1 3818 116 INTRINSIC AND ENVIRONMENTAL BASIS OF AGING: A NARRATIVE REVIEW. LONGEVITY HAS BEEN A TOPIC OF INTEREST SINCE THE BEGINNINGS OF HUMANITY, YET ITS AETIOLOGY AND PRECISE MECHANISMS REMAIN TO BE ELUCIDATED. AGING IS CURRENTLY VIEWED AS A PHYSIOLOGICAL PHENOMENON CHARACTERIZED BY THE GRADUAL DEGENERATION OF ORGANIC PHYSIOLOGY AND MORPHOLOGY DUE TO THE PASSAGE OF TIME WHERE BOTH EXTERNAL AND INTERNAL STIMULI INTERVENE. THE INFLUENCE OF INTRINSIC FACTORS, SUCH AS PROGRESSIVE TELOMERE SHORTENING, GENOME INSTABILITY DUE TO MUTATION BUILDUP, THE DIRECT OR INDIRECT ACTIONS OF AGE-RELATED GENES, AND MARKED CHANGES IN EPIGENETIC, METABOLIC, AND MITOCHONDRIAL PATTERNS CONSTITUTE A BIG PART OF ITS UNDERLYING ENDOGENOUS MECHANISMS. ON THE OTHER HAND, SEVERAL PSYCHOSOCIAL AND DEMOGRAPHIC FACTORS, SUCH AS DIET, PHYSICAL ACTIVITY, SMOKING, AND DRINKING HABITS, MAY HAVE AN EVEN MORE SIGNIFICANT IMPACT ON SHAPING THE AGING PROCESS. CONSEQUENTIALLY, IMPLEMENTING DIETARY AND EXERCISE PATTERNS HAS BEEN PROPOSED AS THE MOST VIABLE ALTERNATIVE STRATEGY FOR ATTENUATING THE MOST TYPICAL DEGENERATIVE AGING CHANGES, THUS INCREASING THE LIKELIHOOD OF PROLONGING LIFESPAN AND ACHIEVING SUCCESSFUL AGING. 2023 2 2855 42 FROM INFLAMMAGING TO HEALTHY AGING BY DIETARY LIFESTYLE CHOICES: IS EPIGENETICS THE KEY TO PERSONALIZED NUTRITION? THE PROGRESSIVELY OLDER POPULATION IN DEVELOPED COUNTRIES IS REFLECTED IN AN INCREASE IN THE NUMBER OF PEOPLE SUFFERING FROM AGE-RELATED CHRONIC INFLAMMATORY DISEASES SUCH AS METABOLIC SYNDROME, DIABETES, HEART AND LUNG DISEASES, CANCER, OSTEOPOROSIS, ARTHRITIS, AND DEMENTIA. THE HETEROGENEITY IN BIOLOGICAL AGING, CHRONOLOGICAL AGE, AND AGING-ASSOCIATED DISORDERS IN HUMANS HAVE BEEN ASCRIBED TO DIFFERENT GENETIC AND ENVIRONMENTAL FACTORS (I.E., DIET, POLLUTION, STRESS) THAT ARE CLOSELY LINKED TO SOCIOECONOMIC FACTORS. THE COMMON DENOMINATOR OF THESE FACTORS IS THE INFLAMMATORY RESPONSE. CHRONIC LOW-GRADE SYSTEMIC INFLAMMATION DURING PHYSIOLOGICAL AGING AND IMMUNOSENESCENCE ARE INTERTWINED IN THE PATHOGENESIS OF PREMATURE AGING ALSO DEFINED AS 'INFLAMMAGING.' THE LATTER HAS BEEN ASSOCIATED WITH FRAILTY, MORBIDITY, AND MORTALITY IN ELDERLY SUBJECTS. HOWEVER, IT IS UNKNOWN TO WHAT EXTENT INFLAMMAGING OR LONGEVITY IS CONTROLLED BY EPIGENETIC EVENTS IN EARLY LIFE. TODAY, HUMAN DIET IS BELIEVED TO HAVE A MAJOR INFLUENCE ON BOTH THE DEVELOPMENT AND PREVENTION OF AGE-RELATED DISEASES. MOST PLANT-DERIVED DIETARY PHYTOCHEMICALS AND MACRO- AND MICRONUTRIENTS MODULATE OXIDATIVE STRESS AND INFLAMMATORY SIGNALING AND REGULATE METABOLIC PATHWAYS AND BIOENERGETICS THAT CAN BE TRANSLATED INTO STABLE EPIGENETIC PATTERNS OF GENE EXPRESSION. THEREFORE, DIET INTERVENTIONS DESIGNED FOR HEALTHY AGING HAVE BECOME A HOT TOPIC IN NUTRITIONAL EPIGENOMIC RESEARCH. INCREASING EVIDENCE HAS REVEALED THAT COMPLEX INTERACTIONS BETWEEN FOOD COMPONENTS AND HISTONE MODIFICATIONS, DNA METHYLATION, NON-CODING RNA EXPRESSION, AND CHROMATIN REMODELING FACTORS INFLUENCE THE INFLAMMAGING PHENOTYPE AND AS SUCH MAY PROTECT OR PREDISPOSE AN INDIVIDUAL TO MANY AGE-RELATED DISEASES. REMARKABLY, HUMANS PRESENT A BROAD RANGE OF RESPONSES TO SIMILAR DIETARY CHALLENGES DUE TO BOTH GENETIC AND EPIGENETIC MODULATIONS OF THE EXPRESSION OF TARGET PROTEINS AND KEY GENES INVOLVED IN THE METABOLISM AND DISTRIBUTION OF THE DIETARY CONSTITUENTS. HERE, WE WILL SUMMARIZE THE EPIGENETIC ACTIONS OF DIETARY COMPONENTS, INCLUDING PHYTOCHEMICALS, AND MACRO- AND MICRONUTRIENTS AS WELL AS METABOLITES, THAT CAN ATTENUATE INFLAMMAGING. WE WILL DISCUSS THE CHALLENGES FACING PERSONALIZED NUTRITION TO TRANSLATE HIGHLY VARIABLE INTERINDIVIDUAL EPIGENETIC DIET RESPONSES TO POTENTIAL INDIVIDUAL HEALTH BENEFITS/RISKS RELATED TO AGING DISEASE. 