Advanced glycoxidation end products in commonly consumed foods

In vivo glycation-interplay between oxidant and carbonyl stress in bone

Metabolic syndromes (eg, obesity, type 2 diabetes (T2D), atherosclerosis, and neurodegenerative diseases) and aging, they all have a strong component of carbonyl and reductive-oxidative (redox) stress. Reactive carbonyl (RCS) and oxidant (ROS) stress species are commonly generated as products or byproducts of cellular metabolism or are derived from the environment. RCS and ROS can play a dual role in living organisms. Some RCS and ROS function as signaling molecules, which control cellular defenses against biological and environmental assaults. However, due to their high reactivity, RCS and ROS inadvertently interact with different cellular and extracellular components, which can lead to the formation of undesired posttranslational modifications of bone matrix proteins. These are advanced glycation (AGEs) and glycoxidation (AGOEs) end products generated in vivo by non-enzymatic amino-carbonyl reactions. In this review, metabolic processes involved in generation of AGEs and AGOEs within and on protein surfaces including extracellular bone matrix are discussed from the perspective of cellular metabolism and biochemistry of certain metabolic syndromes. The impact of AGEs and AGOEs on some characteristics of mineral is also discussed. Different therapeutic approaches with the potential to prevent the formation of RCS, ROS, and the resulting formation of AGEs and AGOEs driven by these chemicals are also briefly reviewed. These are antioxidants, scavenging agents of reactive species, and newly emerging technologies for the development of synthetic detoxifying systems. Further research in the area of in vivo glycation and glycoxidation should lead to the development of diverse new strategies for halting the progression of metabolic complications before irreversible damage to body tissues materializes.

Dose-response association between animal protein sources and risk of gestational diabetes mellitus: a systematic review and meta-analysis

CONTEXT

There are contradictory findings about the relationship between various animal protein sources and the risk of gestational diabetes mellitus (GDM).

OBJECTIVE

The purpose of our study was to understand better the associations between total protein, animal protein, and animal protein sources and the risk of developing GDM.

DATA SOURCES

A systematic literature search was conducted in PubMed, Scopus, and Web of Science encompassing the literature up until August 2022. A random-effects model was used to combine the data. For estimating the dose-response curves, a one-stage linear mixed-effects meta-analysis was conducted.

DATA EXTRACTION

Data related to the association between animal protein consumption and the risk of GDM in the general population was extracted from prospective cohort studies.

DATA ANALYSIS

It was determined that 17 prospective cohort studies with a total of 49 120 participants met the eligibility criteria. It was concluded with high certainty of evidence that there was a significant association between dietary animal protein intake and GDM risk (1.94, 95% CI 1.42 to 2.65, n = 6). Moreover, a higher intake of total protein, total meat, and red meat was positively and significantly associated with an increased risk of GDM. The pooled relative risks of GDM were 1.50 (95% CI: 1.16, 1.94; n = 3) for a 30 g/d increment in processed meat, 1.68 (95% CI: 1.25, 2.24; n = 2) and 1.94 (95% CI: 1.41, 2.67; n = 4) for a 100 g/d increment in total and red meat, and 1.21 (95% CI: 1.10, 1.33; n = 4) and 1.32 (95% CI: 1.15, 1.52; n = 3) for a 5% increment in total protein and animal protein, respectively. GDM had a positive linear association with total protein, animal protein, total meat consumption, and red meat consumption, based on non-linear dose-response analysis.

CONCLUSION

Overall, consuming more animal protein-rich foods can increase the risk of GDM. The results from the current study need to be validated by other, well-designed prospective studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022352303.

Impact of quinoa and food processing on gastrointestinal health: a narrative review

Due to exceptional nutritional quality, quinoa is an ideal candidate to solve food insecurity in many countries. Quinoa's profile of polyphenols, essential amino acids, and lipids make it ideal for digestive health. How the nutrient profile and bioavailability of quinoa metabolites differs across cooking methods such as heat, pressure, and time employed has yet to be elucidated. The objective of this review is to compile available research pertaining to the impact of various cooking methods on quinoa's nutritional properties with specific emphasis on how those properties affect gut health. Replacing small percentages of wheat flour with quinoa flour in baked bread increases the antioxidant activity, essential amino acids, fiber, minerals, and polyphenols. Extruding quinoa flour reduces amino acid, lipid, and polyphenol content of the raw seed, however direct quinoa and cereal grain extrudate comparisons are absent. Boiling quinoa leads to an increase of dietary fiber as well as exceptional retention of amino acids, lipids, and polyphenols. Baking and extruding with quinoa flour results in less optimal texture due to higher density, however minor substitutions can retain acceptable texture and even improve taste. Future research on quinoa's substitution in common processing methods will create equally desirable, yet more nutritious food products.

Monascus pigments suppress fructose-mediated BSA glycation by trapping methylglyoxal and covalent binding to proteins

In this study, four Monascus pigments (ankaflavin, AK; monascin MS; rubropunctatin, O1; monascorubrin, O2) were proved to exhibit considerable anti-glycation properties in bovine serum albumin (BSA)-fructose model. AK (40.62 %) and MS (48.38 %) were found to exert lower inhibitory effects on the formation of fluorescent advanced glycation end products (AGEs) than aminoguanidine (59.4 %), while O1 (90.64 %) and O2 (93.82 %) displayed much stronger abilities. AK and MS could trap methylglyoxal (MGO) with maximum capture rates of 85.67 % and 84.90 %, respectively, and only mono-MGO adducts of them were detected. LC-Orbitrap MS/MS analysis revealed that four pigments significantly altered the type and reduced the number of the glycated sites and they all covalently bound to BSA, with O1 and O2 possessing high reactivity. Altogether, AK and MS suppressed fluorescent AGEs formation mainly via trapping MGO and covalently interacting with BSA, and blocking free amino groups was the dominant mechanism for O1 and O2. These findings presented new insights into Monascus pigments as dietary supplement for inhibiting protein glycation.

Generation of advanced glycation end products from glycated protein or fructose/glyoxal-protein adducts under in vitro simulated gastrointestinal digestion

Advanced glycation end products (AGEs) are a heterogeneous group of compounds formed both endogenously and exogenously through reactions between reducing sugars and amino acids within the proteins. The digestive tract may also serve as a site for endogenous AGEs generation. This study examined whether additional AGEs are formed during the digestion of glycated protein diets and meal-resembling systems (dietary proteins with fructose or glyoxal). The digestion of glycated protein showed that free AGEs were gradually released, but no additional AGEs were generated. In contrast, co-digestion of dietary proteins with fructose or glyoxal resulted in the formation of additional AGEs, and the reaction substrates (fructose or glyoxal) were depleted during digestion. Additionally, the lysine released from proteins decreased, leading to a loss of nutritional value of the food during co-digestion. The formation of AGEs and the depletion of essential amino acids in the gut may have significant implications for human health.

Methylglyoxal induces death in human brain neuronal cells (SH-SY5Y), prevented by metformin and dapagliflozin

Diabetes mellitus is a metabolic disorder caused by a dysfunction in insulin action or secretion, leading to an elevation in blood glucose levels. It is a highly prevalent condition and as a result, the NHS spends 10 % of its entire budget on diabetes mellitus care, that is equivalent to £10 billion a year. Diabetes mellitus has been linked with vascular and neurological complications which may be associated with the progression of neurodegeneration and Alzheimer's disease. Chronic hyperglycaemia increases the production of the reactive oxidant species (ROS) such as methylglyoxal (MGO). MGO has been linked with vascular complications, neuropathy and cytotoxicity. The main aim of this study was to investigate the potential beneficial effect of antidiabetic agents such as metformin and dapagliflozin on human brain neuronal cells (SH-SY5Y) treated with MGO. SH-SY5Y cells were cultured in DMEM/F12 media and subjected overnight incubation with one of the following treatment conditions: Control (untreated); MGO (1 μM); MGO (100 μM); metformin (100 μM) + MGO (100 μM); and dapagliflozin (10 μM) + MGO (100 μM). Several assays were conducted to explore the effect of the treatment groups on the SH-SY5Y cells. These included: MTT assay; LDH assay, peroxynitrite fluorescence assay, and laser scanning confocal microscopy. MGO (100 μM) led to significant cell injury and damage and significantly reduced the survival of the cells by approximately 50-75 %, associated with significant increase in peroxynitrite. The addition of metformin (100 μM) or dapagliflozin (10 μM) represented significant protective effects on the cells and prevented the cell damage caused by the high MGO concentration. As a result, the findings of this research reveal that MGO-induced cell damage may partly be mediated by the generation of peroxynitrite, while the antidiabetic agents such as metformin and dapagliflozin prevent brain cell death, which potentially may play prophylactic roles against the risk of dementia in diabetic patients.

