The effects of equal caloric high fat and western diet on metabolic syndrome, oxidative stress and vascular endothelial function in mice

Systems genetics of metabolic health in the BXD mouse genetic reference population

Susceptibility to metabolic syndrome (MetS) is dependent on genetics, environment, and gene-by-environment interactions, rendering the study of underlying mechanisms challenging. The majority of experiments in model organisms do not incorporate genetic variation and lack specific evaluation criteria for MetS. Here, we derived a continuous metric, the metabolic health score (MHS), based on standard clinical parameters and defined its molecular signatures in the liver and circulation. In human UK Biobank, the MHS associated with MetS status and was predictive of future disease incidence, even in individuals without MetS. Using quantitative trait locus analyses in mice, we found two MHS-associated genetic loci and replicated them in unrelated mouse populations. Through a prioritization scheme in mice and human genetic data, we identified TNKS and MCPH1 as candidates mediating differences in the MHS. Our findings provide insights into the molecular mechanisms sustaining metabolic health across species and uncover likely regulators. A record of this paper's transparent peer review process is included in the supplemental information.

Western diet consumption impairs memory function via dysregulated hippocampus acetylcholine signaling

Western diet (WD) consumption during early life developmental periods is associated with impaired memory function, particularly for hippocampus (HPC)-dependent processes. We developed an early life WD rodent model associated with long-lasting HPC dysfunction to investigate the neurobiological mechanisms mediating these effects. Rats received either a cafeteria-style WD (ad libitum access to various high-fat/high-sugar foods; CAF) or standard healthy chow (CTL) during the juvenile and adolescent stages (postnatal days 26-56). Behavioral and metabolic assessments were performed both before and after a healthy diet intervention period beginning at early adulthood. Results revealed HPC-dependent contextual episodic memory impairments in CAF rats that persisted despite the healthy diet intervention. Given that dysregulated HPC acetylcholine (ACh) signaling is associated with memory impairments in humans and animal models, we examined protein markers of ACh tone in the dorsal HPC (HPCd) in CAF and CTL rats. Results revealed significantly lower protein levels of vesicular ACh transporter in the HPCd of CAF vs. CTL rats, indicating chronically reduced ACh tone. Using intensity-based ACh sensing fluorescent reporter (iAChSnFr) in vivo fiber photometry targeting the HPCd, we next revealed that ACh release during object-contextual novelty recognition was highly predictive of memory performance and was disrupted in CAF vs. CTL rats. Neuropharmacological results showed that alpha 7 nicotinic ACh receptor agonist infusion in the HPCd during training rescued memory deficits in CAF rats. Overall, these findings reveal a functional connection linking early life WD intake with long-lasting dysregulation of HPC ACh signaling, thereby identifying an underlying mechanism for WD-associated memory impairments.

Early- but not late-adolescent Western diet consumption programs for long-lasting memory impairments in male but not female rats

Early life Western diet (WD) consumption leads to impaired memory function, particularly for processes mediated by the hippocampus. However, the precise critical developmental window(s) during which WD exposure negatively impacts hippocampal function are unknown. Here, we exposed male and female rats to a WD model involving free access to a variety of high-fat and/or high-sugar food and drink items during either the early-adolescent period (postnatal days [PN] 26-41; WD-EA) or late-adolescent period (PN 41-56; WD-LA). Control (CTL) rats were given healthy standard chow throughout both periods. To evaluate long-lasting memory capacity well beyond the early life WD exposure periods, we performed behavioral assessments after both a short (4 weeks for WD-EA, 2 weeks for WD-LA) and long (12 weeks for WD-EA, 10 weeks for WD-LA) period of healthy diet intervention. Results revealed no differences in body weight or body composition between diet groups, regardless of sex. Following the shorter period of healthy diet intervention, both male and female WD-EA and WD-LA rats showed deficits in hippocampal-dependent memory compared to CTL rats. Following the longer healthy diet intervention period, memory impairments persisted in male WD-EA but not WD-LA rats. In contrast, in female rats the longer healthy diet intervention reversed the initial memory impairments in both WD-EA and WD-LA rats. Collectively, these findings reveal that early-adolescence is a critical period of long-lasting hippocampal vulnerability to dietary insults in male but not female rats, thus highlighting developmental- and sex-specific effects mediating the relationship between the early life nutritional environment and long-term cognitive health.

Early- but not late-adolescent Western diet consumption programs for long-lasting memory impairments in male but not female rats

Early life Western diet (WD) consumption leads to impaired memory function, particularly for processes mediated by the hippocampus. However, the precise critical developmental window(s) during which WD exposure negatively impacts hippocampal function are unknown. Here, we exposed male and female rats to a WD model involving free access to a variety of high-fat and/or high-sugar food and drink items during either the early-adolescent period (postnatal days [PN] 26-41; WD-EA) or late-adolescent period (PN 41-56; WD-LA). Control (CTL) rats were given healthy standard chow throughout both periods. To evaluate long-lasting memory capacity well beyond the early life WD exposure periods, we performed behavioral assessments after both a short (4 weeks for WD-EA, 2 weeks for WD-LA) and long (12 weeks for WD-EA, 10 weeks for WD-LA) period of healthy diet intervention. Results revealed no differences in body weight or body composition between diet groups, regardless of sex. Following the shorter period of healthy diet intervention, both male and female WD-EA and WD-LA rats showed deficits in hippocampal-dependent memory compared to CTL rats. Following the longer healthy diet intervention period, memory impairments persisted in male WD-EA but not WD-LA rats. In contrast, in female rats the longer healthy diet intervention reversed the initial memory impairments in both WD-EA and WD-LA rats. Collectively, these findings reveal that early-adolescence is a critical period of long-lasting hippocampal vulnerability to dietary insults in male but not female rats, thus highlighting developmental- and sex-specific effects mediating the relationship between the early life nutritional environment and long-term cognitive health.

Western diet consumption impairs memory function via dysregulated hippocampus acetylcholine signaling

Western diet (WD) consumption during development yields long-lasting memory impairments, yet the underlying neurobiological mechanisms remain elusive. Here we developed an early life WD rodent model to evaluate whether dysregulated hippocampus (HPC) acetylcholine (ACh) signaling, a pathology associated with memory impairment in human dementia, is causally-related to WD-induced cognitive impairment. Rats received a cafeteria-style WD (access to various high-fat/high-sugar foods; CAF) or healthy chow (CTL) during the juvenile and adolescent periods (postnatal days 26-56). Behavioral, metabolic, and microbiome assessments were performed both before and after a 30-day healthy diet intervention beginning at early adulthood. Results revealed CAF-induced HPC-dependent contextual episodic memory impairments that persisted despite healthy diet intervention, whereas CAF was not associated with long-term changes in body weight, body composition, glucose tolerance, anxiety-like behavior, or gut microbiome. HPC immunoblot analyses after the healthy diet intervention identified reduced levels of vesicular ACh transporter in CAF vs. CTL rats, indicative of chronically reduced HPC ACh tone. To determine whether these changes were functionally related to memory impairments, we evaluated temporal HPC ACh binding via ACh-sensing fluorescent reporter in vivo fiber photometry during memory testing, as well as whether the memory impairments could be rescued pharmacologically. Results revealed dynamic HPC ACh binding during object-contextual novelty recognition was highly predictive of memory performance and was disrupted in CAF vs. CTL rats. Further, HPC alpha-7 nicotinic receptor agonist infusion during consolidation rescued memory deficits in CAF rats. Overall, these findings identify dysregulated HPC ACh signaling as a mechanism underlying early life WD-associated memory impairments.

High-fat diet-induced elevation of body weight set point in male mice

OBJECTIVE

High-fat diets (HFD) are thought to disrupt energy homeostasis to drive overeating and obesity. However, weight loss resistance in individuals with obesity suggests that homeostasis is intact. This study aimed to reconcile this difference by systematically assessing body weight (BW) regulation under HFD.

METHODS

Male C57BL/6 N mice were fed diets with varying fat and sugar in different durations and patterns. BW and food intake were monitored.