2015 3 6189 29 THE IMPACT OF LIFE STRESS ON HALLMARKS OF AGING AND ACCELERATED SENESCENCE: CONNECTIONS IN SICKNESS AND IN HEALTH. CHRONIC STRESS IS A RISK FACTOR FOR NUMEROUS AGING-RELATED DISEASES AND HAS BEEN SHOWN TO SHORTEN LIFESPAN IN HUMANS AND OTHER SOCIAL MAMMALS. YET HOW LIFE STRESS CAUSES SUCH A VAST RANGE OF DISEASES IS STILL LARGELY UNCLEAR. IN RECENT YEARS, THE IMPACT OF STRESS ON HEALTH AND AGING HAS BEEN INCREASINGLY ASSOCIATED WITH THE DYSREGULATION OF THE SO-CALLED HALLMARKS OF AGING. THESE ARE BASIC BIOLOGICAL MECHANISMS THAT INFLUENCE INTRINSIC CELLULAR FUNCTIONS AND WHOSE ALTERATION CAN LEAD TO ACCELERATED AGING. HERE, WE REVIEW CORRELATIONAL AND EXPERIMENTAL LITERATURE (PRIMARILY FOCUSING ON EVIDENCE FROM HUMANS AND MURINE MODELS) ON THE CONTRIBUTION OF LIFE STRESS - PARTICULARLY STRESS DERIVED FROM ADVERSE SOCIAL ENVIRONMENTS - TO TRIGGER HALLMARKS OF AGING, INCLUDING CELLULAR SENESCENCE, STERILE INFLAMMATION, TELOMERE SHORTENING, PRODUCTION OF REACTIVE OXYGEN SPECIES, DNA DAMAGE, AND EPIGENETIC CHANGES. WE ALSO EVALUATE THE VALIDITY OF STRESS-INDUCED SENESCENCE AND ACCELERATED AGING AS AN ETIOPATHOLOGICAL PROPOSITION. FINALLY, WE HIGHLIGHT CURRENT GAPS OF KNOWLEDGE AND FUTURE DIRECTIONS FOR THE FIELD, AND DISCUSS PERSPECTIVES FOR TRANSLATIONAL GEROSCIENCE. 2023 4 5069 25 PHYSICAL ACTIVITY IN THE PREVENTION OF HUMAN DISEASES: ROLE OF EPIGENETIC MODIFICATIONS. EPIGENETIC MODIFICATION REFERS TO HERITABLE CHANGES IN GENE FUNCTION THAT CANNOT BE EXPLAINED BY ALTERATIONS IN THE DNA SEQUENCE. THE CURRENT LITERATURE CLEARLY DEMONSTRATES THAT THE EPIGENETIC RESPONSE IS HIGHLY DYNAMIC AND INFLUENCED BY DIFFERENT BIOLOGICAL AND ENVIRONMENTAL FACTORS SUCH AS AGING, NUTRIENT AVAILABILITY AND PHYSICAL EXERCISE. AS SUCH, IT IS WELL ACCEPTED THAT PHYSICAL ACTIVITY AND EXERCISE CAN MODULATE GENE EXPRESSION THROUGH EPIGENETIC ALTERNATIONS ALTHOUGH THE TYPE AND DURATION OF EXERCISE ELICITING SPECIFIC EPIGENETIC EFFECTS THAT CAN RESULT IN HEALTH BENEFITS AND PREVENT CHRONIC DISEASES REMAINS TO BE DETERMINED. THIS REVIEW HIGHLIGHTS THE MOST SIGNIFICANT FINDINGS FROM EPIGENETIC STUDIES INVOLVING PHYSICAL ACTIVITY/EXERCISE INTERVENTIONS KNOWN TO BENEFIT CHRONIC DISEASES SUCH AS METABOLIC SYNDROME, DIABETES, CANCER, CARDIOVASCULAR AND NEURODEGENERATIVE DISEASES. 2017 5 285 29 AGING AND AGING-RELATED DISEASES: FROM MOLECULAR MECHANISMS TO INTERVENTIONS AND TREATMENTS. AGING IS A GRADUAL AND IRREVERSIBLE PATHOPHYSIOLOGICAL PROCESS. IT PRESENTS WITH DECLINES IN TISSUE AND CELL FUNCTIONS AND SIGNIFICANT INCREASES IN THE RISKS OF VARIOUS AGING-RELATED DISEASES, INCLUDING NEURODEGENERATIVE DISEASES, CARDIOVASCULAR DISEASES, METABOLIC DISEASES, MUSCULOSKELETAL DISEASES, AND IMMUNE SYSTEM DISEASES. ALTHOUGH THE DEVELOPMENT OF MODERN MEDICINE HAS PROMOTED HUMAN HEALTH AND GREATLY EXTENDED LIFE EXPECTANCY, WITH THE AGING OF SOCIETY, A VARIETY OF CHRONIC DISEASES HAVE GRADUALLY BECOME THE MOST IMPORTANT CAUSES OF DISABILITY AND DEATH IN ELDERLY INDIVIDUALS. CURRENT RESEARCH ON AGING FOCUSES ON ELUCIDATING HOW VARIOUS ENDOGENOUS AND EXOGENOUS STRESSES (SUCH AS GENOMIC INSTABILITY, TELOMERE DYSFUNCTION, EPIGENETIC ALTERATIONS, LOSS OF PROTEOSTASIS, COMPROMISE OF AUTOPHAGY, MITOCHONDRIAL DYSFUNCTION, CELLULAR SENESCENCE, STEM CELL EXHAUSTION, ALTERED INTERCELLULAR COMMUNICATION, DEREGULATED NUTRIENT SENSING) PARTICIPATE IN THE REGULATION OF AGING. FURTHERMORE, THOROUGH RESEARCH ON THE PATHOGENESIS OF AGING TO IDENTIFY INTERVENTIONS THAT PROMOTE HEALTH AND LONGEVITY (SUCH AS CALORIC RESTRICTION, MICROBIOTA TRANSPLANTATION, AND NUTRITIONAL INTERVENTION) AND CLINICAL TREATMENT METHODS FOR AGING-RELATED DISEASES (DEPLETION OF SENESCENT CELLS, STEM CELL THERAPY, ANTIOXIDATIVE AND ANTI-INFLAMMATORY TREATMENTS, AND HORMONE REPLACEMENT THERAPY) COULD DECREASE THE INCIDENCE AND DEVELOPMENT OF AGING-RELATED DISEASES AND IN TURN PROMOTE HEALTHY AGING AND LONGEVITY. 