Dietary glycation compounds - implications for human health

The term "glycation compounds" comprises a wide range of structurally diverse compounds that are formed endogenously and in food via the Maillard reaction, a chemical reaction between reducing sugars and amino acids. Glycation compounds produced endogenously are considered to contribute to a range of diseases. This has led to the hypothesis that glycation compounds present in food may also cause adverse effects and thus pose a nutritional risk to human health. In this work, the Senate Commission on Food Safety (SKLM) of the German Research Foundation (DFG) summarized data on formation, occurrence, exposure and toxicity of glycation compounds (Part A) and systematically assessed potential associations between dietary intake of defined glycation compounds and disease, including allergy, diabetes, cardiovascular and renal disease, gut/gastrotoxicity, brain/cognitive impairment and cancer (Part B). A systematic search in Pubmed (Medline), Scopus and Web of Science using a combination of keywords defining individual glycation compounds and relevant disease patterns linked to the subject area of food, nutrition and diet retrieved 253 original publications relevant to the research question. Of these, only 192 were found to comply with previously defined quality criteria and were thus considered suitable to assess potential health risks of dietary glycation compounds. For each adverse health effect considered in this assessment, however, only limited numbers of human, animal and in vitro studies were identified. While studies in humans were often limited due to small cohort size, short study duration, and confounders, experimental studies in animals that allow for controlled exposure to individual glycation compounds provided some evidence for impaired glucose tolerance, insulin resistance, cardiovascular effects and renal injury in response to oral exposure to dicarbonyl compounds, albeit at dose levels by far exceeding estimated human exposures. The overall database was generally inconsistent or inconclusive. Based on this systematic review, the SKLM concludes that there is at present no convincing evidence for a causal association between dietary intake of glycation compounds and adverse health effects.

Skin autofluorescence and cause-specific mortality in a population-based cohort

We aimed to assess the association of SAF with cardiovascular mortality in the general population and the possible association between SAF with other disease-specific mortality rates. We evaluated 77,143 participants without known diabetes or cardiovascular disease. The cause of death was ascertained by the municipality database. The associations between SAF and all-cause mortality, cardiovascular mortality and cancer mortality were assessed with Cox proportional hazard analysis.After a median follow-up of 115 months, 1447 participants were deceased (1.9%). SAF and age-adjusted SAF-z score were higher in all mortality groups. Cox regression analysis revealed that the highest quartile of SAF was associated with increased odds of cardiovascular mortality, (HR) 12.6 (7.3-21.7) and after adjusting for age (HR 1.8 (1.0-3.2)). Significance was lost after additional adjustments for sex, smoking status, and BMI (HR 1.4 (0.8-2.5). For cancer-related mortality the highest quartile of SAF was associated with higher probability of mortality in all models (unadjusted HR 8.6 (6.6-11.3), adjusted for age HR 2.1 (1.6-2.8)), adjusted for age, sex, smoking status, and BMI HR 1.7 (1.3-2.4)). SAF is associated with all-cause mortality as well as cardiovascular and cancer-related mortality in the general population.

Dietary advanced glycation end products, body composition, and anthropometric measures: A cross-sectional analysis in women with excess body weight

BACKGROUND AND AIMS

To assess the association between dietary advanced glycation end products (dAGEs) versus body composition and anthropometric variables.

METHODS AND RESULTS

Body composition (dual-energy X-ray absorptiometry), anthropometry, and habitual food intake were cross-sectionally evaluated in women with excess body weight and body fat. Mean dAGEs content was estimated using a database containing the Nԑ-(carboxymethyl)lysine (CML) content of 549 foods, which was adjusted by mean energy intake, and categorized into low, medium, and high dAGEs, by the 10th and 50th percentiles of the sample. Associations were tested by linear regression adjusted for age, education, marital status, and physical activity level. Eighty participants had mean ± standard deviation dAGEs 7.85 ± 2.65 AGEs kU/kcal. Compared with high dAGEs, women with low dAGEs ingested more carbohydrate (62% vs. 50% of calories, p < 0.001) and fiber (≈25 g vs. ≈18 g, p = 0.027) and less protein (13% vs. 17% of calories, p = 0.006) and fat (26% vs. 33% of calories, p = 0.011). Women with low dAGEs had waist/hip ratio 0.05 higher than those with high dAGEs (R2 = 0.256, p = 0.005). Low dAGEs relative to medium (p = 0.009) and high (p = 0.002) dAGEs was associated with a ≈5% gynoid fat reduction (R2 = 0.164).

CONCLUSION

Low dAGEs was associated with a higher waist/hip ratio and lower percentage of gynoid fat in women with excess body weight and excess body fat.

REGISTRATION NUMBER

RBR-7z358j.

Estimation of Advanced Glycation End Products in Selected Foods and Beverages by Spectrofluorimetry and ELISA

Advanced glycation end products (AGEs) are formed within the body as a part of normal metabolism and are also the by-products of cooking food. The elevated levels of AGEs in the body are considered pathogenic. The modern diets contain high levels of AGEs which are getting incorporated into the body AGEs pool and contribute to post-diabetic and age-related complications. The objective of the present study is to estimate the cross-linked AGEs (AGE-fluorescence) and the more stable carboxymethyl-lysine (CML) by spectrofluorimetry and ELISA in 58 kinds of foods in India. It was evident from the results that the foods cooked at higher temperatures showed high levels of AGEs. Among the studied foods, the highest fluorescence was observed in Biscuits 2 (362 AU), and the highest level of carboxymethyl lysine (CML) was found in Soya milk (659.3 ng/g). However, there was less correlation between the AGE-fluorescence and the CML content of the food samples. Processed food such as tomato sauce, chilli sauce, and cheese, along with western foods like chicken nuggets, pizza, and biscuits like Biscuits 2, are known to contain high levels of AGEs. In the present study a preliminary database of AGE-fluorescence and CML content of 58 foods was developed, which is the first attempt among Indian foods. Furthermore, elaborated database can be developed including maximum consumed foods in India which will help in suggesting a better diet for the diabetic population.

The dynamic roles of advanced glycation end products

Advanced glycation end products (AGEs) are a heterogeneous group of potentially harmful molecules that can form as a result of a non-enzymatic reaction between reducing sugars and proteins, lipids, or nucleic acids. The total body pool of AGEs reflects endogenously produced AGEs as well as exogeneous AGEs that come from sources such as diet and the environment. Engagement of AGEs with their cellular receptor, the receptor for advanced glycation end products (RAGE), which is expressed on the surface of various cell types, converts a brief pulse of cellular activation to sustained cellular dysfunction and tissue destruction. The AGEs/RAGE interaction triggers a cascade of intracellular signaling pathways such as mitogen-activated protein kinase/extracellular signal-regulated kinase, phosphoinositide 3-kinases, transforming growth factor beta, c-Jun N-terminal kinases (JNK), and nuclear factor kappa B, which leads to the production of pro-inflammatory cytokines, chemokines, adhesion molecules, and oxidative stress. All these events contribute to the progression of several chronic diseases. This chapter will provide a comprehensive understanding of the dynamic roles of AGEs in health and disease which is crucial to develop interventions that prevent and mitigate the deleterious effects of AGEs accumulation.

Exploring the hypoglycemic mechanism of chlorogenic acids from Pyrrosia petiolosa (Christ) Ching on type 2 diabetes mellitus based on network pharmacology and transcriptomics strategy

ETHNOPHARMACOLOGICAL RELEVANCE

Pyrrosia petiolosa (Christ) Ching (YBSW) is a Traditional Chinese medicine rich in chlorogenic acids. It is an important component in many Traditional Chinese medicinal hypoglycemic formulas and is commonly used by the Miao people to treat diabetes with good efficacy. Our previous research has suggested that chlorogenic acids may be the active ingredients in YBSW.

AIM OF THE STUDY

To explore the mechanisms underlying the anti-type 2 diabetes mellitus (T2DM) hypoglycemic effects of chlorogenic acids contained in YBSW.

MATERIALS AND METHODS

In vivo experiments, hematoxylin-eosin staining (HE) staining, and immunohistochemistry (IHC) were used to determine the effects of chlorogenic acids contained in YBSW in rats. mRNA expression profiling, microarray analysis, and network pharmacology were used to analyze the underlying mechanisms of the effects. Finally, apoptosis and changes in the related pathways were evaluated in vitro using a 3-(4,5-dimethyl-2-thia-zolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay, quantitative real-time polymerase chain reaction, immunofluorescence (IF) assessment, and flow cytometry.

RESULTS

After the administration of isochlorogenic acid B, the levels of triglycerides, serum total cholesterol, and fasting blood glucose significantly decreased. HE and IHC staining revealed that isochlorogenic acid B significantly increased insulin expression in islet cells. Using network pharmacology and RNA-seq Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, we screened the advanced glycation end products-receptor for advanced glycation end products (AGE-RAGE) signaling pathway. We also verified that YBSW and its chlorogenic acid can inhibit apoptosis and downregulate the expression of related mRNA in the AGE-RAGE pathway in RIN-m5f cells.

