Acrylamide induces adipocyte differentiation and obesity in mice

Associations between paediatric obesity, chemical mixtures and environmental factors, in a national cross-sectional study of Canadian children

BACKGROUND

Whilst single chemical exposures are suspected to be obesogenic, the combined role of chemical mixtures in paediatric obesity is not well understood.

OBJECTIVES

We aimed to evaluate the potential associations between chemical mixtures and obesity in a population-based sample of Canadian children.

METHODS

We ascertained biomonitoring and health data for children aged 3-11 from the cross-sectional Canadian Health Measures Survey from 2007 to 2019. Several chemicals of interest were measured in blood or urine and paediatric obesity was defined based on measured anthropometrics. Using quantile-based G computational analysis, we quantified the effects of three chemical mixtures selected a priori. Models were adjusted for sociodemographic and environmental factors identified through a directed acyclic graph. Results are presented through adjusted relative risks (RR) with 95% confidence intervals (95% CI).

RESULTS

We included 9147 children. Of these, 24.1% were overweight or obese. Exposure to the mixture of bisphenol A, acrylamide, glycidamide, metals, parabens and arsenic increased the risk of childhood overweight or obesity by 45% (95% CI 1.09, 1.93), obesity by 109% (95% CI 1.27, 3.42) and central obesity by 82% (95% CI 1.30, 2.56).

CONCLUSIONS

Our findings support the role of early childhood chemical exposures in paediatric obesity and the potential combined effects of chemicals.

The antioxidant protective effect of resveratrol on long-term exposure to acrylamide-induced skeletal toxicity in female mice

Background

Acrylamide (AA) is a toxic substance formed when cooking starch-based foods at high temperatures. Studies have shown that AA can cause neurotoxicity, reproductive toxicity and so on. However, there remains limited understanding of the potential skeletal toxicity of AA.

Objective

The aim of this study was to investigate the potential skeletal toxicity of AA, as well as the potential bone protective effects of Resveratrol (RVT).

Methods

Based on the daily intake of adult women, adult female mice was treated with AA at 0, 0.01, 0.1, 1 mg/kg/d or AA/RVT (1 mg/kg/d AA +10 mg/kg/d RVT) for 8 weeks, and skeletal toxicity were evaluated by RT-qPCR and histopathological techniques.

Results

The results found that exposure to AA (0.1 or 1 mg/kg/d) after 8 weeks, osteogenesis exhibited pathological damage characteristics such as inhibition of growth plate function, and reduction of fibrous tissue, and cartilage exhibited pathological damage characteristics such as irregular cell morphology and arrangement, and damage to the tidal line. The results of cellular functional gene testing showed a decrease in the expression of functional genes in osteoblasts and chondrocytes. Meanwhile, after further co-treatment with AA (1 mg/kg/d) and resveratrol (RVT) (10 mg/kg/d), we found that RVT restored AA-induced damage to osteogenesis and cartilage, and reduced the high apoptosis and oxidative stress levels in osteogenesis/cartilage after AA exposure.

Conclusion

In summary, this study confirmed the skeletal toxicity of AA on female adult mice, and further clarified the antioxidant protective effect of RVT on this toxicity.

Obesity Induces DNA Damage in Mammary Epithelial Cells Exacerbated by Acrylamide Treatment through CYP2E1-Mediated Oxidative Stress

Obesity and environmental toxins are risk factors for breast cancer; however, there is limited knowledge on how these risk factors interact to promote breast cancer. Acrylamide, a probable carcinogen and obesogen, is a by-product in foods prevalent in the obesity-inducing Western diet. Acrylamide is metabolized by cytochrome P450 2E1 (CYP2E1) to the genotoxic epoxide, glycidamide, and is associated with an increased risk for breast cancer. To investigate how acrylamide and obesity interact to increase breast cancer risk, female mice were fed a low-fat (LFD) or high-fat diet (HFD) and control water or water supplemented with acrylamide at levels similar to the average daily exposure in humans. While HFD significantly enhanced weight gain in mice, the addition of acrylamide did not significantly alter body weights compared to respective controls. Mammary epithelial cells from obese, acrylamide-treated mice had increased DNA strand breaks and oxidative DNA damage compared to all other groups. In vitro, glycidamide-treated COMMA-D cells showed significantly increased DNA strand breaks, while acrylamide-treated cells demonstrated significantly higher levels of intracellular reactive oxygen species. The knockdown of CYP2E1 rescued the acrylamide-induced oxidative stress. These studies suggest that long-term acrylamide exposure through foods common in the Western diet may enhance DNA damage and the CYP2E1-induced generation of oxidative stress in mammary epithelial cells, potentially enhancing obesity-induced breast cancer risk.

Differential susceptibility of BRL cells with/without insulin resistance and the role of endoplasmic reticulum stress signaling pathway in response to acrylamide-exposure toxicity effects in vitro

Acrylamide (ACR) is an endogenous food contaminant, high levels of ACR have been detected in a large number of foods, causing widespread concern. Since different organism states respond differently to the toxic effects of pollutants, this study establishes an insulin-resistant BRL cell model to explore the differential susceptibility of BRL cells with/without insulin resistance in response to acrylamide-exposure (0.0002, 0.02, or 1 mM) toxicity effects and its mechanism. The results showed that ACR exposure decreased glucose uptake and increased intracellular lipid levels by promoting the expression of fatty acid synthesis, transport, and gluconeogenesis genes and inhibiting the expression of fatty acid metabolism genes, thereby further exacerbating disorders of gluconeogenesis and lipid metabolism in insulin-resistant BRL cells. Simultaneously, its exposure also exacerbated BRL cells with/without insulin-resistant damage. Meanwhile, insulin resistance significantly raised susceptibility to BRL cell response to ACR-induced toxicity. Furthermore, ACR exposure further activated the endoplasmic reticulum stress (ERS) signaling pathway (promoting phosphorylation of PERK, eIF-2α, and IRE-1α) and the apoptosis signaling pathway (activating Caspase-3 and increasing the Bax/Bcl-2 ratio) in BRL cells with insulin-resistant, which were also attenuated after ROS scavenging or ERS signaling pathway blockade. Overall results suggested that ACR evokes a severer toxicity effect on BRL cells with insulin resistance through the overactivation of the ERS signaling pathway.

