysis

Purpose

Chemerin is participating in inflammation procedure and it has role in developing metabolic diseases. In the term of nonalcoholic fatty liver disease (NAFLD), the result of published studies are conflicting. So, in this study, the results of different studies investigating the relationship between chemerin level and NAFLD were summarized.

Method

The databases of PubMed, Scopus, Web of Science, and Embase were systematically searched until October 2022. The inclusion criteria were as follow: measured the mean chemerin level in adults and children with NAFLD and compared it with non-NAFLD population or reported the association between chemerin level and NAFLD. The methodological quality was assessed by the Joanna Briggs Institute (JBI) tool. The meta-analysis was done by STATA software. The pooled results were stated as the standardized mean difference (SMD) and odds ratio (OR) with 95% confidence interval (CI).

Results

Sixteen studies were included in the systematic review, of which 13 studies remained for meta-analysis. The mean serum chemerin level was not significantly different between the groups [SMD: 0.52, 95% CI: -0.35, 1.39]. Moreover, there was no significant correlation between the chemerin level and NAFLD [OR: 1.01, 95% CI: 1, 1.02]. Besides, subgroup analysis indicated a significant correlation between serum chemerin level and NAFLD in children [OR: 1.02, 95% CI: 1.01, 1.03].

Conclusion

There were no significant differences in chemerin levels between the NAFLD and healthy adults; however, the association was significant in children. However, due to the lack of studies in this age group, the conclusion should be made with caution.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01187-4.

Can Nutritional Supplements Benefit Patients With Nonalcoholic Steatohepatitis and Nonalcoholic Fatty Liver Disease?

A characteristic of nonalcoholic fatty liver disease (NAFLD) is the buildup of excess fat in the liver which encompasses various clinical phases, including steatosis, inflammation, ballooning, fibrosis, and liver cirrhosis. Nonalcoholic steatohepatitis (NASH) represents a severe form of NAFLD. The prevalence of NAFLD, particularly NASH, is notably high among Hispanics and those with morbid obesity. Diabetes, obesity, and dyslipidemia are significant risk factors in patients with NAFLD. The pathogenesis of NAFLD involves complex interactions between hormonal, nutritional, and genetic factors. Different clinical trials have been conducted to determine if there are any supplements that could help patients with NASH. Evidence has shown that vitamin E decreased the NAFLD activity score but not fibrosis. Our review summarizes the influence of supplementation on patients with NAFLD and NASH, focusing on the use of different clinical trials, systematic reviews, and meta-analyses. In the future, patients and physicians will play crucial roles in exploring diverse approaches and finding effective solutions to address this growing issue.

Practical dietary advices for subjects with alpha-1 antitrypsin deficiency

Congenital alpha-1 antitrypsin deficiency (AATD) is a rare inherited disorder caused by the mutation of the SERPINA1 gene on chromosome 14. At pulmonary level, AAT deficiency leads to an increased risk of chronic obstructive pulmonary disease (COPD) and emphysema, starting from the third-fourth decade of life. At hepatic level, some variants of the allelic, in particular PI*Z, cause a conformational change of the AAT molecule, which polymerizes within the hepatocytes. Excessive hepatic accumulation of these abnormal molecules can lead to liver disease in both adults and children, with clinical presentation ranging from cholestatic jaundice in the newborn to abnormal blood indices of liver function in children and adults, up to fatty liver, cirrhosis and hepatocarcinoma. Nutritional interventions in AATD aim to provide the necessary calories, stop protein catabolism, prevent and treat malnutrition as in the case of common COPD, and even take into account any liver disease that is a distinctive trait, compared to common COPD. Actually, there is a lack of formal research regarding the effects of specific nutritional recommendations in patients with AATD, proper eating habits may help to preserve lung and liver function. For practical dietary advice in patients with AATD and COPD, recently a food pyramid proposal has been published. It has been observed that there is a marked overlap between AATD liver disease and obesity-related liver disease, suggesting shared molecular basis and, therefore, similar nutritional strategies. In this narrative review dietary advice for all possible stages of liver disease have been reported.

Association between Diet Quality and Index of Non-Alcoholic Steatohepatitis in a Large Population of People with Type 2 Diabetes: Data from the TOSCA.IT Study

Background: There are still open questions with respect to the optimal dietary treatment in patients with type 2 diabetes (T2D) and coexisting non-alcoholic steatohepatitis (NASH). The aim of this study is to investigate, in patients with T2D, the association between NASH, dietary component intake, food groups and adherence to the Mediterranean diet. Methods: Cross-sectional analysis of 2026 people with T2D (1136 men and 890 women). The dietary habits were assessed with the European Prospective Investigation into Cancer and Nutrition (EPIC) questionnaire. NASH was identified by the Index Of NASH (ION). Based on the cluster analysis two dietary patterns were identified: the NASH and the NO-NASH pattern. Results: The macronutrient composition of the diet was similar in the two patterns. However, the NASH pattern compared with the NO-NASH pattern was characterized by a significantly lower content of fibre (p < 0.001), β-carotene (p < 0.001), vitamin C (p < 0.001), vitamin E (p < 0.001), polyphenols (p = 0.026) and antioxidant capacity (p < 0.001). With regard to food consumption, the NASH pattern compared with NO-NASH pattern was characterized by higher intake of rice (p = 0.021), potatoes (p = 0.013), red (p = 0.004) and processed meat (p = 0.003), and a lower intake of wholegrain bread (p = 0.019), legumes and nuts (p = 0.049), vegetables (p = 0.047), fruits (p = 0.002), white meat (p = 0.001), fatty fish (p = 0.005), milk and yogurt (p < 0.001). Conclusions: NO-NASH dietary pattern was characterized by a food consumption close to the Mediterranean dietary model, resulting in a higher content of polyphenols, vitamins, and fibre. These finding highlight the potential for dietary components in the prevention/treatment of NASH in people with T2D.

