The epigenetic aging, obesity, and lifestyle

Causal impact of genetically-determined fish and fish oil intake on epigenetic age acceleration and related serum markers

BACKGROUND

The interplay between diet and healthspan is a topic of great interest in biomedical research. Toward this end, consumption of marine omega-3 fatty acids is of particular significance, as reports suggest that diets focused on seafood can prolong the disease-free portion of the human lifespan. Fish consumption has also been linked to reduced biological aging as measured by epigenetic clocks, but there is no conclusive evidence of a causal relationship. Moreover, fish oils reduce triglycerides, and may affect other lipid profiles, as well as systemic inflammation. To investigate further, we used two-sample Mendelian randomization to investigate potential causality between fish intake and healthspan markers.

METHODS

Bidirectional Mendelian randomization was performed in the two-sample setting with publicly available GWAS summary statistics. GWAS data from the UK Biobank for oily fish consumption (n = 460,443) and fish oil supplementation (n = 461,384) were used as the primary exposures. First-generation epigenetic clocks Hannum age and intrinsic epigenetic age acceleration (IEAA), as well as second-generation clocks GrimAge and PhenoAge were collected from an independent dataset of individuals of European ancestry (n = [34,449-34,667]). Finally, data from the Integrative Epidemiology Unit database was used for serum proxies of lipidemia and systemic inflammation (n = [61,308-78,700]). Additional sensitivity analyses, such as reverse causation testing and the Cochran's Q test were performed for exposure-outcome pairs where the inverse variance weighted (IVW) method was significant (p-value < 0.05), and where the MR Egger method indicated an effect in the same direction as the IVW result.

RESULTS

We report that oily fish consumption appears to decrease PhenoAge acceleration (p < 0.0086), whereas fish oil supplementation appears to decrease GrimAge (p = 0.037). Both omega-3 exposures modify the epigenetic clocks in the expected negative, or age-decelerating, direction. For the serum biomarkers, we find evidence that fish oil consumption leads to a reduction in triglycerides (p = 0.004), although HDL and LDL were not significantly modified. Finally, we also detected a suggestive inverse relationship between oily fish consumption and hsCRP (p = 0.064).

CONCLUSIONS

Our analysis shows that consuming fish oil, whether through whole food or as a supplement, can have a rejuvenating impact as measured by PhenoAge and GrimAge acceleration. We have also provided evidence further linking fish oil intake and lower triglyceride levels. These results, based on robust MR-based analyses, emphasize the effectiveness of dietary choices in modifying emerging measures of healthspan.

Causal associations between epigenetic age and thromboembolism: a bi-directional two-sample Mendelian randomization study

BACKGROUND

Thromboembolism is one of the most prevalent cardiovascular conditions affecting the elder population. The associations between epigenetic aging and thromboembolism risks remain incompletely elucidated. Through Mendelian randomization (MR), this research seeks to assess the causal links between genetically determined epigenetic aging factors and thromboembolism.

RESULTS

Genetic variants were extracted from genome-wide association studies (GWAS) under stringent threshold as instrumental variables (IVs). Bi-directional two-sample MR analyses were conducted to determine the direction of causal associations. We employed the inverse variance weighted (IVW), weighted median, weighted mode and MR Egger to estimate the causal effect, with sensitivity analyses such as Cochran's Q tests, MR-PRESSO and leave-one-out performed to avoid potential heterogeneity and pleiotropy. Our MR analysis revealed a causal association between intrinsic epigenetic age acceleration and deep vein thrombosis of lower extremities (IVW: OR 0.963, 95% CI 0.934-0.992, P = 0.014), and between the genetically determined levels of plasminogen activator inhibitor-1 and other arterial embolism and thrombosis (IVW: OR 1.000, 95% CI 1.000-1.0005, P = 0.029). Causality was also identified between the genetically predicted levels of FGF23 and other arterial embolism and thrombosis (IVW: OR: 1.661, 95% CI 1.051-2.624, P = 0.029) and arterial embolism and thrombosis of lower extremity artery (IVW: OR 1.68, 95% CI 1.031-2.725, P = 0.037). Moreover, bi-directional MR showed reverse effects between portal vein thrombosis and PhenoAge (IVW: OR 0.871, 95% CI 0.765-0.992, P = 0.037) and between venous thromboembolism and GrimAge (IVW: OR 1.186, 95% CI 1.048-1.341, P = 0.007). Sensitivity analysis using Cochran's Q tests, MR-PRESSO and leave-one-out excluded the influence of heterogeneity, horizontal pleiotropy, and outliers.

CONCLUSION

Our results identified a causal association between genetically predicted epigenetic aging factors and thromboembolism. The findings highlight the necessity for further exploration into the underlying etiology of thromboembolism.

Association between triglyceride-glucose index and phenotypic age acceleration: a cross-sectional study based on NHANES database

Objective

To investigate the association between triglyceride-glucose (TyG) index and phenotypic age acceleration (PhenoAgeAccel), given the emerging importance of biological aging as a health determinant and the role of insulin resistance in aging-related processes.

Methods

This cross-sectional study analyzed data from 13,291 adults aged ≥20 years in the National Health and Nutrition Examination Survey (1999-2010). The TyG index served as the exposure variable, calculated from fasting triglycerides and glucose levels. PhenoAgeAccel, derived from clinical biomarkers, was the outcome variable. Analyses adjusted for demographic, socioeconomic, and health-related covariates.