RESULTS

BW gain was transiently accelerated by HFD (≥40%) prior to plateauing. The plateau was consistent regardless of starting age, HFD duration, or fat/sugar content. Reverting to a low-fat diet (LFD) caused transiently accelerated weight loss, which correlated with how heavy mice were before the diet relative to LFD-only controls. Chronic HFD attenuated the efficacy of single or repetitive dieting, revealing a defended BW higher than that of LFD-only controls.

CONCLUSIONS

This study suggests that dietary fat modulates the BW set point immediately upon switching from LFD to HFD. Mice defend a new elevated set point by increasing caloric intake and efficiency. This response is consistent and controlled, suggesting that hedonic mechanisms contribute to rather than disrupt energy homeostasis. An elevated floor of the BW set point after chronic HFD could explain weight loss resistance in individuals with obesity.

Reactive Oxygen Species in the Aorta and Perivascular Adipose Tissue Precedes Endothelial Dysfunction in the Aorta of Mice with a High-Fat High-Sucrose Diet and Additional Factors

Metabolic syndrome (Mets) is the major contributor to the onset of metabolic complications, such as hypertension, type 2 diabetes mellitus (DM), dyslipidemia, and non-alcoholic fatty liver disease, resulting in cardiovascular diseases. C57BL/6 mice on a high-fat and high-sucrose diet (HFHSD) are a well-established model of Mets but have minor endothelial dysfunction in isolated aortas without perivascular adipose tissue (PVAT). The purpose of this study was to evaluate the effects of additional factors such as DM, dyslipidemia, and steatohepatitis on endothelial dysfunction in aortas without PVAT. Here, we employed eight-week-old male C57BL/6 mice fed with a normal diet (ND), HFHSD, steatohepatitis choline-deficient HFHSD (HFHSD-SH), and HFHSD containing 1% cholesterol and 0.1% deoxycholic acid (HFHSD-Chol) for 16 weeks. At week 20, some HFHSD-fed mice were treated with streptozocin to develop diabetes (HFHSD-DM). In PVAT-free aortas, the endothelial-dependent relaxation (EDR) did not differ between ND and HFHSD (p = 0.25), but in aortas with PVAT, the EDR of HFHSD-fed mice was impaired compared with ND-fed mice (p = 0.005). HFHSD-DM, HFHSD-SH, and HFHSD-Chol impaired the EDR in aortas without PVAT (p < 0.001, p = 0.019, and p = 0.009 vs. ND, respectively). Furthermore, tempol rescued the EDR in those models. In the Mets model, the EDR is compromised by PVAT, but with the addition of DM, dyslipidemia, and SH, the vessels themselves may result in impaired EDR.

Western diet augments metabolic and arterial dysfunction in a sex-specific manner in outbred, genetically diverse mice

Western diet (WD), characterized by excess saturated fat and sugar intake, is a major contributor to obesity and metabolic and arterial dysfunction in humans. However, these phenotypes are not consistently observed in traditional inbred, genetically identical mice. Therefore, we sought to determine the effects of WD on visceral adiposity and metabolic/arterial function in UM-HET3 mice, an outbred, genetically diverse strain of mice. Male and female UM-HET3 mice underwent normal chow (NC) or WD for 12 weeks. Body mass and visceral adiposity were higher in WD compared to NC (P < 0.05). Female WD mice had greater visceral adiposity than male WD mice (P < 0.05). The results of glucose and insulin tolerance tests demonstrated that metabolic function was lower in WD compared to NC mice (P < 0.05). Metabolic dysfunction in WD as was driven by male mice, as metabolic function in female WD mice was unchanged (P > 0.05). Systolic blood pressure (BP) and aortic stiffness were increased in WD after 2 weeks compared to baseline and continued to increase through week 12 (P < 0.05). Systolic BP and aortic stiffness were higher from weeks 2-12 in WD compared to NC (P < 0.05). Aortic collagen content was higher in WD compared to NC (P < 0.05). Carotid artery endothelium-dependent dilation was lower in WD compared to NC (P < 0.05). These data suggest sex-related differences in visceral adiposity and metabolic dysfunction in response to WD. Despite this, arterial dysfunction was similar in male and female WD mice, indicating this model may provide unique translational insight into similar sex-related observations in humans that consume WD.

Resting metabolic rate, abdominal fat pad and liver metabolic gene expression in female rats provided a snacking diet from weaning to adulthood

Our female rat model with continuous, ad libitum access to snacks and chow from weaning to adulthood closely mimics human feeding behavior from childhood onwards. It causes weight gain, enlarged abdominal fat pads, reduced insulin sensitivity and leptin resistance without an increase in total caloric intake. Our current study investigated if this change in energy partitioning is due to a decrease in resting metabolic rate (RMR). In addition, we determined if carbohydrate and lipid metabolism changes in abdominal fat pads and liver. RMR, using indirect calorimetry, was determined in control and snacking rats every two weeks from Days 28-29 to Days 76-77. RMR decreased with age in both groups, but there was no difference between snacking and control rats at any age. At termination, abdominal fat pads (parametrial, retroperitoneal and mesenteric) and liver samples were collected for determination of gene expression for 21 genes involved in carbohydrate and lipid metabolism using RT-qPCR. Analysis of gene expression data showed a striking difference between metabolic profiles of control and snacking rats in abdominal fat pads and liver, with a distinct segregation of genes for both lipid and carbohydrate metabolism that correlated with an increase in body weight and fat pad weights. Genes involved in lipogenesis were upregulated in abdominal fat pads, while genes involved in adipogenesis, and lipid recycling were upregulated in the liver. In conclusion, snacking in addition to chow from weaning in female rats causes a repartitioning of energy that is not due to depressed RMR in snacking rats. Rather, snacking from weaning causes a shift in gene expression resulting in energy partitioning toward enhanced abdominal fat pad lipogenesis, and adipogenesis and lipid recycling in liver.

Astaxanthin Alleviates Nonalcoholic Fatty Liver Disease by Regulating the Intestinal Flora and Targeting the AMPK/Nrf2 Signal Axis

Nonalcoholic fatty liver disease (NAFLD) is among the most prevalent chronic liver diseases around the globe. The accumulation of lipids in the liver and oxidative stress are important pathological mechanisms of NAFLD. Astaxanthin (AT) is a carotenoid extracted from shrimps and crabs with beneficial biological activities, including anti-oxidative and anti-inflammatory activities. 16S microflora sequencing, H&E staining, and the western blot technique were employed to investigate the impacts of AT on a high-fat diet (HFD)-induced NAFLD. Significant mitigation in lipid metabolism-related disorders and decreased oxidative stress in HFD-induced mice were observed due to AT, and significant changes in the gut flora of the model mice were also observed. The in vitro study showed that AT considerably lowered the protein expression level of fatty acid synthetase (FAS), sterol regulatory element-binding protein-1c (SREBP-1c), and acetyl-COA carboxylase (ACC) and increased the protein expression of nuclear factor-E2 associated factor 2 (Nrf2) and AMP-activated protein kinase (AMPK) in oleic acid (OA) and palmitic acid (PA)-induced HepG2 cells. Additionally, mechanistic studies revealed that compound C (AMPK inhibitor, CC) inhibited the regulatory effect of AT on the SREBP-1c and Nrf2 signaling pathways. In conclusion, AT can inhibit the SREBP-1c, FAS, and ACC signaling pathways, activate the AMPK and Nrf2 signaling pathways, and improve the structure of intestinal flora.

The association between major dietary patterns with the risk of non-alcoholic fatty liver disease, oxidative stress and metabolic parameters: A case-control study

Purpose

Non-alcoholic fatty liver disease (NAFLD) is caused by the increase of fat in the liver. The present study aimed to study the association between different dietary patterns and NAFLD in adults.

Methods

This study included 121 adult patients with NAFLD and 119 non-NAFLD. Dietary intake was calculated by a 168-item food frequency questionnaire. Biochemical markers were measured. Dietary patterns were determined by factor analysis. The association between dietary patterns and NAFLD was evaluated using multiple logistic regression analysis.

