Health outcomes of a high fructose intake: the importance of physical activity

Effect of Administration of Selenium Nanoparticles Synthesized Using Onion Extract on Biochemical and Inflammatory Parameters in Mice Fed with High-Fructose Diet: In Vivo and In Silico Analysis

Fructose consumption has increased globally and has been linked to obesity, insulin resistance, and diabetes. Selenium nanoparticles (SeNPs) can regulate glucose and lipid concentrations and have immunoregulatory properties. Four study groups (n = 7/group) of eight-week-old male mice (Balb/c) were formed for this investigation. One group received a standard diet (C), another standard diet plus SeNPs (C + SeNPs), a high fructose diet (F), and a group with a high fructose diet plus SeNPs (F + SeNPs). Weight, glucose, triglycerides, and cholesterol were evaluated. In the end, mice were sacrificed, blood samples were obtained to assess cytokine profile, and liver, kidney, and pancreas were removed for histological examination. The study was complemented with an in silico analysis where the CTD, STITCH, ToppGene Suite, ShinyGO 0.76.3 databases, and Cytoscape software were implemented. The results of in vivo analysis showed that SeNPs regulated biochemical parameters and showed anti-inflammatory effects by decreasing the concentrations of TNF-alpha, IL-1beta, and IFN-gamma and increasing IL-10. No damage was observed in the studied organs. In addition, SeNPs regulate oxidative stress, preserve cell organelles, and regulate metabolic pathways to avoid the adverse effects of fructose consumption, according to bioinformatics analysis. In conclusion, SeNPs protect against the undesirable effects of a diet rich in fructose.

Fructose: a modulator of intestinal barrier function and hepatic health?

PURPOSE

Consumption of fructose has repeatedly been discussed to be a key factor in the development of health disturbances such as hypertension, diabetes type 2, and non-alcoholic fatty liver disease. Despite intense research efforts, the question if and how high dietary fructose intake interferes with human health has not yet been fully answered.

RESULTS

Studies suggest that besides its insulin-independent metabolism dietary fructose may also impact intestinal homeostasis and barrier function. Indeed, it has been suggested by the results of human and animal as well as in vitro studies that fructose enriched diets may alter intestinal microbiota composition. Furthermore, studies have also shown that both acute and chronic intake of fructose may lead to an increased formation of nitric oxide and a loss of tight junction proteins in small intestinal tissue. These alterations have been related to an increased translocation of pathogen-associated molecular patterns (PAMPs) like bacterial endotoxin and an induction of dependent signaling cascades in the liver but also other tissues.

CONCLUSION

In the present narrative review, results of studies assessing the effects of fructose on intestinal barrier function and their impact on the development of health disturbances with a particular focus on the liver are summarized and discussed.

Human α-Defensin 51-9 and Human β-Defensin 2 Improve Metabolic Parameters and Gut Barrier Function in Mice Fed a Western-Style Diet

Obesity and metabolic comorbidities are associated with gut permeability. While high-fructose and Western-style diet (WSD) disrupt intestinal barrier function, oral administration of human α-defensin 5 (HD5) and β-defensin 2 (hBD2) is believed to improve intestinal integrity and metabolic disorders. Eighty-four male C57BL/6J mice were fed a WSD or a control diet (CD) ± fructose (F) for 18 weeks. In week 13, mice were randomly divided into three intervention groups, receiving defensin fragment HD51-9, full-length hBD2, or bovine serum albumin (BSA)-control for six weeks. Subsequently, parameters of hepatic steatosis, glucose metabolism, and gut barrier function were assessed. WSDF increased body weight and hepatic steatosis (p < 0.01) compared to CD-fed mice, whereas peptide intervention decreased liver fat (p < 0.05) and number of hepatic lipid droplets (p < 0.01) compared to BSA-control. In addition, both peptides attenuated glucose intolerance by reducing blood glucose curves in WSDF-fed mice. Evaluation of gut barrier function revealed that HD51-9 and hBD2 improve intestinal integrity by upregulating tight junction and mucin expression. Moreover, peptide treatment restored ileal host defense peptides (HDP) expression, likely by modulating the Wnt, Myd88, p38, and Jak/STAT pathways. These findings strongly suggest that α- and β-defensin treatment improve hepatic steatosis, glucose metabolism, and gut barrier function.

Effects of early-life voluntary exercise and fructose on adult activity levels, body composition, aerobic capacity, and organ masses in mice bred for high voluntary wheel-running behavior

Fructose (C₆H₁₂O₆) is acutely obesogenic and is a risk factor for hypertension, cardiovascular disease, and nonalcoholic fatty liver disease. However, the possible long-lasting effects of early-life fructose consumption have not been studied. We tested for effects of early-life fructose and/or wheel access (voluntary exercise) in a line of selectively bred High Runner (HR) mice and a non-selected Control (C) line. Exposures began at weaning and continued for 3 weeks to sexual maturity, followed by a 23-week "washout" period (equivalent to ∼17 human years). Fructose increased total caloric intake, body mass, and body fat during juvenile exposure, but had no effect on juvenile wheel running and no important lasting effects on adult physical activity or body weight/composition. Interestingly, adult maximal aerobic capacity (VO₂max) was reduced in mice that had early-life fructose and wheel access. Consistent with previous studies, early-life exercise promoted adult wheel running. In a 3-way interaction, C mice that had early-life fructose and no wheel access gained body mass in response to 2 weeks of adult wheel access, while all other groups lost mass. Overall, we found some long-lasting positive effects of early-life exercise, but minimal effects of early-life fructose, regardless of the mouse line.