2022 6 6034 31 THE CHALLENGE BY MULTIPLE ENVIRONMENTAL AND BIOLOGICAL FACTORS INDUCE INFLAMMATION IN AGING: THEIR ROLE IN THE PROMOTION OF CHRONIC DISEASE. THE AGING PROCESS IS DRIVEN BY MULTIPLE MECHANISMS THAT LEAD TO CHANGES IN ENERGY PRODUCTION, OXIDATIVE STRESS, HOMEOSTATIC DYSREGULATION AND EVENTUALLY TO LOSS OF FUNCTIONALITY AND INCREASED DISEASE SUSCEPTIBILITY. MOST AGED INDIVIDUALS DEVELOP CHRONIC LOW-GRADE INFLAMMATION, WHICH IS AN IMPORTANT RISK FACTOR FOR MORBIDITY, PHYSICAL AND COGNITIVE IMPAIRMENT, FRAILTY, AND DEATH. AT ANY AGE, CHRONIC INFLAMMATORY DISEASES ARE MAJOR CAUSES OF MORBIMORTALITY, AFFECTING UP TO 5-8% OF THE POPULATION OF INDUSTRIALIZED COUNTRIES. SEVERAL ENVIRONMENTAL FACTORS CAN PLAY AN IMPORTANT ROLE FOR MODIFYING THE INFLAMMATORY STATE. GENETICS ACCOUNTS FOR ONLY A SMALL FRACTION OF CHRONIC-INFLAMMATORY DISEASES, WHEREAS ENVIRONMENTAL FACTORS APPEAR TO PARTICIPATE, EITHER WITH A CAUSATIVE OR A PROMOTIONAL ROLE IN 50% TO 75% OF PATIENTS. SEVERAL OF THOSE CHANGES DEPEND ON EPIGENETIC CHANGES THAT WILL FURTHER MODIFY THE INDIVIDUAL RESPONSE TO ADDITIONAL STIMULI. THE INTERACTION BETWEEN INFLAMMATION AND THE ENVIRONMENT OFFERS IMPORTANT INSIGHTS ON AGING AND HEALTH. THESE CONDITIONS, OFTEN DEPENDING ON THE INDIVIDUAL'S SEX, APPEAR TO LEAD TO DECREASED LONGEVITY AND PHYSICAL AND COGNITIVE DECLINE. IN ADDITION TO BIOLOGICAL FACTORS, THE ENVIRONMENT IS ALSO INVOLVED IN THE GENERATION OF PSYCHOLOGICAL AND SOCIAL CONTEXT LEADING TO STRESS. POOR PSYCHOLOGICAL ENVIRONMENTS AND OTHER SOURCES OF STRESS ALSO RESULT IN INCREASED INFLAMMATION. HOWEVER, THE MECHANISMS UNDERLYING THE ROLE OF ENVIRONMENTAL AND PSYCHOSOCIAL FACTORS AND NUTRITION ON THE REGULATION OF INFLAMMATION, AND HOW THE RESPONSE ELICITED FOR THOSE FACTORS INTERACT AMONG THEM, ARE POORLY UNDERSTOOD. WHEREAS CERTAIN DELETERIOUS ENVIRONMENTAL FACTORS RESULT IN THE GENERATION OF OXIDATIVE STRESS DRIVEN BY AN INCREASED PRODUCTION OF REACTIVE OXYGEN AND NITROGEN SPECIES, ENDOPLASMIC RETICULUM STRESS, AND INFLAMMATION, OTHER FACTORS, INCLUDING NUTRITION (POLYUNSATURATED FATTY ACIDS) AND BEHAVIORAL FACTORS (EXERCISE) CONFER PROTECTION AGAINST INFLAMMATION, OXIDATIVE AND ENDOPLASMIC RETICULUM STRESS, AND THUS AMELIORATE THEIR DELETERIOUS EFFECT. HERE, WE DISCUSS PROCESSES AND MECHANISMS OF INFLAMMATION ASSOCIATED WITH ENVIRONMENTAL FACTORS AND BEHAVIOR, THEIR LINKS TO SEX AND GENDER, AND THEIR OVERALL IMPACT ON AGING. 2020 7 3102 32 GENOMIC INSTABILITIES, CELLULAR SENESCENCE, AND AGING: IN VITRO, IN VIVO AND AGING-LIKE HUMAN SYNDROMES. AS AVERAGE LIFE SPAN AND ELDERLY PEOPLE PREVALENCE IN THE WESTERN WORLD POPULATION IS GRADUALLY INCREASING, THE INCIDENCE OF AGE-RELATED DISEASES SUCH AS CANCER, HEART DISEASES, DIABETES, AND DEMENTIA IS INCREASING, BEARING SOCIAL AND ECONOMIC CONSEQUENCES WORLDWIDE. UNDERSTANDING THE MOLECULAR BASIS OF AGING-RELATED PROCESSES CAN HELP EXTEND THE ORGANISM'S HEALTH SPAN, I.E., THE LIFE PERIOD IN WHICH THE ORGANISM IS FREE OF CHRONIC DISEASES OR DECREASE IN BASIC BODY FUNCTIONS. DURING THE LAST FEW DECADES, IMMENSE PROGRESS WAS MADE IN THE UNDERSTANDING OF MAJOR COMPONENTS OF AGING AND HEALTHY AGING BIOLOGY, INCLUDING GENOMIC INSTABILITY, TELOMERE ATTRITION, EPIGENETIC CHANGES, PROTEOSTASIS, NUTRIENT SENSING, MITOCHONDRIAL DYSFUNCTION, CELLULAR SENESCENCE, STEM CELL EXHAUSTION, AND INTRACELLULAR COMMUNICATIONS. THIS PROGRESS HAS BEEN MADE BY THREE SPEAR-HEADED STRATEGIES: IN VITRO (CELL AND TISSUE CULTURE FROM VARIOUS SOURCES), IN VIVO (INCLUDES DIVERSE MODEL AND NON-MODEL ORGANISMS), BOTH CAN BE