Results

Two dietary patterns (healthy, western) were recognized in participants. Western dietary pattern was related with 72 percent increase in the odds of NAFLD (OR: 1.72; 95% CI: 1.32,2.14), after adjustment for covariates. Healthy dietary pattern was associated with 38 percent lower odds of NAFLD (OR: 0.38; 95% CI: 0.11, 0.65). Adherence to the western diet was related to 0.486 greater amounts of ALT, 3.248 mg/dl higher levels of FBS, and 3.989 mg/dl greater amounts of TG and 2.354 mg/dl greater amounts of MDA after adjusting for confounding factors (p > 0.001, p = 0.042, p > 0.001, p = 0.036 respectively). The healthy dietary pattern score was negatively associated with FBS and Cholesterol and TG levels (p = 0.035, p = 0.048, and p = 0.025), respectively. Moreover, it was associated with 3.211 mg/dl higher levels of TAC (p = 0.049).

Conclusions

There is a significant relationship between dietary patterns and non-alcoholic fatty liver disease. Adherence to a western dietary pattern is related to an increase in non-alcoholic fatty liver disease.

Metabolic syndrome and its determinants among professional drivers: a systematic review and meta-analysis

Background

Drivers are one of the trade unions that are most exposed to various health-related risks, especially metabolic diseases. The present study aimed to systematically assess the overall prevalence of metabolic syndrome and its determinants among drivers in the world.

Methods

All retrospective, cross-sectional, or prospective studies evaluating the prevalence and risk for metabolic syndrome and its main components among male professional drivers were eligible for the initial assessment. PRISMA guideline was used. Two blinded reviewers independently screened the titles and abstracts of the manuscripts followed by a deep assessment of the full texts for determining the inclusion appropriateness.

Results

In the final, 12 articles were eligible for the final analysis. Overall, 19,350 professional male drivers with a total average age of 43.06 years (ranged from 35.5 to 51.1 years) were included in the study. The prevalence of metabolic syndrome was estimated to be 32.8% (95%CI: 32.1% to 33.5%), and the major determinants of appearing this syndrome among professional drivers were advanced age, years of driving experience, higher body mass index, smoking, high cholesterol dietary regimen, high Framingham risk score, low regular exercising, history of diabetes mellitus, history of gout, and shift work pattern.

Conclusion

According to the 32.8% prevalence rate of metabolic syndrome among drivers, managerial measures are needed to prevent and control metabolic disturbances among professional drivers are recommended.

Postnatally induced metabolic and oxidative changes associated with maternal high-fat consumption were mildly affected by Quercetin-3-O-rutinoside treatment in rats

Oxidative stress is usually associated with prolonged intake of high-fat diet (HFD). However, little is known about the impact of maternal HFD on endogenous modulation of antioxidant-defence-enzyme-network, its link to adverse fetal growth and overall effects of Quercetin-3-o-rutinoside (QR) supplementation. Sprague-Dawley rats were initially assigned to normal diet (ND) or HFD for 8 weeks and mated. Post-conception, rats were further divided into four groups, of which two groups had diets supplemented with QR while others continued with their respective diets until delivery. Measurements include food and water consumption, physical parameters (body weight, body mass index (BMI) and fur appearance), oral glucose tolerance, lipid profiles, and placental/liver oxidative changes. We observed that water consumption was significantly increased in dams fed HFD without marked differences in food intake, body weight, BMI and glucose tolerance. Surprisingly, offspring of HFD-fed dams had reduced body weight marked by delayed fur appearance compared to the ND offspring. In dams, there were alterations in lipid profile. Lipid peroxidation was increased in the placenta and liver of gestational day (GD) 19 HFD-fed dams and their postnatal day (PND) 21 male offspring. There was evidence of HFD-induced nitrosative stress in dams and PND28 female offspring. Adaptive defence indicate decreased placenta and liver superoxide dismutase (SOD) levels as well as differential changes in total antioxidant capacity (TAC) and catalase (CAT) activity in HFD treated dams and their progenies. Overall, the results indicate that intrauterine metabolic alterations associated with maternal high-fat consumption may induce oxidative challenge in the offspring accompanied by mild developmental consequences, while QR supplementation has little or no beneficial effects.

Fortifying Butterfat with Soybean Oil Attenuates the Onset of Diet-Induced Non-Alcoholic Steatohepatitis and Glucose Intolerance

The addition of plant oils such as soybean oil (S) to a diet rich in saturated fatty acids is discussed as a possible route to prevent or diminish the development of metabolic disease. Here, we assessed whether a butterfat-rich diet fortified with S affects the development of early non-alcoholic steatohepatitis (NASH) and glucose intolerance. Female C57BL/6J mice were fed a standard-control diet (C); a fat-, fructose-, and cholesterol-rich diet (FFC, 25E% butterfat, 50% (wt./wt.) fructose, 0.16% (wt./wt.) cholesterol); or FFC supplemented with S (FFC + S, 21E% butterfat + 4E% S) for 13 weeks. Indicators of liver damage, inflammation, intestinal barrier function, and glucose metabolism were measured. Lipopolysaccharide (LPS)-challenged J774A.1 cells were incubated with linolenic and linoleic acids (ratio 1:7.1, equivalent to S). The development of early NASH and glucose intolerance was significantly attenuated in FFC + S–fed mice compared to FFC-fed mice associated with lower hepatic toll-like receptor-4 mRNA expression, while markers of intestinal barrier function were significantly higher than in C-fed mice. Linolenic and linoleic acid significantly attenuated LPS-induced formation of reactive nitrogen species and interleukin-1 beta mRNA expression in J774A.1 cells. Our results indicate that fortifying butterfat with S may attenuate the development of NASH and glucose intolerance in mice.

Antioxidant and Anti-Inflammatory Potential of Polyphenols Contained in Mediterranean Diet in Obesity: Molecular Mechanisms

Nutrition transition can be defined as shifts in food habits, and it is characterized by high-fat (chiefly saturated animal fat), hypercaloric and salty food consumption at the expense of dietary fibers, minerals and vitamins. Western dietary patterns serve as a model for studying the impact of nutrition transition on civilization diseases, such as obesity, which is commonly associated with oxidative stress and inflammation. In fact, reactive oxygen species (ROS) overproduction can be associated with nuclear factor-κB (NF-κB)-mediated inflammation in obesity. NF-κB regulates gene expression of several oxidant-responsive adipokines including tumor necrosis factor-α (TNF-α). Moreover, AMP-activated protein kinase (AMPK), which plays a pivotal role in energy homeostasis and in modulation of metabolic inflammation, can be downregulated by IκB kinase (IKK)-dependent TNF-α activation. On the other hand, adherence to a Mediterranean-style diet is highly encouraged because of its healthy dietary pattern, which includes antioxidant nutraceuticals such as polyphenols. Indeed, hydroxycinnamic derivatives, quercetin, resveratrol, oleuropein and hydroxytyrosol, which are well known for their antioxidant and anti-inflammatory activities, exert anti-obesity proprieties. In this review, we highlight the impact of the most common polyphenols from Mediterranean foods on molecular mechanisms that mediate obesity-related oxidative stress and inflammation. Hence, we discuss the effects of these polyphenols on a number of signaling pathways. We note that Mediterranean diet (MedDiet) dietary polyphenols can de-regulate nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) and NF-κB-mediated oxidative stress, and metabolic inflammation. MedDiet polyphenols are also effective in upregulating downstream effectors of several proteins, chiefly AMPK.

Impact of overall diet quality on association between alcohol consumption and risk of hypertension: evidence from two national surveys with multiple ethnics

BACKGROUND/OBJECTIVES

Alcohol is commonly consumed around mealtimes. This study hypothesized that the association between alcohol and hypertension was influenced by overall diet quality. This study aims to test the hypothesis that overall diet quality influenced associations between alcohol and risk of hypertension across different ethnicities.