ALDOC- and ENO2- driven glucose metabolism sustains 3D tumor spheroids growth regardless of nutrient environmental conditions: a multi-omics analysis

BACKGROUND

Metastases are the major cause of cancer-related morbidity and mortality. By the time cancer cells detach from their primary site to eventually spread to distant sites, they need to acquire the ability to survive in non-adherent conditions and to proliferate within a new microenvironment in spite of stressing conditions that may severely constrain the metastatic process. In this study, we gained insight into the molecular mechanisms allowing cancer cells to survive and proliferate in an anchorage-independent manner, regardless of both tumor-intrinsic variables and nutrient culture conditions.

METHODS

3D spheroids derived from lung adenocarcinoma (LUAD) and breast cancer cells were cultured in either nutrient-rich or -restricted culture conditions. A multi-omics approach, including transcriptomics, proteomics, and metabolomics, was used to explore the molecular changes underlying the transition from 2 to 3D cultures. Small interfering RNA-mediated loss of function assays were used to validate the role of the identified differentially expressed genes and proteins in H460 and HCC827 LUAD as well as in MCF7 and T47D breast cancer cell lines.

RESULTS

We found that the transition from 2 to 3D cultures of H460 and MCF7 cells is associated with significant changes in the expression of genes and proteins involved in metabolic reprogramming. In particular, we observed that 3D tumor spheroid growth implies the overexpression of ALDOC and ENO2 glycolytic enzymes concomitant with the enhanced consumption of glucose and fructose and the enhanced production of lactate. Transfection with siRNA against both ALDOC and ENO2 determined a significant reduction in lactate production, viability and size of 3D tumor spheroids produced by H460, HCC827, MCF7, and T47D cell lines.

CONCLUSIONS

Our results show that anchorage-independent survival and growth of cancer cells are supported by changes in genes and proteins that drive glucose metabolism towards an enhanced lactate production. Notably, this finding is valid for all lung and breast cancer cell lines we have analyzed in different nutrient environmental conditions. broader Validation of this mechanism in other cancer cells of different origin will be necessary to broaden the role of ALDOC and ENO2 to other tumor types. Future in vivo studies will be necessary to assess the role of ALDOC and ENO2 in cancer metastasis.

Fructose consumption from different food sources and cardiometabolic biomarkers: cross-sectional associations in US men and women

BACKGROUND

Previous studies on the relationship between fructose intake and cardiometabolic biomarkers have yielded inconsistent results, and the metabolic effects of fructose are likely to vary across food sources such as fruit versus sugar-sweetened beverages (SSB).

OBJECTIVES

We aimed to examine associations of fructose from 3 major sources (SSB, fruit juice, and fruit) with 14 insulinemic/glycemic, inflammatory, and lipid markers.

METHODS

We utilized cross-sectional data from 6858 men in the Health Professionals Follow-up Study, 15,400 women in NHS, and 19,456 women in NHSII who were free of type 2 diabetes, CVDs, and cancer at blood draw. Fructose intake was assessed via a validated FFQ. Multivariable linear regression was used to estimate the percentage differences of biomarker concentrations according to fructose intake.

RESULTS

We found a 20 g/d increase in total fructose intake was associated with 1.5%- 1.9% higher concentrations of proinflammatory markers plus 3.5% lower adiponectin, as well as 5.9% higher TG/HDL cholesterol ratio. Unfavorable profiles of most biomarkers were only associated with fructose from SSB and juice. In contrast, fruit fructose was associated with lower concentrations of C-peptide, CRP, IL-6, leptin, and total cholesterol. Substituting 20 g/d fruit fructose for SSB fructose was associated with 10.1% lower C-peptide, 2.7%-14.5% lower proinflammatory markers and 1.8%-5.2% lower blood lipids.

CONCLUSIONS

Beverage fructose intake was associated with adverse profiles of multiple cardiometabolic biomarkers.

Nutrient-sensing mTORC1 and AMPK pathways in chronic kidney diseases

Nutrients such as glucose, amino acids and lipids are fundamental sources for the maintenance of essential cellular processes and homeostasis in all organisms. The nutrient-sensing kinases mechanistic target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK) are expressed in many cell types and have key roles in the control of cell growth, proliferation, differentiation, metabolism and survival, ultimately contributing to the physiological development and functions of various organs, including the kidney. Dysregulation of these kinases leads to many human health problems, including cancer, neurodegenerative diseases, metabolic disorders and kidney diseases. In the kidney, physiological levels of mTOR and AMPK activity are required to support kidney cell growth and differentiation and to maintain kidney cell integrity and normal nephron function, including transport of electrolytes, water and glucose. mTOR forms two functional multi-protein kinase complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Hyperactivation of mTORC1 leads to podocyte and tubular cell dysfunction and vulnerability to injury, thereby contributing to the development of chronic kidney diseases, including diabetic kidney disease, obesity-related kidney disease and polycystic kidney disease. Emerging evidence suggests that targeting mTOR and/or AMPK could be an effective therapeutic approach to controlling or preventing these diseases.

Association between Sugar-Sweetened Beverage Consumption and the Risk of the Metabolic Syndrome: A Systematic Review and Meta-Analysis

(1) Background: The increasing occurrence of the metabolic syndrome (MetS) is largely related to harmful food habits. Among them, the consumption of sugar-sweetened beverages (SSBs) is noteworthy. However, to our knowledge, there are not enough high-quality methodological studies summarizing the association between the intake of SSBs and the MetS. Therefore, the aim of this study is to examine the existing published results on this association among adults by synthesizing the existing evidence. (2) Methods: Systematic review and meta-analysis of observational studies following the PRISMA guidelines. Relevant information was extracted and presented following the PRISMA recommendations. PubMed and SCOPUS databases were searched for studies published until June 2022 that assessed the association between SSB consumption (including soft drinks, bottled fruit juices, energy drinks, and milkshakes) and the occurrence of MetS. Random effect models were used to estimate pooled odds ratios (ORs) with their 95% coefficient interval, and I² was used to assess heterogeneity. (3) Results: A total of 14 publications from 6 different countries were included in this meta-analysis (9 cross-sectional and 5 cohort studies). For the cross-sectional studies, which included 62,693 adults, the pooled OR for the risk of MetS was 1.35 (95% CI 1.15, 1.58; I² 57%) when the highest versus the lowest categories of SSB consumption were compared. For the cohort studies, which included 28,932 adults, the pooled OR was 1.18 (95% CI 1.06, 1.32; I² 70%). (4) Conclusions: The consumption of SSBs was positively associated with an increased risk of MetS. The published literature supports public health strategies and the need to reduce the consumption of SSBs to prevent MetS.