MANIPULATED AND TRANSLATED TO HUMAN BIOLOGY, AND THE STUDY OF AGING-LIKE HUMAN SYNDROMES AND HUMAN POPULATIONS. HEREIN, WE WILL FOCUS ON CURRENT REPOSITORY OF GENOMIC "SENESCENCE" STAGE OF AGING, WHICH INCLUDES HEALTH DECLINE, STRUCTURAL CHANGES OF THE GENOME, FAULTY DNA DAMAGE RESPONSE AND DNA DAMAGE, TELOMERE SHORTENING, AND EPIGENETIC ALTERATIONS. ALTHOUGH AGING IS A COMPLEX PROCESS, MANY OF THE "HALLMARKS" OF AGING ARE DIRECTLY RELATED TO DNA STRUCTURE AND FUNCTION. THIS REVIEW WILL ILLUSTRATE THE VARIETY OF THESE STUDIES, DONE IN IN VITRO, IN VIVO AND HUMAN LEVELS, AND HIGHLIGHT THE UNIQUE POTENTIAL AND CONTRIBUTION OF EACH RESEARCH LEVEL AND EVENTUALLY THE LINK BETWEEN THEM. 2018 8 4985 28 PATHWAYS TO AGING: THE MITOCHONDRION AT THE INTERSECTION OF BIOLOGICAL AND PSYCHOSOCIAL SCIENCES. COMPELLING EVIDENCE SUGGESTS THAT BOTH BIOLOGICAL AND PSYCHOSOCIAL FACTORS IMPACT THE PROCESS OF AGING. HOWEVER, OUR UNDERSTANDING OF THE DYNAMIC INTERPLAY AMONG BIOLOGICAL AND PSYCHOSOCIAL FACTORS ACROSS THE LIFE COURSE IS STILL FRAGMENTARY. FOR EXAMPLE, IT NEEDS TO BE ESTABLISHED HOW THE INTERACTION OF INDIVIDUAL FACTORS (E.G., GENETIC AND EPIGENETIC ENDOWMENT AND PERSONALITY), BEHAVIORAL FACTORS (E.G., PHYSICAL ACTIVITY, DIET, AND STRESS MANAGEMENT), AND PSYCHOSOCIAL EXPERIENCES (E.G., SOCIAL SUPPORT, WELL-BEING, SOCIOECONOMIC STATUS, AND MARRIAGE) IN PERINATAL, CHILDHOOD, AND ADULTHOOD INFLUENCE HEALTH ACROSS THE AGING CONTINUUM. THIS PAPER AIMS TO OUTLINE POTENTIAL INTERSECTION POINTS SERVING AS AN INTERFACE BETWEEN BIOLOGICAL AND PSYCHOSOCIAL FACTORS, WITH AN EMPHASIS ON THE MITOCHONDRION. MITOCHONDRIA ARE CELLULAR ORGANELLES WHICH PLAY A CRITICAL ROLE IN CELLULAR SENESCENCE. BOTH CHRONIC EXPOSURE TO PSYCHOSOCIAL STRESS AND GENETIC-BASED MITOCHONDRIAL DYSFUNCTION HAVE STRIKINGLY SIMILAR BIOLOGICAL CONSEQUENCES; BOTH PREDISPOSE INDIVIDUALS TO ADVERSE AGE-RELATED HEALTH DISORDERS AND EARLY MORTALITY. EXPLORING THE INTERACTIVE NATURE OF THE FACTORS RESULTING IN PATHWAYS TO NORMAL HEALTHY AGING, AS WELL AS THOSE LEADING TO MORBIDITY AND EARLY MORTALITY, WILL CONTINUE TO ENHANCE OUR ABILITY TO TRANSLATE RESEARCH INTO EFFECTIVE PRACTICES THAT CAN BE IMPLEMENTED THROUGHOUT THE LIFE COURSE TO OPTIMISE THE AGING PROCESS. 2011 9 6412 31 THE SPECTRUM OF FUNDAMENTAL BASIC SCIENCE DISCOVERIES CONTRIBUTING TO ORGANISMAL AGING. AGING RESEARCH HAS UNDERGONE UNPRECEDENTED ADVANCES AT AN ACCELERATING RATE IN RECENT YEARS, LEADING TO EXCITEMENT IN THE FIELD AS WELL AS OPPORTUNITIES FOR IMAGINATION AND INNOVATION. NOVEL INSIGHTS INDICATE THAT, RATHER THAN RESULTING FROM A PREPROGRAMMED SERIES OF EVENTS, THE AGING PROCESS IS PREDOMINANTLY DRIVEN BY FUNDAMENTAL NON-ADAPTIVE MECHANISMS THAT ARE INTERCONNECTED, LINKED, AND OVERLAP. TO VARYING DEGREES, THESE MECHANISMS ALSO MANIFEST WITH AGING IN BONE WHERE THEY CAUSE SKELETAL FRAGILITY. BECAUSE THESE MECHANISMS OF AGING CAN BE MANIPULATED, IT MIGHT BE POSSIBLE TO SLOW, DELAY, OR ALLEVIATE MULTIPLE AGE-RELATED DISEASES AND THEIR COMPLICATIONS BY TARGETING CONSERVED GENETIC SIGNALING PATHWAYS, CONTROLLED FUNCTIONAL NETWORKS, AND BASIC BIOCHEMICAL PROCESSES. INDEED, FINDINGS IN VARIOUS MAMMALIAN SPECIES SUGGEST THAT TARGETING FUNDAMENTAL AGING MECHANISMS (EG, VIA EITHER LOSS-OF-FUNCTION OR GAIN-OF-FUNCTION MUTATIONS OR ADMINISTRATION OF PHARMACOLOGICAL THERAPIES) CAN EXTEND HEALTHSPAN; IE, THE HEALTHY PERIOD OF LIFE FREE OF CHRONIC DISEASES. IN THIS REVIEW, WE SUMMARIZE THE EVIDENCE SUPPORTING THE ROLE OF THE SPECTRUM OF FUNDAMENTAL BASIC SCIENCE DISCOVERIES CONTRIBUTING TO ORGANISMAL AGING, WITH EMPHASIS ON MAMMALIAN STUDIES AND IN PARTICULAR AGING MECHANISMS IN BONE THAT DRIVE SKELETAL FRAGILITY. THESE MECHANISMS OR AGING HALLMARKS INCLUDE: GENOMIC