CONCLUSIONS

YBSW exhibits a significant hypoglycemic effect, with chlorogenic acid being an effective component. The therapeutic effect of chlorogenic acids contained in YBSW is mainly realized by promoting insulin secretion and pancreatic tissue repair. Moreover, YBSW substantially mitigates apoptosis via the AGE-RAGE pathway in T2DM.

Qualitative and quantitative assessment of key aroma compounds, advanced glycation end products and heterocyclic amines in different varieties of commercially roasted meat products

Studies on the interactions and links between aroma and hazardous compounds were inadequately investigated. A complete analysis was conducted on the key aroma compounds, typical hazardous compounds and their precursors in 25 samples of roasted meats. Forty-nine aroma compounds were identified as essential odorants with odor-activity values exceeds 1. Nε-carboxymethyl lysine (CML, 11.78-49.32 μg/g) and Nε-carboxyethyl lysine (CEL, 8.48-171.00 μg/g) were identified as representative advanced glycation end products (AGEs) of meats with high concentrations. Harman and Norharman were typical heterocyclic aromatic amines. Meanwhile, correlation analysis indicated that aldehyde and alcohols showed a negative correlation with AGEs (p < 0.01), while pyrazines might affect the formation of Harman and Norharman. The furaldehyde, 1-hexanol, 2, 4-Decadienal, AGEs, and creatine were regarded as potential biomarkers that distinguished different roasted meat products. Therefore, the study could provide new insights for synergistic regulation of aroma and hazardous compounds in roasted meat products.

Role of Advanced Glycation End Products as New Biomarkers in Systemic Lupus Erythematosus

Advanced glycation end-products (AGEs) may play a relevant role as inducers in the chronic inflammatory pathway present in immune-mediated diseases, such as systemic lupus erythematosus (SLE). AGEs concentrations have been associated, with discrepant results to date, with some parameters such as disease activity or accrual damage, suggesting their potential usefulness as biomarkers of the disease. Our objectives are to confirm differences in AGEs levels measured by cutaneous autofluorescence between SLE patients and healthy controls (HC) and to study their correlation with various disease parameters. Cross-sectional study, where AGEs levels were measured by skin autofluorescence, and SLE patients' data were compared with those of sex- and age-matched HC in a 1:3 proportion through a multiple linear regression model. Associations of AGEs levels with demographic and clinical data were analyzed through ANOVA tests. Both analyses were adjusted for confounders. AGEs levels in SLE patients were significantly higher than in HC (p < 0.001). We found statistically significant positive associations with SLE disease activity index (SLEDAI) and damage index (SDI), physician and patient global assessment, C-reactive protein, leukocyturia, complement C4, IL-6 and oral ulcers. We also found a negative statistically significant association with current positivity of anti-nuclear and anti-Ro60 antibodies. AGEs seem to have a contribution in LES pathophysiology, being associated with activity and damage and having a role as a new management and prognosis biomarker in this disease. The association with specific antibodies and disease manifestations may indicate a specific clinical phenotype related to higher or lower AGEs levels.

Evaluation of the effects of dietary advanced glycation end products on inflammation

Advanced glycation end products (AGEs) are a large number of heterogeneous compounds formed by the glycation of proteins, fats or nucleic acids. Endogenous AGEs have been associated with various health problems such as obesity, type 2 diabetes mellitus and cardiovascular disease. Inflammation is thought to be one of the main mechanisms in the development of these disorders. Although AGEs are produced endogenously in the body, exogenous sources such as smoking and diet also contribute to the body pool. Therefore, when the AGE pool in the body rises above physiological levels, different pathological conditions may occur through various mechanisms, especially inflammation. While the effects of endogenous AGEs on the development of inflammation have been studied relatively extensively, and current evidence indicates that dietary AGEs (dAGEs) contribute to the body's AGE pool, it is not yet known whether dAGEs have the same effect on the development of inflammation as endogenous AGEs. Therefore, this review aimed to evaluate the results of cross-sectional and intervention studies to understand whether dAGEs are associated with inflammation and, if there is an effect on inflammation, through which mechanisms this effect might occur.

The AGE-RAGE axis associates with chronic pulmonary diseases and smoking in the Rotterdam study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) and asthma associate with high morbidity and mortality. High levels of advanced glycation end products (AGEs) were found in tissue and plasma of COPD patients but their role in COPD and asthma is unclear.

METHODS

In the Rotterdam Study (n = 2577), AGEs (by skin autofluorescence (SAF)), FEV1 and lung diffusing capacity (DLCOc and DLCOc /alveolar volume [VA]) were measured. Associations of SAF with asthma, COPD, GOLD stage, and lung function were analyzed using logistic and linear regression adjusted for covariates, followed by interaction and stratification analyses. sRAGE and EN-RAGE associations with COPD prevalence were analyzed by logistic regression.

RESULTS

SAF associated with COPD prevalence (OR = 1.299 [1.060, 1.591]) but not when adjusted for smoking (OR = 1.106 [0.89, 1.363]). SAF associated with FEV1% predicted (β=-3.384 [-4.877, -1.892]), DLCOc (β=-0.212 [-0.327, -0.097]) and GOLD stage (OR = 4.073, p = 0.001, stage 3&4 versus 1). Stratified, the association between SAF and FEV1%predicted was stronger in COPD (β=-6.362 [-9.055, -3.670]) than non-COPD (β=-1.712 [-3.306, -0.118]). Association of SAF with DLCOc and DLCOc/VA were confined to COPD (β=-0.550 [-0.909, -0.191]; β=-0.065 [-0.117, -0.014] respectively). SAF interacted with former smoking and COPD prevalence for associations with lung function. Lower sRAGE and higher EN-RAGE associated with COPD prevalence (OR = 0.575[0.354, 0.931]; OR = 1.778[1.142, 2.768], respectively).

CONCLUSIONS

Associations between SAF, lung function and COPD prevalence were strongly influenced by smoking. SAF associated with COPD severity and its association with lung function was more prominent within COPD. These results fuel further research into interrelations and causality between SAF, smoking and COPD.

TAKE-HOME MESSAGE

Skin AGEs associated with prevalence and severity of COPD and lung function in the general population with a stronger effect in COPD, calling for further research into interrelations and causality between SAF, smoking and COPD.

Association of total and different food-derived advanced glycation end-products with risks of all-cause and cause-specific mortality

Background: advanced glycation end-products (AGEs), formed through a series of non-enzymatic reactions, can promote inflammation and oxidative stress. Their accumulation in the body has been linked to cardiovascular disease (CVD) and cancer. However, the association of total AGEs and AGEs from different food sources with risks of all-cause, CVD, and cancer mortality is still unknown. Methods: we conducted a prospective cohort study of a nationally representative sample of 22 124 participants from the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and NHANES 2003-2006. A food frequency questionnaire (FFQ) was utilized to calculate total and different food-derived AGE intake. Associations between various dietary AGE scores and the risk of all-cause, CVD, and cancer mortality were assessed by weighted Cox proportional hazard regression models. Results: over a median follow-up period of 27.1 years, we found that in the general population, AGE scores of both baked foods and meat were risk factors for all-cause, CVD, and cancer mortality. Specially, higher AGE scores in total and those derived from 10 of the 13 food groups were statistically associated with an increased risk of CVD mortality. Egg-, fruit-, and vegetable-derived AGE scores were positively correlated with the risk of cancer mortality. Additionally, there were positive multiplicative and additive interactions between smoking and meat-derived AGE scores on all-cause mortality. Conclusions: high amounts of AGE consumption is associated with an increased risk of CVD mortality, and meat and baked food-derived AGEs were positively linked to all-cause, CVD, and cancer mortalities. Adherence to unhealthy lifestyles, such as smoking, may increase mortality from leading causes in individuals with AGE-enriched diet habits.

Associations of circulating advanced glycation end products and their soluble receptors with cancer risk: A systematic review and meta-analysis of observational studies

Advanced glycation end products (AGE) in complex with their receptors (RAGE) cause a chronic inflammatory state in the body, which is the major mechanism in cancer development. This study aimed to conduct a systematic review and meta-analysis on the observational studies investigating the association between AGEs / sRAGE and cancer incidence. The PubMed, Scopus, and Web of Science databases were comprehensively searched to identify papers focused on the associations of sRAGE and AGEs with cancer incidence up to May 2023. Eight studies with a total of 7690 participants were included in the analysis to evaluate the association between circulating sRAGE and cancer incidence. The results indicated that circulating sRAGE (per 100 ng/L) had a significant inverse association with cancer incidence (RR 0.977; 95% CI 0.956, 0.999; p = 0.036; I 2 = 73.3%). The association between AGEs and cancer incidence was evaluated in 8 studies with a total of 3718 individuals. Serum concentrations of AGEs (per 100 µg/L) were not associated with the risk of cancer incidence (RR 0.988; 95% CI 0.974, 1.002; p = 0.08; I2 = 78.8%). Our findings revealed that a higher circulating sRAGE may have a protective effect against cancer incidence.