Sugar-sweetened beverage consumption and weight gain in children and adults: a systematic review and meta-analysis of prospective cohort studies and randomized controlled trials

BACKGROUND

Sugar-sweetened beverages (SSBs) have been implicated in fueling the obesity epidemic.

OBJECTIVES

This study aimed to update a synthesis of the evidence on SSBs and weight gain in children and adults.

METHODS

MEDLINE, Embase, and Cochrane databases were searched through September 8, 2022, for prospective cohort studies and randomized controlled trials (RCTs) that evaluated intake of SSBs in relation to BMI and body weight in children and adults, respectively. Eligible interventions were compared against a noncaloric control. Study-level estimates were pooled using random-effects meta-analysis and presented as β-coefficients with 95% CIs for cohorts and weighted mean differences (MDs) with 95% CIs for RCTs.

RESULTS

We identified 85 articles including 48 in children (40 cohorts, n = 91,713; 8 RCTs, n = 2783) and 37 in adults (21 cohorts, n = 448,661; 16 RCTs, n = 1343). Among cohort studies, each serving/day increase in SSB intake was associated with a 0.07-kg/m² (95% CI: 0.04 kg/m², 0.10 kg/m²) higher BMI in children and a 0.42-kg (95% CI: 0.26 kg, 0.58 kg) higher body weight in adults. RCTs in children indicated less BMI gain with SSB reduction interventions compared with control (MD: -0.21 kg/m²; 95% CI: -0.40 kg/m², -0.01 kg/m²). In adults, randomization to addition of SSBs to the diet led to greater body weight gain (MD: 0.83 kg; 95% CI: 0.47 kg, 1.19 kg), and subtraction of SSBs led to weight loss (MD: -0.49 kg; 95% CI: -0.66 kg, -0.32 kg) compared with the control groups. A positive linear dose-response association between SSB consumption and weight gain was found in all outcomes assessed.

CONCLUSIONS

Our updated systematic review and meta-analysis expands on prior evidence to confirm that SSB consumption promotes higher BMI and body weight in both children and adults, underscoring the importance of dietary guidance and public policy strategies to limit intake. This meta-analysis was registered at the International Prospective Register of Systematic Reviews as CRD42020209915.

Dietary Polyphenols and In Vitro Intestinal Fructose Uptake and Transport: A Systematic Literature Review

Recent evidence links chronic consumption of large amounts of fructose (FRU) with several non-communicable disease. After ingestion, dietary FRU is absorbed into the intestinal tract by glucose transporter (GLUT) 5 and transported to the portal vein via GLUT2. GLUT2 is primarily localized on the basolateral membrane, but GLUT2 may be dislocated post-prandially from the basolateral membrane of intestinal cells to the apical one. Polyphenols (PP) are plant secondary metabolites that exert hypoglycemic properties by modulating intracellular insulin signaling pathways and by inhibiting intestinal enzymes and transporters. Post-prandially, PP may reach high concentrations in the gut lumen, making the inhibition of FRU absorption a prime target for exploring the effects of PP on FRU metabolism. Herein, we have systematically reviewed studies on the effect of PP and PP-rich products on FRU uptake and transport in intestinal cells. In spite of expectations, the very different experimental conditions in the various individual studies do not allow definitive conclusions to be drawn. Future investigations should rely on standardized conditions in order to obtain comparable results that allow a credible rating of polyphenols and polyphenol-rich products as inhibitors of fructose uptake.

High fat high fructose diet induces mild oxidative stress and reorganizes intermediary metabolism in male mouse liver: Alpha-ketoglutarate effects

BACKGROUND

Diets rich in fats and/or carbohydrates are used to study obesity and related metabolic complications. We studied the effects of a high fat high fructose diet (HFFD) on intermediary metabolism and the development of oxidative stress in mouse liver and tested the ability of alpha-ketoglutarate to prevent HFFD-induced changes.

METHODS

Male mice were fed a standard diet (10% kcal fat) or HFFD (45% kcal fat, 15% kcal fructose) with or without addition of 1% alpha-ketoglutarate (AKG) in drinking water for 8 weeks.

RESULTS

The HFFD had no effect on body mass but activated fructolysis and glycolysis and induced inflammation and oxidative stress with a concomitant increase in activity of antioxidant enzymes in the mouse liver. HFFD-fed mice also showed lower mRNA levels of pyruvate dehydrogenase kinase 4 (PDK4) and slightly increased intensity of mitochondrial respiration in liver compared to mice on the standard diet. No significant effects of HFFD on transcription of PDK2 and PGC1α, a peroxisome proliferator-activated receptor co-activator-1α, or protein levels of p-AMPK, an active form of AMP-activated protein kinase, were found. The addition of AKG to HFFD decreased oxidized glutathione levels, did not affect levels of lipid peroxides and PDK4 transcripts but increased activities of hexokinase and phosphofructokinase in mouse liver.

CONCLUSIONS

Supplementation with AKG had weak modulating effects on HFFD-induced oxidative stress and changes in energetics in mouse liver.

GENERAL SIGNIFICANCE

Our research expands the understanding of diet-induced metabolic switching and elucidates further roles of alpha-ketoglutarate as a metabolic regulator.