Results

A significant non-linear relationship was observed between TyG index and PhenoAgeAccel, with an inflection point at 9.60. In the fully adjusted model, each unit increase in TyG index was associated with 2.21 years increase in PhenoAgeAccel (95% CI: 1.99, 2.43). The association was stronger above the inflection point (β = 8.21, 95% CI: 7.59, 8.82) compared to below it (β = 0.56, 95% CI: 0.29, 0.83).

Conclusion

Higher TyG index levels are significantly associated with accelerated biological aging, particularly above a threshold of 9.60. These findings suggest the importance of metabolic health in biological aging processes and potential interventional strategies.

Sex-Specific Factors Influencing Obesity in Women: Bridging the Gap Between Science and Clinical Practice

Obesity in women is a significant public health issue with serious implications for cardiovascular-kidney-metabolic syndrome and cardiovascular disease. This complex challenge is influenced by physiological, hormonal, socioeconomic, and cultural factors. Women face unique weight management challenges due to hormonal changes during pregnancy, perimenopause, and menopause, which affect fat distribution and increase cardiovascular-kidney-metabolic syndrome risk. Current clinical guidelines often overlook these sex-specific factors, potentially limiting the effectiveness of obesity management strategies in women. This review explores the sex-specific aspects of obesity's pathophysiology, epidemiological trends, and associated comorbidities, focusing on cardiovascular and metabolic complications. This review synthesizes literature on obesity in women, emphasizing sex-specific factors influencing its development and progression. It examines the limitations of body mass index as an obesity measure and explores alternative classification methods. Additionally it investigates the relationship between obesity and comorbidities such as diabetes, hypertension, and dyslipidemia, with a focus on postmenopausal women. Obesity in women is linked to increased risks of cardiovascular-kidney-metabolic syndrome and cardiovascular disease. Hormonal fluctuations throughout life contribute to weight gain and fat distribution patterns specific to women, increasing cardiovascular disease risk. Effective obesity management strategies in women must account for these sex-specific variations. Postmenopausal women are particularly affected by obesity-related complications. Lifestyle interventions, pharmacotherapy, and bariatric surgery have shown efficacy in weight management, though success rates vary. Addressing obesity in women requires a comprehensive approach that considers sex-specific physiological factors, life-stage challenges, and sociocultural barriers. Integrating precision medicine and emerging therapies offers potential for more personalized and effective interventions. Personalized strategies that consider women's biological and life-stage challenges can enhance obesity management and improve cardiovascular outcomes. Future research and clinical practice should focus on developing tailored strategies that address women's unique vulnerabilities to obesity and its associated health risks and on validating sex-specific interventions to improve obesity management in women.

The epigenetic impact of fatty acids as DNA methylation modulators

DNA methylation is a key epigenetic mechanism that regulates gene expression. Fatty acids, the building blocks of many essential lipids, play a crucial role in various biological events. Aberrant acetylation and methylation profiles are linked to a number of non-communicable diseases. Various fatty acids have been identified as potential 'epi-drugs' because of their ability to correct aberrant acetylation and methylation profiles in a number of non-communicable diseases, enhancing the value of their biochemical properties. This review summarizes the effects of selected saturated and unsaturated fatty acids and fatty-acid-rich food items on disease-associated DNA methylation profiles, aiming to justify the classification of fatty acids as DNA methylation modulators.

Treating Metabolic Dysregulation and Senescence by Caloric Restriction: Killing Two Birds with One Stone?

Cellular senescence is a state of permanent cell cycle arrest accompanied by metabolic activity and characteristic phenotypic changes. This process is crucial for developing age-related diseases, where excessive calorie intake accelerates metabolic dysfunction and aging. Overnutrition disturbs key metabolic pathways, including insulin/insulin-like growth factor signaling (IIS), the mammalian target of rapamycin (mTOR), and AMP-activated protein kinase. The dysregulation of these pathways contributes to insulin resistance, impaired autophagy, exacerbated oxidative stress, and mitochondrial dysfunction, further enhancing cellular senescence and systemic metabolic derangements. On the other hand, dysfunctional endothelial cells and adipocytes contribute to systemic inflammation, reduced nitric oxide production, and altered lipid metabolism. Numerous factors, including extracellular vesicles, mediate pathological communication between the vascular system and adipose tissue, amplifying metabolic imbalances. Meanwhile, caloric restriction (CR) emerges as a potent intervention to counteract overnutrition effects, improve mitochondrial function, reduce oxidative stress, and restore metabolic balance. CR modulates pathways such as IIS, mTOR, and sirtuins, enhancing glucose and lipid metabolism, reducing inflammation, and promoting autophagy. CR can extend the health span and mitigate age-related diseases by delaying cellular senescence and improving healthy endothelial-adipocyte interactions. This review highlights the crosstalk between endothelial cells and adipocytes, emphasizing CR potential in counteracting overnutrition-induced senescence and restoring vascular homeostasis.

Association between phenotypic age and mortality risk in individuals with obesity: a retrospective cohort study

Objective

This study investigates the association between phenotypic age acceleration (PAA) and all-cause and cause-specific mortality in obese individuals.

Methods

Data were drawn from the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2018, including 9,925 obese adults (BMI ≥ 30 kg/m2). PAA, defined as phenotypic age exceeding chronological age, was assessed using clinical biomarkers. Kaplan-Meier survival analysis and Cox proportional hazards models were used to assess the relationship between PAA and all-cause, cardiovascular, and cancer mortality, adjusting for covariates such as age, gender, race, lifestyle, and health status. Subgroup and sensitivity analyses were performed to ensure the robustness of the findings.