Advanced glycation end products consumption and the decline of functional capacity in patients with Parkinson's disease: Cross-sectional study

INTRODUCTION

Advanced Glycation End-Products (AGEs) are a diverse group of highly reactive molecules that play a vital role in the development of neurodegenerative disorders, such as Parkinson's Disease (PD), leading to a decline in functional and cognitive capacity. The objective of this study was to assess the intake and quantification of AGEs in individuals with PD and to correlate them with their functional and cognitive abilities.

METHODS

This was a cross-sectional study involving 20 PD patients and 20 non-PD individuals as the Control group (C). The autofluorescence reader was used to evaluate skin AGEs, while food recall was used to quantify AGEs consumed for three different days. The Montreal Cognitive Assessment, Short Physical Performance Battery, and handgrip tests were used. PD patients demonstrated greater impairment in functional capacity compared to the control group.

RESULTS

Dominant Handgrip (p = 0.02) and motor performance, in the sit and stand test (p = 0.01) and Short Physical Performance Battery (SPPB) (p = 0.01) were inferior in PD patients than the control group. Although PD patients tended to consume less AGEs than the control group, AGE intake was negatively correlated with handgrip strength in individuals with PD (r = -0.59; p < 0.05).

CONCLUSION

PD patients had lower strength and functional capacity, suggesting that the effects of AGEs might be exacerbated during chronic diseases like Parkinson's.

Dietary and serum advanced glycation end-products and clinical outcomes in breast cancer

One in five women with breast cancer will relapse despite ideal treatment. Body weight and physical activity are strongly associated with recurrence risk, thus lifestyle modification is an attractive strategy to improve prognosis. Trials of dietary modification in breast cancer are promising but the role of specific diets is unclear, as is whether high-quality diet without weight loss can impact prognosis. Advanced glycation end-products (AGEs) are compounds produced in the body during sugar metabolism. Exogenous AGEs, such as those found in food, combined with endogenous AGEs, make up the total body AGE load. AGEs deposit in tissues over time impacting cell signaling pathways and altering protein functions. AGEs can be measured or estimated in the diet and measured in blood through their metabolites. Studies demonstrate an association between AGEs and breast cancer risk and prognosis. Here, we review the clinical data on dietary and serum AGEs in breast cancer.

Inhibitory effect of Paliurus spina-christi Mill., Celtis tournefortii L. and Nigella sativa L. on Nε-(Carboxymethyl) lysine in meatballs

This study was conducted to examine the effect of cooking at different temperatures on the formation of Nε-(carboxymethyl) lysine (CML) after adding Paliurus spina-christi Mill. (PSC), Celtis tournefortii L. (CT) fruits, and Nigella Sativa L. (NS) seeds to the meatballs. Phytochemical and bioactivity properties were determined before adding PSC, CT fruits, and NS seeds to the meatballs. Then, PSC, CT fruits, and NS seeds were added to the meatballs at a rate of 2% and stored at 4 ± 1 °C for 16 days. CML, TBARS, pH, and aw analyses were performed on the meatballs. The highest phytochemical and bioactivity levels were detected in PSC fruit. The aw values detected in the meatball groups were found to be between 0.931 and 0.951 on the 0th day and between 0.963 and 0.985 on the 16th day, and the pH values ranged from 5.66 to 6.06 on the 0th day and from 6.10 to 6.74 on the 16th day. TBARS values of the meatballs were found to be between 1.17 and 1.98 on day 0 and 1.70-3.34 mg MDA/kg on day 16. CML levels in the meatballs were determined to be between 11.15 and 13.45 on day 0 and between 13.43 and 18.17 μg/g on day 16. The highest a* value was found in the meatballs with added CT fruit. It was determined that NS seeds had a negative effect on the a* value of the meatballs. In conclusion, adding PSC, CT fruits, and NS seeds can imbue meatballs with functional properties, thereby creating a more health-beneficial product for humans.

Involvement of the Receptor for Advanced Glycation End Products (RAGE) in high fat-high sugar diet-induced anhedonia in rats

Clinical and basic science investigation indicates a link between insulin resistance and anhedonia. Previous results of this laboratory point to impaired nucleus accumbens (NAc) insulin signaling as an underpinning of diet-induced anhedonia, based on use of a glucose lick microstructure assay. The present study evaluated whether advanced glycation end products (AGEs) and their receptor (RAGE), known to mediate obesogenic diet-induced inflammation and pathological metabolic conditions, are involved in this behavioral change. Six weeks maintenance of male and female rats on a high fat-high sugar liquid diet (chocolate Ensure) increased body weight gain, and markedly increased circulating insulin and leptin, but induced anhedonia (decreased first minute lick rate and lick burst size) in males only. In these subjects, anhedonia correlated with plasma concentrations of insulin. Although the diet did not alter plasma or NAc AGEs, or the expression of RAGE in the NAc, marginally significant correlations were seen between anhedonia and plasma content of several AGEs and NAc RAGE. Importantly, a small molecule RAGE antagonist, RAGE229, administered twice daily by oral gavage, prevented diet-induced anhedonia. This beneficial effect was associated with improved adipose function, reflected in the adiponectin/leptin ratio, and increased pCREB/total CREB in the NAc, and a shift in the pCREB correlation with pThr34-DARPP-32 from near-zero to strongly positive, such that both phospho-proteins correlated with the rescued hedonic response. This set of findings suggests that the receptor/signaling pathway and cell type underlying the RAGE229-mediated increase in pCREB may mediate anhedonia and its prevention. The possible role of adipose tissue as a locus of diet-induced RAGE signaling, and source of circulating factors that target NAc to modify hedonic reactivity are discussed.

Dietary advanced glycation end products are associated with an increased risk of breast cancer in Iranian adults

BACKGROUND

Dietary advanced glycation end products (AGEs) can play an important role in increasing inflammatory factors and oxidative stress as risk factors for cancers. In the present study, we aimed to assess the relationship between dietary AGEs and the risk of breast cancer (BC) in Iranian adult women.

METHODS

This hospital-based case-control study includes 401 participants aged ≥ 30 years old. The cases group consisted of 134 women diagnosed with histologically confirmed BC. The control group included 267 women enrolled randomly from patients admitted to the same hospitals. Dietary intake information was determined using a validated food frequency questionnaire, and dietary AGEs intake was computed for all participants. Logistic regression models, adjusted for potential confounders, were used to determine the odds ratios (OR) and 95% confidence interval (CI) of BC across tertiles of dietary AGEs.

RESULTS

The mean ± SD age and body mass index of the study population were 47.92 ± 10.33 years and 29.43 ± 5.51 kg/m2, respectively. The median (interquartile) of dietary AGEs in all individuals was 9251(7450, 11,818) kU/day. After adjusting for age, first pregnancy age, and energy intake, participants in the highest tertile of dietary AGEs intakes had higher odds of BC compared to those in the lowest tertile of dietary AGEs (OR:2.29;95%CI:1.19-4.39, Ptrend:0.012). Additionally, in the multivariable model, after adjusting for age, age at first pregnancy, energy, menopausal status, family history of cancer, anti-inflammatory drug use, Vitamin D supplementation, physical activity, body mass index, number of childbirths, and history of abortion, breastfeeding, and oral contraceptive pills use, the odds of BC were increased across tertiles of dietary AGEs intake (OR: 2.33; 95%CI: 1.18-4.60, Ptrend: 0.017).

CONCLUSION

The present findings suggest that a diet with high AGEs is associated with a higher likelihood of BC in adult women.

Follicular fluid advanced glycation end products in assisted reproduction: A systematic review

Follicular fluid (FF) advanced glycation end products (AGEs) have been associated with low oocyte quality and number, low fertilization rate, impaired embryonic development and low pregnancy rate. These findings are especially relevant in women undergoing in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), ie, assisted reproductive technology (ART). A systematic literature search was conducted to examine various AGEs including pentosidine, carboxymethyl-lysine (CML), methylglyoxal 5-hydro-5-methylimidazolones (MG-H1), toxic AGE (TAGE), and soluble receptor for AGE (sRAGE) with ART outcomes. Studies showed that total AGEs and sRAGE in FF were associated with the ovarian response, follicle number, retrieved oocyte number, mature (MII) oocyte number, fertilization rate, embryo number, embryo quality, and successful pregnancy. Although FF AGEs could be considered predictive biomarkers, population heterogeneity and differences in ovulation induction protocols make the findings less clear. This review highlights important role of AGEs in ART and necessity of evaluating AGEs in serum vs with FF to better predict ART outcomes.