Fructose-mediated NLRP3 activation induces inflammation and lipogenesis in adipose tissue

Adipose tissue plays a crucial role in energy intake and regulation of metabolic homeostasis. Fructose consumption implicates in development and progression of metabolic dysfunctions. Fructose is a lipogenic sugar known to induce inflammatory response. However, the role of specific inflammatory signal such as nucleotide-binding and oligomerization domain-like receptor, leucine-rich repeat and pyrin domain containing protein 3 (NLRP3) in fructose-induced inflammatory response and its relevance to lipogenesis in adipose tissue are elusive. We assessed NLRP3 activation and its significance in inflammatory response and lipogenesis in epididymal adipose tissue of 60% fructose diet (HFrD)-fed rats. The long term consumption of HFrD led to impairment of glucose metabolism, development of visceral adiposity, insulin resistance, and elevation of serum triglycerides level, accompanied by activation of NLRP3 in adipose tissue. NLRP3 inflammasome activation in adipose tissue was associated with up-regulated expression of Nlrp3, Asc, and Caspase-1, and raised caspase-1 activity, which resulted in increased expression of IL-1β and IL-18 and secretion of IL-1β. Moreover, lipid accumulation and expression of transcription factors exacerbating accumulation of lipids were augmented in adipose tissue of HFrD-fed rats. Treatment with glyburide, quercetin or allopurinol corrected HFrD-induced dyslipidemia or hyperuricemia, and blocked NLRP3 activation, leading to mitigated inflammatory signalling and lipid accumulation in adipose tissue, improved glucose tolerance and insulin sensitivity in HFrD-fed rats. These data suggest the role of NLRP3 inflammasome to establish linkage among inflammation, lipid accumulation and insulin resistance in adipose tissue, and targeting NLRP3 inflammasome may be a plausible approach for prevention and management for fructose-induced metabolic impairments.

Differential effects of acute versus chronic dietary fructose consumption on metabolic responses in FVB/N mice

Increased human consumption of hgh fructose corn syrup has been linked to the marked increase in obesity and metabolic syndrome. Previous studies on the rapid effects of a high fructose diet in mice have largely been confined to the C57Bl6 strains. In the current studied, the FVB/N strain of mice that are resistant to diet induced weight gain were utilized and fed a control or high fructose diet for 48 hours or 12 weeks. Many of the previously reported changes that occurred upon high fructose feeding for 48 hours in C57Bl6 mice were recapitulated in the FVB/N mice. However, the acute increases in fructolytic and lipogenic gene expression were completely lost during the 12 week dietary intervention protocol. Furthermore, there was no significant weight gain in FVB/N mice fed a high fructose diet for 12 weeks, despite an overall increase in caloric consumption and an increase in average epididymal adipocyte cell size. These findings may be in part explained by a commensurate increase in energy expenditure and in carbohydrate utilization in high fructose fed animals. Overall, these findings demonstrate that FVB/N mice are a suitable model for the study of the effects of dietary intervention on metabolic and molecular parameters. Furthermore, the rapid changes in hepatic gene expression that have been widely reported were not sustained over a longer time course. Compensatory changes in energy expenditure and utilization may be in part responsible for the differences obtained between acute and chronic high fructose feeding protocols.

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.

Dietary Transitions and Health Outcomes in Four Populations - Systematic Review

IMPORTANCE

Non-communicable chronic diseases (NCDs) such as obesity, type 2 diabetes, heart disease, and cancer were rare among non-western populations with traditional diets and lifestyles. As populations transitioned toward industrialized diets and lifestyles, NCDs developed.

OBJECTIVE

We performed a systematic literature review to examine the effects of diet and lifestyle transitions on NCDs.

EVIDENCE REVIEW

We identified 22 populations that underwent a nutrition transition, eleven of which had sufficient data. Of these, we chose four populations with diverse geographies, diets and lifestyles who underwent a dietary and lifestyle transition and explored the relationship between dietary changes and health outcomes. We excluded populations with features overlapping with selected populations or with complicating factors such as inadequate data, subgroups, and different study methodologies over different periods. The selected populations were Yemenite Jews, Tokelauans, Tanushimaru Japanese, and Maasai. We also review transition data from seven excluded populations (Pima, Navajo, Aboriginal Australians, South African Natal Indians and Zulu speakers, Inuit, and Hadza) to assess for bias.

FINDINGS

The three groups that replaced saturated fats (SFA) from animal (Yemenite Jews, Maasai) or plants (Tokelau) with refined carbohydrates had negative health outcomes (e.g., increased obesity, diabetes, heart disease). Yemenites reduced SFA consumption by >40% post-transition but men's BMI increased 19% and diabetes increased ~40-fold. Tokelauans reduced fat, dramatically reduced SFA, and increased sugar intake: obesity and diabetes rose. The Tanushimaruans transitioned to more fats and less carbohydrates and used more anti-hypertensive medications; stroke and breast cancer declined while heart disease was stable. The Maasai transitioned to lower fat, SFA and higher carbohydrates and had increased BMI and diabetes. Similar patterns were observed in the seven other populations.

CONCLUSION

The nutrient category most strongly associated with negative health outcomes - especially obesity and diabetes - was sugar (increased 600-650% in Yemenite Jews and Tokelauans) and refined carbohydrates (among Maasai, total carbohydrates increased 39% in men and 362% in women), while increased calories was less strongly associated with these disorders. Across 11 populations, NCDs were associated with increased refined carbohydrates more than increased calories, reduced activity or other factors, but cannot be attributed to SFA or total fat consumption.