INSTABILITY, TELOMERE ATTRITION, EPIGENETIC ALTERATIONS, LOSS OF PROTEOSTASIS, DEREGULATED NUTRIENT SENSING, MITOCHONDRIAL DYSFUNCTION, CELLULAR SENESCENCE, STEM CELL EXHAUSTION, AND ALTERED INTERCELLULAR COMMUNICATION. BECAUSE THESE MECHANISMS ARE LINKED, INTERVENTIONS THAT AMELIORATE ONE HALLMARK CAN IN THEORY AMELIORATE OTHERS. IN THE FIELD OF BONE AND MINERAL RESEARCH, CURRENT CHALLENGES INCLUDE DEFINING THE RELATIVE CONTRIBUTIONS OF EACH AGING HALLMARK TO THE NATURAL SKELETAL AGING PROCESS, BETTER UNDERSTANDING THE COMPLEX INTERCONNECTIONS AMONG THE HALLMARKS, AND IDENTIFYING THE MOST EFFECTIVE THERAPEUTIC STRATEGIES TO SAFELY TARGET MULTIPLE HALLMARKS. BASED ON THEIR INTERCONNECTIONS, IT MAY BE FEASIBLE TO SIMULTANEOUSLY INTERFERE WITH SEVERAL FUNDAMENTAL AGING MECHANISMS TO ALLEVIATE A WIDE SPECTRUM OF AGE-RELATED CHRONIC DISEASES, INCLUDING OSTEOPOROSIS. (C) 2018 AMERICAN SOCIETY FOR BONE AND MINERAL RESEARCH. 2018 10 6109 35 THE EPIGENETIC AGING, OBESITY, AND LIFESTYLE. THE PREVALENCE OF OBESITY HAS DRAMATICALLY INCREASED WORLDWIDE OVER THE PAST DECADES. AGING-RELATED CHRONIC CONDITIONS, SUCH AS TYPE 2 DIABETES AND CARDIOVASCULAR DISEASE, ARE MORE PREVALENT IN INDIVIDUALS WITH OBESITY, THUS REDUCING THEIR LIFESPAN. EPIGENETIC CLOCKS, THE NEW METRICS OF BIOLOGICAL AGE BASED ON DNA METHYLATION PATTERNS, COULD BE CONSIDERED A REFLECTION OF THE STATE OF ONE'S HEALTH. SEVERAL ENVIRONMENTAL EXPOSURES AND LIFESTYLE FACTORS CAN INDUCE EPIGENETIC AGING ACCELERATIONS, INCLUDING OBESITY, THUS LEADING TO AN INCREASED RISK OF AGE-RELATED DISEASES. THE INSIGHT INTO THE COMPLEX LINK BETWEEN OBESITY AND AGING MIGHT HAVE SIGNIFICANT IMPLICATIONS FOR THE PROMOTION OF HEALTH AND THE MITIGATION OF FUTURE DISEASE RISK. THE PRESENT NARRATIVE REVIEW TAKES INTO ACCOUNT THE INTERACTION BETWEEN EPIGENETIC AGING AND OBESITY, SUGGESTING THAT EPIGENOME MAY BE AN INTRIGUING TARGET FOR AGE-RELATED PHYSIOLOGICAL CHANGES AND THAT ITS MODIFICATION COULD INFLUENCE AGING AND PROLONG A HEALTHY LIFESPAN. THEREFORE, WE HAVE FOCUSED ON DNA METHYLATION AGE AS A CLINICAL BIOMARKER, AS WELL AS ON THE POTENTIAL REVERSAL OF EPIGENETIC AGE USING A PERSONALIZED DIET- AND LIFESTYLE-BASED INTERVENTION. 2022 11 1360 30 DEVELOPMENTAL ASPECTS OF A LIFE COURSE APPROACH TO HEALTHY AGEING. WE EXAMINE THE MECHANISTIC BASIS AND WIDER IMPLICATIONS OF ADOPTING A DEVELOPMENTAL PERSPECTIVE ON HUMAN AGEING. PREVIOUS MODELS OF AGEING HAVE CONCENTRATED ON ITS GENETIC BASIS, OR THE DETRIMENTAL EFFECTS OF ACCUMULATED DAMAGE, BUT ALSO HAVE RAISED ISSUES ABOUT WHETHER AGEING CAN BE VIEWED AS ADAPTIVE ITSELF, OR IS A CONSEQUENCE OF OTHER ADAPTIVE PROCESSES, FOR EXAMPLE IF MAINTENANCE AND REPAIR PROCESSES IN THE PERIOD UP TO REPRODUCTION ARE TRADED OFF AGAINST LATER DECLINE IN FUNCTION. A LIFE COURSE MODEL PLACES AGEING IN THE CONTEXT OF THE ATTAINMENT OF PEAK CAPACITY FOR A BODY SYSTEM, STARTING IN EARLY DEVELOPMENT WHEN PLASTICITY PERMITS CHANGES IN STRUCTURE AND FUNCTION INDUCED BY A RANGE OF ENVIRONMENTAL STIMULI, FOLLOWED BY A PERIOD OF DECLINE, THE RATE OF WHICH DEPENDS ON THE PEAK ATTAINED AS WELL AS THE LATER LIFE CONDITIONS. SUCH PATH DEPENDENCY IN THE RATE OF AGEING MAY OFFER NEW INSIGHTS INTO ITS MODIFICATION. FOCUSING ON MUSCULOSKELETAL AND CARDIOVASCULAR FUNCTION, WE DISCUSS THIS MODEL AND THE POSSIBLE UNDERLYING MECHANISMS, INCLUDING ENDOTHELIAL FUNCTION, OXIDATIVE STRESS, STEM CELLS AND NUTRITIONAL FACTORS SUCH AS VITAMIN D STATUS. EPIGENETIC CHANGES INDUCED DURING DEVELOPMENTAL PLASTICITY, AND IMMUNE FUNCTION MAY PROVIDE A COMMON MECHANISTIC PROCESS UNDERLYING A LIFE COURSE MODEL OF AGEING. THE LIFE COURSE TRAJECTORY DIFFERS IN HIGH AND LOW RESOURCE SETTINGS. NEW INSIGHTS INTO THE DEVELOPMENTAL COMPONENTS OF THE LIFE COURSE MODEL OF AGEING MAY LEAD TO THE DESIGN OF BIOMARKERS OF LATER CHRONIC DISEASE RISK AND TO NEW INTERVENTIONS TO PROMOTE HEALTHY AGEING, WITH IMPORTANT IMPLICATIONS FOR PUBLIC HEALTH. 