Correlation between serum advanced glycation end products and dietary intake of advanced glycation end products estimated from home cooking and food frequency questionnaires

BACKGROUND & AIMS

To our knowledge the association between dietary advanced glycation end-products (dAGEs) and cardiometabolic disease is limited. Our aim was to examine the association between dAGEs and serum concentration of carboxymethyl-lysine (CML) or soluble receptor advanced glycation end-products (sRAGEs), and to assess the difference on dAGEs and circulating AGEs according to lifestyle and biochemical measures.

METHODS AND RESULTS

52 overweight or obese adults diagnosed with type 2 diabetes were included in this cross-sectional analysis. dAGEs were estimated from a Food Frequency Questionnaire (FFQ) or from a FFQ + Home Cooking Frequency Questionnaire (HCFQ). Serum concentrations of CML and sRAGEs were measured by ELISA. Correlation tests were used to analyze the association between dAGEs derived from the FFQ or FFQ + HCFQ and concentrations of CML or sRAGEs. Demographic characteristics, lifestyle factors and biochemical measures were analyzed according to sRAGEs and dAGEs using student t-test and ANCOVA. A significant inverse association was found between serum sRAGEs and dAGEs estimated using the FFQ + HCFQ (r = -0.36, p = 0.010), whereas no association was found for dAGEs derived from the FFQ alone. No association was observed between CML and dAGEs. dAGEs intake estimated from the FFQ + HCFQ was significantly higher among younger and male participants, and in those with higher BMI, higher Hb1Ac levels, longer time with type 2 diabetes, lower adherence to Mediterranean diet, and higher use of culinary techniques that generate more AGEs (all p values p < 0.05).

CONCLUSIONS

These results show knowledge on culinary techniques is relevant to derive the association between dAGEs intake and cardiometabolic risk factors.

Dietary Approach of Patients with Hormone-Related Cancer Based on the Glycemic Index and Glycemic Load Estimates

Hormone-related cancers, namely breast, endometrial, cervical, prostate, testicular, and thyroid, constitute a specific group of cancers dependent on hormone levels that play an essential role in cancer growth. In addition to the traditional risk factors, diet seems to be an important environmental factor that partially explains the steadily increased prevalence of this group of cancer. The composition of food, the dietary patterns, the endocrine-disrupting chemicals, and the way of food processing and preparation related to dietary advanced glycation end-product formation are all related to cancer. However, it remains unclear which specific dietary components mediate this relationship. Carbohydrates seem to be a risk factor for cancer in general and hormone-related cancers, in particular, with a difference between simple and complex carbohydrates. Glycemic index and glycemic load estimates reflect the effect of dietary carbohydrates on postprandial glucose concentrations. Several studies have investigated the relationship between the dietary glycemic index and glycemic load estimates with the natural course of cancer and, more specifically, hormone-related cancers. High glycemic index and glycemic load diets are associated with cancer development and worse prognosis, partially explained by the adverse effects on insulin metabolism, causing hyperinsulinemia and insulin resistance, and also by inflammation and oxidative stress induction. Herein, we review the existing data on the effect of diets focusing on the glycemic index and glycemic load estimates on hormone-related cancers.

Glycemic Index and Glycemic Load Estimates in the Dietary Approach of Polycystic Ovary Syndrome

Polycystic ovary syndrome is a common endocrine disorder characterized by hormonal imbalances and various metabolic abnormalities linked to insulin resistance via a vicious cycle. Genetic and environmental factors underlie its pathogenesis and evolution. Nutrition, in terms of nutrient composition, dietary patterns, endocrine-disrupting chemicals, and food processing and preparation, has gained significant attention in the pathogenesis and the therapeutic approach of polycystic ovary syndrome. Carbohydrate intake seems to be a critical point in the diet assignment. Glycemic index and glycemic load constitute indexes of the impacts of dietary carbohydrates on postprandial glucose levels. Numerous studies have indicated that a high glycemic index and glycemic load diet may exacerbate insulin resistance, a key feature of the syndrome, and offer a risk for its development and its complications. Conversely, low-glycemic index and low-glycemic load diets seem to improve insulin sensitivity, regulate menstrual cycles, and mitigate the risk of comorbidities associated with polycystic ovary syndrome, such as obesity, alterations in body composition, type 2 diabetes, cardiovascular disease, and quality of life. This comprehensive review aims to explore the relevance of nutrition and more specifically, the association of glycemic index and glycemic load with the various aspects of polycystic ovary syndrome, as well as to assess the potential benefits of manipulating those indexes in the dietary approach for the syndrome.

Extraction optimization and identification of four advanced glycation-end products inhibitors from lotus leaves and interaction mechanism analysis

Previous research indicated lotus leaves extract could effectively inhibit advanced glycation end-products (AGEs) formation, but the optimal extraction condition, bio-active compounds and interaction mechanism remain unclear. The current study was designed to optimize the extraction parameters of AGEs inhibitors from lotus leaves by bio-activity-guided approach. The bio-active compounds were enriched and identified, the interaction mechanisms of inhibitors with ovalbumin (OVA) were investigated by fluorescence spectroscopy and molecular docking. The optimum extraction parameters were solid-liquid ratio of 1:30, ethanol concentration of 70 %, ultrasonic time of 40 min, temperature of 50 °C, and power of 400 W. Isoquercitrin, hyperoside, astragalin, and trifolin were identified from the 80 % ethanol fraction of lotus leaves (80HY). Hyperoside and isoquercitrin were dominant AGEs inhibitors and accounted for 55.97 % of 80HY. Isoquercitrin, hyperoside, trifolin interacted with OVA via the same mechanism, hyperoside exhibited the strongest affinity, trifolin caused the most conformational changes.

Advanced glycation end product signaling and metabolic complications: Dietary approach

Advanced glycation end products (AGEs) are a heterogeneous collection of compounds formed during industrial processing and home cooking through a sequence of nonenzymatic glycation reactions. The modern western diet is full of heat-treated foods that contribute to AGE intake. Foods high in AGEs in the contemporary diet include processed cereal products. Due to industrialization and marketing strategies, restaurant meals are modified rather than being traditionally or conventionally cooked. Fried, grilled, baked, and boiled foods have the greatest AGE levels. Higher AGE-content foods include dry nuts, roasted walnuts, sunflower seeds, fried chicken, bacon, and beef. Animal proteins and processed plant foods contain furosine, acrylamide, heterocyclic amines, and 5-hydroxymethylfurfural. Furosine (2-furoil-methyl-lysine) is an amino acid found in cooked meat products and other processed foods. High concentrations of carboxymethyl-lysine, carboxyethyl-lysine, and methylglyoxal-O are found in heat-treated nonvegetarian foods, peanut butter, and cereal items. Increased plasma levels of AGEs, which are harmful chemicals that lead to age-related diseases and physiological aging, diabetes, and autoimmune/inflammatory rheumatic diseases such as systemic lupus erythematosus and rheumatoid arthritis. AGEs in the pathophysiology of metabolic diseases have been linked to individuals with diabetes mellitus who have peripheral nerves with high amounts of AGEs and diabetes has been linked to increased myelin glycation. Insulin resistance and hyperglycemia can impact numerous human tissues and organs, leading to long-term difficulties in a number of systems and organs, including the cardiovascular system. Plasma AGE levels are linked to all-cause mortality in individuals with diabetes who have fatal or nonfatal coronary artery disease, such as ventricular dysfunction. High levels of tissue AGEs are independently associated with cardiac systolic dysfunction in diabetic patients with heart failure compared with diabetic patients without heart failure. It is widely recognized that AGEs and oxidative stress play a key role in the cardiovascular complications of diabetes because they both influence and are impacted by oxidative stress. All chronic illnesses involve protein, lipid, or nucleic acid modifications including crosslinked and nondegradable aggregates known as AGEs. Endogenous AGE formation or dietary AGE uptake can result in additional protein modifications and stimulation of several inflammatory signaling pathways. Many of these systems, however, require additional explanation because they are not entirely obvious. This review summarizes the current evidence regarding dietary sources of AGEs and metabolism-related complications associated with AGEs.

A Role for Advanced Glycation End Products in Molecular Ageing

Ageing is a composite process that involves numerous changes at the cellular, tissue, organ and whole-body levels. These changes result in decreased functioning of the organism and the development of certain conditions, which ultimately lead to an increased risk of death. Advanced glycation end products (AGEs) are a family of compounds with a diverse chemical nature. They are the products of non-enzymatic reactions between reducing sugars and proteins, lipids or nucleic acids and are synthesised in high amounts in both physiological and pathological conditions. Accumulation of these molecules increases the level of damage to tissue/organs structures (immune elements, connective tissue, brain, pancreatic beta cells, nephrons, and muscles), which consequently triggers the development of age-related diseases, such as diabetes mellitus, neurodegeneration, and cardiovascular and kidney disorders. Irrespective of the role of AGEs in the initiation or progression of chronic disorders, a reduction in their levels would certainly provide health benefits. In this review, we provide an overview of the role of AGEs in these areas. Moreover, we provide examples of lifestyle interventions, such as caloric restriction or physical activities, that may modulate AGE formation and accumulation and help to promote healthy ageing.