Verifying the Use of Food Labeling Data for Compiling Branded Food Databases: A Case Study of Sugars in Beverages

Branded food composition databases are an important tool for research, education, healthcare, and policy making, amongst others. Such databases are typically compiled using food labeling data without chemical analyses of specific products. This study aimed to verify whether the labeled sugar content in sugar-sweetened beverages (SSBs) corresponds to the actual sugar content in these products, thus enabling food monitoring studies to be conducted. A secondary objective was to determine the specific types of sugars in these SSBs. A case study was conducted using market share-driven sampling of these beverages from the Slovenian food supply. On the basis of nationwide yearly sales data, 51 best-selling products were sampled in 2020 and analyzed using high-performance liquid chromatography. This sales-driven approach to sampling has been shown to be very useful for conducting food monitoring studies. With the careful selection of a small proportion of available products, we finished with a manageable sample size, reflecting the composition of a majority (69%) of the national market share volume. The analyzed total sugar content was compared with labeled data, within the context of the European Union's regulatory labeling tolerances. In all samples, the sugar content was within the tolerance levels. The most common (N = 41) deviation was within ±10% of the labeled sugar content. In the subcategories, the differences between the analyzed and labeled median sugar contents were not statistically significant. Sucrose was most commonly (N = 36; 71%) used for sweetening, suggesting that the proportion of fructose in most SSBs was around 50%. A higher fructose content was only observed in beverages with fructose–glucose syrup or a higher content of fruit juice. The study results show that the labeled sugar content information in SSBs is reliable and can be used to compile branded food databases and monitor the nutritional quality of foods in the food supply.

From NAFLD to MAFLD: Aligning Translational In Vitro Research to Clinical Insights

Although most same-stage non-alcoholic fatty liver disease (NAFLD) patients exhibit similar histologic sequelae, the underlying mechanisms appear to be highly heterogeneous. Therefore, it was recently proposed to redefine NAFLD to metabolic dysfunction-associated fatty liver disease (MAFLD) in which other known causes of liver disease such as alcohol consumption or viral hepatitis do not need to be excluded. Revised nomenclature envisions speeding up and facilitating anti-MAFLD drug development by means of patient stratification whereby each subgroup would benefit from distinct pharmacological interventions. As human-based in vitro research fulfils an irrefutable step in drug development, action should be taken as well in this stadium of the translational path. Indeed, most established in vitro NAFLD models rely on short-term exposure to fatty acids and use lipid accumulation as a phenotypic benchmark. This general approach to a seemingly ambiguous disease such as NAFLD therefore no longer seems applicable. Human-based in vitro models that accurately reflect distinct disease subgroups of MAFLD should thus be adopted in early preclinical disease modeling and drug testing. In this review article, we outline considerations for setting up translational in vitro experiments in the MAFLD era and allude to potential strategies to implement MAFLD heterogeneity into an in vitro setting so as to better align early drug development with future clinical trial designs.

Dietary fructose and risk of metabolic syndrome in Chinese residents aged 45 and above: results from the China National Nutrition and Health Survey

BACKGROUND

A growing number of researches supported that dietary fructose was associated with most of the key features of metabolic syndrome (MetS). However, there was no related epidemiological studies among Chinese population, despite the sharp increase in MetS cases. This study explores the relationship between dietary fructose and MetS among Chinese residents aged 45 and above.

METHODS

A total of 25,528 participants (11,574 males and 13,954 females) were included in this nationwide representative cross-sectional study of China National Nutrition and Health Survey. Dietary fructose intake was assessed by 3-day 24-h dietary records. MetS was defined by the International Diabetes Federation and Chinese Diabetes Society criteria.

RESULTS

The consumption of dietary fructose was 11.6 g/day for urban residents and 7.6 g/day for rural residents. Fruits and vegetables as well as their products were the main sources of fructose intake. There was no association between dietary fructose intake and the odds of having MetS in both urban (P = 0.315) and rural residents (P = 0.230) after adjustment for confounding factors. Moreover, for urban residents participating physical activities, the odds of having MetS in the fourth quartiles (OR: 0.67; 95%CI: 0.52-0.87) was lower than that in the first quartile. In the sensitivity analysis, a significant reduction in the odds of having MetS was also found in the fourth quartiles (OR, 95%CI: 0.68, 0.51-0.90; 0.67, 0.49-0.91; 0.74, 0.56-0.99) compared with the first quartile when excluding smokers, alcohol users, and underweight/obesity, respectively. And there was no association between dietary fructose intake and the odds of having MetS after multivariate adjustment stratified by gender, smoking and alcohol use.

CONCLUSIONS

Under the current dietary fructose intake status, there was no association between dietary fructose intake and the odds of having MetS among Chinese residents aged 45 and above. Physical activity and relatively low fructose intake may have a beneficial synergistic effect on MetS.

Effects of High Dietary Carbohydrate and Lipid Intake on the Lifespan of C. elegans

Health and lifespan are influenced by dietary nutrients, whose balance is dependent on the supply or demand of each organism. Many studies have shown that an increased carbohydrate–lipid intake plays a critical role in metabolic dysregulation, which impacts longevity. Caenorhabditis elegans has been successfully used as an in vivo model to study the effects of several factors, such as genetic, environmental, diet, and lifestyle factors, on the molecular mechanisms that have been linked to healthspan, lifespan, and the aging process. There is evidence showing the causative effects of high glucose on lifespan in different diabetic models; however, the precise biological mechanisms affected by dietary nutrients, specifically carbohydrates and lipids, as well as their links with lifespan and longevity, remain unknown. Here, we provide an overview of the deleterious effects caused by high-carbohydrate and high-lipid diets, as well as the molecular signals that affect the lifespan of C. elegans; thus, understanding the detailed molecular mechanisms of high-glucose- and lipid-induced changes in whole organisms would allow the targeting of key regulatory factors to ameliorate metabolic disorders and age-related diseases.