Marked gut microbiota dysbiosis and increased imidazole propionate are associated with a NASH Göttingen Minipig model

Background

Gut microbiota dysbiosis is associated with the development of non-alcoholic steatohepatitis (NASH) through modulation of gut barrier, inflammation, lipid metabolism, bile acid signaling and short-chain fatty acid production. The aim of this study was to describe the impact of a choline-deficient amino acid defined high fat diet (CDAHFD) on the gut microbiota in a male Göttingen Minipig model and on selected pathways implicated in the development of NASH.

Results

Eight weeks of CDAHFD resulted in a significantly altered colon microbiota mainly driven by the bacterial families Lachnospiraceae and Enterobacteriaceae, being decreased and increased in relative abundance, respectively. Metabolomics analysis revealed that CDAHFD decreased colon content of short-chain fatty acid and increased colonic pH. In addition, serum levels of the microbially produced metabolite imidazole propionate were significantly elevated as a consequence of CDAHFD feeding. Hepatic gene expression analysis showed upregulation of mechanistic target of rapamycin (mTOR) and Ras Homolog, MTORC1 binding in addition to downregulation of insulin receptor substrate 1, insulin receptor substrate 2 and the glucagon receptor in CDAHFD fed minipigs. Further, the consequences of CDAHFD feeding were associated with increased levels of circulating cholesterol, bile acids, and glucagon but not total amino acids.

Conclusions

Our results indicate imidazole propionate as a new potentially relevant factor in relation to NASH and discuss the possible implication of gut microbiota dysbiosis in the development of NASH. In addition, the study emphasizes the need for considering the gut microbiota and its products when developing translational animal models for NASH.

The effect of evening primrose oil (Oenothera biennis) on the level of adiponectin and some biochemical parameters in rats with fructose induced metabolic syndrome

The effect of evening primrose oil on adiponectin level and some biochemical parameters in model of fructose-induced metabolic syndrome were investigated. The rats were divided into 4 groups: control, evening primrose oil, fructose, fructose + evening primrose oil. Body weight, daily feed and water consumptions and systolic blood pressures of animals were measured. At the end of trial, blood samples were taken, livers were excised and histopathological examination was performed. Glucose, uric acid, triglyceride, T.cholesterol, LDL, HDL, VLDL, ALT, AST, ALP, LDH, adiponectin, insulin, IL-6, TNF-α, TAC, and TOS levels were analysed. Some analysed parameters and systolic blood pressure of fructose + evening primrose oil group decreased significantly compared to fructose group and adiponectin, TAC, and HDL levels were significantly increased. As conclusion, evening primrose oil can be considered as antioxidant agent by reducing oxidative stress, increasing adiponectin levels and insulin sensitivity, anti-inflammatory properties, exhibiting anti-atherogenic effect by regulating dyslipidemia and systolic blood pressure.

Protein and carbohydrate content of infant formula purchased in the United States

BACKGROUND

The protein and carbohydrate composition of formula fed infants' diets in the United States (US) has not been described. The aims of this study were to characterize these dietary exposures in infant formula purchased in the US and to estimate the proportion of formula purchased which is hypoallergenic or lactose-reduced formula.

METHODS

Powdered infant formula purchase data from all major physical stores in the US prior to the COVID-19 pandemic, between 2017 and 2019, were obtained from Information Resources, Inc. Protein and carbohydrate composition and scoop sizes for each formula were obtained from manufacturers. Ready to feed liquid products, products for premature infants and products for over 1 year old were not included.

RESULTS

Total volumes of term formula purchased were 216 million kg of formula powder (equivalent to 1.65 billion litres) over 3 years. Intact protein formula was 67.9% of formula purchased, 26.6% was partially hydrolysed and 5.5% was hypoallergenic (5.2% extensively hydrolysed protein; 0.3% amino acid based). Soy protein formula represented 5.1% of formula purchased. Carbohydrate content overall was 52.7% lactose, 42.3% glucose polymers and 5.0% sucrose. 23.7% of formula purchased included sucrose as a carbohydrate. Of all formula purchased, 59.0% was lactose reduced, containing a non-lactose carbohydrate. Of 'standard' formula, defined as intact protein, non-thickened, cow's milk formula, 32.3% was lactose reduced. The proportion of hypoallergenic formula purchased significantly exceeded the prevalence of cow's milk protein allergy and increased over the 3-year study period from 4.9% to 7.6% of all formula sold.

CONCLUSIONS

US infants are exposed to unnecessarily high levels of non-lactose carbohydrates and hypoallergenic formula, and this may represent a significant nutritional health risk.

Dietary Recommendations for the Management of Non-alcoholic Fatty Liver Disease (NAFLD): A Nutritional Geometry Perspective

Diet could be both culprit and solution of NAFLD. Dietary modifications have been associated with histological features improvement in NAFLD. The Western diet was related to a greater risk of disease progression while the Mediterranean diet (MD) could promote regression of histological lesions. Modifications in the nutrient composition seems to have lesser impact on NAFLD than dietary modifications. An intrinsic interaction between nutrients in the diet support a specific effect not seen when added separately. Dietary modifications should focus on promoting weight loss but also look for patterns that are able to promote histological improvement. Although several micronutrients' deficit has been related to NAFLD progression, prescribing these micronutrients' supplementation did not reach a positive impact. However, an enriching diet with specific nutrients could be useful, like olive oil supplemented in MD. Geometry of nutrition defines a framework to better understand the interaction between nutrients, foods, and dietetic pattern in the model of diseases and how we could approach taking into consideration the interaction between meals and disease features. After analyzing baseline diet and histological lesions, we could calculate the distance to optimal diet and to promote changes in lifestyle to reach all these goals. A standard MD menu would be recommended.