Causal relationship of cereal intake and type with cardiovascular disease: a Mendelian randomization study

Background

Observational studies have suggested that cereal consumption is associated with a reduced risk of cardiovascular disease (CVD). However, the potential causal relationship is not clear. We aimed to investigate the association of cereal intake and cereal type with CVD risk.

Methods

Two-step Mendelian randomization (MR) analysis was performed to confirm the causal association of cereal intake and cereal type with the risk of several common CVDs. Furthermore, two-step MR analysis was used to explore the mediating effect of cardiovascular metabolic factors, and multivariable MR analysis was used to assess the impact of socioeconomic status, such as education and income, on the causal association.

Results

The MR analysis indicated that genetically predicted cereal intake is associated with reduced risk of large artery stroke (LAS) (odd ratio (OR): 0.421; 95% confidence interval (CI) [0.193, 0.918]; p = 0.030), and muesli as the primary cereal intake is associated with reduced risk of coronary heart disease (CHD) (OR: 0.100; 95% CI [0.023, 0.437]; p = 0.002), myocardial infarction (MI) (OR: 0.101; 95% CI [0.020, 0.509]; p = 0.005), heart failure (OR: 0.210; 95% CI [0.064, 0.684]; p = 0.010), ischemic stroke (IS) (OR: 0.130; 95% CI [0.029, 0.591]; p = 0.008), LAS (OR: 0.017; 95% CI [0.0004, 0.737]; p = 0.034), and small-vessel stroke (OR: 0.021; 95% CI [0.001, 0.708]; p = 0.005). In contrast, genetically predicted biscuits as the primary cereal intake increased the risk of CHD (OR: 6.557; 95% CI [1.197, 36.031]; p = 0.031), and other cereals, such as cornflakes, as the primary cereal intake increased the risk of CHD (OR: 3.803; 95% CI [1.194, 12.111]; p = 0.024), MI (OR: 4.240; 95% CI [1.185, 15.174]; p = 0.026), stroke (OR: 3.154; 95% CI [1.070, 9.298]; p = 0.037), and IS (OR: 3.736; 95% CI [1.185, 11.782]; p = 0.024). Multivariable MR analysis underscored the significant role of education and income in the causal association, and two-step MR analysis indicated that body mass index, lipids, and blood glucose exerted important mediating effects in the causal association.

Conclusion

The findings of our study underscore the causal beneficial influence of muesli as the primary cereal intake on CVDs. A reasonable consumption of muesli may provide primary prevention of CVDs.

From a toxin to an obesogen: a review of potential obesogenic roles of acrylamide with a mechanistic approach

Obesity and obesity-related disorders such as cancer, type 2 diabetes, and fatty liver have become a global health problem. It is well known that the primary cause of obesity is positive energy balance. In addition, obesity is the consequence of complex gene and environment interactions that result in excess calorie intake being stored as fat. However, it has been revealed that there are other factors contributing to the worsening of obesity. The presence of nontraditional risk factors, such as environmental endocrine-disrupting chemicals, has recently been associated with obesity and comorbidities caused by obesity. The aim of this review was to examine the evidence and potential mechanisms for acrylamide having endocrine-disrupting properties contributing to obesity and obesity-related comorbidities. Recent studies have suggested that exposure to environmental endocrine-disrupting obesogens may be a risk factor contributing to the current obesity epidemic, and that one of these obesogens is acrylamide, an environmental and industrial compound produced by food processing, particularly the processing of foods such as potato chips, and coffee. In addition to the known harmful effects of acrylamide in humans and experimental animals, such as neurotoxicity, genotoxicity, and carcinogenicity, acrylamide also has an obesogenic effect. It has been shown in the literature to a limited extent that acrylamide may disrupt energy metabolism, lipid metabolism, adipogenesis, adipocyte differentiation, and various signaling pathways, and may exacerbate the disturbances in metabolic and biochemical parameters observed as a result of obesity. Acrylamide exerts its main potential obesogenic effects through body weight increase, worsening of the levels of obesity-related blood biomarkers, and induction of adipocyte differentiation and adipogenesis. Additional mechanisms may be discovered. Further experimental studies and prospective cohorts are needed, both to supplement existing knowledge about acrylamide and its effects, and to clarify its established relationship with obesity and its comorbidities.

Nova diet quality scores and risk of weight gain in the NutriNet-Brasil cohort study

OBJECTIVE

To assess the prospective association of two diet quality scores based on the Nova food classification with BMI gain.

DESIGN

The NutriNet-Brasil cohort is an ongoing web-based prospective study with continuous recruitment of participants aged ≥ 18 years since January 2020. A short 24-h dietary recall screener including 'yes/no' questions about the consumption of whole plant foods (WPF) and ultra-processed foods (UPF) was completed by participants at baseline. The Nova-WPF and the Nova-UPF scores were computed by adding up positive responses regarding the consumption of thirty-three varieties of WPF and twenty-three varieties of UPF, respectively. Participants reported their height at baseline and their weight at both baseline and after approximately 15 months of follow-up. A 15-month BMI (kg/m2) increase of ≥5 % was coded as BMI gain.

SETTING

Brazil.

PARTICIPANTS

9551 participants from the NutriNet-Brasil cohort.