2016 12 625 31 BIOLOGICAL AGE AND ENVIRONMENTAL RISK FACTORS FOR DEMENTIA AND STROKE: MOLECULAR MECHANISMS. SINCE THE DEVELOPMENT OF ANTIBIOTICS AND VACCINATION, AS WELL AS MAJOR IMPROVEMENTS IN PUBLIC HYGIENE, THE MAIN RISK FACTORS FOR MORBIDITY AND MORTALITY ARE AGE AND CHRONIC EXPOSURE TO ENVIRONMENTAL FACTORS, BOTH OF WHICH CAN INTERACT WITH GENETIC PREDISPOSITIONS. AS THE AVERAGE AGE OF THE POPULATION INCREASES, THE PREVALENCE AND COSTS OF CHRONIC DISEASES, ESPECIALLY NEUROLOGICAL CONDITIONS, ARE RAPIDLY INCREASING. THE DELETERIOUS EFFECTS OF AGE AND ENVIRONMENTAL RISK FACTORS, DEVELOP CHRONICALLY OVER RELATIVELY LONG PERIODS OF TIME, IN CONTRAST TO THE RELATIVELY RAPID DELETERIOUS EFFECTS OF INFECTIOUS DISEASES OR ACCIDENTS. OF PARTICULAR INTEREST IS THE HYPOTHESIS THAT THE DELETERIOUS EFFECTS OF ENVIRONMENTAL FACTORS MAY BE MEDIATED BY ACCELERATION OF BIOLOGICAL AGE. THIS HYPOTHESIS IS SUPPORTED BY EVIDENCE THAT DIETARY RESTRICTION, WHICH UNIVERSALLY DELAYS AGE-RELATED DISEASES, ALSO AMELIORATES DELETERIOUS EFFECTS OF ENVIRONMENTAL FACTORS. CONVERSELY, BOTH AGE AND ENVIRONMENTAL RISK FACTORS ARE ASSOCIATED WITH THE ACCUMULATION OF SOMATIC MUTATIONS IN MITOTIC CELLS AND EPIGENETIC MODIFICATIONS THAT ARE A MEASURE OF "BIOLOGICAL AGE", A BETTER PREDICTOR OF AGE-RELATED MORBIDITY AND MORTALITY THAN CHRONOLOGICAL AGE. HERE WE REVIEW EVIDENCE THAT ENVIRONMENTAL RISK FACTORS SUCH AS SMOKING AND AIR POLLUTION MAY ALSO DRIVE NEUROLOGICAL CONDITIONS, INCLUDING ALZHEIMER'S DISEASE, BY THE ACCELERATION OF BIOLOGICAL AGE, MEDIATED BY CUMULATIVE AND PERSISTENT EPIGENETIC EFFECTS AS WELL AS SOMATIC MUTATIONS. ELUCIDATION OF SUCH MECHANISMS COULD PLAUSIBLY ALLOW THE DEVELOPMENT OF INTERVENTIONS WHICH DELAY DELETERIOUS EFFECTS OF BOTH AGING AND ENVIRONMENTAL RISK FACTORS. 2022 13 2916 28 GENE VARIANTS AS DETERMINANTS OF LONGEVITY: FOCUS ON THE INFLAMMATORY FACTORS. HUMAN LONGEVITY IS AN EXTREMELY COMPLEX TRAIT WITH VARIOUS GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS ACTING UPON THE LONGEVITY PHENOTYPE. IT IS NOW BECOMING EVIDENT THAT WHILST THE GENETIC DIFFERENCES CONTRIBUTE ONLY MODESTLY TO LIFE EXPECTANCY BEFORE THE AGE OF 60 YEARS, THEIR IMPACT ON SURVIVAL BECOMES MORE PROMINENT AT THE EXTREME AGES. SEVERAL LONGEVITY GENE CANDIDATES HAVE EMERGED DURING THE PAST DECADE; THE MAJORITY OF THEM ARE RELATED EITHER TO INFLAMMATORY FUNCTIONS, STRESS RESPONSE OR TO LIPID AND GLUCOSE METABOLISM. THE VARIANTS OF INFLAMMATORY AND IMMUNE RESPONSE GENES ARE OF SPECIAL INTEREST SINCE ADVANCING AGES IS ACCOMPANIED BY A DECLINE IN SEVERAL IMMUNE FUNCTIONS--A PHENOMENON CALLED IMMUNOSENESCENCE. PARADOXICALLY, AGEING IS ALSO CHARACTERISED BY CHRONIC LOW-GRADE INFLAMMATION TERMED "INFLAMMAGING", WHICH MANIFESTS AS A TWO- TO FOURFOLD INCREASE IN THE PRODUCTION OF PROINFLAMMATORY CYTOKINES AND ACUTE PHASE PROTEINS. THESE CONTRASTING PHENOMENA PROVIDE A FUNCTIONAL RATIONALE OF HOW THE GENETIC DIFFERENCES IN INFLAMMATORY MEDIATORS MAY MODIFY THE LIFE SPAN OF THE ELDERLY. BESIDES DESCRIBING THE PRE-EXISTING INFLAMMATORY AND IMMUNE-RELATED LONGEVITY GENE VARIANTS, IN THIS REVIEW, WE ALSO EXPLAIN SOME OF THE THEORETICAL AND PRACTICAL CHALLENGES THAT GENETIC LONGEVITY STUDIES OFTEN ENCOUNTER. 