Chronic intake of high dietary sucrose induces sexually dimorphic metabolic adaptations in mouse liver and adipose tissue

Almost all effective treatments for non-alcoholic fatty liver disease (NAFLD) involve reduction of adiposity, which suggests the metabolic axis between liver and adipose tissue is essential to NAFLD development. Since excessive dietary sugar intake may be an initiating factor for NAFLD, we have characterized the metabolic effects of liquid sucrose intake at concentrations relevant to typical human consumption in mice. We report that sucrose intake induces sexually dimorphic effects in liver, adipose tissue, and the microbiome; differences concordant with steatosis severity. We show that when steatosis is decoupled from impairments in insulin responsiveness, sex is a moderating factor that influences sucrose-driven lipid storage and the contribution of de novo fatty acid synthesis to the overall hepatic triglyceride pool. Our findings provide physiologic insight into how sex influences the regulation of adipose-liver crosstalk and highlight the importance of extrahepatic metabolism in the pathogenesis of diet-induced steatosis and NAFLD.

Non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis belongs to the spectrum of metabolic-associated fatty liver diseases characterized by steatosis linked to obesity, diabetes, metabolic syndrome, dyslipidemia and immune-mediated disorders. The main features of MAFLD include high prevalence, heterogeneity, complexity and dynamic disease. Pruritus and asthenia are the main clinical manifestation that impact on quality of life and patient-reported outcomes. Biochemical or imagen-based non-invasive test have been implemented in the diagnostic process. Liver biopsy remains as the gold standard. Therapeutic options included life-style intervention. Mediterranean hypocaloric Diet to lose weight, exercise to fight sarcopenia and alcohol abstinence. In non-responders, drug-therapy focusing on obesity, diabetes and fibrosis using sequentially or combined to promote steatosis, inflammation and fibrosis regression.

Dietary fructose as a metabolic risk factor

Over the last decades, the role of the intestinal microbiota in metabolic diseases has come forward. In this regard, both composition and function of our intestinal microbiota is highly variable and influenced by multiple factors, of which diet is one of the major elements. Between 1970 and 1990 diet composition has changed and consumption of dietary sugars has increased, of which fructose intake rose by more than tenfold. This increased intake of sugars and fructose is considered as one of the major risk factors in the developments of obesity and several metabolic disturbances. In this review, we describe the association of dietary fructose intake with insulin resistance, non-alcoholic fatty liver disease (NAFLD) and lipid metabolism. Moreover, we will focus on the potential causality of this altered gut microbiota using fecal transplantation studies in human metabolic disease and whether fecal microbial transplant can reverse this phenotype.

Important Food Sources of Fructose-Containing Sugars and Non-Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis of Controlled Trials

Background: Fructose providing excess calories in the form of sugar sweetened beverages (SSBs) increases markers of non-alcoholic fatty liver disease (NAFLD). Whether this effect holds for other important food sources of fructose-containing sugars is unclear. To investigate the role of food source and energy, we conducted a systematic review and meta-analysis of controlled trials of the effect of fructose-containing sugars by food source at different levels of energy control on non-alcoholic fatty liver disease (NAFLD) markers. Methods and Findings: MEDLINE, Embase, and the Cochrane Library were searched through 7 January 2022 for controlled trials ≥7-days. Four trial designs were prespecified: substitution (energy-matched substitution of sugars for other macronutrients); addition (excess energy from sugars added to diets); subtraction (excess energy from sugars subtracted from diets); and ad libitum (energy from sugars freely replaced by other macronutrients). The primary outcome was intrahepatocellular lipid (IHCL). Secondary outcomes were alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Independent reviewers extracted data and assessed risk of bias. The certainty of evidence was assessed using GRADE. We included 51 trials (75 trial comparisons, n = 2059) of 10 food sources (sugar-sweetened beverages (SSBs); sweetened dairy alternative; 100% fruit juice; fruit; dried fruit; mixed fruit sources; sweets and desserts; added nutritive sweetener; honey; and mixed sources (with SSBs)) in predominantly healthy mixed weight or overweight/obese younger adults. Total fructose-containing sugars increased IHCL (standardized mean difference = 1.72 [95% CI, 1.08 to 2.36], p < 0.001) in addition trials and decreased AST in subtraction trials with no effect on any outcome in substitution or ad libitum trials. There was evidence of influence by food source with SSBs increasing IHCL and ALT in addition trials and mixed sources (with SSBs) decreasing AST in subtraction trials. The certainty of evidence was high for the effect on IHCL and moderate for the effect on ALT for SSBs in addition trials, low for the effect on AST for the removal of energy from mixed sources (with SSBs) in subtraction trials, and generally low to moderate for all other comparisons. Conclusions: Energy control and food source appear to mediate the effect of fructose-containing sugars on NAFLD markers. The evidence provides a good indication that the addition of excess energy from SSBs leads to large increases in liver fat and small important increases in ALT while there is less of an indication that the removal of energy from mixed sources (with SSBs) leads to moderate reductions in AST. Varying uncertainty remains for the lack of effect of other important food sources of fructose-containing sugars at different levels of energy control.

Nonalcoholic Steatohepatitis (NASH) and Atherosclerosis: Explaining Their Pathophysiology, Association and the Role of Incretin-Based Drugs

Nonalcoholic steatohepatitis (NASH) is the most severe manifestation of nonalcoholic fatty liver disease (NAFLD), a common complication of type 2 diabetes, and may lead to cirrhosis and hepatocellular carcinoma. Oxidative stress and liver cell damage are the major triggers of the severe hepatic inflammation that characterizes NASH, which is highly correlated with atherosclerosis and coronary artery disease. Regarding drug therapy, research on the role of GLP-1 analogues and DPP4 inhibitors, novel classes of antidiabetic drugs, is growing. In this review, we outline the association between NASH and atherosclerosis, the underlying molecular mechanisms, and the effects of incretin-based drugs, especially GLP-1 RAs, for the therapeutic management of these conditions.