RESULTS

Increasing quintiles of the Nova-UPF score were linearly associated with higher risk of BMI gain (relative risk Q5/Q1 = 1·34; 95 % CI 1·15, 1·56), whereas increasing quintiles of the Nova-WPF score were linearly associated with lower risk (relative risk Q5/Q1 = 0·80; 95 % CI 0·69, 0·94). We identified a moderate inverse correlation between the two scores (-0·33) and a partial mediating effect of the alternative score: 15 % for the total effect of the Nova-UPF score and 25 % for the total effect of the Nova-WPF score.

CONCLUSIONS

The Nova-UPF and Nova-WPF scores are independently associated with mid-term BMI gain further justifying their use in diet quality monitoring systems.

The association between dietary acrylamide intake and the risk of type 2 diabetes incidence in the Tehran lipid and glucose study

This study aimed at investigating the association of acrylamide consumption with the incidence of type 2 diabetes (T2D) in adults. The 6022 subjects of the Tehran lipid and glucose study participants were selected. The acrylamide content of food items were summed and computed cumulatively across follow up surveys. Multivariable Cox proportional hazard regression analyses were performed to estimate the hazards ratio (HR) and 95% confidence interval (CI) of incident T2D. This study was done on men and women, respectively aged 41.5 ± 14.1 and 39.2 ± 13.0 years. The mean ± SD of dietary acrylamide intake was 57.0 ± 46.8 µg/day. Acrylamide intake was not associated with the incidence of T2D after adjusting for confounding variables. In women, a higher acrylamide intake was positively associated with T2D [HR (CI) for Q4: 1.13 (1.01-1.27), P trend: 0.03] after adjusting for confounding factors. Our results demonstrated that dietary intake of acrylamide was associated with an increased risk of T2D in women.

Acrylamide in food: Occurrence, metabolism, molecular toxicity mechanism and detoxification by phytochemicals

Acrylamide (ACR) is a common pollutant formed during food thermal processing such as frying, baking and roasting. ACR and its metabolites can cause various negative effects on organisms. To date, there have been some reviews summarizing the formation, absorption, detection and prevention of ACR, but there is no systematic summary on the mechanism of ACR-induced toxicity. In the past five years, the molecular mechanism for ACR-induced toxicity has been further explored and the detoxification of ACR by phytochemicals has been partly achieved. This review summarizes the ACR level in foods and its metabolic pathways, as well as highlights the mechanisms underlying ACR-induced toxicity and ACR detoxification by phytochemicals. It appears that oxidative stress, inflammation, apoptosis, autophagy, biochemical metabolism and gut microbiota disturbance are involved in various ACR-induced toxicities. In addition, the effects and possible action mechanisms of phytochemicals, including polyphenols, quinones, alkaloids, terpenoids, as well as vitamins and their analogs on ACR-induced toxicities are also discussed. This review provides potential therapeutic targets and strategies for addressing various ACR-induced toxicities in the future.

Study of Potential Synergistic Effect of Probiotic Formulas on Acrylamide Reduction

Acrylamide (AA) is a food processing contaminant commonly found in fried and baked food products. In this study, the potential synergistic effect of probiotic formulas in reducing AA was studied. Five selected probiotic strains (Lactiplantibacillus plantarum subsp. plantarum ATCC14917 (L. Pl.), Lactobacillus delbrueckii subsp. bulgaricus ATCC11842 (L. B.), Lacticaseibacillus paracasei subsp. paracasei ATCC25302 (L. Pa), Streptococcus thermophilus ATCC19258, and Bifidobacterium longum subsp. longum ATCC15707) were selected for investigating their AA reducing capacity. It was found that L. Pl. (10⁸ CFU/mL) showed the highest AA reduction percentage (43-51%) when exposed to different concentrations of AA standard chemical solutions (350, 750, and 1250 ng/mL). The potential synergistic effect of probiotic formulas was also examined. The result demonstrated a synergistic AA reduction effect by the probiotic formula: L. Pl. + L. B., which also showed the highest AA reduction ability among the tested formulas. A further study was conducted by incubating selected probiotic formulas with potato chips and biscuit samples followed by an in vitro digestion model. The findings demonstrated a similar trend in AA reduction ability as those found in the chemical solution. This study firstly indicated the synergistic effect of probiotic formulas on AA reduction and its effect was also highly strain-dependent.

Quercetin ameliorates acute acrylamide induced spleen injury

Acrylamide is used for industrial and laboratory purposes; it also is produced during cooking of carbohydrate-rich food at high temperature. We investigated the therapeutic potential of quercetin for treatment of acute acrylamide induced injury to the spleen. We used female albino rats treated with acrylamide for 10 days followed by oral administration of quercetin in three doses for 5 days. We observed significantly reduced total body weight, spleen weight, red blood cells, total proteins, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phophate dehydrogenase, reduced glutathione, concentration of serum IgG and IgM after acrylamide induced toxicity compared to controls. We also found that white blood cells, triglycerides, cholesterol and lipid oxidation were increased significantly after acrylamide induced toxicity in rats compared to controls. Histoarchitecture of spleen was affected adversely by acrylamide toxicity. Administration of quercetin ameliorated adverse effects of acrylamide in a dose-dependent manner. Quercetin appears to ameliorate acrylamide induced injury to the spleen by increasing endogenous antioxidants and improving histoarchitecture and immune function.

The association analysis between exposure to volatile organic chemicals and obesity in the general USA population: A cross-sectional study from NHANES program

BACKGROUND

Increasing evidence have been provided that the exposure to environment pollutants was associated obesity, while whether the exposure to volatile organic chemicals (VOC) was associated with obesity or abdominal obesity is yet to be clarified.