Dietary fructose intake is correlated with fat distribution in the Newfoundland population

OBJECTIVE

Increased dietary fructose intake is associated with elevated body weight and body mass index. Few studies are available regarding the relationship between fat distribution and dietary fructose intake. The aim of this study was to investigate the association between dietary fructose intake and fat distribution in adults in a large Newfoundland cohort.

METHODS

We analyzed 2298 adults from CODING (Complex Diseases in the New found land Population: Environment and Genetics) study. Intake of dietary fructose was evaluated from the Willett food frequency questionnaire. Fat distribution was estimated by dual-energy x-ray absorptiometry. Partial correlation analysis was used to determine the correlations of dietary fructose intake with fat distribution adjusted for major confounding factors.

RESULTS

Daily dietary fructose intake was negatively associated with arm fat in postmenopausal women (r = -0.080, P < 0.05), but positively associated with arm fat in premenopausal women after adjusting for age, total calorie intake, and physical activity levels (r = 0.079, P < 0.05). Dietary fructose intake was negatively correlated with both arm fat (r = -0.131, P < 0.05) and visceral fat (r = -0.124 measured in mass, r = -0.124 measured in volume respectively; P < 0.05) in men <45 y of age, not in men ≥45 y.

CONCLUSION

This study demonstrated that dietary fructose intake is significantly correlated with arm fat in both women and men, and visceral fat in men in the Newfoundland free-living population. The correlations are sex- and menopause-status dependent.

Recent Developments in Rodent Models of High-Fructose Diet-Induced Metabolic Syndrome: A Systematic Review

Metabolic syndrome (MetS) is the physiological clustering of hypertension, hyperglycemia, hyperinsulinemia, dyslipidemia, and insulin resistance. The MetS-related chronic illnesses encompass obesity, the cardiovascular system, renal operation, hepatic function, oncology, and mortality. To perform pre-clinical research, it is imperative that these symptoms be successfully induced and optimized in lower taxonomy. Therefore, novel and future applications for a disease model, if proven valid, can be extrapolated to humans. MetS model establishment is evaluated based on the significance of selected test parameters, paradigm shifts from new discoveries, and the accessibility of the latest technology or advanced methodologies. Ultimately, the outcome of animal studies should be advantageous for human clinical trials and solidify their position in advanced medicine for clinicians to treat and adapt to serious or specific medical situations. Rodents (Rattus norvegicus and Mus musculus) have been ideal models for mammalian studies since the 18th century and have been mapped extensively. This review compiles and compares studies published in the past five years between the multitude of rodent comparative models. The response factors, niche parameters, and replicability of diet protocols are also compiled and analyzed to offer insight into MetS-related disease-specific modelling.

Impact of Energy Turnover on the Regulation of Energy and Macronutrient Balance

Energy turnover, defined as the average daily total metabolic rate, can be normalized for basal metabolic rate in order to compare physical activity level between individuals, whereas normalization of energy turnover for energy intake (energy flux) allows investigation of its impact on regulation of energy partitioning independent of energy balance. Appetite sensations better correspond to energy requirements at a high compared with a low energy turnover. Adaptation of energy intake to habitual energy turnover may, however, contribute to the risk of weight gain associated with accelerated growth, pregnancy, detraining in athletes, or after weight loss in people with obesity. The dose-response relationship between energy turnover and energy intake as well as the metabolic effects of energy turnover varies with the habitual level of physical activity and the etiology of energy turnover (e.g., cold-induced thermogenesis, growth, or lactation; aerobic vs. anaerobic exercise). Whether a high energy turnover due to physical activity or exercise may compensate for adverse effects of overfeeding or an unhealthy diet needs to be further investigated using the concept of energy flux. In summary, the beneficial effects of a high energy turnover on regulation of energy and macronutrient balance facilitate the prevention and treatment of obesity and associated metabolic risk.

Physiological responses to carbohydrate overfeeding

PURPOSE OF REVIEW

To consider emerging research into the physiological effects of excessive dietary carbohydrate intake, with a particular focus on interactions with physical activity.

RECENT FINDINGS

A single episode of massive carbohydrate overload initiates physiological responses to stimulate additional peptide hormone secretion by the gut and the conversion of carbohydrate into lipid by the intestine, liver and adipose tissue. These acute responses maintain glycaemic control both via increased oxidation of carbohydrate (rather than lipid) and via nonoxidative disposal of surplus carbohydrate into endogenous glycogen and lipid storage depots. Sustained carbohydrate overfeeding therefore results in a chronic accumulation of lipid in the liver, skeletal muscle and adipose tissue, which can impair insulin sensitivity and cardiometabolic health in general. Beyond any direct effect of such lipid deposition on body mass/composition, there is not yet clear evidence of physiologically meaningful metabolic or behavioural adaptations to carbohydrate overfeeding in terms of other components of energy balance. However, regular physical exercise can mitigate the negative health effects of carbohydrate overfeeding, independent of any effect on the net carbohydrate surplus.

SUMMARY

Research in this area has advanced understanding regarding the mechanisms of weight gain and associated health outcomes within the modern context of an abundant supply of dietary carbohydrate.

Sugar Fructose Triggers Gut Dysbiosis and Metabolic Inflammation with Cardiac Arrhythmogenesis

Fructose is a main dietary sugar involved in the excess sugar intake-mediated progression of cardiovascular diseases and cardiac arrhythmias. Chronic intake of fructose has been the focus on the possible contributor to the metabolic diseases and cardiac inflammation. Recently, the small intestine was identified to be a major organ in fructose metabolism. The overconsumption of fructose induces dysbiosis of the gut microbiota, which, in turn, increases intestinal permeability and activates host inflammation. Endotoxins and metabolites of the gut microbiota, such as lipopolysaccharide, trimethylamine N-oxide, and short-chain fatty acids, also influence the host inflammation and cardiac biofunctions. Thus, high-fructose diets cause heart-gut axis disorders that promote cardiac arrhythmia. Understanding how gut microbiota dysbiosis-mediated inflammation influences the pathogenesis of cardiac arrhythmia may provide mechanisms for cardiac arrhythmogenesis. This narrative review updates our current understanding of the roles of excessive intake of fructose on the heart-gut axis and proposes potential strategies for inflammation-associated cardiac vascular diseases.