Results

During a median follow-up of 10.6 years, 1,537 deaths were recorded, including 419 from cardiovascular disease and 357 from cancer. PAA was significantly associated with all-cause mortality (HR = 1.84, 95% CI: 1.64-2.06), cardiovascular mortality (HR = 1.86, 95% CI: 1.50-2.31), and cancer mortality (HR = 1.47, 95% CI: 1.17-1.85). These associations remained significant after adjusting for multiple variables, and sensitivity analyses confirmed the robustness of the results.

Conclusion

PAA is an independent predictor of all-cause, cardiovascular, and cancer mortality in obese individuals. This study highlights the importance of PAA in mortality risk assessment and health management in the obese population.

Navigating Illumina DNA methylation data: biology versus technical artefacts

Illumina-based BeadChip arrays have revolutionized genome-wide DNA methylation profiling, pushing it into diagnostics. However, comprehensive quality assessment remains challenging within a wide range of available tissue materials and sample preparation methods. This study tackles two critical issues: differentiating between biological effects and technical artefacts in suboptimal quality samples and the impact of the first sample on the Illumina-like normalization algorithm. We introduce three quality control scores based on global DNA methylation distribution (DB-Score), bin distance from copy number variation analysis (BIN-Score) and consistently methylated CpGs (CM-Score) that rely on biological features rather than internal array controls. These scores, designed to be adjustable for different analysis tools and sample cohort characteristics, were explored and benchmarked across independent cohorts. Additionally, we reveal deviations in beta values caused by different sample rankings with the Illumina-like normalization algorithm, verified these with whole-genome methylation sequencing data and showed effects on differential DNA methylation analysis. Our findings underscore the necessity of consistently utilizing a pre-defined normalization sample within the ranking process to boost reproducibility of the Illumina-like normalization algorithm. Overall, our study delivers valuable insights, practical recommendations and R functions designed to enhance reproducibility and quality assurance of DNA methylation analysis, particularly for challenging sample types.

Obesity prevention across the lifespan: assessing the efficacy of intervention studies and discussing future challenges

INTRODUCTION

Obesity is intricately linked with metabolic conditions that disrupt hormones and metabolism, often resulting in weight-related challenges. Given the heightened mortality rates associated with cardiovascular and metabolic disorders linked to obesity, there is a pressing call to mobilize medical professionals, researchers, and policymakers towards advocating for healthy lifestyles and preventing obesity. Traditionally, obesity prevention and treatment have been viewed as separate endeavors, with prevention primarily falling under public health initiatives and treatment within the purview of clinicians. However, this division has led to significant healthcare costs without a substantial reduction in obesity rates.

EVIDENCE ACQUISITION

Our search encompassed published articles focused on prevention, excluding any mention of "treatment". Data was gathered from diverse sources including academic databases, government health agency websites like the CDC, research organizations, clinical trials registries, and public health campaigns.

EVIDENCE SYNTHESIS

Due to the diverse range of interventions (encompassing dietary modifications, physical activity promotion, policy initiatives, education, and community-based programs, either independently or in combination), and the variability in study design and population demographics, we conducted a narrative review to systematically present and critically analyze evidence on preventing overweight and obesity across different age groups.

CONCLUSIONS

Effectively addressing obesity prevention necessitates a comprehensive, multidisciplinary approach that establishes an environment where healthier choices are accessible and viable for all. This requires collaborative efforts between individuals, communities, healthcare providers, policymakers, and industries to institute enduring change. Furthermore, there remains a critical need for national and international guidelines tailored to age-related risk factors, paving the way for innovative precision medicine approaches centered on salutogenesis rather than pathogenesis.

Now and then in eukaryotic DNA methylation

Since the mid-1970s, increasingly innovative methods to detect DNA methylation provided detailed information about its distribution, functions, and dynamics. As a result, new concepts were formulated and older ones were revised, transforming our understanding of the associated biology and catalyzing unprecedented advances in biomedical research, drug development, anthropology, and evolutionary biology. In this review, we discuss a few of the most notable advances, which are intimately intertwined with the study of DNA methylation, with a particular emphasis on the past three decades. Examples of these strides include elucidating the intricacies of 5-methylcytosine (5-mC) oxidation, which are at the core of the reversibility of this epigenetic modification; the three-dimensional structural characterization of eukaryotic DNA methyltransferases, which offered insights into the mechanisms that explain several disease-associated mutations; a more in-depth understanding of DNA methylation in development and disease; the possibility to learn about the biology of extinct species; the development of epigenetic clocks and their use to interrogate aging and disease; and the emergence of epigenetic biomarkers and therapies.

Epigenetic mechanisms and oral mucositis in children with acute lymphoblastic leukaemia

This study aimed to investigate the relationship between epigenetic mechanisms and oral mucositis (OM) in paediatric patients with acute lymphoblastic leukaemia. Oral cells were collected from 76 participants, including 15 healthy individuals, 10 patients with acute lymphoblastic leukaemia but without a history of OM and 51 acute lymphoblastic leukaemia patients with a history of OM (35 with active OM and 16 who had recovered from OM). Global DNA methylation in the miR-9-1 and miR-9-3 genes was performed. Seven polymorphisms rs1801131, rs1801133 (MTHFR), rs2228611 (DNMT1), rs7590760, rs1550117 (DNMT3A), rs6087990, rs2424913 (DNMT3B) were genotyped and an analysis of association with global DNA methylation was performed. The global methylation levels were lower in cancer patients recovered from OM than in the other groups. A higher frequency of unmethylated profile for miR-9-1 and partially methylated profile for miR-9-3 was observed in cancer patients regardless of OM history compared to healthy patients. The GG genotype of the rs2228611 (DNMT1) polymorphism was associated with higher levels of global methylation in cancer patients irrespective of OM. It was concluded that global methylation is associated with mucosal recovery. The effect of DNMT1 genotype on the global DNA methylation profile, as well as the methylation profile of miR-9-1 and miR-9-3 in cancer patients is independent of OM.