Sugar-Sweetened Beverages and Cancer Risk: A Narrative Review

Cancer continues to be a major public health challenge worldwide, not only for being one of the leading causes of death but also because the number of incident cases is projected to grow in the next decades. Meanwhile, sugar-sweetened beverages (SSB) consumption has risen since the past century and constitutes a considerable fraction of added sugars in daily diet. Several studies have analyzed the relationship between SSB intake and health and found substantial evidence for effects on obesity, type 2 diabetes and metabolic syndrome. However, there is little knowledge about the relationship of SSB with cancer risk. It may be speculated that there is an indirect relationship between SSB and cancer through obesity and metabolic syndrome, but obesity-independent associations through hormonal imbalances or chronic inflammation could also exist. In this review, we describe the epidemiological evidence of the association of SSB and the risk of cancer in adults. Although the epidemiological evidence linking SSB consumption and cancer risk is still limited, prospective studies suggest that high SSB intake may increase the risk of obesity-related cancers, breast and prostate cancer.

The role of sugar-sweetened beverages in the global epidemics of obesity and chronic diseases

Sugar-sweetened beverages (SSBs) are a major source of added sugars in the diet. A robust body of evidence has linked habitual intake of SSBs with weight gain and a higher risk (compared with infrequent SSB consumption) of type 2 diabetes mellitus, cardiovascular diseases and some cancers, which makes these beverages a clear target for policy and regulatory actions. This Review provides an update on the evidence linking SSBs to obesity, cardiometabolic outcomes and related cancers, as well as methods to grade the strength of nutritional research. We discuss potential biological mechanisms by which constituent sugars can contribute to these outcomes. We also consider global trends in intake, alternative beverages (including artificially-sweetened beverages) and policy strategies targeting SSBs that have been implemented in different settings. Strong evidence from cohort studies on clinical outcomes and clinical trials assessing cardiometabolic risk factors supports an aetiological role of SSBs in relation to weight gain and cardiometabolic diseases. Many populations show high levels of SSB consumption and in low-income and middle-income countries, increased consumption patterns are associated with urbanization and economic growth. As such, more intensified policy efforts are needed to reduce intake of SSBs and the global burden of obesity and chronic diseases.

Nonalcoholic fatty liver disease: lifestyle and quality of life

Nonalcoholic fatty liver disease (NAFLD) is a metabolic disorder whose current rapidly expanding prevalence is causing it to develop into a major global health concern. NAFLD is closely linked to the modern, unhealthy lifestyle. The Western diet, characterized by excessive energy intake, frequent consumption of red meat, processed meat and foods, soft drinks, and sugar-sweetened beverages (SSBs), irregular meal distribution throughout the day, and unhealthy ways of cooking, predisposes to development of NAFLD. Low levels of physical activity and prolonged sedentary time are additional lifestyle risk factors for NAFLD. Given the present lack of effective pharmacological treatment, lifestyle modifications are regarded as the cornerstone of NAFLD management. Reducing daily calorie intake together with following the Mediterranean diet (MD) is an increasingly accepted approach. Furthermore, increasing the level of physical activity and limiting sedentary behavior are additional measures proposed to improve the outcomes of the disease. Apart from being affected by lifestyle, NAFLD may also affect patients' quality of life (QoL), mostly in the domain of physical function. In this regard, while the early and more benign form of the disease, i.e., simple hepatic steatosis, may not affect QoL, there is evidence, though conflicting, of the impact of nonalcoholic steatohepatitis (NASH) on this index, with, however, most studies showing that QoL is consistently affected in advanced disease, i.e., hepatic fibrosis, cirrhosis, and hepatocellular carcinoma. Considering all the above, appropriate management of lifestyle is likely to attenuate the severity of the disease and improve the QoL of NAFLD patients.

Correlation of Adiponectin Gene Polymorphisms rs266729 and rs3774261 With Risk of Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Increasing evidence has suggested an association of adiponectin gene polymorphisms rs1501299, rs2241766, rs266729 and rs3774261 with risk of nonalcoholic fatty liver disease (NAFLD). This correlation has been extensively meta-analyzed for the first two polymorphisms, but not the second two.

METHODS

The PubMed, EMBASE, Google Scholar, and China National Knowledge Infrastructure databases were searched for relevant literature. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.

RESULTS

A total of 10 case-control studies on rs266729 (2,619 cases and 1,962 controls) and 3 case-control studies on rs3774261 (562 cases and 793 controls) were included. Meta-analysis showed that rs266729 was associated with significantly higher NAFLD risk based on the following five models: allelic, OR 1.72, 95% CI 1.34-2.21, P < 0.001; recessive, OR 2.35, 95% CI 1.86-2.95, P < 0.001; dominant, OR 1.84, 95% CI 1.34-2.53, P < 0.001; homozygous, OR 2.69, 95% CI 1.84-3.92, P < 0.001; and heterozygous, OR 1.72, 95% CI 1.28-2.32, P < 0.001. This association between rs266729 and NAFLD risk remained significant for all five models among studies with Asian, Chinese and Caucasian samples. The rs2241766 polymorphism was associated with significantly higher NAFLD risk according to the recessive model (OR 1.87, 95% CI 1.15-3.04, P = 0.01).

CONCLUSION

Polymorphisms rs266729 and rs3774261 in the adiponectin gene may be risk factors for NAFLD. These findings may pave the way for novel therapeutic strategies, but they should be verified in large, well-designed studies.

Metabolic-Associated Fatty Liver Disease (MAFLD), Diabetes, and Cardiovascular Disease: Associations with Fructose Metabolism and Gut Microbiota

Non-alcoholic fatty liver disease (NAFLD) is an increasingly common condition associated with type 2 diabetes (T2DM) and cardiovascular disease (CVD). Since systemic metabolic dysfunction underlies NAFLD, the current nomenclature has been revised, and the term metabolic-associated fatty liver disease (MAFLD) has been proposed. The new definition emphasizes the bidirectional relationships and increases awareness in looking for fatty liver disease among patients with T2DM and CVD or its risk factors, as well as looking for these diseases among patients with NAFLD. The most recommended treatment method of NAFLD is lifestyle changes, including dietary fructose limitation, although other treatment methods of NAFLD have recently emerged and are being studied. Given the focus on the liver-gut axis targeting, bacteria may also be a future aim of NAFLD treatment given the microbiome signatures discriminating healthy individuals from those with NAFLD. In this review article, we will provide an overview of the associations of fructose consumption, gut microbiota, diabetes, and CVD in patients with NAFLD.