METHOD

A cross-sectional study using data from the 6 survey cycles (2005-2006, 2011-2018, 2017-2020) of NHANES program was performed. Obesity and abdominal obesity were identified as a BMI >30 and a waist circumference >102 cm for men or >88 cm for women respectively. The quantile logistic regression method was used to analyze the association between VOC metabolites (VOCs) in urine and obesity, and the quantile regression method was used for the association analysis between VOCs in urine and BMI, as well as waist circumference.

RESULTS

A total of 17 524 participants (4965 obesity, 7317 abdominal obesity) were included, and participants in the obesity or abdominal obesity groups showed higher VOCs in urine than that in the control group. The CEMA was identified as the risk factor for obesity and abdominal obesity in all the 4 models, and its detected OR for obesity in the Q2 to Q4 of model 3 was 1.169 (Q2, p < 0.05), 1.306 (Q3, p < 0.001) and 1.217 (Q4, p < 0.01) respectively. And its OR for abdominal obesity in the Q2 to Q4 of model 3 was 1.222 (Q2, p < 0.01), 1.448 (Q3, p < 0.001) and 1.208 (Q4, p < 0.05) respectively. A significantly positive association between CEMA and BMI, as well as waist circumference, was also detected.

CONCLUSION

In this study, we found that the exposure to VOC (Acrolein, Acrylamide, Acrylonitrile, 1,3-Butadiene, Crotonaldehyde, Cyanide, N,N-Dimethylformamide, Ethylbenzene, styrene, Propylene oxide, Toluene and Xylene) was significantly associated with obesity or abdominal obesity. And also, more prospective studies and related experimental researches should be carried out to further demonstrate the conclusion of this study.

Anti-obesity effects of red pepper (Capsicum annuum L.) leaf extract on 3T3-L1 preadipocytes and high fat diet-fed mice

Patients with obesity mostly have metabolic syndrome and this can lead to multiple health problems. In the present study, we evaluated the anti-obesity effect of water-soluble red pepper (Capsicum annuum L.) leaf extract (PLE) on 3T3-L1 adipocytes and high-fat diet (HFD)-fed mice. The adipocyte lipid content was determined using Oil Red O staining, which revealed that 100 μg mL^-1 PLE markedly reduced fat accumulation without affecting the cell viability. PLE exhibited high prebiotic activity scores by modulating probiotic strains, contributing to host health improvement. In vivo investigation in HFD-fed mice revealed that PLE supplementation significantly decreased the HFD-induced increases in the body weight, amount of white adipose tissue, and serum triglyceride, total cholesterol, leptin, and insulin levels. Consistent with its effects on reduced lipid droplet formation in the liver, PLE supplementation suppressed the expression of lipid synthesis-related proteins including SREBP-1, FAS, and PPAR-γ in the liver and increased that of PGC-1α, CPT1, and adiponectin in epididymal WAT. PLE treatment improved intestinal barrier function and inflammation and reduced harmful intestinal enzyme activities in the feces. Collectively, these results indicate that PLE inhibits fat accumulation in HFD-fed mice via the suppression of adipogenesis and lipogenesis, suggesting its potential in preventing obesity.

How advanced are we on the consequences of oral exposure to food contaminants on the occurrence of chronic non communicable diseases?

The development of an individual during fetal life and childhood is characterized by rapid growth as well as gradual maturation of organs and systems. Beyond the nutritional intake in essential nutrients, food contaminants can permanently influence the way organs mature and function. These processes are called "programming" and play an essential role in the occurrence of non-communicable chronic diseases throughout the lifespan. Populations as pregnant women, fetuses and young children are vulnerable and particularly sensitive to food contaminants which can induce epigenetic modifications transmissible to future generations. Among these contaminants, pesticides are found in most food matrices exposing humans to cocktails of molecules through variable concentrations and duration of exposure. The Maillard reaction products (MRPs) represent other food contaminants resulting from heat treatment of food. Modern diet, rich in fats and sugars, is also rich in neoformed pathogenic compounds, Advanced Glycation End products (AGEs), the levels of which depend on the heat treatment of foods and eating habits and whose effects on health are controversial. In this review, we have chosen to present the current knowledge on the impacts of selected pesticides and MRPs, on the risk of developing during life non-communicable chronic diseases such as IBD, metabolic disorders or allergies. A large review of literature was performed via Pubmed, and the most appropriate studies were summarised.

The relationship between ultra-processed food intake and cardiometabolic risk factors in overweight and obese women: A cross-sectional study

Background

Cardiovascular diseases (CVDs) are the leading cause of death globally. Based on recent studies, one of the factors that can have detrimental effects on CVD is the consumption of ultra-processed foods (UPFs). The current study investigated the relationship between UPF intake and cardiometabolic risk factors among Iranian women.

Methods

The current cross-sectional study was conducted on 391 women aged 18-65 years with a body mass index (BMI) ≥ 25 kg/m². Dietary intake was assessed using a 147-item food frequency questionnaire (FFQ). Anthropometric and biochemistry parameters were also collected. UPFs were identified using the NOVA classification.

Results

In the present study, women had a mean (standard deviation) age of 36.67 (9.10) years and the mean BMI of 31.26 (4.29) kg/m². According to our findings, there was a significant association between UPF consumption and transforming growth factor (TGF) (β: 0.101, 95% CI: 0.023, 0.180, p = 0.012), atherogenic coefficient (AC) (β: 0.011, 95% CI: 0.001, 0.032, p = 0.034), visceral fat level (VFL) (β: 0.006, 95% CI: -0.017, 0.029, p = 0.076), and the quantitative insulin sensitivity check index (QUICKI) (β: -3.775, 95%CI: 0.001, 0.001, p = 0.042).

Conclusion

In conclusion, an increase in consumption of one gram of UPFs is associated with an increase in TGF, AC, and VFL but with a decrease in QUICKI. Despite this, further experimental studies are necessary to draw a more definite conclusion and disentangle the mechanisms by which UPFs may affect health.