The epigenetic modification of DNA methylation in neurological diseases

Methylation, a key epigenetic modification, is essential for regulating gene expression and protein function without altering the DNA sequence, contributing to various biological processes, including gene transcription, embryonic development, and cellular functions. Methylation encompasses DNA methylation, RNA methylation and histone modification. Recent research indicates that DNA methylation is vital for establishing and maintaining normal brain functions by modulating the high-order structure of DNA. Alterations in the patterns of DNA methylation can exert significant impacts on both gene expression and cellular function, playing a role in the development of numerous diseases, such as neurological disorders, cardiovascular diseases as well as cancer. Our current understanding of the etiology of neurological diseases emphasizes a multifaceted process that includes neurodegenerative, neuroinflammatory, and neurovascular events. Epigenetic modifications, especially DNA methylation, are fundamental in the control of gene expression and are critical in the onset and progression of neurological disorders. Furthermore, we comprehensively overview the role and mechanism of DNA methylation in in various biological processes and gene regulation in neurological diseases. Understanding the mechanisms and dynamics of DNA methylation in neural development can provide valuable insights into human biology and potentially lead to novel therapies for various neurological diseases.

Cross-sectional and longitudinal associations among healthcare costs and deficit accumulation

BACKGROUND

Type 2 diabetes mellitus and overweight/obesity increase healthcare costs. Both are also associated with accelerated aging. However, the contributions of this accelerated aging to increased healthcare costs are unknown.

METHODS

We use data from a 8-year longitudinal cohort followed at 16 U.S. clinical research sites. Participants were adults aged 45-76 years with established type 2 diabetes and overweight or obesity who had enrolled in the Action for Health in Diabetes clinical trial. They were randomly (1:1) assigned to either an intensive lifestyle intervention focused on weight loss versus a comparator of diabetes support and education. A validated deficit accumulation frailty index (FI) was used to characterize biological aging. Discounted annual healthcare costs were estimated using national databases in 2012 dollars. Descriptive characteristics were collected by trained and certified staff.

RESULTS

Compared with participants in the lowest tertile (least frail) of baseline FI, those in the highest tertile (most frail) at Year 1 averaged $714 (42%) higher medication costs, $244 (22%) higher outpatient costs, and $800 (134%) higher hospitalization costs (p < 0.001). At Years 4 and 8, relatively greater increases in FI (third vs. first tertile) were associated with an approximate doubling of total healthcare costs (p < 0.001). Mean (95% confidence interval) relative annual savings in healthcare costs associated with randomization to the intensive lifestyle intervention were $437 ($195, $579) per year during Years 1-4 and $461 ($232, $690) per year during Years 1-8. These were attenuated and the 95% confidence interval no longer excluded $0 after adjustment for the annual FI differences from baseline.

CONCLUSIONS

Deficit accumulation frailty tracks well with healthcare costs among adults with type 2 diabetes and overweight or obesity. It may serve as a useful marker to project healthcare needs and as an intermediate outcome in clinical trials.

Exercise training decreases lactylation and prevents myocardial ischemia-reperfusion injury by inhibiting YTHDF2

Exercise improves cardiac function and metabolism. Although long-term exercise leads to circulating and micro-environmental metabolic changes, the effect of exercise on protein post-translational lactylation modifications as well as its functional relevance is unclear. Here, we report that lactate can regulate cardiomyocyte changes by improving protein lactylation levels and elevating intracellular N6-methyladenosine RNA-binding protein YTHDF2. The intrinsic disorder region of YTHDF2 but not the RNA m6A-binding activity is indispensable for its regulatory function in influencing cardiomyocyte cell size changes and oxygen glucose deprivation/re-oxygenation (OGD/R)-stimulated apoptosis via upregulating Ras GTPase-activating protein-binding protein 1 (G3BP1). Downregulation of YTHDF2 is required for exercise-induced physiological cardiac hypertrophy. Moreover, myocardial YTHDF2 inhibition alleviated ischemia/reperfusion-induced acute injury and pathological remodeling. Our results here link lactate and lactylation modifications with RNA m6A reader YTHDF2 and highlight the physiological importance of this innovative post-transcriptional intrinsic regulation mechanism of cardiomyocyte responses to exercise. Decreasing lactylation or inhibiting YTHDF2/G3BP1 might represent a promising therapeutic strategy for cardiac diseases.

Discovering the direct relations between nutrients and epigenetic ageing

BACKGROUND

Along with the ageing of society, the absolute prevalence of age-related diseases is expected to rise, leading to a substantial burden on healthcare systems and society. Thus, there is an urgent need to promote healthy ageing. As opposed to chronological age, biological age was introduced to accurately represent the ageing process, as it considers physiological deterioration that is linked to morbidity and mortality risk. Furthermore, biological age responds to various factors, including nutritional factors, which have the potential to mitigate the risk of age-related diseases. As a result, a promising biomarker of biological age known as the epigenetic clock has emerged as a suitable measure to investigate the direct relations between nutritional factors and ageing, thereby identifying potential intervention targets to improve healthy ageing.