SUBJECTS/METHODS

Using nationally representative data from National Health and Nutrition Examination Survey(NHANES 03-12), China Health Nutrition Survey (CHNS), and an independent population-based study, 43,914 adults were included. Subgroup analysis included 6984 adults from CHNS with a 14-year follow-up. Light alcohol consumption was defined as <7standard drinks/week, moderate as 7-21 drinks/week, and heavy as >21 drinks/week. Alternative healthy eating index and diet balance index were calculated as indicators of diet quality.

RESULTS

There were 3968 hypertensives in Caucasians (N = 11,325), 1976 in Africans (N = 5010), 1907 in Hispanics (N = 7274) and 5267 (N = 20,305) in Chinese. In context of high diet quality, light alcohol consumption was significantly associated with decreased risk of hypertension in Caucasians, and the risk of hypertension was not significantly increased with increasing in alcohol consumption in Caucasians, Chinese, and Hispanics (all P_{for trend} > 0.05). On the contrary, in context of low diet quality, the risk of hypertension was significantly increased with increasing in alcohol consumption in Caucasians (P_{for trend} = 0.005), Chinese (P_{for trend} = 0.001) and Hispanics (P_{for trend} = 0.022). Associations between alcohol consumption and risk of hypertension significantly varied by diet-quality scores in Caucasians, Hispanics, and Chinese (all P_{for interaction} < 0.01) showing gradually changing from nonsignificant increasing trend to linear association.

CONCLUSIONS

This study firstly demonstrated that overall diet quality influenced associations between alcohol and risk of hypertension across different ethnicities, emphasizing that when examining health effects of alcohol on blood pressure, diet quality should be considered.

Modeling Diet-Induced Metabolic Syndrome in Rodents

Standardized animal models represent one of the most valuable tools available to understand the mechanism underlying the metabolic syndrome (MetS) and to seek for new therapeutic strategies. However, there is considerable variability in the studies conducted with this essential purpose. This review presents an updated discussion of the most recent studies using diverse experimental conditions to induce MetS in rodents with unbalanced diets, discusses the key findings in metabolic outcomes, and critically evaluates what we have been learned from them and how to advance in the field. The study includes scientific reports sourced from the Web of Science and PubMed databases, published between January 2013 and June 2020, which used hypercaloric diets to induce metabolic disorders, and address the impact of the diet on metabolic parameters. The collected data are used as support to discuss variables such as sex, species, and age of the animals, the most favorable type of diet, and the ideal diet length to generate metabolic changes. The experimental characteristics propose herein improve the performance of a preclinical model that resembles the human MetS and will guide researchers to investigate new therapeutic alternatives with confidence and higher translational validity.

Fortifying diet with rapeseed oil instead of butterfat attenuates the progression of diet-induced non-alcoholic fatty liver disease (NAFLD) and impairment of glucose tolerance

BACKGROUND

Absolute dietary fat intake but even more so fatty acid pattern is discussed to be critical in the development of non-alcoholic fatty liver disease (NAFLD). Here, we determined if switching a butterfat enriched diet to a rapeseed oil (RO) enriched diet affects progression of an existing NAFLD and glucose intolerance in mice.

METHODS

For eight weeks, female C57Bl/6J mice were either fed a liquid control (C) or a butterfat-, fructose- and cholesterol-rich diet (BFC, 25E% butterfat) to induce early signs of steatohepatitis and glucose intolerance in mice. For additional five weeks mice received either BFC or C or a fat-, fructose- and cholesterol-rich and control diet, in which butterfat was replaced with RO (ROFC and CRO). Markers of glucose metabolism, liver damage and intestinal barrier were assessed.

RESULTS

Exchanging butterfat with RO attenuated the progression of BFC diet-induced NAFLD and glucose intolerance. Beneficial effects of RO were associated with lower portal endotoxin levels and an attenuation of the induction of the toll-like receptor-4-dependent signaling cascades in liver. Peroxisome proliferator-activated receptor γ activity was induced in small intestine of ROFC-fed mice.

CONCLUSION

Taken together, exchanging butterfat with RO attenuated the progression of diet-induced steatohepatitis and glucose intolerance in mice.

The Potential for Reducing Lynch Syndrome Cancer Risk with Nutritional Nrf2 Activators

Lynch syndrome (LS), is an autosomal dominant disorder predisposing patients to multiple cancers, predominantly colorectal (CRC) and endometrial, and is implicated in 2-4% of all CRC cases. LS is characterized by mutations of four mismatch repair (MMR) genes which code for proteins responsible for recognizing and repairing DNA lesions occurring through multiple mechanisms including oxidative stress (OS). Increased OS can cause DNA mutations and is considered carcinogenic. Due to reduced MMR activity, LS patients have an increased risk of cancer as a result of a decreased ability to recognize and repair DNA lesions caused by OS. Due to its carcinogenic properties, reducing the level of OS may reduce the risk of cancer. Nutritional Nrf2 activators have been shown to reduce the risk of carcinogenesis in the general population through activation of the endogenous antioxidant system. Common nutritional Nrf2 activators include sulforaphane, curcumin, DATS, quercetin, resveratrol, and EGCG. Since LS patients are more susceptible to carcinogenesis caused by OS, it is hypothesized that nutritional Nrf2 activators may have the potential to reduce the risk of cancer in those with LS by modulating OS and inflammation. The purpose of this paper is to review the available evidence in support of this statement.

Chitin-glucan and pomegranate polyphenols improve endothelial dysfunction

The vascular dysfunction is the primary event in the occurrence of cardio-vascular risk, and no treatment exists until now. We tested for the first time the hypothesis that chitin-glucan (CG) - an insoluble fibre with prebiotic properties- and polyphenol-rich pomegranate peel extract (PPE) can improve endothelial and inflammatory disorders in a mouse model of cardiovascular disease (CVD), namely by modulating the gut microbiota. Male Apolipoprotein E knock-out (ApoE-/-) mice fed a high fat (HF) diet developed a significant endothelial dysfunction attested by atherosclerotic plaques and increasing abundance of caveolin-1 in aorta. The supplementation with CG + PPE in the HF diet reduced inflammatory markers both in the liver and in the visceral adipose tissue together with a reduction of hepatic triglycerides. In addition, it increased the activating form of endothelial NO-synthase in mesenteric arteries and the heme-nitrosylated haemoglobin (Hb-NO) blood levels as compared with HF fed ApoE-/- mice, suggesting a higher capacity of mesenteric arteries to produce nitric oxide (NO). This study allows to pinpoint gut bacteria, namely Lactobacillus and Alistipes, that could be implicated in the management of endothelial and inflammatory dysfunctions associated with CVD, and to unravel the role of nutrition in the modulation of those bacteria.

Utilizing a low-carbohydrate/high-protein diet to improve metabolic health in individuals with spinal cord injury (DISH): study protocol for a randomized controlled trial

Background

Metabolic disorders (e.g., impaired glucose tolerance, insulin resistance, and type 2 diabetes) are more prevalent in people with spinal cord injury (SCI) than able-bodied individuals. Dietary modification is a more cost-effective treatment option than pharmacological therapies for reducing the risk of metabolic dysfunction. Lowering carbohydrate, increasing protein, and maintaining a proper dietary fat intake are expected to induce favorable adaptations in glucose control, body fat distribution, and the composition of the gut microbiome. However, dietary modification has not been rigorously investigated in people with SCI. The purpose of this study is to determine if an 8-week low-carbohydrate/high-protein (LC/HP) dietary intervention will show improvements in clinically important metrics of metabolic function, body composition, the composition of gut bacteria, and quality of life.

Methods/design

We intend to recruit 100 participants with chronic traumatic SCI (3 years postinjury, C5–L2, American Spinal Injury Association impairment scale A–D, and aged 18–65 years) and insulin resistance, impaired glucose tolerance or untreated type 2 diabetes and randomly assign them to an 8-week LC/HP dietary intervention group or a control group. The daily LC/HP dietary intervention includes ~ 30% total energy as protein (1.6 g/kg per day) with a carbohydrate-to-protein ratio < 1.5 and fat intake set at ~ 30% of the total energy intake. The control group does not receive any dietary intervention and are continuing with their regular daily diets. Glucose tolerance, insulin sensitivity, β-cell function, body composition, gut microbiome composition, and quality of life measures are assessed at week 1, before starting the LC/HP dietary intervention, and at week 8, after completion of the LC/HP dietary intervention.