Molecular aspects of fructose metabolism and metabolic disease

Excessive sugar consumption is increasingly considered as a contributor to the emerging epidemics of obesity and the associated cardiometabolic disease. Sugar is added to the diet in the form of sucrose or high-fructose corn syrup, both of which comprise nearly equal amounts of glucose and fructose. The unique aspects of fructose metabolism and properties of fructose-derived metabolites allow for fructose to serve as a physiological signal of normal dietary sugar consumption. However, when fructose is consumed in excess, these unique properties may contribute to the pathogenesis of cardiometabolic disease. Here, we review the biochemistry, genetics, and physiology of fructose metabolism and consider mechanisms by which excessive fructose consumption may contribute to metabolic disease. Lastly, we consider new therapeutic options for the treatment of metabolic disease based upon this knowledge.

Sleep disruption in nonalcoholic fatty liver disease: What is the role of lifestyle and diet?

BACKGROUND

Patients with nonalcoholic fatty liver disease (NAFLD) have sleep disruption. The aim of this study is to understand how underlying factors such as diet, degree of liver disease and morningness-eveningness tendencies contribute to this sleep disruption.

METHODS

Patients with NAFLD were recruited from liver clinics at a University and Veterans Affairs practice. Patients with decompensated cirrhosis were excluded. Patients completed self-reported surveys to evaluate sleep disturbance using the Epworth Sleepiness Scale (ESS) and chronotype (circadian preference) using the morningness-eveningness questionnaire (MEQ). Information on occupation, physical activity and dietary intake were collected at clinic intake. Dietary intake was evaluated via food-frequency questionnaire and analyzed as individual categories or grouped on the basis of dietary composition.

RESULTS

A 54 patients completed the survey; 37% were female. Median ESS was 8 ± 4.2 and 37% of NAFLD patients were found to have sleep disturbance as defined by ESS >10. Sleep disturbance was common in NAFLD regardless of the liver disease stage. Dietary factors, including higher added sugar (P = 0.01), candy intake (P = 0.01), elevated Ferritin level (P = 0.04) and elevated platelet count (P = 0.05), were significantly associated with sleep disturbance. Chronotype, time to sleep, and duration of sleep were not associated with sleep disruption.

CONCLUSIONS

Sleep disruption is present in NAFLD regardless of underlying cirrhosis. Interventions aimed at improving dietary and lifestyle practices such as reduced sugar intake may help mitigate the risk for sleep disruption in NAFLD. Further longitudinal studies are needed to further delineate these links.

Features of the Course of Non-alcoholic Fatty Liver Disease in Experimental Animals at High Altitudes

Background: Nearly 25% of adults worldwide are affected by non-alcoholic fatty liver disease (NAFLD). taged changes in the liver from steatosis progress to non-alcoholic steatohepatitis (NASH) and its complicated forms such as fibrosis, cirrhosis, and hepatocellular carcinoma. There are very few data in the literature on the development of NAFLD in conditions of high altitude. There are no data on the state of pro- and anti-inflammatory cytokines in NAFLD in high altitude conditions. Thus, simulating NAFLD on animals in artificial highlands will help find answers to these questions. Aim: to study the features of the course of non-alcoholic fatty liver disease (NAFLD) in experimental animals in artificial high-mountain conditions. Material and methods: The study was carried out on 180 male Wistar rats. 7 groups of experimental animals were formed, which were divided into control and experimental groups. The rats of the control group were on a standard diet. Non-alcoholic fatty liver disease was modeled by keeping animals on a diet (Ackermann et al., 2005) rich in fructose and fat in low and high mountain conditions (in a pressure chamber 6000 m above sea level) for 35 and 70 days. In all groups of animals, the following was determined: the concentration of total bilirubin (TB), the activity of the enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), the level of total cholesterol (TC), low-density lipoprotein cholesterol (LDL), the total protein content in plasma (TP), pro- and anti-inflammatory cytokines. Results: In animals on a diet enriched with fructose and fat, it equally led to the inhibition of the synthetic function of the liver, both in high altitude and in low altitudes. Liver enzyme levels were uncertain. AST levels were high in all major groups, with a similar upward trend at 5 and 10 weeks on the fructose-fortified diet. The greatest shift was observed on the part of ALT in animals under conditions of hypobaric hypoxia, the growth of which was statistically significantly lower than in the low- altitude groups. The opposite picture was observed in pigment metabolism. Indicators of total cholesterol and LDL increased almost twofold in the main high- altitude groups, and were significantly higher than the indicators of low- altitude animals with p <0.001. The activity of pro- and anti-inflammatory cytokines in the main group, when the animals were raised in the pressure chamber, statistically significantly increased after 5 weeks compared to the low-altitude group by more than 2 times and statistically significantly correlated with cytolysis syndromes, hypercholesterolemia and impaired synthetic function against the background of liver hypoergosis. Conclusion: Non-alcoholic fatty liver disease in animals on a special diet enriched with fructose under conditions of hypobaric hypoxia is characterized by deeper violations of pigment metabolism, pro- and anti-inflammatory cytokines and lipid spectrum with simultaneously statistically significant low alanine aminotransferase indices compared to low-altitude groups on an identical diet.

Impact of Genetic Polymorphism on Response to Therapy in Non-Alcoholic Fatty Liver Disease

In the last decades, the global prevalence of non-alcoholic fatty liver disease (NAFLD) has reached pandemic proportions with derived major health and socioeconomic consequences; this tendency is expected to be further aggravated in the coming years. Obesity, insulin resistance/type 2 diabetes mellitus, sedentary lifestyle, increased caloric intake and genetic predisposition constitute the main risk factors associated with the development and progression of the disease. Importantly, the interaction between the inherited genetic background and some unhealthy dietary patterns has been postulated to have an essential role in the pathogenesis of NAFLD. Weight loss through lifestyle modifications is considered the cornerstone of the treatment for NAFLD and the inter-individual variability in the response to some dietary approaches may be conditioned by the presence of different single nucleotide polymorphisms. In this review, we summarize the current evidence on the influence of the association between genetic susceptibility and dietary habits in NAFLD pathophysiology, as well as the role of gene polymorphism in the response to lifestyle interventions and the potential interaction between nutritional genomics and other emerging therapies for NAFLD, such as bariatric surgery and several pharmacologic agents.