METHODS

In this study, we analysed data from 3,969 postmenopausal women from the Women's Health Initiative to identify nutrients that are associated with the rate of ageing by using an accurate measure of biological age called the PhenoAge epigenetic clock. We used Copula Graphical Models, a data-driven exploratory analysis tool, to identify direct relationships between nutrient intake and age-acceleration, while correcting for every variable in the dataset.

RESULTS

We revealed that increased dietary intakes of coumestrol, beta-carotene and arachidic acid were associated with decelerated epigenetic ageing. In contrast, increased intakes of added sugar, gondoic acid, behenic acid, arachidonic acid, vitamin A and ash were associated with accelerated epigenetic ageing in postmenopausal women.

CONCLUSION

Our study discovered direct relations between nutrients and epigenetic ageing, revealing promising areas for follow-up studies to determine the magnitude and causality of our estimated diet-epigenetic relationships.

Investigating the Relationship between Epigenetic Age and Cardiovascular Risk in a Population with Overweight/Obesity

Introduction: Cardiovascular diseases stand as the leading global cause of mortality. Major modifiable risk factors encompass overweight/obese conditions, high blood pressure, elevated LDL cholesterol, diabetes, smoking, secondhand smoke exposure, unhealthy diet, and physical inactivity. In the present study, we explored the relationship between cardiovascular risk factors and epigenetic age (DNAm age), an estimate reflecting an individual's actual physiological functionality and overall health. Additionally, we assessed the association between DNAm age acceleration and cardiovascular risk, as evaluated through the Framingham risk score (FRS). Methods: The study includes 190 subjects with overweight/obese conditions. We calculated their DNAm age using Zbieć-Piekarska et al.'s DNAm age estimator on five sets of CpGs analyzed in the peripheral leucocytes. Linear regression models were employed to test the associations. Results: Various parameters contributing to increased cardiovascular risk were associated with DNAm age acceleration, such as systolic blood pressure (β = 0.045; SE = 0.019; p = 0.019), heart rate (β = 0.096; SE = 0.032; p = 0.003), blood glucose (β = 0.025; SE = 0.012; p = 0.030), glycated hemoglobin (β = 0.105; SE = 0.042; p = 0.013), diabetes (β = 2.247; SE = 0.841; p = 0.008), and menopausal conditions (β = 2.942; SE = 1.207; p = 0.016), as well as neutrophil (β = 0.100; SE = 0.042; p = 0.018) and granulocyte (β = 0.095; SE = 0.044; p = 0.033) counts. Moreover, DNAm age acceleration raised the FRS (∆% 5.3%, 95% CI 0.8; 9.9, p = 0.019). Conclusion: For the first time, we report that cardiovascular risk factors accelerated DNAm age in a selected population of hypersusceptible individuals with overweight or obesity. Our results highlight the potential of DNAm age acceleration as a biomarker of cumulative effects in cardiovascular risk assessment.

Cellular Senescence and Extracellular Vesicles in the Pathogenesis and Treatment of Obesity-A Narrative Review

This narrative review explores the pathophysiology of obesity, cellular senescence, and exosome release. When exposed to excessive nutrients, adipocytes develop mitochondrial dysfunction and generate reactive oxygen species with DNA damage. This triggers adipocyte hypertrophy and hypoxia, inhibition of adiponectin secretion and adipogenesis, increased endoplasmic reticulum stress and maladaptive unfolded protein response, metaflammation, and polarization of macrophages. Such feed-forward cycles are not resolved by antioxidant systems, heat shock response pathways, or DNA repair mechanisms, resulting in transmissible cellular senescence via autocrine, paracrine, and endocrine signaling. Senescence can thus affect preadipocytes, mature adipocytes, tissue macrophages and lymphocytes, hepatocytes, vascular endothelium, pancreatic β cells, myocytes, hypothalamic nuclei, and renal podocytes. The senescence-associated secretory phenotype is closely related to visceral adipose tissue expansion and metaflammation; inhibition of SIRT-1, adiponectin, and autophagy; and increased release of exosomes, exosomal micro-RNAs, pro-inflammatory adipokines, and saturated free fatty acids. The resulting hypernefemia, insulin resistance, and diminished fatty acid β-oxidation lead to lipotoxicity and progressive obesity, metabolic syndrome, and physical and cognitive functional decline. Weight cycling is related to continuing immunosenescence and exposure to palmitate. Cellular senescence, exosome release, and the transmissible senescence-associated secretory phenotype contribute to obesity and metabolic syndrome. Targeted therapies have interrelated and synergistic effects on cellular senescence, obesity, and premature aging.

Towards a Novel Frontier in the Use of Epigenetic Clocks in Epidemiology

Health problems associated with aging are a major public health concern for the future. Aging is a complex process with wide intervariability among individuals. Therefore, there is a need for innovative public health strategies that target factors associated with aging and the development of tools to assess the effectiveness of these strategies accurately. Novel approaches to measure biological age, such as epigenetic clocks, have become relevant. These clocks use non-sequential variable information from the genome and employ mathematical algorithms to estimate biological age based on DNA methylation levels. Therefore, in the present study, we comprehensively review the current status of the epigenetic clocks and their associations across the human phenome. We emphasize the potential utility of these tools in an epidemiological context, particularly in evaluating the impact of public health interventions focused on promoting healthy aging. Our review describes associations between epigenetic clocks and multiple traits across the life and health span. Additionally, we highlighted the evolution of studies beyond mere associations to establish causal mechanisms between epigenetic age and disease. We explored the application of epigenetic clocks to measure the efficacy of interventions focusing on rejuvenation.