Discussion

New information derived from this project will result in the development of a low-cost, simple, self-administered LC/HP dietary intervention for improving metabolic function in individuals with chronic SCI, improved understanding of the composition of gut bacteria in SCI, and how a LC/HP dietary intervention alters gut bacteria composition. In addition, this project will improve our understanding of the relationship between metabolic function and quality of life in individuals with long-standing SCI.

Trial registration

ClinicalTrials.gov, NCT03207841. Registered on 5 June 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3520-3) contains supplementary material, which is available to authorized users.

How Western Diet And Lifestyle Drive The Pandemic Of Obesity And Civilization Diseases

Westernized populations are plagued by a plethora of chronic non-infectious degenerative diseases, termed as "civilization diseases", like obesity, diabetes, cardiovascular diseases, cancer, autoimmune diseases, Alzheimer's disease and many more, diseases which are rare or virtually absent in hunter-gatherers and other non-westernized populations. There is a growing awareness that the cause of this amazing discrepancy lies in the profound changes in diet and lifestyle during recent human history. This paper shows that the transition from Paleolithic nutrition to Western diets, along with lack of corresponding genetic adaptations, cause significant distortions of the fine-tuned metabolism that has evolved over millions of years of human evolution in adaptation to Paleolithic diets. With the increasing spread of Western diet and lifestyle worldwide, overweight and civilization diseases are also rapidly increasing in developing countries. It is suggested that the diet-related key changes in the developmental process include an increased production of reactive oxygen species and oxidative stress, development of hyperinsulinemia and insulin resistance, low-grade inflammation and an abnormal activation of the sympathetic nervous system and the renin-angiotensin system, all of which play pivotal roles in the development of diseases of civilization. In addition, diet-related epigenetic changes and fetal programming play an important role. The suggested pathomechanism is also able to explain the well-known but not completely understood close relationship between obesity and the wide range of comorbidities, like type 2 diabetes mellitus, cardiovascular disease, etc., as diseases of the same etiopathology. Changing our lifestyle in accordance with our genetic makeup, including diet and physical activity, may help prevent or limit the development of these diseases.

Luteolin Prevents Cardiometabolic Alterations and Vascular Dysfunction in Mice With HFD-Induced Obesity

Purpose: Luteolin exerts beneficial effects against obesity-associated comorbidities, although its influence on vascular dysfunction remains undetermined. We examined the effects of luteolin on endothelial dysfunction in a mouse model of diet-induced obesity. Methods: Standard diet (SD) or high-fat diet (HFD)-fed mice were treated daily with luteolin intragastrically. After 8 weeks, body and epididymal fat weight, as well as blood cholesterol, glucose, and triglycerides were evaluated. Endothelium-dependent relaxations of resistance mesenteric vessels was assessed by a concentration-response curve to acetylcholine, repeated upon N^w-nitro-L-arginine methylester (L-NAME) or ascorbic acid infusion to investigate the influence of nitric oxide (NO) availability and reactive oxygen species (ROS) on endothelial function, respectively. Intravascular ROS production and TNF levels were measured by dihydroethidium dye and ELISA, respectively. Endothelial NO synthase (eNOS) and superoxide dismutase 1 (SOD1), as well as microRNA-214-3p expression were examined by Western blot and RT-PCR assays, respectively. Results: HFD animals displayed elevated body weight, epididymal fat weight and metabolic indexes. Endothelium-dependent relaxation was resistant to L-NAME and enhanced by ascorbic acid, which restored also the inhibitory effect of L-NAME, suggesting a ROS-dependent reduction of NO availability in HFD vessels. Moreover, media-lumen ratio, intravascular superoxide anion and TNF levels were increased, while vascular eNOS, SOD1, and microRNA-214-3p expression were decreased. In HFD mice, luteolin counteracted the increase in body and epididymal fat weight, and metabolic alterations. Luteolin restored vascular endothelial NO availability, normalized the media-lumen ratio, decreased ROS and TNF levels, and normalized eNOS, SOD1 and microRNA-214-3p expression. Conclusion: Luteolin prevents systemic metabolic alterations and vascular dysfunction associated with obesity, likely through antioxidant and anti-inflammatory mechanisms.

Flavonoids as putative modulators of Δ4-, Δ5-, and Δ6-desaturases: Studies in cultured hepatocytes, myocytes, and adipocytes

This study was conducted to screen flavonoids for affecting expression of desaturases involved in omega-3 fatty acid synthesis and ceramide (CER) metabolism. To this end, cultured HepG2 hepatocytes, C2C12 myocytes, and 3T3-L1 adipocytes were treated with nontoxic concentrations of 12 selected flavonoids and expression of Δ4-, Δ5-, and Δ6-desaturases (DEGS1, FADS1, and FADS2, respectively) was determined. The flavonoids tested were more cytotoxic to HepG2 and 3T3-L1 than to C2C12 cells. In HepG2 cells, FADS1 was induced by quercetin and FADS2 expression was increased by daidzein, genistein, and pratensein treatment. DEGS1 was increased by apigenin, luteolin, orobol, and quercetin administration. In differentiated C2C12 cells, substances had no inducing effect or even lowered target gene expression. Pratensein induced both FADS1 and FADS2 in differentiated 3T3-L1 cells and DEGS1 was increased by treatment with apigenin, genistein, luteolin, orobol, and quercetin. In conclusion, pratensein may be an interesting test compound for further studies in vitro and in vivo on omega-3 synthesis since it induces its rate-limiting enzyme FADS2. Apigenin, luteolin, orobol, and quercetin induced DEGS1 and thereby possibly synthesis of proapoptotic CER in malignant HepG2 cells and 3T3-L1. In contrast, in benign C2C12 cells, they did not elevate mRNA steady state levels of DEGS1. That may partly explain the higher resistance of C2C12 cells against flavonoids compared to the other cell lines. By affecting tumor cells and nontumor cells differently, these flavonoids may be promising substances for further research regarding anticancer properties. © 2018 BioFactors, 44(5):485-495, 2018.

Decreased EDHF-mediated relaxation is a major mechanism in endothelial dysfunction in resistance arteries in aged mice on prolonged high-fat sucrose diet

High‐fat sucrose (HFS) diet in aged individuals causes severe weight gain (obesity) with much higher risk of cardiovascular diseases such as hypertension or atherosclerosis. Endothelial dysfunction is a major contributor for these vascular disorders. We hypothesize that prolonged ingestion of HFS diet by aged mice would accentuate endothelial dysfunction in the small resistance arteries. Male C57BL/6J mice at 12 weeks of age were divided into four groups and fed either normal chow (NC) or high‐fat sucrose diet (HFS). Young group received NC for 4 months, and high‐fat diet (HFD) for 3 months and 1 month HFS + 10% Sucrose (HFS diet). Aged mice received NC for 12 months. Aged HFS group received HFD for 4 months + 1 month HFD + 10% sucrose + 8 months HFD. Total body weight, plasma blood glucose levels, and glucose tolerance were determined in all groups. Isolated mesenteric arteries were assessed for arterial remodeling, myogenic tone, and vasomotor responses using pressure and wire myography. Both young and aged HFS mice showed impaired glucose tolerance (Y‐NC, 137 ± 8.5 vs. Y‐NC HFS, 228 ± 11.71; A‐NC, 148 ± 6.42 vs. A‐HFS, 225 ± 10.99), as well as hypercholesterolemia (Y‐NC 99.50 ± 6.35 vs. Y‐HFS 220.40 ± 16.34 mg/dL; A‐NC 108.6 ± vs. A‐HFS 279 ± 21.64) and significant weight gain (Y‐NC 32.13 ± 0.8 g vs. Y‐HFS 47.87 ± 2.18 g; A‐NC 33.72 vs. A‐HFS 56.28 ± 3.47 g) compared to both groups of mice on NC. The mesenteric artery from mice with prolonged HFS diet resulted in outward hypertrophic remodeling, increased stiffness, reduced myogenic tone, impaired vasodilation, increased contractility and blunted nitric oxide (NO) and EDH‐mediated relaxations. Ebselen, a peroxinitrite scavenger rescued the endothelium derived relaxing factor (EDHF)‐mediated relaxations. Our findings suggest that prolonged diet‐induced obesity of aged mice can worsen small resistance artery endothelial dysfunction due to decrease in NO and EDHF‐mediated relaxation, but, EDHF‐mediated relaxation is a major contributor to overall endothelial dysfunction.