Associations of Hemoglobin Adducts of Acrylamide and Glycidamide with Prevalent Metabolic Syndrome in a Nationwide Population-Based Study

Environmental and dietary exposures to acrylamide (AA) have been linked with various metabolic-related outcomes, but the results are mixed. However, the association between long-term exposure to AA and the prevalence of metabolic syndrome (MetS) remains unknown. In this study, we aimed to assess the relationship between hemoglobin adducts of AA, biomarkers of internal exposure to AA, and MetS prevalence among a U.S. nationwide population. MetS patients were defined by meeting three or more of the following five characteristics: elevated blood pressure, high fasting glucose, abdominal obesity, hypertriglyceridemia, and lower high-density lipoprotein cholesterol (HDL-C). Multivariate-adjusted logistic regression models and restricted cubic spline models were used to analyze the associations between AA hemoglobin biomarkers and MetS prevalence. A total of 1552 MetS cases were documented. After adjustment for the potential confounders, the odds ratios (95% confidence intervals) of MetS prevalence in the highest quartile of AA hemoglobin biomarkers were 0.60 (0.40-0.89), 1.26 (0.84-1.89), 0.93 (0.71-1.21), and 1.61 (1.18-2.20) for HbAA, HbGA, the sum of HbAA and HbGA (HbAA + HbGA), and the ratio of HbGA to HbAA (HbGA/HbAA), compared with the lowest quartile, respectively. HbAA was significantly and inversely associated with blood pressure, fasting glucose, abdominal obesity, hypertriglyceridemia, and low HDL-C, while the HbGA/HbAA ratio was also positively associated with abdominal obesity, hypertriglyceridemia, and low HDL-C. The restricted cubic spline models revealed a positive relationship between the HbGA/HbAA ratio and the prevalence of MetS, while the HbAA level was inversely associated with MetS prevalence. Our current findings provided epidemiological evidence that HbAA and the HbGA/HbAA ratio were significantly associated with MetS prevalence among general U.S. adults. Further studies should be conducted to examine the association between internal exposure to AA and MetS prevalence.

Biscuit consumption and diabetic retinopathy incidence in adults in the United States

BACKGROUND

Foods have a considerable influence on human health and were directly related to glycemic control for diabetes patients. However, little is known about the effects of biscuits, a traditional food consumed in large amounts in several countries, on diabetic retinopathy. This study aimed to explore the association between biscuit consumption and diabetic retinopathy prevalence in adults of the United States population.

METHODS

A cross-sectional study with 1904 participants from the National Health and Nutrition Examination Survey database were included in this population-based, cross-sectional study. The association between different consumption frequencies of biscuit and diabetic retinopathy prevalence was evaluated using a binary logistic regression model. Trend test, stratified and interaction analyses were also performed.

RESULTS

After possible confounders including sex, age, ethnicity, education, marital status, family poverty income ratio, smoking and alcohol consumption habit, fasting blood glucose level, hemoglobin A1c level, diagnosis of diabetes, insulin use, blood pressure, body mass index were adjusted, the participants who consumed biscuit 1-11 times a year, 1-3 times a month, and more than once a week had a 139.8% (95% confidence interval, 1.003-5.734), 182.1% (95% confidence interval, 1.106-7.191), and 236.2% (95% confidence interval, 1.335-9.844) higher risk of diabetic retinopathy prevalence, respectively, compared with those who never ate biscuit. For male, non-Hispanic, and overweight (body mass index ≥ 25 kg/m²) subgroups, the trend test demonstrated that the diabetic retinopathy prevalence significantly elevated with increased frequency of biscuit consumption (P _trend = 0.021, 0.009, and 0.002, respectively). The interaction analysis suggested that no aforementioned confounders played an interactive role in the relationship between biscuit consumption and diabetic retinopathy prevalence.

CONCLUSIONS

The risk of diabetic retinopathy was positively associated with biscuit consumption. Moreover, for male, non-Hispanic, or overweight individuals, the risk of diabetic retinopathy significantly increased with the frequency of biscuit consumption.

The metabolic regulation of Fuzhuan brick tea in high-fat diet-induced obese mice and the potential contribution of gut microbiota

This study investigated the metabolic effects of Fuzhuan brick tea (FBT) in high-fat diet (HFD)-induced obese mice and the potential contribution of gut microbiota. The results showed that FBT ameliorated the HFD-induced glycerophospholipid metabolic aberrance, specifically increased the serum levels of phosphatidylcholines (PCs), lysophosphatidylcholines (LysoPCs), and the ratio of PC to phosphatidylethanolamines (PE). Besides, FBT increased the serum level of gut microbiota-derived aryl hydrocarbon receptor (AhR) ligand, 3-indole propionic acid, as well as the relative abundance of intestinal AhR-ligand producing bacteria such as Clostridiaceae, Bacteroidales_S24-7_group, and Lactobacillaceae. However, the metabolic benefits of FBT were weakened when the gut microbiota were depleted by antibiotic treatment, thereby suggesting that gut microbiota was required for FBT to regulate glycerophospholipid metabolism. Indeed, the metabolites regulated by FBT were significantly correlated with the AhR-ligand producing bacteria. The KEGG pathway enrichment analysis and expressions of AhR target genes indicated that FBT would improve the glycerophospholipid metabolism via the AhR-Pemt signal axis, in which the gut microbiota and their metabolites played pivotal mediators. Overall, FBT could be a functional beverage to improve HFD-induced metabolic disorders in a gut microbiota dependent manner.