Metabolism of sugars: A window to the regulation of glucose and lipid homeostasis by splanchnic organs

BACKGROUND &AIMS

Dietary sugars are absorbed in the hepatic portal circulation as glucose, fructose, or galactose. The gut and liver are required to process fructose and galactose into glucose, lactate, and fatty acids. A high sugar intake may favor the development of cardio-metabolic diseases by inducing Insulin resistance and increased concentrations of triglyceride-rich lipoproteins.

METHODS

A narrative review of the literature regarding the metabolic effects of fructose-containing sugars.

RESULTS

Sugars' metabolic effects differ from those of starch mainly due to the fructose component of sucrose. Fructose is metabolized in a set of fructolytic cells, which comprise small bowel enterocytes, hepatocytes, and kidney proximal tubule cells. Compared to glucose, fructose is readily metabolized in an insulin-independent way, even in subjects with diabetes mellitus, and produces minor increases in glycemia. It can be efficiently used for energy production, including during exercise. Unlike commonly thought, fructose when ingested in small amounts is mainly metabolized to glucose and organic acids in the gut, and this organ may thus shield the liver from potentially deleterious effects.

CONCLUSIONS

The metabolic functions of splanchnic organs must be performed with homeostatic constraints to avoid exaggerated blood glucose and lipid concentrations, and thus to prevent cellular damages leading to non-communicable diseases. Excess fructose intake can impair insulin-induced suppression of glucose production, stimulate de novo lipogenesis, and increase intrahepatic and blood triglyceride concentrations. With chronically high fructose intake, enterocyte can switch to lipid synthesis and accumulation of triglyceride, possibly causing an enterocyte dysfunction.

Fructose Metabolism in Cancer

The interest in fructose metabolism is based on the observation that an increased dietary fructose consumption leads to an increased risk of obesity and metabolic syndrome. In particular, obesity is a known risk factor to develop many types of cancer and there is clinical and experimental evidence that an increased fructose intake promotes cancer growth. The precise mechanism, however, in which fructose induces tumor growth is still not fully understood. In this article, we present an overview of the metabolic pathways that utilize fructose and how fructose metabolism can sustain cancer cell proliferation. Although the degradation of fructose shares many of the enzymes and metabolic intermediates with glucose metabolism through glycolysis, glucose and fructose are metabolized differently. We describe the different metabolic fates of fructose carbons and how they are connected to lipogenesis and nucleotide synthesis. In addition, we discuss how the endogenous production of fructose from glucose via the polyol pathway can be beneficial for cancer cells.

Metabolic Syndrome Triggered by Fructose Diet Impairs Neuronal Function and Vascular Integrity in ApoE-KO Mouse Retinas: Implications of Autophagy Deficient Activation

Metabolic syndrome is a disorder characterized by a constellation of clinical findings such as elevated blood glucose, hyperinsulinemia, dyslipidemia, hypertension, and obesity. A positive correlation has been found between metabolic syndrome or its components and retinopathy, mainly at microvascular level, in patients without a history of diabetes. Here, we extend the investigations beyond the vascular component analyzing functional changes as well as neuronal and glial response in retinas of Apolipoprotein E knockout (ApoE-KO) mice fed with 10% w/v fructose diet. Given that autophagy dysfunction is implicated in retinal diseases related to hyperglycemia and dyslipidemia, the activation of this pathway was also analyzed. Two months of fructose intake triggered metabolic derangements in ApoE-KO mice characterized by dyslipidemia, hyperglycemia and hyperinsulinemia. An increased number of TUNEL positive cells, in addition to the ganglion cell layer, was observed in the inner nuclear layer in retina. Vascular permeability, evidenced by albumin–Evans blue leakage and extravasation of albumin was also detected. Furthermore, a significant decrease of the glial fibrillary acidic protein expression was confirmed by Western blot analysis. Absence of both Müller cell gliosis and pro-angiogenic response was also demonstrated. Finally, retinas of ApoE-KO FD mice showed defective autophagy activation as judged by LC3B mRNA and p62 protein levels correlating with the increased cell death. These results demonstrated that FD induced in ApoE-KO mice biochemical alterations compatible with metabolic syndrome associated with neuronal impairment and mild vascular alterations in the retina.

Dose-response association between sugar- and artificially sweetened beverage consumption and the risk of metabolic syndrome: a meta-analysis of population-based epidemiological studies

OBJECTIVE

The associations between sugar-sweetened beverage (SSB) and artificially sweetened beverage (ASB) consumption and the risk of metabolic syndrome (MetS) remain controversial. A quantitative assessment of dose-response associations has not been reported. This study aims to assess the associations between the risk of MetS and SSB, ASB, and total sweetened beverage (TSB, the combination of SSB and ASB) consumption by reviewing population-based epidemiological studies.

DESIGN

Meta-analysis.

SETTING

We searched PubMed, Embase and Web of Science databases prior to 4 November 2019, for relevant studies investigating the SSB-MetS and ASB-MetS associations. A random effects model was used to estimate pooled relative risks (RR) and 95 % CI. Dose-response association was assessed using a restricted cubic splines model.

PARTICIPANTS

We identified seventeen articles (twenty-four studies, including 93 095 participants and 20 749 MetS patients).