Longitudinal effects of developmental bisphenol A, variable diet, and physical activity on age-related methylation in blood

Research indicates that environmental factors can alter DNA methylation, but the specific effects of environmental exposures on epigenetic aging remain unclear. Here, using a mouse model of human-relevant exposures, we tested the hypothesis that early-life exposure to bisphenol A (BPA), variable diet, and/or changes in physical activity would modify rates of age-related methylation at several target regions, as measured from longitudinal blood samples (2, 4, and 10 months old). DNA methylation was quantified at two repetitive elements (LINE-1, IAP), two imprinted genes (Igf2, H19), and one non-imprinted gene (Esr1) in isogenic mice developmentally exposed to Control, Control + BPA (50 µg/kg diet), Western high-fat diet (WHFD), or Western + BPA diets. In blood samples, Esr1 DNA methylation increased significantly with age, but no other investigated loci showed significant age-related methylation. LINE-1 and IAP both showed significant negative environmental deflection by WHFD exposure (P < 0.05). Esr1also showed significant negative environmental deflection by WHFD exposure in female mice (P = 0.02), but not male mice. Physical activity had a non-significant positive effect on age-related Esr1 methylation in female blood, suggesting that it may partially abrogate the effects of WHFD on the aging epigenome. These results suggest that developmental nutritional exposures can modify age-related DNA methylation patterns at a gene related to growth and development. As such, environmental deflection of the aging epigenome may help to explain the growing prevalence of chronic diseases in human populations.

Pepsin egg white hydrolysate ameliorates metabolic syndrome in high-fat/high-dextrose fed rats

The aim of this study was to examine the effect of a pepsin egg white hydrolysate (EWH) on metabolic complications using a high-fat/high-dextrose diet-induced Metabolic Syndrome (MetS) experimental model. Male Wistar rats were divided into 4 groups which received: standard diet and water (C), standard diet and a solution with 1 g kg^-1 day^-1 of EWH (CH), high-fat/high-dextrose diet and water (MS), and high-fat/high-dextrose diet and a solution with 1 g kg^-1 day^-1 of EWH (MSH). EWH consumption normalized body weight gain; abdominal obesity and peripheral neuropathy developed in MetS animals, and adipose tissue and liver weight, as well as plasma glucose were reduced. Oxidative stress and inflammation biomarkers were normalized in MSH animals. In conclusion, the oral administration of EWH could be used as a functional food ingredient to improve some complications associated with MetS induced by unhealthy diets.

Exposure to Vinyl Chloride and Its Influence on Western Diet-Induced Cardiac Remodeling

Obesity, usually caused by high fat diets (HFD), is a major public health issue worldwide, causing obesity associated cardiomyopathy. Moreover, the environmental toxicant vinyl chloride (VC) can exacerbate HFD-induced fatty liver disease. However, whether VC serves to enhance obesity-associated cardiomyopathy remains unclear. This study aims to investigate the interaction of western diet (WD) containing relatively low fat (42%) with VC on cardiac remodeling and its underling mechanisms. Adult male C57BL/6J mice were exposed to WD coinhalation of low-dose VC (<1 ppm/d) for 12 weeks. Results showed that WD feeding for 12 weeks caused slight cardiac systolic dysfunction without significant hypertrophy or fibrosis, even with VC. Nevertheless, WD upregulated NF-κB function and expression of IL-1β and PAI-1, while VC showed no significant impact on these effects. In contrast, WD together with VC significantly increased the expression of CHOP and TGF-β1, key markers for endoplasmic reticulum stress and profibrotic cytokine, respectively. In summary, exposure to low-dose of environmental toxicant VC while a WD is consumed for a relatively short time does not have significant impact on cardiac remodeling except for a mild systolic dysfunction of the heart.

Nutritionally recommended food for semi- to strict vegetarian diets based on large-scale nutrient composition data

Diet design for vegetarian health is challenging due to the limited food repertoire of vegetarians. This challenge can be partially overcome by quantitative, data-driven approaches that utilise massive nutritional information collected for many different foods. Based on large-scale data of foods' nutrient compositions, the recent concept of nutritional fitness helps quantify a nutrient balance within each food with regard to satisfying daily nutritional requirements. Nutritional fitness offers prioritisation of recommended foods using the foods' occurrence in nutritionally adequate food combinations. Here, we systematically identify nutritionally recommendable foods for semi- to strict vegetarian diets through the computation of nutritional fitness. Along with commonly recommendable foods across different diets, our analysis reveals favourable foods specific to each diet, such as immature lima beans for a vegan diet as an amino acid and choline source, and mushrooms for ovo-lacto vegetarian and vegan diets as a vitamin D source. Furthermore, we find that selenium and other essential micronutrients can be subject to deficiency in plant-based diets, and suggest nutritionally-desirable dietary patterns. We extend our analysis to two hypothetical scenarios of highly personalised, plant-based methionine-restricted diets. Our nutrient-profiling approach may provide a useful guide for designing different types of personalised vegetarian diets.

Sex-Specific Mechanisms of Resistance Vessel Endothelial Dysfunction Induced by Cardiometabolic Risk Factors

Background

The incidence of obesity is rising, particularly among women. Microvascular dysfunction is more common with female sex, obesity, and hyperlipidemia and predicts adverse cardiovascular outcomes, but the molecular mechanisms are unclear. Because obesity is associated with mineralocorticoid receptor (MR) activation, we tested the hypothesis that MR in endothelial cells contribute to sex differences in resistance vessel dysfunction in response to cardiometabolic risk factors.

Methods and Results

Male and female endothelial cell–specific MR knockout mice and MR‐intact littermates were randomized to high‐fat‐diet–induced obesity or obesity with hyperlipidemia induced by adeno‐associated virus–based vector targeting transfer of the mutant stable form (DY mutation) of the human PCSK9 (proprotein convertase subtilisin/kexin type 9) gene and compared with control diet. Female but not male mice were sensitive to obesity‐induced endothelial dysfunction, whereas endothelial function was impaired in obese hyperlipidemic males and females. In males, obesity or hyperlipidemia decreased the nitric oxide component of vasodilation without altering superoxide production or endothelial nitric oxide synthase expression or phosphorylation. Decreased nitric oxide content in obese males was overcome by enhanced endothelium‐derived hyperpolarization–mediated relaxation along with increased SK3 expression. Conversely, in females, endothelium‐derived hyperpolarization was significantly impaired by obesity with lower IK1 expression and by hyperlipidemia with lower IK1 and SK3 expression, loss of H₂O₂‐mediated vasodilation, and increased superoxide production. Endothelial cell–MR deletion prevented endothelial dysfunction induced by risk factors only in females. Rather than restoring endothelium‐derived hyperpolarization in females, endothelial cell–MR deletion enhanced nitric oxide and prevented hyperlipidemia‐induced oxidative stress.

Conclusions

These data reveal distinct mechanisms driving resistance vessel dysfunction in males versus females and suggest that personalized treatments are needed to prevent the progression of vascular disease in the setting of obesity, depending on both the sex and the metabolic profile of each patient.

Near-infrared spectroscopy can detect differences in vascular responsiveness to a hyperglycaemic challenge in individuals with obesity compared to normal-weight individuals

OBJECTIVE

To examine whether the near-infrared spectroscopy combined with vascular occlusion test technique could detect differences in vascular responsiveness during hyperglycaemia between normal-weight individuals and individuals with obesity.