Short-term exposure to acrylamide exacerbated metabolic disorders and increased metabolic toxicity susceptibility on adult male mice with diabetes

Diabetes mellitus is a common endocrine metabolic disorder, and previous studies have shown that diabetics are more sensitive to the toxic environmental contaminants. Acrylamide (ACR) is both an industrially multipurpose compound and a common endogenous food contaminant to which people are frequently exposed and at high risk. However, the toxicity of ACR on diabetes hasn't attracted much attention. In this study, both healthy mice and diabetic mice received ACR administration orally to investigate the ACR-induced metabolic toxicity, mechanism and susceptibility to ACR toxicity in adult diabetic male mice. The results showed that ACR significantly increased FBG level and decreased bodyweight, serum lipid and liver lipid biomarkers (TC, TG, LDL-C, HDL-C) levels as well as expression of lipid and glucose metabolism-related genes in diabetic mice, indicating that ACR can exacerbate metabolic disorders of glucose and lipid in diabetic male mice. Moreover, ACR exposure significantly increased levels of MDA and COX-2), decreased GSH level and antioxidant enzyme activity (SOD, GSH-PX and CAT) by downregulating expression of Nrf2 and Keap1 in diabetic mice. Factorial analysis showed ACR had a more significant disturbance in diabetic mice compared with healthy mice. Our results indicated that ACR exposure can cause oxidative stress and inflammatory damage, which can exacerbate abnormal glucose and lipid metabolism. This work helps to elucidate the effects and underlying mechanisms of ACR-induced metabolic toxicity in adults with diabetes.

Negative Association between Acrylamide Exposure and Metabolic Syndrome Markers in Adult Population

Metabolic syndrome encompasses multiple conditions that increase the risk of cardiovascular disease, and exposure to environmental chemicals can cause metabolic syndrome. This cross-sectional study analyzed data from the US National Health and Nutrition Examination Survey (2003-2006) on 4318 adult participants to assess the association between acrylamide (AA) exposure and metabolic syndrome. Concentrations of hemoglobin-adducted AA (HbAA) and hemoglobin-adducted glycidamide (HbGA) were evaluated. Metabolic syndrome markers related to HbAA and HbGA and the effect of exposure to AA and GA on the prevalence of metabolic syndrome were studied by ANOVA and multivariate logistic regression analyses, respectively. HbAA concentration inversely correlated with the number of metabolic syndrome markers (p < 0.05). An increased HbAA concentration was noted with reduced high triglyceride and low high-density lipoprotein cholesterol levels in the adjusted model (p < 0.05). High fasting plasma glucose level significantly correlated with HbGA concentration in the adjusted model. In conclusion, AA exposure alters metabolic syndrome markers in adults. Additional clinical and animal studies will clarify the role of AA exposure at different stages in the progression of metabolic syndrome-related diseases.

The new kids on the block: Emerging obesogens

The current obesity epidemic is calling for action in the determination of contributing factors. Although social and life-style factors have been traditionally associated with metabolic disruption, a subset of endocrine-disrupting chemicals (EDCs), called obesogens are garnering increasing attention for their ability to promote adipose tissue differentiation and accumulation. For some chemicals, such as tributyltin, there is conclusive evidence regarding their ability to promote adipogenesis and their mechanism of action. In recent years, the list of chemicals that exert obesogenic potential is increasing. In this chapter, we review current knowledge of the most recent developments in the field of emerging obesogens with a specific focus on food additives, surfactants, and sunscreens, for which the mechanism of action remains unclear. We also review new evidence relative to the obesogenic potential of environmentally relevant chemical mixtures and point to potential therapeutic approaches to minimize the detrimental effects of obesogens. We conclude by discussing the available tools to investigate new obesogenic chemicals, strategies to maximize reproducibility in adipogenic studies, and future directions that will help propel the field forward.

Obesity and endocrine-disrupting chemicals

Obesity is now a worldwide pandemic. The usual explanation given for the prevalence of obesity is that it results from consumption of a calorie dense diet coupled with physical inactivity. However, this model inadequately explains rising obesity in adults and in children over the past few decades, indicating that other factors must be important contributors. An endocrine-disrupting chemical (EDC) is an exogenous chemical, or mixture that interferes with any aspect of hormone action. EDCs have become pervasive in our environment, allowing humans to be exposed daily through ingestion, inhalation, and direct dermal contact. Exposure to EDCs has been causally linked with obesity in model organisms and associated with obesity occurrence in humans. Obesogens promote adipogenesis and obesity, in vivo, by a variety of mechanisms. The environmental obesogen model holds that exposure to obesogens elicits a predisposition to obesity and that such exposures may be an important yet overlooked factor in the obesity pandemic. Effects produced by EDCs and obesogen exposure may be passed to subsequent, unexposed generations. This "generational toxicology" is not currently factored into risk assessment by regulators but may be another important factor in the obesity pandemic as well as in the worldwide increases in the incidence of noncommunicable diseases that plague populations everywhere. This review addresses the current evidence on how obesogens affect body mass, discusses long-known chemicals that have been more recently identified as obesogens, and how the accumulated knowledge can help identify EDCs hazards.