Diagnostic and Therapy of Nonalcoholic Fatty Liver Disease: A Narrative Review

<b><i>Background:</i></b> The prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing and strongly associated with the metabolic syndrome, especially with obesity. A subtype, nonalcoholic steatohepatitis (NASH), might progress to advanced fibrosis and cirrhosis. NASH patients have an increased all-cause mortality. First and foremost are malignancies, followed by cardiovascular diseases. <b><i>Summary:</i></b> The NAFLD fibrosis score and noninvasive liver stiffness measurement (transient hepatic elastography) are essential components for the diagnostic risk assessment of NAFLD patients. Other steatoses (alcohol, genetic disorders, drugs, toxins, malnutrition, etc.) must be considered in the differential diagnosis. So far, there is no approved liver-specific drug therapy with a proven effect on NAFLD for patients without diabetes mellitus. Obeticholic acid (FXR agonist), cenicriviroc (a dual inhibitor of the chemokine receptors (CCR), CCR2 and CCR5), acetyl-CoA carboxylase inhibitors, and several thyroid hormone analogs are the most advanced substances in clinical development in ongoing phase 2 and 3 studies. <b><i>Key Messages:</i></b> Weight loss, physical training, and the screening and treatment of risk factors represent the cornerstones of NAFLD therapy. Treatment with glucagon-like peptide 1 analogs (e.g., liraglutide, semaglutide) and sodium-dependent glucose transporter 2 inhibitors can be recommended in patients with diabetes and NASH.

Consuming Sucrose- or HFCS-sweetened Beverages Increases Hepatic Lipid and Decreases Insulin Sensitivity in Adults

CONTEXT

Studies in rodents and humans suggest that high-fructose corn syrup (HFCS)-sweetened diets promote greater metabolic dysfunction than sucrose-sweetened diets.

OBJECTIVE

To compare the effects of consuming sucrose-sweetened beverage (SB), HFCS-SB, or a control beverage sweetened with aspartame on metabolic outcomes in humans.

METHODS

A parallel, double-blinded, NIH-funded study. Experimental procedures were conducted during 3.5 days of inpatient residence with controlled feeding at a research clinic before (baseline) and after a 12-day outpatient intervention period. Seventy-five adults (18-40 years) were assigned to beverage groups matched for sex, body mass index (18-35 kg/m2), and fasting triglyceride, lipoprotein and insulin concentrations. The intervention was 3 servings/day of sucrose- or HFCS-SB providing 25% of energy requirement or aspartame-SB, consumed for 16 days. Main outcome measures were %hepatic lipid, Matsuda insulin sensitivity index (ISI), and Predicted M ISI.

RESULTS

Sucrose-SB increased %hepatic lipid (absolute change: 0.6 ± 0.2%) compared with aspartame-SB (-0.2 ± 0.2%, P < 0.05) and compared with baseline (P < 0.001). HFCS-SB increased %hepatic lipid compared with baseline (0.4 ± 0.2%, P < 0.05). Compared with aspartame-SB, Matsuda ISI decreased after consumption of HFCS- (P < 0.01) and sucrose-SB (P < 0.01), and Predicted M ISI decreased after consumption of HFCS-SB (P < 0.05). Sucrose- and HFCS-SB increased plasma concentrations of lipids, lipoproteins, and uric acid compared with aspartame-SB. No outcomes were differentially affected by sucrose- compared with HFCS-SB. Beverage group effects remained significant when analyses were adjusted for changes in body weight.

CONCLUSION

Consumption of both sucrose- and HFCS-SB induced detrimental changes in hepatic lipid, insulin sensitivity, and circulating lipids, lipoproteins and uric acid in 2 weeks.

Nonalcoholic fatty liver disease (NAFLD) from pathogenesis to treatment concepts in humans

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) comprises hepatic alterations with increased lipid accumulation (steatosis) without or with inflammation (nonalcoholic steatohepatitis, NASH) and/or fibrosis in the absence of other causes of liver disease. NAFLD is developing as a burgeoning health challenge, mainly due to the worldwide obesity and diabetes epidemics.

SCOPE OF REVIEW

This review summarizes the knowledge on the pathogenesis underlying NAFLD by focusing on studies in humans and on hypercaloric nutrition, including effects of saturated fat and fructose, as well as adipose tissue dysfunction, leading to hepatic lipotoxicity, abnormal mitochondrial function, and oxidative stress, and highlights intestinal dysbiosis. These mechanisms are discussed in the context of current treatments targeting metabolic pathways and the results of related clinical trials.

MAJOR CONCLUSIONS

Recent studies have provided evidence that certain conditions, for example, the severe insulin-resistant diabetes (SIRD) subgroup (cluster) and the presence of an increasing number of gene variants, seem to predispose for excessive risk of NAFLD and its accelerated progression. Recent clinical trials have been frequently unsuccessful in halting or preventing NAFLD progression, perhaps partly due to including unselected cohorts in later stages of NAFLD. On the basis of this literature review, this study proposed screening in individuals with the highest genetic or acquired risk of disease progression, for example, the SIRD subgroup, and developing treatment concepts targeting the earliest pathophysiolgical alterations, namely, adipocyte dysfunction and insulin resistance.