Epigenetic-based age prediction in blood samples: Model development

Aging is a complex process influenced by genetic, epigenetic, and environmental factors that lead to tissue deterioration and frailty. Epigenetic mechanisms, such as DNA methylation, play a significant role in gene expression regulation and aging. This study presents a new age estimation model developed for the Turkish population using blood samples. Eight CpG sites in loci TOM1L1, ELOVL2, ASPA, FHL2, C1orf132, CCDC102B, cg07082267, and RASSF5 were selected based on their correlation with age. Methylation patterns of these sites were analyzed in blood samples from 100 volunteers, grouped into age categories (20-35, 36-55, and ≥56). Sensitivity analysis indicated a reliable performance with DNA inputs ≥1 ng. Statistical modeling, utilizing Multiple Linear Regression, underscores the reliability of the primary 6-CpG model, excluding cg07082267 and TOM1L1. This model demonstrates strong correlations with chronological age (r = 0.941) and explains 88% of the age variance with low error rates (MAE = 4.07, RMSE = 5.73 years). Validation procedures, including a training-test split and fivefold cross-validation, consistently confirm the model's accuracy and consistency. The study indicates minimal variation in error scores across age cohorts and no significant gender differences. The developed model showed strong predictive accuracy, with the ability to estimate age within certain prediction intervals. This study contributes to the age prediction by using DNA methylation patterns, which can have disparate applications, including forensic and clinical assessments.

Body Size, Diet Quality, and Epigenetic Aging: Cross-Sectional and Longitudinal Analyses

Epigenetic age is an emerging marker of health that is highly predictive of disease and mortality risk. There is a lack of evidence on whether lifestyle changes are associated with changes in epigenetic aging. We used data from 1 041 participants in the Melbourne Collaborative Cohort Study with blood DNA methylation measures at baseline (1990-1994, mean age: 57.4 years) and follow-up (2003-2007, mean age: 68.8 years). The Alternative Healthy Eating Index-2010 (AHEI-2010), the Mediterranean Dietary Score, and the Dietary Inflammatory Index were used as measures of diet quality, and weight, waist circumference, and waist-to-hip ratio as measures of body size. Five age-adjusted epigenetic aging measures were considered: GrimAge, PhenoAge, PCGrimAge, PCPhenoAge, and DunedinPACE. Multivariable linear regression models including restricted cubic splines were used to assess the cross-sectional and longitudinal associations of body size and diet quality with epigenetic aging. Associations between weight and epigenetic aging cross-sectionally at both time points were positive and appeared greater for DunedinPACE (per SD: β ~0.24) than for GrimAge and PhenoAge (β ~0.10). The longitudinal associations with weight change were markedly nonlinear (U-shaped) with stable weight being associated with the lowest epigenetic aging at follow-up, except for DunedinPACE, for which only weight gain showed a positive association. We found negative, linear associations for AHEI-2010 both cross-sectionally and longitudinally. Other adiposity measures and dietary scores showed similar results. In middle-aged to older adults, declining diet quality and weight gain may increase epigenetic age, while the association for weight loss may require further investigation. Our study sheds light on the potential of weight management and dietary improvement in slowing aging processes.

Obesity-associated epigenetic alterations and the obesity-breast cancer axis

Both breast cancer and obesity can regulate epigenetic changes or be regulated by epigenetic changes. Due to the well-established link between obesity and an increased risk of developing breast cancer, understanding how obesity-mediated epigenetic changes affect breast cancer pathogenesis is critical. Researchers have described how obesity and breast cancer modulate the epigenome individually and synergistically. In this review, the epigenetic alterations that occur in obesity, including DNA methylation, histone, and chromatin modification, accelerated epigenetic age, carcinogenesis, metastasis, and tumor microenvironment modulation, are discussed. Delineating the relationship between obesity and epigenetic regulation is vital to furthering our understanding of breast cancer pathogenesis.

Emerging Trends in Atherosclerosis: Time to Address Atherosclerosis From a Younger Age

Over the past two decades, research efforts into cardiovascular disease (CVD) have uncovered findings that fundamentally challenge our understanding of CVD, particularly atherosclerosis. Atherosclerosis was primarily attributed to the well-described abnormal lipid accumulation theory, involving plaque growth with subsequent plaque hemorrhage resulting in acute vessel thrombosis that may or may not rupture. This perspective has now evolved to encompass more complex pathways, wherein the accumulation of abnormal products of oxidation and inflammation is the most likely factor mediating atherosclerotic plaque growth. Furthermore, atherosclerosis was traditionally thought of as a disease in patients aged 40 and older. However, mounting evidence has demonstrated that significant atherosclerosis and CVD events are more prevalent in younger patients than previously realized and accelerating in incidence. With this alarming trend among younger individuals, our review sought to explore why this trend may be happening and what can be done about this developing problem.

Dysregulation of different modes of programmed cell death by epigenetic modifications and their role in cancer

Modifications of epigenetic factors affect our lives and can give important information regarding one's state of health. In cancer, epigenetic modifications play a crucial role, as they influence various programmed cell death types. The purpose of this review is to investigate how epigenetic modifications, such as DNA methylation, histone modifications, and non-coding RNAs, influence various cell death processes in suppressing or promoting cancer development. Autophagy and apoptosis are the most investigated programmed cell death modes, as based on the tumor stage these cell death types can either promote or prevent cancer evolution. Therefore, our discussion focuses on how epigenetic modifications affect autophagy and apoptosis, as well as their diagnostic and therapeutical potential in combination with available chemotherapeutics. Additionally, we summarize the available data regarding the role of epigenetic modifications on other programmed cell death modes, such as ferroptosis, necroptosis, and parthanatos in cancer and discuss current advancements.