Life-Time Environmental Chemical Exposure and Obesity: Review of Epidemiological Studies Using Human Biomonitoring Methods

The exponential global increase in the incidence of obesity may be partly attributable to environmental chemical (EC) exposure. Humans are constantly exposed to ECs, primarily through environmental components. This review compiled human epidemiological study findings of associations between blood and/or urinary exposure levels of ECs and anthropometric overweight and obesity indices. The findings reveal research gaps that should be addressed. We searched MEDLINE (PubMed) for full text English articles published in 2006-2020 using the keywords "environmental exposure" and "obesity". A total of 821 articles were retrieved; 102 reported relationships between environmental exposure and obesity indices. ECs were the predominantly studied environmental exposure compounds. The ECs were grouped into phenols, phthalates, and persistent organic pollutants (POPs) to evaluate obesogenic roles. In total, 106 articles meeting the inclusion criteria were summarized after an additional search by each group of EC combined with obesity in the PubMed and Scopus databases. Dose-dependent positive associations between bisphenol A (BPA) and various obesity indices were revealed. Both individual and summed di(2-ethylhexyl) phthalate (DEHP) and non-DEHP metabolites showed inconsistent associations with overweight and obesity indices, although mono-butyl phthalate (MBP), mono-ethyl phthalate (MEP), and mono-benzyl phthalate (MBzP) seem to have obesogenic roles in adolescents, adults, and the elderly. Maternal exposure levels of individual POP metabolites or congeners showed inconsistent associations, whereas dichlorodiphenyldichloroethylene (DDE) and perfluorooctanoic acid (PFOA) were positively associated with obesity indices. There was insufficient evidence of associations between early childhood EC exposure and the subsequent development of overweight and obesity in late childhood. Overall, human evidence explicitly reveals the consistent obesogenic roles of BPA, DDE, and PFOA, but inconsistent roles of phthalate metabolites and other POPs. Further prospective studies may yield deeper insights into the overall scenario.

Control of Adipose Cell Browning and Its Therapeutic Potential

Adipose tissue is the largest endocrine organ in humans and has an important influence on many physiological processes throughout life. An increasing number of studies have described the different phenotypic characteristics of fat cells in adults. Perhaps one of the most important properties of fat cells is their ability to adapt to different environmental and nutritional conditions. Hypothalamic neural circuits receive peripheral signals from temperature, physical activity or nutrients and stimulate the metabolism of white fat cells. During this process, changes in lipid inclusion occur, and the number of mitochondria increases, giving these cells functional properties similar to those of brown fat cells. Recently, beige fat cells have been studied for their potential role in the regulation of obesity and insulin resistance. In this context, it is important to understand the embryonic origin of beige adipocytes, the response of adipocyte to environmental changes or modifications within the body and their ability to transdifferentiate to elucidate the roles of these cells for their potential use in therapeutic strategies for obesity and metabolic diseases. In this review, we discuss the origins of the different fat cells and the possible therapeutic properties of beige fat cells.

Ultra-processed food intake in association with BMI change and risk of overweight and obesity: A prospective analysis of the French NutriNet-Santé cohort

BACKGROUND

Ultra-processed food (UPF) consumption has increased drastically worldwide and already represents 50%-60% of total daily energy intake in several high-income countries. In the meantime, the prevalence of overweight and obesity has risen continuously during the last century. The objective of this study was to investigate the associations between UPF consumption and the risk of overweight and obesity, as well as change in body mass index (BMI), in a large French cohort.

METHODS AND FINDINGS

A total of 110,260 adult participants (≥18 years old, mean baseline age = 43.1 [SD 14.6] years; 78.2% women) from the French prospective population-based NutriNet-Santé cohort (2009-2019) were included. Dietary intakes were collected at baseline using repeated and validated 24-hour dietary records linked to a food composition database that included >3,500 different food items, each categorized according to their degree of processing by the NOVA classification. Associations between the proportion of UPF in the diet and BMI change during follow-up were assessed using linear mixed models. Associations with risk of overweight and obesity were assessed using Cox proportional hazard models. After adjusting for age, sex, educational level, marital status, physical activity, smoking status, alcohol intake, number of 24-hour dietary records, and energy intake, we observed a positive association between UPF intake and gain in BMI (β Time × UPF = 0.02 for an absolute increment of 10 in the percentage of UPF in the diet, P < 0.001). UPF intake was associated with a higher risk of overweight (n = 7,063 overweight participants; hazard ratio (HR) for an absolute increase of 10% of UPFs in the diet = 1.11, 95% CI: 1.08-1.14; P < 0.001) and obesity (n = 3,066 incident obese participants; HR10% = 1.09 (1.05-1.13); P < 0.001). These results remained statistically significant after adjustment for the nutritional quality of the diet and energy intake. Study limitations include possible selection bias, potential residual confounding due to the observational design, and a possible item misclassification according to the level of processing. Nonetheless, robustness was tested and verified using a large panel of sensitivity analyses.

CONCLUSIONS

In this large observational prospective study, higher consumption of UPF was associated with gain in BMI and higher risks of overweight and obesity. Public health authorities in several countries recently started to recommend privileging unprocessed/minimally processed foods and limiting UPF consumption.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03335644 (https://clinicaltrials.gov/ct2/show/NCT03335644).

Acrylamide Exposure and Oxidative DNA Damage, Lipid Peroxidation, and Fasting Plasma Glucose Alteration: Association and Mediation Analyses in Chinese Urban Adults

OBJECTIVE

Acrylamide exposure from daily-consumed food has raised global concern. We aimed to assess the exposure-response relationships of internal acrylamide exposure with oxidative DNA damage, lipid peroxidation, and fasting plasma glucose (FPG) alteration and investigate the mediating role of oxidative DNA damage and lipid peroxidation in the association of internal acrylamide exposure with FPG.

RESEARCH DESIGN AND METHODS

FPG and urinary biomarkers of oxidative DNA damage (8-hydroxy-deoxyguanosine [8-OHdG]), lipid peroxidation (8-iso-prostaglandin-F2α [8-iso-PGF2α]), and acrylamide exposure (N-acetyl-S-[2-carbamoylethyl]-l-cysteine [AAMA], N-acetyl-S-[2-carbamoyl-2-hydroxyethyl]-l-cysteine [GAMA]) were measured for 3,270 general adults from the Wuhan-Zhuhai cohort. The associations of urinary acrylamide metabolites with 8-OHdG, 8-iso-PGF2α, and FPG were assessed by linear mixed models. The mediating roles of 8-OHdG and 8-iso-PGF2α were evaluated by mediation analysis.