METHODS

A total of 16 normal-weight individuals (body mass index, 21.3 ± 1.7 kg/m²) and 13 individuals with obesity (body mass index, 34.4 ± 2.0 kg/m²) were submitted to five vascular occlusion tests (Pre, 30, 60, 90 and 120 min after glucose challenge). Vascular responsiveness was determined by the Slope 2 (Slope 2 StO₂) and the area under the curve (StO_2AUC) of oxygen saturation derived from near-infrared spectroscopy-vascular occlusion test.

RESULTS

The Slope 2 StO₂ increased from 1.07 ± 0.16%/s (Pre) to 1.53 ± 0.21%/s at 90 min ( p < 0.05) in the control group, while in obese it increased from 0.71 ± 0.09%/s (Pre) to 0.92 ± 0.14%/s at 60 min ( p < 0.05), and to 0.97 ± 0.10%/s ( p < 0.01) at 120 min after glucose ingestion. The StO_2AUC decreased from 1729 ± 214% . sec (Pre) to 1259 ± 232% . sec at 60 min ( p < 0.05) and to 1034 ± 172% . sec at 90 min ( p < 0.05) in the normal-weight group, whereas it decreased at 90 min (637 ± 98% . sec; p < 0.05) and at 120 min (590 ± 93% . sec; p < 0.01) compared to 30 min (1232 ± 197% . sec) after glucose ingestion in individuals with obesity.

CONCLUSION

Near-infrared spectroscopy-vascular occlusion test technique was capable of detecting differences in vascular responsiveness during hyperglycaemia between normal-weight individuals and individuals with obesity.

Metabolic inflexibility in individuals with obesity assessed by near-infrared spectroscopy

OBJECTIVE

To non-invasively evaluate differences in oxidative metabolism in individuals with obesity compared to normal weight using the near-infrared spectroscopy and vascular occlusion technique during hyperglycaemia.

METHODS

In all, 16 normal-weight individuals (body mass index: 21.3 ± 1.7 kg/m²) and 13 individuals with obesity (body mass index: 34.4 ± 2.0 kg/m²) had five vascular occlusion tests (pre, 30, 60, 90 and 120 min after glucose ingestion). Oxygen utilization was estimated from the area under the curve of the deoxyhemoglobin [HHb] signal during occlusion. Muscle reperfusion was derived from the area above the curve after cuff release.

RESULTS

The deoxyhemoglobin area under the curve during occlusion of the normal-weight individuals increased from 15,732 ± 2344 (% . s) at pre to 18,930 ± 3226 (% . s) ( p < 0.05) at 90 min after glucose ingestion. The deoxyhemoglobin area under the curve during occlusion decreased significantly from 14,695 ± 3341 (% . s) at pre to 11,273 ± 1825 (% . s) ( p < 0.05) and 11,360 ± 1750 (% . s) ( p < 0.05) at 30 and 60 min, respectively, after glucose ingestion. The area above the curve of deoxyhemoglobin during reperfusion decreased significantly from 6450 ± 765 (% . s) at pre to 4830 ± 963 (% . s) ( p < 0.05) at 60 min and to 4210 ± 595 (% . s) ( p < 0.01) at 90 min in normal-weight individuals after glucose ingestion, with no changes observed in individuals with obesity.

CONCLUSION

This study confirmed in vivo and non-invasively the metabolic inflexibility of skeletal muscle in individuals with obesity during hyperglycaemia.

Effects of α-Galactooligosaccharides from Chickpeas on High-Fat-Diet-Induced Metabolic Syndrome in Mice

The gut microbiota has the ability to modulate host energy homeostasis, which may regulate metabolic disorders. Functional oligosaccharide may positively regulate the intestinal microbiota. Therefore, effects of α-galactooligosaccharides (α-GOS) from chickpea on high-fat-diet (HFD)-induced metabolic syndrome and gut bacterial dysbiosis were investigated. After 6 weeks of intervention, HFD led to significant increases in levels of blood glucose, total cholesterol, triglyceride, glycated serum protein, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol of mice compared to normal-chow-fed mice. Meanwhile, all of the α-GOS-treated groups significantly decreased above parameters compared to the HFD group. HFD could significantly decrease the content of all bacteria, especially Bacteroides (9.82 ± 0.09 versus 10.3 ± 0.10; p < 0.05) and Lactobacillus (6.67 ± 0.18 versus 7.30 ± 0.24; p < 0.05), and a decrease in the production of short-chain fatty acids was also observed. Treatment with α-GOS significantly increased the number of Bifidobacterium (6.07 ± 0.23 of the low-dose treatment versus 5.65 ± 0.20 of the HFD group) and Lactobacillus (7.22 ± 0.16 of the low-dose treatment). It also significantly promoted the secretion of propionic and butyric acids. These results indicate that α-GOS from chickpeas may affect the metabolic disorders and gut bacterial ecosystem in a positive way.

A Combination of Flaxseed Oil and Astaxanthin Improves Hepatic Lipid Accumulation and Reduces Oxidative Stress in High Fat-Diet Fed Rats

Hepatic lipid accumulation and oxidative stress are crucial pathophysiological mechanisms for non-alcoholic fatty liver disease (NAFLD). Thus, we examined the effect of a combination of flaxseed oil (FO) and astaxanthin (ASX) on hepatic lipid accumulation and oxidative stress in rats fed a high-fat diet. ASX was dissolved in flaxseed oil (1 g/kg; FO + ASX). Animals were fed diets containing 20% fat, where the source was lard, or 75% lard and 25% FO + ASX, or 50% lard and 50% FO + ASX, or FO + ASX, for 10 weeks. Substitution of lard with FO + ASX reduced steatosis and reduced hepatic triacylglycerol and cholesterol. The combination of FO and ASX significantly decreased hepatic sterol regulatory element-binding transcription factor 1 and 3-hydroxy-3-methylglutaryl-CoA reductase but increased peroxisome proliferator activated receptor expression. FO + ASX significantly suppressed fatty acid synthase and acetyl CoA carboxylase but induced carnitine palmitoyl transferase-1 and acyl CoA oxidase expression. FO + ASX also significantly elevated hepatic SOD, CAT and GPx activity and GSH, and markedly reduced hepatic lipid peroxidation. Thus, FO and ASX may reduce NAFLD by reversing hepatic steatosis and reducing lipid accumulation and oxidative stress.

Parental influences on weight-related health behaviors in western and eastern cultures

BACKGROUND

Excessive bodyweight contributes to a myriad of risk factors for chronic diseases, and multiple reports have demonstrated that parents influence the development of their children's behaviors that contribute to bodyweight. However, studies that include considerations for cultural influences are limited, and methodology that considers direct reports from young adults and their parents across cultures does not exist.

METHODS

A sample of young adults (N = 327) and their parents in the U.S. and in China were recruited and completed a series of questionnaires in two cycles (2010 and 2014). With correlation and multiple regression analyses, parents' characteristics, behaviors, and parental authority styles were examined and compared to weight-related health behaviors and bodyweight of their young-adult children. Additionally, similarities and differences of parental influences between the two cultures were explored.

RESULTS

Parents' body mass indexes (BMIs) and dietary behaviors were positively associated with those of their young adult children in the mixed-culture sample (P < .001 for both). When controlling for gender, at high levels of authoritarian and permissive parental authority, the relationships between young adults' and their parents' BMIs were negative for U.S. participants and positive for Chinese participants (P < .05 for both). Further, at high levels of authoritarian parenting, the relationship between young adults' and their parents' dietary consumption behaviors was negative for U.S. participants and positive for Chinese participants (P < .001).

CONCLUSIONS

This study provides evidence that the development of life-long health behaviors that contribute to BMI are significantly influenced by parents' behaviors and parenting styles. Moreover, an interaction of parental characteristics and cultural norms is indicated.