Advanced Glycation End Products: A Comprehensive Review of Their Detection and Occurrence in Food

The Maillard reaction (MR) is a complicated chemical process that has been extensively studied. Harmful chemicals known as advanced glycation end products (AGEs), with complex structures and stable chemical characteristics, are created during the final stage of the MR. AGEs can be formed both during the thermal processing of food and in the human body. The number of AGEs formed in food is much higher compared to endogenous AGEs. A direct connection exists between human health and the build-up of AGEs in the body, which can result in diseases. Therefore, it is essential to understand the content of AGEs in the food we consume. The detection methods of AGEs in food are expounded upon in this review, and the advantages, disadvantages, and application fields of these detection methods are discussed in depth. Additionally, the production of AGEs in food, their content in typical foods, and the mechanisms influencing their formation are summarized. Since AGEs are closely related to the food industry and human health, it is hoped that this review will further the detection of AGEs in food so that their content can be evaluated more conveniently and accurately.

Dietary advanced glycation end products are associated with an increased risk of non-alcoholic fatty liver disease in Iranian adults

BACKGROUND

Dietary advanced glycation end products(AGEs) may contribute to increased inflammation and oxidative stress as risk factors for chronic diseases such as liver disease. In the current study, we aimed to examine the possible association of dietary AGEs with the odds of non-alcoholic fatty liver disease (NAFLD) in Iranian adults.

METHODS

A total of 675 participants (225 newly diagnosed NAFLD cases and 450 controls), aged  20-60 years, were recruited for this case-control study. Nutritional data were measured using a validated food frequency questionnaire, and dietary AGEs were determined for all participants. An ultrasound scan of the liver performed the detection of NAFLD in participants of the case group without alcohol consumption and other causes of hepatic disorders. We used logistic regression models, adjusted for potential confounders, to estimate the odds ratios(ORs) and 95% confidence interval(CI) of NAFLD across tertiles of dietary AGEs.

RESULTS

Mean ± SD age and body mass index of the participants were 38.13 ± 8.85 years and 26.85 ± 4.31 kg/m², respectively. The median(IQR) of dietary AGEs in participants was 3262(2472-4301). In the sex and age-adjusted model, the odds of NAFLD were increased across tertiles of dietary AGEs intake(OR:16.48;95%CI:9.57-28.40, P_trend<0.001). Also, in the final model, after controlling for confounding effects of BMI, smoking, physical activity, marital status, socio-economic status, and energy intake, the odds of NAFLD were increased across tertiles of dietary AGEs intake(OR:12.16; 95%CI:6.06-24.39, P_trend<0.001).

CONCLUSION

Our results showed that greater adherence to dietary pattern with high dietary AGEs intake was significantly related to increased odds of NAFLD.

The AGE-RAGE Axis and the Pathophysiology of Multimorbidity in COPD

Chronic obstructive pulmonary disease (COPD) is a disease of the airways and lungs due to an enhanced inflammatory response, commonly caused by cigarette smoking. Patients with COPD are often multimorbid, as they commonly suffer from multiple chronic (inflammatory) conditions. This intensifies the burden of individual diseases, negatively affects quality of life, and complicates disease management. COPD and comorbidities share genetic and lifestyle-related risk factors and pathobiological mechanisms, including chronic inflammation and oxidative stress. The receptor for advanced glycation end products (RAGE) is an important driver of chronic inflammation. Advanced glycation end products (AGEs) are RAGE ligands that accumulate due to aging, inflammation, oxidative stress, and carbohydrate metabolism. AGEs cause further inflammation and oxidative stress through RAGE, but also through RAGE-independent mechanisms. This review describes the complexity of RAGE signaling and the causes of AGE accumulation, followed by a comprehensive overview of alterations reported on AGEs and RAGE in COPD and in important co-morbidities. Furthermore, it describes the mechanisms by which AGEs and RAGE contribute to the pathophysiology of individual disease conditions and how they execute crosstalk between organ systems. A section on therapeutic strategies that target AGEs and RAGE and could alleviate patients from multimorbid conditions using single therapeutics concludes this review.

Blood and Tissue Advanced Glycation End Products as Determinants of Cardiometabolic Disorders Focusing on Human Studies

Cardiometabolic disorders are characterised by a cluster of interactive risk determinants such as increases in blood glucose, lipids and body weight, as well as elevated inflammation and oxidative stress and gut microbiome changes. These disorders are associated with onset of type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). T2DM is strongly associated with CVD. Dietary advanced glycation end products (dAGEs) attributable from modern diets high in sugar and/or fat, highly processed foods and high heat-treated foods can contribute to metabolic etiologies of cardiometabolic disorders. This mini review aims to determine whether blood dAGEs levels and tissue dAGEs levels are determinants of the prevalence of cardiometabolic disorders through recent human studies. ELISA (enzyme-linked immunosorbent assay), high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) for blood dAGEs measurement and skin auto fluorescence (SAF) for skin AGEs measurement can be used. Recent human studies support that a diet high in AGEs can negatively influence glucose control, body weight, blood lipid levels and vascular health through the elevated oxidative stress, inflammation, blood pressure and endothelial dysfunction compared with a diet low in AGEs. Limited human studies suggested a diet high in AGEs could negatively alter gut microbiota. SAF could be considered as one of the predictors affecting risks for cardiometabolic disorders. More intervention studies are needed to determine how dAGEs are associated with the prevalence of cardiometabolic disorders through gut microbiota changes. Further human studies are conducted to find the association between CVD events, CVD mortality and total mortality through SAF measurement, and a consensus on whether tissue dAGEs act as a predictor of CVD is required.

Pathophysiological Effects of Contemporary Lifestyle on Evolutionary-Conserved Survival Mechanisms in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is increasingly being characterized as an evolutionary mismatch disorder that presents with a complex mixture of metabolic and endocrine symptoms. The Evolutionary Model proposes that PCOS arises from a collection of inherited polymorphisms that have been consistently demonstrated in a variety of ethnic groups and races. In utero developmental programming of susceptible genomic variants are thought to predispose the offspring to develop PCOS. Postnatal exposure to lifestyle and environmental risk factors results in epigenetic activation of developmentally programmed genes and disturbance of the hallmarks of health. The resulting pathophysiological changes represent the consequences of poor-quality diet, sedentary behaviour, endocrine disrupting chemicals, stress, circadian disruption, and other lifestyle factors. Emerging evidence suggests that lifestyle-induced gastrointestinal dysbiosis plays a central role in the pathogenesis of PCOS. Lifestyle and environmental exposures initiate changes that result in disturbance of the gastrointestinal microbiome (dysbiosis), immune dysregulation (chronic inflammation), altered metabolism (insulin resistance), endocrine and reproductive imbalance (hyperandrogenism), and central nervous system dysfunction (neuroendocrine and autonomic nervous system). PCOS can be a progressive metabolic condition that leads to obesity, gestational diabetes, type two diabetes, metabolic-associated fatty liver disease, metabolic syndrome, cardiovascular disease, and cancer. This review explores the mechanisms that underpin the evolutionary mismatch between ancient survival pathways and contemporary lifestyle factors involved in the pathogenesis and pathophysiology of PCOS.

Mechanisms of ovarian aging in women: a review

Ovarian aging is a natural and physiological aging process characterized by loss of quantity and quality of oocyte or follicular pool. As it is generally accepted that women are born with a finite follicle pool that will go through constant decline without renewing, which, together with decreased oocyte quality, makes a severe situation for women who is of advanced age but desperate for a healthy baby. The aim of our review was to investigate mechanisms leading to ovarian aging by discussing both extra- and intra- ovarian factors and to identify genetic characteristics of ovarian aging. The mechanisms were identified as both extra-ovarian alternation of hypothalamic-pituitary-ovarian axis and intra-ovarian alternation of ovary itself, including telomere, mitochondria, oxidative stress, DNA damage, protein homeostasis, aneuploidy, apoptosis and autophagy. Moreover, here we reviewed related Genome-wide association studies (GWAS studies) from 2009 to 2021 and next generation sequencing (NGS) studies of primary ovarian insufficiency (POI) in order to describe genetic characteristics of ovarian aging. It is reasonable to wish more reliable anti-aging interventions for ovarian aging as the exploration of mechanisms and genetics being progressing.