RESULTS

We found significant linear positive dose-response relationships of urinary acrylamide metabolites with 8-OHdG, 8-iso-PGF2α, and FPG (except GAMA with FPG) and 8-iso-PGF2α with FPG. Each 1-unit increase in log-transformed level of AAMA, AAMA + GAMA (ΣUAAM), or 8-iso-PGF2α was associated with a 0.17, 0.15, or 0.23 mmol/L increase in FPG, respectively (P and/or P trend < 0.05). Each 1% increase in AAMA, GAMA, or ΣUAAM was associated with a 0.19%, 0.27%, or 0.22% increase in 8-OHdG, respectively, and a 0.40%, 0.48%, or 0.44% increase in 8-iso-PGF2α, respectively (P and P trend < 0.05). Increased 8-iso-PGF2α rather than 8-OHdG significantly mediated 64.29% and 76.92% of the AAMA- and ΣUAAM-associated FPG increases, respectively.

CONCLUSIONS

Exposure of the general adult population to acrylamide was associated with FPG elevation, oxidative DNA damage, and lipid peroxidation, which in turn partly mediated acrylamide-associated FPG elevation.

Dietary Fat and Cancer-Which Is Good, Which Is Bad, and the Body of Evidence

A high-fat diet (HFD) induces changes in gut microbiota leading to activation of pro-inflammatory pathways, and obesity, as a consequence of overnutrition, exacerbates inflammation, a known risk factor not only for cancer. However, experimental data showed that the composition of dietary fat has a greater impact on the pathogenesis of cancer than the total fat content in isocaloric diets. Similarly, human studies did not prove that a decrease in total fat intake is an effective strategy to combat cancer. Saturated fat has long been considered as harmful, but the current consensus is that moderate intake of saturated fatty acids (SFAs), including palmitic acid (PA), does not pose a health risk within a balanced diet. In regard to monounsaturated fat, plant sources are recommended. The consumption of plant monounsaturated fatty acids (MUFAs), particularly from olive oil, has been associated with lower cancer risk. Similarly, the replacement of animal MUFAs with plant MUFAs decreased cancer mortality. The impact of polyunsaturated fatty acids (PUFAs) on cancer risk depends on the ratio between ω-6 and ω-3 PUFAs. In vivo data showed stimulatory effects of ω-6 PUFAs on tumour growth while ω-3 PUFAs were protective, but the results of human studies were not as promising as indicated in preclinical reports. As for trans FAs (TFAs), experimental data mostly showed opposite effects of industrially produced and natural TFAs, with the latter being protective against cancer progression, but human data are mixed, and no clear conclusion can be made. Further studies are warranted to establish the role of FAs in the control of cell growth in order to find an effective strategy for cancer prevention/treatment.

Environmental Obesogens and Their Impact on Susceptibility to Obesity: New Mechanisms and Chemicals

The incidence of obesity has reached an all-time high, and this increase is observed worldwide. There is a growing need to understand all the factors that contribute to obesity to effectively treat and prevent it and associated comorbidities. The obesogen hypothesis proposes that there are chemicals in our environment termed obesogens that can affect individual susceptibility to obesity and thus help explain the recent large increases in obesity. This review discusses current advances in our understanding of how obesogens act to affect health and obesity susceptibility. Newly discovered obesogens and potential obesogens are discussed, together with future directions for research that may help to reduce the impact of these pervasive chemicals.

Silymarin Ameliorates Acrylamide-Induced Hyperlipidemic Cardiomyopathy in Male Rats

Acrylamide (AA) is a well-known potent carcinogen and neurotoxin that has been recently linked to atherosclerotic pathogenesis. The present study is aimed at investigating the protective effect of silymarin (SIL) as an antioxidant against AA-induced hyperlipidemic cardiomyopathy in male rats. The obtained results showed that animals exposed to AA exhibited a significant increase in the levels of cardiac serum markers, serum total cholesterol, triglycerides, low-density lipoprotein cholesterol, and very-low-density lipoprotein cholesterol with a significant decrease in high-density lipoprotein cholesterol. Furthermore, AA intoxication significantly increased the malondialdehyde level (a hallmark of lipid peroxidation) and reduced antioxidant enzyme activities (i.e., superoxide dismutase, catalase, and glutathione peroxidase). SIL administration significantly attenuated all these biochemical perturbations in AA-treated rats, except for the decreased high-density lipoprotein cholesterol. Our results were confirmed by histopathological assessment of the myocardium. In conclusion, this study demonstrated a beneficial effect of SIL therapy in the prevention of AA-induced cardiotoxicity by reversing the redox stress and dyslipidemia in experimental animals.

Transgenerational effects of obesogens

Obesity and associated disorders are now a global pandemic. The prevailing clinical model for obesity is overconsumption of calorie-dense food and diminished physical activity (the calories in-calories out model). However, this explanation does not account for numerous recent research findings demonstrating that a variety of environmental factors can be superimposed on diet and exercise to influence the development of obesity. The environmental obesogen model proposes that exposure to chemical obesogens during in utero and/or early life can strongly influence later predisposition to obesity. Obesogens are chemicals that inappropriately stimulate adipogenesis and fat storage, in vivo either directly or indirectly. Numerous obesogens have been identified in recent years and some of these elicit transgenerational effects on obesity as well as a variety of health end-points after exposure of pregnant F0 females. Prenatal exposure to environmental obesogens can produce lasting effects on the exposed animals and their offspring to at least the F4 generation. Recent results show that some of these transgenerational effects of obesogen exposure can be carried across the generations via alterations in chromatin structure and accessibility. That some chemicals can have permanent effects on the offspring of exposed animals suggests increased caution in the debate about whether and to what extent exposure to endocrine-disrupting chemicals and obesogens should be regulated.