Cardiovascular function in male and female JCR:LA-cp rats: effect of high-fat/high-sucrose diet

Thirty percent of the world population is diagnosed with metabolic syndrome. High-fat/high-sucrose (HF/HS) diet (Western diet) correlates with metabolic syndrome prevalence. We characterized effects of the HF/HS diet on vascular (arterial stiffness, vasoreactivity, and coronary collateral development) and cardiac (echocardiography) function, oxidative stress, and inflammation in a rat model of metabolic syndrome (JCR rats). Furthermore, we determined whether male versus female animals were affected differentially by the Western diet. Cardiovascular function in JCR male rats was impaired versus normal Sprague-Dawley (SD) rats. HF/HS diet compromised cardiovascular (dys)function in JCR but not SD male rats. In contrast, cardiovascular function was minimally impaired in JCR female rats on normal chow. However, cardiovascular function in JCR female rats on the HF/HS diet deteriorated to levels comparable to JCR male rats on the HF/HS diet. Similarly, oxidative stress was markedly increased in male but not female JCR rats on normal chow but was equally exacerbated by the HF/HS diet in male and female JCR rats. These results indicate that the Western diet enhances oxidative stress and cardiovascular dysfunction in metabolic syndrome and eliminates the protective effect of female sex on cardiovascular function, implying that both males and females with metabolic syndrome are at equal risk for cardiovascular disease.NEW & NOTEWORTHY Western diet abolished protective effect of sex against cardiovascular disease (CVD) development in premenopausal animals with metabolic syndrome. Western diet accelerates progression of CVD in male and female animals with preexisting metabolic syndrome but not normal animals. Exacerbation of baseline oxidative stress correlates with accelerated progression of CVD in metabolic syndrome animals on Western diet.

Body Mass Index Can Increase the Risk of Gallbladder Cancer: A Meta-Analysis of 14 Cohort Studies

BACKGROUND This study sought to appraise the association between raised body mass index (BMI) and the risk of gallbladder cancer (GBC) by performing a meta-analysis of 14 cohort studies. MATERIAL AND METHODS Eligible cohort studies were selected by searching PubMed and EMBASE from their inception to May 26, 2016, and the reference lists of retrieved articles were also consulted. The information was screened by two authors separately. We used a fixed-effects model to calculate the overall pooled risk estimates. A random-effects model was used to identify heterogeneity. RESULTS The meta-analysis incorporated 14 cohort studies. Nine papers were deemed to be of high quality based on the Newcastle-Ottawa Scale (NOS). Compared with normal weight (BMI 18.5-24.9 kg/m²), the overall pooled relative risks (RR) of GBC was 1.45 (95% CI 1.30-1.61) for excess body weight individuals (BMI ≥25 kg/m²); 1.10 (95% CI 1.02-1.18) for overweight persons (BMI 25-29.9 kg/m²) and 1.69(95% CI 1.54-1.86) for obese folks (BMI ≥30 kg/m²). A higher risk of GBC was presented in obese women (women: RR 1.78, 95% CI 1.59-1.99; men: RR 1.50, 95% CI 1.25-1.79). And a positive relationship between overweight and GBC risk was also displayed in female (RR 1.25, 95% CI 1.11-1.40), but not in male (RR 1.01, 95% CI 0.93-1.11). The sensitivity analysis indicated stable results, and no publication bias was observed. CONCLUSIONS This meta-analysis of 14 cohort studies demonstrated that raised BMI has a dramatic association with risk of GBC, especially in women. But, no association between overweight and GBC in men was found.

The Impact of Macronutrients on Retinal Microvasculature among Singapore Pregnant Women during the Mid-Late Gestation

Background

Imbalanced macronutrient intakes can induce impairment of endothelial and vascular function, and further lead to metabolic and cardiovascular disease. However, little is known about the influence of such diets on endothelial and vascular dysfunction in pregnant women, even though high-fat diet is a known risk for pregnancy complications such as gestational diabetes and pre-eclampsia.

Objective

We aimed to assess the association between maternal macronutrient intakes (protein, fat and carbohydrates), dietary quality and retinal microvascular changes in a multi-ethnic Asian mother-offspring cohort.

Methods

Pregnant women (n = 614) with singleton pregnancies were recruited during their first trimester from June 2009 to Sep 2010. Maternal diet quality and macronutrient intakes, expressed as a percentage of total energy during pregnancy, were ascertained using 24 hr recalls and 3 d food diaries at 26–28 weeks gestation. Retinal examination was completed at the same clinic visit. Dietary quality was assessed and scored using the Health Eating Index in Asian Pregnant women (HEI-AP), while macronutrients intakes ware expressed as percentages of total energy and further log transformed for analysis. Associations were examined cross-sectionally by substitution models with the use of multiple linear regression.

Results

In adjusted model, each 20 points decrease in HEI-AP score was associated with a significant increase of 1.70 μm (p<0.05) in retinal venular calibre. Each 0.1 log increase in percentage of total fat intake was associated with a significant increment of 1.84 μm (p<0.05) in retinal venular caliber. Additionally, each 0.1 log increase in percentage of mono-unsaturated fat intake was associated with an increment of 1.84 μm (p<0.01) in retinal venular caliber.

Conclusions

In this cross-sectional study, we found that women with higher fat and lower protein intakes, and lower diet quality tended to have wider retinal venular caliber, which is suggestive of suboptimal microvasculature.

Pharmacological modulation of dietary lipid-induced cerebral capillary dysfunction: Considerations for reducing risk for Alzheimer's disease

An increasing body of evidence suggests that cerebrovascular dysfunction and microvessel disease precede the evolution of hallmark pathological features that characterise Alzheimer's disease (AD), consistent with a causal association for onset or progression. Recent studies, principally in genetically unmanipulated animal models, suggest that chronic ingestion of diets enriched in saturated fats and cholesterol may compromise blood-brain barrier (BBB) integrity resulting in inappropriate blood-to-brain extravasation of plasma proteins, including lipid macromolecules that may be enriched in amyloid-β (Aβ). Brain parenchymal retention of blood proteins and lipoprotein bound Aβ is associated with heightened neurovascular inflammation, altered redox homeostasis and nitric oxide (NO) metabolism. Therefore, it is a reasonable proposition that lipid-lowering agents may positively modulate BBB integrity and by extension attenuate risk or progression of AD. In addition to their robust lipid lowering properties, reported beneficial effects of lipid-lowering agents were attributed to their pleiotropic properties via modulation of inflammation, oxidative stress, NO and Aβ metabolism. The review is a contemporary consideration of a complex body of literature intended to synthesise focussed consideration of mechanisms central to regulation of BBB function and integrity. Emphasis is given to dietary fat driven significant epidemiological evidence consistent with heightened risk amongst populations consuming greater amounts of saturated fats and cholesterol. In addition, potential neurovascular benefits associated with the use of hypolipidemic statins, probucol and fenofibrate are also presented in the context of lipid-lowering and pleiotropic properties.

Sex-specific increase in susceptibility to metabolic syndrome in adult offspring after prenatal ethanol exposure with post-weaning high-fat diet

Prenatal ethanol exposure (PEE) is an established risk factor for intrauterine growth retardation. The present study was designed to determine whether PEE can increase the susceptibility of high-fat diet (HFD)-induced metabolic syndrome (MS) in adult offspring in a sex-specific manner, based on a generalized linear model analysis. Pregnant Wistar rats were administered ethanol (4 g/kg.d) from gestational day 11 until term delivery. All offspring were fed either a normal diet or a HFD after weaning and were sacrificed at postnatal week 20, and blood samples were collected. Results showed that PEE reduced serum adrenocorticotropic hormone (ACTH) and corticosterone levels but enhanced serum glucose, insulin, insulin resistant index (IRI), triglyceride and total cholesterol (TC) concentrations. Moreover, the analysis showed interactions among PEE, HFD and sex. In the PEE offspring, HFD aggravated the decrease in ACTH and corticosterone levels and further increased serum glucose, insulin, triglyceride and TC levels. The changes of serum ACTH, glucose and IRI levels in the female HFD rats were greater than those in the male HFD rats. Our findings suggest that PEE enhances the susceptibility to MS induced by HFD in a sex-specific manner, which might be primarily associated with the neuroendocrine metabolic programming by PEE.