RESULTS

The pooled RR for the risk of MetS were 1·51 (95 % CI 1·34, 1·69), 1·56 (1·32, 1·83) and 1·44 (1·19, 1·75) in high consumption group of TSB, SSB and ASB, respectively; and 1·20 (1·13, 1·28), 1·19 (1·11, 1·28) and 1·31 (1·05, 1·65) per 250 ml/d increase in TSB, SSB and ASB consumption, respectively. Additionally, we found evidence of non-linear, TSB-MetS and SSB-MetS dose-response associations and a linear ASB-MetS dose-response association.

CONCLUSIONS

TSB, SSB and ASB consumption was associated with the risk of MetS. The present findings provide evidence that supports reducing intake of these beverages to lower the TSB-, SSB- and ASB-related risk of MetS.

Bone Growth is Influenced by Fructose in Adolescent Male Mice Lacking Ketohexokinase (KHK)

Fructose is metabolized in the cytoplasm by the enzyme ketohexokinase (KHK), and excessive consumption may affect bone health. Previous work in calcium-restricted, growing mice demonstrated that fructose disrupted intestinal calcium transport. Thus, we hypothesized that the observed effects on bone were dependent on fructose metabolism and took advantage of a KHK knockout (KO) model to assess direct effects of high plasma fructose on the long bones of growing mice. Four groups (n = 12) of 4-week-old, male, C57Bl/6 background, congenic mice with intact KHK (wild-type, WT) or global knockout of both isoforms of KHK-A/C (KHK-KO), were fed 20% glucose (control diet) or fructose for 8 weeks. Dietary fructose increased by 40-fold plasma fructose in KHK-KO compared to the other three groups (p < 0.05). Obesity (no differences in epididymal fat or body weight) or altered insulin was not observed in either genotype. The femurs of KHK-KO mice with the highest levels of plasma fructose were shorter (2%). Surprisingly, despite the long-term blockade of KHK, fructose feeding resulted in greater bone mineral density, percent volume, and number of trabeculae as measured by µCT in the distal femur of KHK-KO. Moreover, higher plasma fructose concentrations correlated with greater trabecular bone volume, greater work-to-fracture in three-point bending of the femur mid-shaft, and greater plasma sclerostin. Since the metabolism of fructose is severely inhibited in the KHK-KO condition, our data suggest mechanism(s) that alter bone growth may be related to the plasma concentration of fructose.

The Role of Dietary Advanced Glycation End Products in Metabolic Dysfunction

Advanced glycation end products (AGEs) are a heterogeneous group of molecules produced, non-enzymatically, from the interaction between reducing sugars and the free amino groups of proteins, nucleic acids, and lipids. AGEs are formed as a normal consequence of metabolism but can also be absorbed from the diet. They have been widely implicated in the complications of diabetes affecting cardiovascular health, the nervous system, eyes, and kidneys. Increased levels of AGEs are also detrimental to metabolic health and may contribute to the metabolic abnormalities induced by the Western diet, which is high in processed foods and represents a significant source of AGEs. While increased AGE levels are a consequence of diabetic hyperglycaemia, AGEs themselves activate signaling pathways, which compromise insulin signaling and pancreatic β-cell function, thus, contributing to the development of type 2 diabetes mellitus (T2DM). Furthermore, AGEs may also contribute to the obesogenic effects of the Western diet by promoting hypothalamic inflammation and disrupting the central control of energy balance. Here, the role of dietary AGEs in metabolic dysfunction is reviewed with a focus on the mechanisms underpinning their detrimental role in insulin resistance, pancreatic β-cell dysfunction, hypothalamic control of energy balance, and the pathogenesis of T2DM and obesity.

Sugar-Sweetened Beverages and Cardiometabolic Health: An Update of the Evidence

Sugar-sweetened beverages (SSBs) have little nutritional value and a robust body of evidence has linked the intake of SSBs to weight gain and risk of type 2 diabetes (T2D), cardiovascular disease (CVD), and some cancers. Metabolic Syndrome (MetSyn) is a clustering of risk factors that precedes the development of T2D and CVD; however, evidence linking SSBs to MetSyn is not clear. To make informed recommendations about SSBs, new evidence needs to be considered against existing literature. This review provides an update on the evidence linking SSBs and cardiometabolic outcomes including MetSyn. Findings from prospective cohort studies support a strong positive association between SSBs and weight gain and risk of T2D and coronary heart disease (CHD), independent of adiposity. Associations with MetSyn are less consistent, and there appears to be a sex difference with stroke with greater risk in women. Findings from short-term trials on metabolic risk factors provide mechanistic support for associations with T2D and CHD. Conclusive evidence from cohort studies and trials on risk factors support an etiologic role of SSB in relation to weight gain and risk of T2D and CHD. Continued efforts to reduce intake of SSB should be encouraged to improve the cardiometabolic health of individuals and populations.

Fructose and metabolic health: governed by hepatic glycogen status?

Fructose is a commonly ingested dietary sugar which has been implicated in playing a particularly harmful role in the development of metabolic disease. Fructose is primarily metabolised by the liver in humans, and increases rates of hepatic de novo lipogenesis. Fructose increases hepatic de novo lipogenesis via numerous mechanisms: by altering transcriptional and allosteric regulation, interfering with cellular energy sensing, and disrupting the balance between lipid synthesis and lipid oxidation. Hepatic de novo lipogenesis is also upregulated by the inability to synthesise glycogen, either when storage is inhibited in knock‐down animal models or storage is saturated in glycogen storage disease. Considering that fructose has the capacity to upregulate hepatic glycogen storage, and replenish these stores more readily following glycogen depleting exercise, the idea that hepatic glycogen storage and hepatic de novo lipogenesis are linked is an attractive prospect. We propose that hepatic glycogen stores may be a key factor in determining the metabolic responses to fructose ingestion, and saturation of hepatic glycogen stores could exacerbate the negative metabolic effects of excessive fructose intake. Since physical activity potently modulates glycogen metabolism, this provides a rationale for considering nutrient–physical activity interactions in metabolic health.