National and sub-national burden and trend of type 1 diabetes in 31 provinces of Iran, 1990-2019

The aim of the study was to report the burden of type one diabetes mellitus (T1DM) by sex, age, year, and province in Iran over the past 30 years, according to data provided by the global burden of disease (GBD) study. Incidence, prevalence, death, disability-adjusted life-years (DALYs), years of life lost, and years lived with disability due to T1DM by age groups and sex was reported for 31 provinces of Iran from 1990 to 2019 with their 95% uncertainty intervals (UI). In 2019, national age-standardized incidence (11.0 (95% UI: 8.9-13.5)), prevalence (388.9 (306.1-482.1)), death (0.7 (0.6-0.8)), and DALYs (51.7 (40.9-65.1)) rates per 100,000 wre higher than 1990 except for death. Also, the mortality to incidence ratio reduced in all provinces over time particularly after 2014 as well. GBD data analysis showed that age-standardized incidence and prevalence rates of T1DM have increased, the death rate reduced, and DALYs remained unchanged during the past 30 years in Iran and its 31 provinces. death rate reduced and DALYs remained unchanged during the past 30 years in Iran and its 31 provinces.

Nϵ -(carboxymethyl)lysine in bakery products: A review

The purpose of this review is to draw attention to the N^ϵ -(carboxymethyl)lysine (CML) content of bakery products with respect to their formation during baking and their health effects. Phenolic components added to the formulation in bakery products significantly reduce the formation of CML. Among the phenolic components, ferulic acid showed the most significant lowering effect on CML. Among the flavanones tested in the model cookie system, dihydromyricetin exhibited the strongest CML-reducing effect. The addition of fat-, sugar-, and protein-rich ingredients to the formulations of bakery products generally increases the CML content in these products. In addition, the addition of components that have a water activity-reducing effect, such as dietary fiber, and the high temperature in baking also increase the formation of CML. Therefore, the food industry should also focus on optimizing food production to minimize CML formation while maintaining the safety and organoleptic properties of bakery products. PRACTICAL APPLICATION: The CML level in foods is likely to increase 200 times with an increase in cooking temperature. The addition of protein and fat to bakery product formulations can increase CML formation. The addition of glucose in cakes can produce higher levels of CML than fructose, refined sucrose, or unrefined sucrose. Phenolic compounds have a reducing effect on CML formation in bakery products.

Formation of Nε-Carboxymethyl-Lysine and Nε-Carboxyethyl-Lysine in Heated Fish Myofibrillar Proteins with Glucose: Relationship with Its Protein Structural Characterization

The formation of advanced glycation end products (AGEs), including N^ε-carboxymethyl-lysine (CML) and N^ε-carboxyethyl-lysine (CEL), in a fish myofibrillar protein and glucose (MPG) model system at 80 °C and 98 °C for up to 45 min of heating were investigated. The characterization of protein structures, including their particle size, ζ-potential, total sulfhydryl (T-SH), surface hydrophobicity (H₀), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared spectroscopy (FTIR), were also analyzed. It was found that the covalent binding of glucose and myofibrillar protein at 98 °C promoted protein aggregation when compared with the fish myofibrillar protein (MP) heated alone, and this aggregation was associated with the formation of disulfide bonds between myofibrillar proteins. Furthermore, the rapid increase of CEL level with the initial heating at 98 °C was related to the unfolding of fish myofibrillar protein caused by thermal treatment. Finally, correlation analysis indicated that the formation of CEL and CML had a significantly negative correlation with T-SH content (r = -0.68 and r = -0.86, p ≤ 0.011) and particle size (r = -0.87 and r = -0.67, p ≤ 0.012), but was weakly correlated with α-Helix, β-Sheet and H₀ (r² ≤ 0.28, p > 0.05) during thermal treatment. Overall, these findings provide new insights into the formation of AGEs in fish products based on changes of protein structure.

Characterizing Dietary Advanced Glycation End-Product (dAGE) Exposure and the Relationship to Colorectal Adenoma Recurrence: A Secondary Analysis

Limited studies have evaluated the association between dietary advanced glycation end-product AGE (dAGEs) intake and cancer risk; however, no studies have addressed adenoma risk or recurrence. The objective of this study was to determine an association between dietary AGEs and adenoma recurrence. A secondary analysis was conducted using an existing dataset from a pooled sample of participants in two adenoma prevention trials. Participants completed a baseline Arizona Food Frequency Questionnaire (AFFQ) to estimate AGE exposure. NƐ- carboxymethyl-lysine (CML)-AGE values were assigned to quantify foods in the AFFQ using a published AGE database, and participants' exposure was evaluated as a CML-AGE (kU/1000 kcal) intake. Regression models were run to determine the relationship between CML-AGE intake and adenoma recurrence. The sample included 1976 adults with a mean age of 67.2 y ± 7.34. The average CML-AGE intake was 5251.1 ± 1633.1 (kU/1000 kcal), ranging between 4960 and 17032.4 (kU/1000 kcal). A higher intake of CML-AGE had no significant association with the odds of adenoma recurrence [OR(95% CI) = 1.02 (0.71,1.48)] compared to participants with a lower intake. In this sample, CML-AGE intake was not associated with adenoma recurrence. Future research is needed and should be expanded to examine the intake of different types of dAGEs with consideration for the direct measurement of AGE.

Dietary Advanced Glycation End Products and Risk of Overall and Cause-Specific Mortality: Results from the Golestan Cohort Study

Controversy exists regarding the association of dietary advanced glycation end products (dAGEs) with the risk of disease outcomes and mortality. We aimed to examine, prospectively, the association between dAGEs intake and the risk of overall and cause-specific mortality in the Golestan Cohort Study. The cohort was conducted between 2004 and 2008 in Golestan Province (Iran) recruiting 50,045 participants aged 40-75 years. Assessment of dietary intake over the last year was performed at baseline using a 116-item food frequency questionnaire. The dAGEs values for each individual were calculated based on published databases of AGE values of various food items. The main outcome was overall mortality at the time of follow-up (13.5 years). Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall and cause-specific mortality were estimated according to the dAGEs quintiles. During 656, 532 person-years of follow-up, 5406 deaths in men and 4722 deaths in women were reported. Participants at the highest quintile of dAGE had a lower risk of overall mortality (HR: 0.89, 95% CI: 0.84, 0.95), CVD mortality (HR: 0.89, 95% CI: 0.84, 0.95), and death from other causes (HR: 0.89, 95% CI: 0.84, 0.95) compared to those in the first quintile after adjusting for confounders. We found no association of dAGEs with risk of mortality from cancer (all), respiratory and infectious diseases, and injuries. Our findings do not confirm a positive association between dAGEs and the risk of mortality in Iranian adults. There is still no agreement among studies investigating dAGEs and their health-related aspects. So, further high-quality studies are required to clarify this association.

Friend or Foe? The Role of Animal-Source Foods in Healthy and Environmentally Sustainable Diets

Scientific and political discussions around the role of animal-source foods (ASFs) in healthy and environmentally sustainable diets are often polarizing. To bring clarity to this important topic, we critically reviewed the evidence on the health and environmental benefits and risks of ASFs, focusing on primary trade-offs and tensions, and summarized the evidence on alternative proteins and protein-rich foods. ASFs are rich in bioavailable nutrients commonly lacking globally and can make important contributions to food and nutrition security. Many populations in Sub-Saharan Africa and South Asia could benefit from increased consumption of ASFs through improved nutrient intakes and reduced undernutrition. Where consumption is high, processed meat should be limited, and red meat and saturated fat should be moderated to lower noncommunicable disease risk-this could also have cobenefits for environmental sustainability. ASF production generally has a large environmental impact; yet, when produced at the appropriate scale and in accordance with local ecosystems and contexts, ASFs can play an important role in circular and diverse agroecosystems that, in certain circumstances, can help restore biodiversity and degraded land and mitigate greenhouse gas emissions from food production. The amount and type of ASF that is healthy and environmentally sustainable will depend on the local context and health priorities and will change over time as populations develop, nutritional concerns evolve, and alternative foods from new technologies become more available and acceptable. Efforts by governments and civil society organizations to increase or decrease ASF consumption should be considered in light of the nutritional and environmental needs and risks in the local context and, importantly, integrally involve the local stakeholders impacted by any changes. Policies, programs, and incentives are needed to ensure best practices in production, curb excess consumption where high, and sustainably increase consumption where low.

Comparison of pharmacokinetics, biodistribution, and excretion of free and bound Nε-carboxymethyllysine in rats by HPLC-MS/MS

As a representative product of advanced glycation end products, Nɛ-carboxymethyllysine (CML) exists in free and bound forms in vivo and in food with different bioavailability. To thoroughly understand the bioavailability of free Nɛ-carboxymethyllysine (CML) and bovine serum albumin (BSA)-CML in vivo after intragastric administration, pharmacokinetics, biodistribution, and excretion of CML in rats were investigated by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Pharmacokinetics results revealed that free CML peaked at 1.83 h (1684.72 ± 78.08 ng/mL) and 1.33 h (1440.84 ± 72.48 ng/mL) in serum after intragastric administration of free CML and BSA-CML, demonstrating the higher absorption of free CML than BSA-CML. Besides, dietary free CML exhibited a relatively lower body clearance and tissue distribution than dietary BSA-CML based on the apparent volume of distribution and body clearance. Moreover, free CML was concentrated in the kidneys, indicating that kidneys were the target organ for the uptake of absorbed free CML. Additionally, the total excretion rate of CML in urine and feces were 37% and 60% after oral administration of free CML and BSA-CML. These results shed pivotal light on a better understanding of the biological effects of free and bound CML on health.