Assessing Interactions between PNPLA3 and Dietary Intake on Liver Steatosis in Mexican-Origin Adults

Mexican-origin (MO) adults have among the highest rates of nonalcoholic fatty liver disease (NAFLD) placing them at increased risk of liver cancer. Evidence suggests that a single nucleotide polymorphism (SNP) in the PNPLA3 gene, rs738409, increases the risk and progression of NAFLD and may modify the relationship between certain dietary factors and liver steatosis. The purpose of this study was to identify whether interactions exist between specific dietary factors and rs738409 genotype status among MO adults in relation to levels of liver steatosis. We analyzed cross-sectional data from a sample of 288 MO adults. Participants completed at least two 24-h dietary recalls. Multiple linear regression was performed assuming an additive genetic model to test the main effects of several dietary variables on levels of hepatic steatosis, adjusting for covariates. To test for effect modification, the product of the genotype and the dietary variable was included as a covariate in the model. No significant association between dietary intake and level of hepatic steatosis was observed, nor any significant gene-diet interactions. Our findings suggest that dietary intake may have the same magnitude of protective or deleterious effect even among MO adults with high genetic risk for NAFLD and NAFLD progression.

High fructose and streptozotocin induced diabetic impairments are mitigated by Indirubin-3-hydrazone via downregulation of PKR pathway in Wistar rats

Metabolic disorders are becoming more common in young population due to increased consumption of carbohydrate rich diet, lack of physical activity and stress. Fructose is used as a sweetener in many carbonated beverages and is a known inducer of oxidative stress and hypertension. Up-regulation of the double-stranded RNA-dependent protein kinase (PKR) causes impairment in insulin signaling pathway and metabolic dysfunctions in type 2 diabetes mellitus. In the present study we investigated the role of PKR and associated pathways in high fructose (HF) and streptozotocin (STZ) induced diabetes and whether indirubin-3-hydrazone (IHZ), a novel PKR inhibitor can reverse the HF and STZ induced diabetic impairments in Wistar rats. Diabetes was induced by feeding rats 20% high fructose in drinking water for 6 weeks and by giving a single dose of STZ (35 mg/kg., i.p) at the end of week 5. Glucose and lipid levels were measured by using assay kits. Expression of PKR and its downstream genes were determined by immunohistochemistry, qRT-PCR and western blotting techniques. Histo-pathological studies were performed using H&E staining. Fibrosis was detected in insulin sensitive tissues and organs using Sirius red and Masson’s trichrome staining and apoptosis by TUNEL assay. HF and STZ induced hyperglycemia, fibrosis, oxidative stress, and inflammation in liver, pancreas, skeletal muscle and adipose tissue are mediated via PKR pathway and its downstream effectors, and these effects were attenuated by PKR inhibitor IHZ. Thus, inhibition of PKR can protect insulin sensitive organs and tissues from HF induced diabetic impairments via the inhibition of c-Jun N-terminal kinase (JNK) pathway.

Fructose Consumption-Free Sugars and Their Health Effects

BACKGROUND

The excessive consumption of free sugars, including fructose, is considered a cause of overweight and metabolic syndrome throughout the Western world. In Germany, the prevalence of overweight and obesity among adults (54%, 18%) and children (15%, 6%) has risen in the past few decades and has now become stable at a high level. The causative role of fructose is unclear.

METHODS

This review is based on publications retrieved by a selective search in PubMed and the Cochrane Library, with special attention to international guidelines and expert recommendations.

RESULTS

The hepatic metabolism of fructose is insulin-independent; because of the lack of a feedback mechanism, it leads to substrate accumulation, with de novo lipogenesis and gluconeogenesis. Recent meta-analyses with observation periods of one to ten weeks have shown that the consumption of fructose in large amounts leads to weight gain (+ 0.5 kg [0.26; 0.79]), elevated triglyceride levels (+ 0.3 mmol/L [0.11; 0.41]), and steatosis hepatis (intrahepatocellular fat content: + 54% [29; 79%]) when it is associated with a positive energy balance (fructose dose + 25-40% of the total caloric requirement). Meta-analyses in the isocaloric setting have not shown any comparable effects. Children, with their preference for sweet foods and drinks, are prone to excessive sugar consumption. Toddlers under age two are especially vulnerable.

CONCLUSION

The effects that have been observed with the consumption of large amounts of fructose cannot be reliably distinguished from the effects of a generally excessive caloric intake. Further randomized and controlled intervention trials of high quality are needed in order to determine the metabolic effects of fructose consumed under isocaloric conditions. To lessen individual consumption of sugar, sugary dietary items such as sweetened soft drinks, fruit juice, and smoothies should be avoided in favor of water as a beverage and fresh fruit.

Studies on effect of Tongfengxiaofang in HUM model mice using a UPLC-ESI-Q-TOF/MS metabolomic approach

Hyperuricemia (HUM) is a major risk factor for the development of gout. The traditional Chinese medicine (TCM) complex prescription Tongfengxiaofang (TFXF) is composed of a variety of TCMs. To study the therapeutic effect of TFXF on HUM mice and the mechanisms by which it exerts a therapeutic effect, the biochemical indices were measured and qPCR technique was used. In addition, plasma metabolomics analysis was carried out based on UPLC-Q-TOF/MS to evaluate the characteristics of the metabolic spectrum changes. TFXF significantly downregulated the contents of uric acid, urea nitrogen and creatinine in serum and the concentration of xanthine oxidase in liver of HUM mice. In addition, TFXF significantly inhibited the overexpression of uric acid transporter 1 and glucose transporter 9 and upregulated the expression of organic anion transporter 1 in the kidney. A total of 152 metabolites were identified and 11 key biomarkers were further selected from these pathways to understand the mechanism of TFXF on the arginine biosynthesis, galactose metabolism, pyrimidine metabolism, glycerophospholipid metabolism, tryptophan metabolism and the citrate cycle (TCA cycle). The results of this confirmed the effect of TFXF on HUM and revealed the metabolic activity mechanism.