Biological Aging Acceleration Due to Environmental Exposures: An Exciting New Direction in Toxicogenomics Research

Biological clock technologies are designed to assess the acceleration of biological age (B-age) in diverse cell types, offering a distinctive opportunity in toxicogenomic research to explore the impact of environmental stressors, social challenges, and unhealthy lifestyles on health impairment. These clocks also play a role in identifying factors that can hinder aging and promote a healthy lifestyle. Over the past decade, researchers in epigenetics have developed testing methods that predict the chronological and biological age of organisms. These methods rely on assessing DNA methylation (DNAm) levels at specific CpG sites, RNA levels, and various biomolecules across multiple cell types, tissues, and entire organisms. Commonly known as 'biological clocks' (B-clocks), these estimators hold promise for gaining deeper insights into the pathways contributing to the development of age-related disorders. They also provide a foundation for devising biomedical or social interventions to prevent, reverse, or mitigate these disorders. This review article provides a concise overview of various epigenetic clocks and explores their susceptibility to environmental stressors.

Histone Modifications in NAFLD: Mechanisms and Potential Therapy

Nonalcoholic fatty liver disease (NAFLD) is a progressive condition that encompasses a spectrum of liver disorders, beginning with the simple steatosis, progressing to nonalcoholic steatohepatitis (NASH), and possibly leading to more severe diseases, including liver cirrhosis and hepatocellular carcinoma (HCC). In recent years, the prevalence of NAFLD has increased due to a shift towards energy-dense dietary patterns and a sedentary lifestyle. NAFLD is also strongly associated with metabolic disorders such as obesity and hyperlipidemia. The progression of NAFLD could be influenced by a variety of factors, such as diet, genetic factors, and even epigenetic factors. In contrast to genetic factors, epigenetic factors, including histone modifications, exhibit dynamic and reversible features. Therefore, the epigenetic regulation of the initiation and progression of NAFLD is one of the directions under intensive investigation in terms of pathogenic mechanisms and possible therapeutic interventions. This review aims to discuss the possible mechanisms and the crucial role of histone modifications in the framework of epigenetic regulation in NAFLD, which may provide potential therapeutic targets and a scientific basis for the treatment of NAFLD.

Dietary inflammation index is associated with dyslipidemia: evidence from national health and nutrition examination survey, 1999-2019

BACKGROUND AND AIMS

This study aimed to investigate the association between the Dietary Inflammatory Index (DII) and dyslipidemia, as well as to evaluate the mortality risk associated with DII in participants with dyslipidemia.

METHODS

Data from the National Health and Nutrition Examination Survey database were divided into dyslipidemia and non-dyslipidemia groups. The association between DII and dyslipidemia was investigated using the weighted chi-square test, weighted t-test, and weighted logistic regression. Weighted Cox proportional hazards models were used to estimate the hazard ratios and 95% confidence intervals for all-cause and cardiovascular disease-related mortality within the dyslipidemia group.

RESULTS

A total of 17,820 participants, including 4,839 without and 12,981 with dyslipidemia were analyzed in this study. The results showed that DII was higher in the dyslipidemia group compared to the non-dyslipidemia group (1.42 ± 0.03 vs. 1.23 ± 0.04, P < 0.01). However, for energy, protein, carbohydrates, total fat, saturated fat, and iron, DII was lower in participants with dyslipidemia. Logistic regression analysis revealed a strong positive association between DII and dyslipidemia. The odds ratios for dyslipidemia from Q1 to Q4 were 1.00 (reference), 1.12 (0.96-1.31), 1.23 (1.04-1.44), and 1.33 (1.11-1.59), respectively. In participants with dyslipidemia, a high DII was associated with high all-cause and cardiovascular mortality.

CONCLUSION

DII was closely associated with dyslipidemia. A pro-inflammatory diet may play a role in unfavorable consequences and is linked to both all-cause mortality and cardiovascular death in patients with dyslipidemia. Participants with dyslipidemia should pay attention to their anti-inflammatory dietary patterns.

Fecal Microbiota Transplantation for Weight and Glycemic Control of Obesity as Well as the Associated Metabolic Diseases: Meta-Analysis and Comprehensive Assessment

Objectives: An analysis of the weight and blood glucose management associated with fecal microbiota transplantation (FMT) as well as metabolic diseases associated with FMT was conducted by the authors in order to provide clinical recommendations regarding the treatment of nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM). Methods: We searched PubMed, Embase, and the Cochrane Library for papers that were published between the creation of the database and October 2022. We reviewed research that investigated how FMT affected weight and glycemic management in cases of obesity and metabolic conditions that are related to obesity. Studies that were published more than once, lacked the entire text, included insufficient information, or were impossible to extract data from were excluded. Additionally, case reports, reviews, and systematic reviews were excluded from the analysis. In order to analyze the data, STATA 15.1 was used. Outcomes: When we combined all of our findings, we discovered that pooled outcomes showed that weight levels (WMD equals -4.77, 95%CI: -7.40~-2.14), BMI levels (WMD equals -1.59, 95%CI: -2.21~-0.97), HOMA-IR (WMD equals -0.79, 95%CI: -1.57~-0.00), and HbA1c (WMD equals -0.65, 95%CI: -0.75~-0.55) after FMT treatment were significantly lower than before treatment. However, FMT treatment may have no effect on glucose and insulin levels in obese patients at fasting and related metabolic diseases. Additionally, subgroup analysis outcomes found that FMT significantly reduced fasting blood glucose in people with diabetes. Conclusions: As a weight loss and glycemic control therapy, FMT helps to prevent and treat metabolic problems linked to obesity, and is a viable alternative to bariatric surgery for patients who do not wish to undergo the procedure.