Advanced Glycation End Products and Nitrosamines in Sausages Influenced by Processing Parameters, Food Additives and Fat during Thermal Processing

Advanced glycation end products (AGEs) and nitrosamines (NAs) in sausage are associated with pathogenic and carcinogenic risks. However, the multiple reaction parameters affecting the production of AGEs and NAs during sausage processing remain unclear. This experiment evaluated the effects of processing parameters, food additives and fat ratios on the formation of AGEs and NAs in sausages. The results showed a 2-3-fold increase in N^ε-(carboxymethyl)lysine (CML) and N^ε-(carboxyethyl)lysine (CEL) when the sausage processing temperature was increased from 90 °C to 130 °C, and N-nitrosodimethylamine (NDEA) increased from 3.68 ng/g to 6.41 ng/g. The addition of salt inhibited the formation of AGEs and NAs, and the inhibitory ability of 2 g/100 g of salt was 63.6% for CML and 36.5% for N-nitrosodimethylamine (NDMA). The addition of 10 mg/kg nitrite to sausages reduced CML formation by 43.9%, however, nitrite had a significant contribution to the formation of NAs. The addition of fat only slightly contributed to the production of CML. In addition, the relationship between α-dicarbonyl compounds and the formation of AGEs was investigated by measuring the changes in α-dicarbonyl compounds in sausages. The results showed two trends of AGEs and α-dicarbonyl compounds: AGEs increased with the increase in α-dicarbonyl compounds and AGE level increased but α-dicarbonyl compound level decreased.

Advanced Glycation End-Products and Their Effects on Gut Health

Dietary advanced glycation end-products (AGEs) are a heterogeneous group of compounds formed when reducing sugars are heated with proteins, amino acids, or lipids at high temperatures for a prolonged period. The presence and accumulation of AGEs in numerous cell types and tissues are known to be prevalent in the pathology of many diseases. Modern diets, which contain a high proportion of processed foods and therefore a high level of AGE, cause deleterious effects leading to a multitude of unregulated intracellular and extracellular signalling and inflammatory pathways. Currently, many studies focus on investigating the chemical and structural aspects of AGEs and how they affect the metabolism and the cardiovascular and renal systems. Studies have also shown that AGEs affect the digestive system. However, there is no complete picture of the implication of AGEs in this area. The gastrointestinal tract is not only the first and principal site for the digestion and absorption of dietary AGEs but also one of the most susceptible organs to AGEs, which may exert many local and systemic effects. In this review, we summarise the current evidence of the association between a high-AGE diet and poor health outcomes, with a special focus on the relationship between dietary AGEs and alterations in the gastrointestinal structure, modifications in enteric neurons, and microbiota reshaping.

Diet's Role in Modifying Risk of Alzheimer's Disease: History and Present Understanding

Diet is an important nonpharmacological risk-modifying factor for Alzheimer's disease (AD). The approaches used here to assess diet's role in the risk of AD include multi-country ecological studies, prospective and cross-sectional observational studies, and laboratory studies. Ecological studies have identified fat, meat, and obesity from high-energy diets as important risk factors for AD and reported that AD rates peak about 15-20 years after national dietary changes. Observational studies have compared the Western dietary pattern with those of the Dietary Approaches to Stop Hypertension (DASH), Mediterranean (MedDi), and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diets. Those studies identified AD risk factors including higher consumption of saturated and total fats, meat, and ultraprocessed foods and a lower risk of AD with higher consumption of fruits, legumes, nuts, omega-3 fatty acids, vegetables, and whole grains. Diet-induced factors associated with a significant risk of AD include inflammation, insulin resistance, oxidative stress, elevated homocysteine, dietary advanced glycation end products, and trimethylamine N-oxide. The molecular mechanisms by which dietary bioactive components and specific foods affect risk of AD are discussed. Given most countries' entrenched food supply systems, the upward trends of AD rates would be hard to reverse. However, for people willing and able, a low-animal product diet with plenty of anti-inflammatory, low-glycemic load foods may be helpful.

Role of Advanced Glycation End Products in Intervertebral Disc Degeneration: Mechanism and Therapeutic Potential

The incidence of low back pain caused by lumbar disc degeneration is high, and it can lead to loss of work ability and impose heavy social and economic burdens. The pathogenesis of low back pain is unclear, and there are no effective treatments. With age, the deposition of advanced glycation end products (AGEs) in intervertebral disc (IVD) gradually increases and is accelerated by diabetes and a high-AGEs diet, leading to destruction of the annulus fibrosus (AF), nucleus pulposus (NP), and cartilage endplate (CEP) and finally intervertebral disc degeneration (IDD). Reducing the accumulation of AGEs in IVD and blocking the transmission of downstream signals caused by AGEs have a significant effect on alleviating IDD. In this review, we summarize the mechanism by which AGEs induce IDD and potential treatment strategies.

Research Trends in Advanced Glycation End Products and Obesity: Bibliometric Analysis

The aim of this study was to conduct a bibliometric analysis of the scientific articles on advanced glycation end products (AGEs) and obesity. English-language journal articles about AGEs and obesity were retrieved from the Scopus database. The OpenRefine application was used for data cleaning, the VOSviewer software program for analysis of the trends of year of publication, country, institution, journal, authors, references, and keywords. Microsoft Excel and Tableau Public were applied for the visualizing of the publication trends. Data collection was performed on 3 February 2022, from a total of 1170 documents. The Mann−Whitney test and Spearman test with software SPSS ver.28.0.1.1. were used to assess the relation between open access journal statuses, years of publications, and CiteScore. The results of the study showed that there was an increase in studies on processed foods, including AGEs and obesity. The United States was the country with the largest contribution in this field, with the highest number of citations. The Nutrients journal published the largest number of articles on this topic, particularly in the last two years. The present focus of the studies is on ultra-processed foods. The open access journals have younger medians of the year of publication and higher medians for number of citations than do closed access journals (p < 0.001 and p < 0.05, respectively). A strong negative association was seen between CiteScore and the year of publication (r = −0.64 [95% CI: −0.67, −0.60]), p < 0.001. We present this bibliometric analysis to furnish the most recent data on the description, visualization, and analysis of AGEs and obesity.

Dietary advanced glycation end-products (dAGEs) intake and its relation to sarcopenia and frailty - The Rotterdam Study

Studies on mice have shown a relationship between dietary intake of advanced glycation end-products (dAGEs) and deterioration of musculoskeletal health, but human studies are absent. We investigated the relationship between dietary intake of carboxymethyllysine (dCML) - an AGE prototype - and risk of sarcopenia at baseline and after 5 years of follow-up and a single evaluation of physical frailty in participants from the population-based Rotterdam Study. Appendicular lean mass (ALM) was obtained using insight dual-energy X-ray absorptiometry and hand grip strength (HGS) using a hydraulic hand dynamometer. Subjects with both low ALM and weak HGS were classified as having sarcopenia. Frailty (yes/no) was defined by presence of ≥3 and pre-frailty by presence of 1 or 2 components namely, exhaustion, weakness, slowness, weight loss or low physical activity. dCML was calculated using a food frequency questionnaire and dAGE databases. Logistic regression analysis was used to evaluate the odds of physical frailty and prevalent sarcopenia at baseline and follow-up and incident sarcopenia. 2782 participants with an age 66.4 ± 9.9 years and dCML intake 3.3 ± 1.3 mg/day, had data on sarcopenia at both time points. Of whom 84 had sarcopenia at baseline and 73 developed sarcopenia at follow-up. We observed an association of one SD increase in dCML intake with prevalent sarcopenia at baseline [odds ratio, OR = 1.27 (1.01-1.59)] and no association of dCML with incident sarcopenia at 5-year follow-up [OR = 1.12 (0.86-1.44)]. For frailty we analyzed 3577 participants, of whom 1972 were pre-frail and 158 were frail. We observed no association of dCML with either pre-frailty [OR = 0.99 (0.91-1.07)] or frailty [OR = 1.01 (0.83-1.22)] when non-frail subjects were used as reference. Our results show an association of dAGEs with sarcopenia cross-sectionally but not longitudinally where inconclusive findings are observed possibly due to a very low incidence of sarcopenia. There was no association with frailty cross-sectionally.