2010 14 3676 32 INFLAMMATION AND NEUTROPHIL IMMUNOSENESCENCE IN HEALTH AND DISEASE: TARGETED TREATMENTS TO IMPROVE CLINICAL OUTCOMES IN THE ELDERLY. DESPITE INCREASING LONGEVITY, MANY OLD PEOPLE ARE NOT IN GOOD HEALTH. THERE HAS BEEN AN INCREASE IN THE PREVALENCE OF AGE-ASSOCIATED MULTI-MORBIDITY (TWO OR MORE CHRONIC CONDITIONS IN THE SAME PERSON). ALSO, SEVERE INFECTIONS, SUCH AS PNEUMONIA, REMAIN SIGNIFICANT CAUSES OF MORTALITY AND MORBIDITY IN THIS AGING GROUP. MANY CHRONIC HEALTH CONDITIONS SHARE RISK FACTORS SUCH AS INCREASING AGE, SMOKING, A SEDENTARY LIFE STYLE AND BEING PART OF A LOWER SOCIOECONOMIC GROUP. HOWEVER, DESPITE THIS, MULTI-MORBIDITIES OFTEN CO-OCCUR MORE COMMONLY THAN WOULD BE PREDICTED. THIS HAS LED TO THE HYPOTHESIS THAT THEY SHARE COMMON UNDERLYING MECHANISMS. THIS IS AN IMPORTANT CONCEPT, FOR IF IT WERE TRUE, TREATMENTS COULD BE DEVISED WHICH TARGET THESE COMMON PATHWAYS AND IMPROVE A NUMBER OF AGE-ASSOCIATED HEALTH CONDITIONS. MANY CHRONIC ILLNESSES ASSOCIATED WITH MULTI-MORBIDITY AND SEVERE INFECTIONS ARE CHARACTERIZED BY AN ABNORMAL AND SUSTAINED INFLAMMATORY RESPONSE, WITH NEUTROPHILS BEING KEY EFFECTOR CELLS IN THE PATHOLOGICAL PROCESS. STUDIES HAVE DESCRIBED ABERRANT NEUTROPHIL FUNCTIONS ACROSS THESE CONDITIONS, AND SOME HAVE HIGHLIGHTED POTENTIAL MECHANISMS FOR ALTERED CELL BEHAVIOURS WHICH APPEAR SHARED ACROSS DISEASE STATES. IT HAS BEEN SUGGESTED THAT ALTERED FUNCTIONS MAY REPRESENT NEUTROPHIL "SENESCENCE". THIS REVIEW CONSIDERS HOW AND WHY NEUTROPHIL FUNCTIONS CHANGE AS THE CELL AGES, AND HOW AND WHY NEUTROPHIL FUNCTIONS CHANGE AS THE HOST AGES IN HEALTH AND DISEASE AND DISCUSSES WHETHER NEUTROPHIL FUNCTIONS COULD BE TARGETED TO IMPROVE HEALTH OUTCOMES IN OLDER ADULTS. 2018 15 5263 33 PROMISING BIOMARKERS OF HUMAN AGING: IN SEARCH OF A MULTI-OMICS PANEL TO UNDERSTAND THE AGING PROCESS FROM A MULTIDIMENSIONAL PERSPECTIVE. THE AGING PROCESS HAS BEEN LINKED TO THE OCCURRENCE OF CHRONIC DISEASES AND FUNCTIONAL IMPAIRMENTS, INCLUDING CANCER, SARCOPENIA, FRAILTY, METABOLIC, CARDIOVASCULAR, AND NEURODEGENERATIVE DISEASES. NONETHELESS, AGING IS HIGHLY VARIABLE AND HETEROGENEOUS AND REPRESENTS A CHALLENGE FOR ITS CHARACTERIZATION. IN THIS SENSE, INTRINSIC CAPACITY (IC) STANDS AS A NOVEL PERSPECTIVE BY THE WORLD HEALTH ORGANIZATION, WHICH INTEGRATES THE INDIVIDUAL WELLBEING, ENVIRONMENT, AND RISK FACTORS TO UNDERSTAND AGING. HOWEVER, THERE IS A LACK OF QUANTITATIVE AND QUALITATIVE ATTRIBUTES TO DEFINE IT OBJECTIVELY. THEREFORE, IN THIS REVIEW WE ATTEMPT TO SUMMARIZE THE MOST RELEVANT AND PROMISING BIOMARKERS DESCRIBED IN CLINICAL STUDIES AT DATE OVER DIFFERENT MOLECULAR LEVELS, INCLUDING EPIGENOMICS, TRANSCRIPTOMICS, PROTEOMICS, METABOLOMICS, AND THE MICROBIOME. TO AID GERONTOLOGISTS, GERIATRICIANS, AND BIOMEDICAL RESEARCHERS TO UNDERSTAND THE AGING PROCESS THROUGH THE IC. AGING BIOMARKERS REFLECT THE PHYSIOLOGICAL STATE OF INDIVIDUALS AND THE UNDERLYING MECHANISMS RELATED TO HOMEOSTATIC CHANGES THROUGHOUT AN INDIVIDUAL LIFESPAN; THEY DEMONSTRATED THAT AGING COULD BE MEASURED INDEPENDENTLY OF TIME (THAT MAY EXPLAIN ITS HETEROGENEITY) AND TO BE HELPFUL TO PREDICT AGE-RELATED SYNDROMES AND MORTALITY. IN SUMMARY, WE HIGHLIGHT THE AREAS OF OPPORTUNITY AND GAPS OF KNOWLEDGE THAT MUST BE ADDRESSED TO FULLY INTEGRATE BIOMEDICAL FINDINGS INTO CLINICALLY USEFUL TOOLS AND INTERVENTIONS. 2020 16 6346 27 THE ROLE OF EPIGENETICS IN CARDIOVASCULAR HEALTH AND AGEING: A FOCUS ON PHYSICAL ACTIVITY AND NUTRITION. THE CARDIOVASCULAR SYSTEM IS RESPONSIBLE FOR TRANSPORT OF BLOOD AND NUTRIENTS TO TISSUES, AND IS PIVOTAL TO THE PHYSIOLOGICAL HEALTH AND LONGEVITY. EPIGENETIC MODIFICATION IS A NATURAL, AGE-ASSOCIATED PROCESS RESULTING IN HIGHLY CONTEXTUALISED GENE EXPRESSION WITH CLEAR IMPLICATIONS FOR CELL DIFFERENTIATION AND DISEASE ONSET. BIOLOGICAL/EPIGENETIC AGE IS INDEPENDENT OF CHRONOLOGICAL AGE, CONSTITUTING A HIGHLY REFLECTIVE SNAPSHOT OF AN INDIVIDUAL'S OVERALL HEALTH. ACCELERATED VASCULAR AGEING IS OF MAJOR CONCERN, EFFECTIVELY LOWERING DISEASE THRESHOLD. AGE-RELATED CHRONIC ILLNESS