Biomarkers of aging

Aging biomarkers are a combination of biological parameters to (i) assess age-related changes, (ii) track the physiological aging process, and (iii) predict the transition into a pathological status. Although a broad spectrum of aging biomarkers has been developed, their potential uses and limitations remain poorly characterized. An immediate goal of biomarkers is to help us answer the following three fundamental questions in aging research: How old are we? Why do we get old? And how can we age slower? This review aims to address this need. Here, we summarize our current knowledge of biomarkers developed for cellular, organ, and organismal levels of aging, comprising six pillars: physiological characteristics, medical imaging, histological features, cellular alterations, molecular changes, and secretory factors. To fulfill all these requisites, we propose that aging biomarkers should qualify for being specific, systemic, and clinically relevant.

Epigenetic Regulation and its Effects on Aging and Cardiovascular Disease

Cardiovascular disease (CVD), specifically coronary atherosclerosis, is regulated by an interplay between genetic and lifestyle factors. Most recently, a factor getting much attention is the role epigenetics play in atherosclerosis; particularly the development of coronary artery disease. Furthermore, it is important to understand the intricate interaction between the environment and each individual genetic material and how this interaction affects gene expression and consequently influences the development of atherosclerosis. Our main goal is to discuss epigenetic regulations; particularly, the factors contributing to coronary atherosclerosis and their role in aging and longevity. We reviewed the current literature and provided a simplified yet structured and reasonable appraisal of this topic. This role has also been recently linked to longevity and aging. Epigenetic regulations (modifications) whether through histone modifications or DNA or RNA methylation have been shown to be regulated by environmental factors such as social stress, smoking, chemical contaminants, and diet. These sensitive interactions are further aggravated by racial health disparities that ultimately impact cardiovascular disease outcomes through epigenetic interactions. Certainly, limiting our exposure to such causative events at younger ages seems our "golden opportunity" to tackle the incidence of coronary atherosclerosis and probably the answer to longevity.

Epigenetic clocks and female fertility timeline: A new approach to an old issue?

Worldwide increase in life expectancy has boosted research on aging. Overcoming the concept of chronological age, higher attention has been addressed to biological age, which reflects a person's real health state, and which may be the resulting combination of both intrinsic and environmental factors. As epigenetics may exert a pivotal role in the biological aging, epigenetic clocks were developed. They are based on mathematical models aimed at identifying DNA methylation patterns that can define the biological age and that can be adopted for different clinical scopes (i.e., estimation of the risks of developing age-related disorders or predicting lifespan). Recently, epigenetic clocks have gained a peculiar attention in the fertility research field, in particular in the female counterpart. The insight into the possible relations between epigenetic aging and women's infertility might glean additional information about certain conditions that are still not completely understood. Moreover, they could disclose significant implications for health promotion programs in infertile women. Of relevance here is that the impact of biological age and epigenetics may not be limited to fertility status but could translate into pregnancy issues. Indeed, epigenetic alterations of the mother may transfer into the offspring, and pregnancy itself as well as related complications could contribute to epigenetic modifications in both the mother and newborn. However, even if the growing interest has culminated in the conspicuous production of studies on these topics, a global overview and the availability of validated instruments for diagnosis is still missing. The present narrative review aims to explore the possible bonds between epigenetic aging and fertility timeline. In the "infertility" section, we will discuss the advances on epigenetic clocks focusing on the different tissues examined (endometrium, peripheral blood, ovaries). In the "pregnancy" section, we will discuss the results obtained from placenta, umbilical cord and peripheral blood. The possible role of epigenetic aging on infertility mechanisms and pregnancy outcomes represents a question that may configure epigenetic clock as a bond between two apparently opposite worlds: infertility and pregnancy.

Chrono-Nutrition: Circadian Rhythm and Personalized Nutrition

The human circadian system has a period of approximately 24 h and studies on the consequences of "chornodisruption" have greatly expanded. Lifestyle and environmental factors of modern societies (i.e., artificial lighting, jetlag, shift work, and around-the-clock access to energy-dense food) can induce disruptions of the circadian system and thereby adversely affect individual health. Growing evidence demonstrates a complex reciprocal relationship between metabolism and the circadian system, in which perturbations in one system affect the other one. From a nutritional genomics perspective, genetic variants in clock genes can both influence metabolic health and modify the individual response to diet. Moreover, an interplay between the circadian rhythm, gut microbiome, and epigenome has been demonstrated, with the diet in turn able to modulate this complex link suggesting a remarkable plasticity of the underlying mechanisms. In this view, the study of the impact of the timing of eating by matching elements from nutritional research with chrono-biology, that is, chrono-nutrition, could have significant implications for personalized nutrition in terms of reducing the prevalence and burden of chronic diseases. This review provides an overview of the current evidence on the interactions between the circadian system and nutrition, highlighting how this link could in turn influence the epigenome and microbiome. In addition, possible nutritional strategies to manage circadian-aligned feeding are suggested.