Overview of Non-Alcoholic Fatty Liver Disease (NAFLD) and the Role of Sugary Food Consumption and Other Dietary Components in Its Development

NAFLD is the world's most common chronic liver disease, and its increasing prevalence parallels the global rise in diabetes and obesity. It is characterised by fat accumulation in the liver evolving to non-alcoholic steatohepatitis (NASH), an inflammatory subtype that can lead to liver fibrosis and cirrhosis. Currently, there is no effective pharmacotherapeutic treatment for NAFLD. Treatment is therefore based on lifestyle modifications including changes to diet and exercise, although it is unclear what the most effective form of intervention is. The aim of this review, then, is to discuss the role of specific nutrients and the effects of different dietary interventions on NAFLD. It is well established that an unhealthy diet rich in calories, sugars, and saturated fats and low in polyunsaturated fatty acids, fibre, and micronutrients plays a critical role in the development and progression of this disease. However, few clinical trials have evaluated the effects of nutrition interventions on NAFLD. We, therefore, summarise what is currently known about the effects of macronutrients, foods, and dietary patterns on NAFLD prevention and treatment. Most current guidelines recommend low-calorie, plant-based diets, such as the Mediterranean diet, as the most effective dietary pattern to treat NAFLD. More clinical trials are required, however, to identify the best evidence-based dietary treatment approach.

Fructose and Non-Alcoholic Steatohepatitis

Background: The excessive consumption of free sugars is mainly responsible for the high prevalence of obesity and metabolic syndrome in industrialized countries. More and more studies indicate that fructose is involved in the pathophysiology and also in the degree of disease of non-alcoholic fatty liver disease (NAFLD). In epidemiologic studies, energy-adjusted higher fructose consumption correlates with NAFLD in overweight adults. In addition to glucose, fructose, as an equivalent component of conventional household sugar, appears to have negative metabolic effects in particular due to its exclusive hepatic metabolism. Liver-related mortality is strictly associated with the degree of fibrosis, whereas the most common cause of death in patients suffering from NAFLD and non-alcoholic steatohepatitis (NASH) are still cardiovascular diseases. In this review article, we have summarized the current state of knowledge regarding a relationship between fructose consumption, liver fibrosis and life expectancy in NASH. Method: Selective literature search in PubMed using the keywords 'non-alcoholic fatty liver', 'fructose', and 'fibrosis' was conducted. Results: The rate of overweight and obesity is significantly higher in both, adult and pediatric NASH patients. The consumption of free sugars is currently three times the maximum recommended amount of 10% of the energy intake. The current literature shows weight gain, negative effects on fat and carbohydrate metabolism and NASH with hypercaloric intake of fructose. Conclusions: Excessive fructose consumption is associated with negative health consequences. Whether this is due to an excess of energy or the particular metabolism of fructose remains open with the current study situation. The urgently needed reduction in sugar consumption could be achieved through a combination of binding nutritional policy measures including taxation of sugary soft drinks. Previous studies suggest that diet-related fructose intake exceeding the amount contained in vegetables and fruits lead to an increase of hepatic lipogenesis. Thus, further studies to clarify the protective contribution of low-fructose intake to positively influence NAFLD in industrial population are urgently required.

Fructose and high fructose corn syrup: are they a two-edged sword?

High-fructose syrups are used as sugar substitutes due to their physical and functional properties. High fructose corn syrup (HFCS) is used in bakery products, dairy products, breakfast cereals and beverages, but it has been reported that there might be a direct relationship between high fructose intake and adverse health effects such as obesity and the metabolic syndrome. Thus, fructose has recently received much attention, most of which was negative. Although studies have indicated that there might be a correlation between high fructose-rich diet and several adverse effects, however, the results of these studies cannot be certainly generalised to the effects of HFCS; because they have investigated pure fructose at very high concentrations in measurement of metabolic upsets. This review critically considered the advantages and possible disadvantages of HFCS application and consumption in food industry, as a current challenging issue between nutritionists and food technologists.

Management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease is a very common medical condition, driven by a combination of genetic and lifestyle factors, ultimately producing a severe chronic liver disease and increased cardiovascular risk. Most people are asymptomatic for a long time, and their daily life is unaffected, leading to difficulty in identifying and managing people who slowly progress to non-alcoholic steatohepatitis (NASH), NASH-cirrhosis, and eventually hepatocellular carcinoma. Despite advances in the understanding of pathogenic mechanisms and the identification of liver fibrosis as the strongest factor in predicting disease progression, no specific treatments have been approved by regulatory agencies. Outside controlled trials, treatment is generally limited to lifestyle intervention aimed at weight loss. Pioglitazone remains the drug of choice to reduce progression of fibrosis in people with diabetes, although it is often used off-label in the absence of diabetes. Vitamin E is mainly used in children and may be considered in adults without diabetes. Several drugs are under investigation according to the agreed targets of reduced NASH activity without worsening of fibrosis or improving fibrosis without worsening of NASH. Anti-inflammatory, anti-fibrotic agents and metabolism modulators have been tested in either phase III or phase IIb randomized controlled trials; a few failed, and others have produced marginally positive results, but only a few are being tested in extension studies. The development of non-invasive, easily repeatable surrogate biomarkers and/or imaging tools is crucial to facilitate clinical studies and limit liver biopsy.

Organismal Fructose Metabolism in Health and Non-Alcoholic Fatty Liver Disease

NAFLD has alarmingly increased, yet FDA-approved drugs are still lacking. An excessive intake of fructose, especially in liquid form, is a dietary risk factor of NAFLD. While fructose metabolism has been studied for decades, it is still controversial how fructose intake can cause NAFLD. It has long been believed that fructose metabolism solely happens in the liver and accordingly, numerous studies have investigated liver fructose metabolism using primary hepatocytes or liver cell lines in culture. While cultured cells are useful for studying detailed signaling pathways and metabolism in a cell-autonomous manner, it is equally important to understand fructose metabolism at the whole-body level in live organisms. In this regard, recent in vivo studies using genetically modified mice and stable isotope tracing have tremendously expanded our understanding of the complex interaction between fructose-catabolizing organs and gut microbiota. Here, we discuss how the aberrant distribution of fructose metabolism between organs and gut microbiota can contribute to NAFLD. We also address potential therapeutic interventions of fructose-elicited NAFLD.