INVOLVES A COMPLEX INTERPLAY BETWEEN MANY BIOLOGICAL PROCESSES AND IS MODULATED BY NON-MODIFIABLE AND MODIFIABLE RISK FACTORS. THESE ALTER THE STATIC GENOME BY A NUMBER OF EPIGENETIC MECHANISMS, WHICH CHANGE GENE EXPRESSION IN AN AGE AND LIFESTYLE DEPENDENT MANNER. THIS 'EPIGENETIC DRIFT' IMPACTS HEALTH AND CONTRIBUTES TO THE ETIOLOGY OF CHRONIC ILLNESS. LIFESTYLE FACTORS MAY CAUSE ACCELERATION OF THIS EPIGENETIC "CLOCK", PRE-DISPOSING INDIVIDUALS TO CARDIOVASCULAR DISEASE. NUTRITION AND PHYSICAL ACTIVITY ARE MODIFIABLE LIFESTYLE CHOICES, SYNERGISTICALLY CONTRIBUTING TO CARDIOVASCULAR HEALTH. THEY REPRESENT A POWERFUL POTENTIAL EPIGENETIC INTERVENTION POINT FOR EFFECTIVE CARDIOVASCULAR PROTECTIVE AND MANAGEMENT STRATEGIES. THUS, TOGETHER WITH TRADITIONAL RISK FACTORS, MONITORING THE EPIGENETIC SIGNATURE OF AGEING MAY PROVE BENEFICIAL FOR TAILORING LIFESTYLE TO FIT BIOLOGY - SUPPORTING THE INCREASINGLY POPULAR CONCEPT OF "AGEING WELL". 2018 17 6629 23 UNDERSTANDING THE HUMAN AGING PROTEOME USING EPIDEMIOLOGICAL MODELS. HUMAN AGING IS A COMPLEX MULTIFACTORIAL PROCESS ASSOCIATED WITH A DECLINE OF PHYSICAL AND COGNITIVE FUNCTION AND HIGH SUSCEPTIBILITY TO CHRONIC DISEASES, INFLUENCED BY GENETIC, EPIGENETIC, ENVIRONMENTAL, AND DEMOGRAPHIC FACTORS. THIS CHAPTER WILL PROVIDE AN OVERVIEW ON THE USE OF EPIDEMIOLOGICAL MODELS WITH PROTEOMICS DATA AS A METHOD THAT CAN BE USED TO IDENTIFY FACTORS THAT MODULATE THE AGING PROCESS IN HUMANS. THIS IS DEMONSTRATED WITH PROTEOMICS DATA FROM HUMAN PLASMA AND SKELETAL MUSCLE, WHERE THE COMBINATION WITH EPIDEMIOLOGICAL MODELS IDENTIFIED A SET OF MITOCHONDRIAL, SPLICEOSOME, AND SENESCENCE PROTEINS AS WELL AS THE ROLE OF ENERGETIC PATHWAYS SUCH AS GLYCOLYSIS, AND ELECTRON TRANSPORT PATHWAYS THAT REGULATE THE AGING PROCESS. 2022 18 6183 29 THE IMPACT OF ENVIRONMENTAL FACTORS IN INFLUENCING EPIGENETICS RELATED TO OXIDATIVE STATES IN THE CARDIOVASCULAR SYSTEM. OXIDATIVE STATES EXERT A SIGNIFICANT INFLUENCE ON A WIDE RANGE OF BIOLOGICAL AND MOLECULAR PROCESSES AND FUNCTIONS. WHEN THEIR BALANCE IS SHIFTED TOWARDS ENHANCED AMOUNTS OF FREE RADICALS, PATHOLOGICAL PHENOMENA CAN OCCUR, AS THE GENERATION OF REACTIVE OXYGEN SPECIES (ROS) IN TISSUE MICROENVIRONMENT OR IN THE SYSTEMIC CIRCULATION CAN BE DETRIMENTAL. EPIDEMIC CHRONIC DISEASES OF WESTERN SOCIETIES, SUCH AS CARDIOVASCULAR DISEASE, OBESITY, AND DIABETES CORRELATE WITH THE IMBALANCE OF REDOX HOMEOSTASIS. CURRENT ADVANCES IN OUR UNDERSTANDING OF EPIGENETICS HAVE REVEALED A PARALLEL SCENARIO SHOWING THE INFLUENCE OF OXIDATIVE STRESS AS A MAJOR REGULATOR OF EPIGENETIC GENE REGULATION VIA MODIFICATION OF DNA METHYLATION, HISTONES, AND MICRORNAS. THIS HAS PROVIDED BOTH THE BIOLOGICAL LINK AND A POTENTIAL MOLECULAR EXPLANATION BETWEEN OXIDATIVE STRESS AND CARDIOVASCULAR/METABOLIC PHENOMENA. ACCORDINGLY, IN THIS REVIEW, WE WILL PROVIDE CURRENT INSIGHTS ON THE PHYSIOLOGICAL AND PATHOLOGICAL IMPACT OF CHANGES IN OXIDATIVE STATES ON CARDIOVASCULAR DISORDERS, BY SPECIFICALLY FOCUSING ON THE INFLUENCE OF EPIGENETIC REGULATION. A SPECIAL EMPHASIS WILL HIGHLIGHT THE EFFECT ON EPIGENETIC REGULATION OF HUMAN'S CURRENT LIFE HABITS, EXTERNAL AND ENVIRONMENTAL FACTORS, INCLUDING FOOD INTAKE, TOBACCO, AIR POLLUTION, AND ANTIOXIDANT-BASED APPROACHES. ADDITIONALLY, THE STRATEGY TO QUANTIFY OXIDATIVE STATES IN HUMANS IN ORDER TO DETERMINE WHICH BIOLOGICAL MARKER COULD BEST MATCH A SUBJECT'S PROFILE WILL BE DISCUSSED. 2017 19 6287 25 THE POTENTIAL ROLE OF ENVIRONMENTAL FACTORS IN MODULATING MITOCHONDRIAL DNA EPIGENETIC MARKS. MANY STUDIES IMPLICATE MITOCHONDRIAL DYSFUNCTION IN THE DEVELOPMENT AND PROGRESSION OF NUMEROUS CHRONIC DISEASES. MITOCHONDRIA ARE RESPONSIBLE FOR MOST CELLULAR ENERGY PRODUCTION, AND UNLIKE OTHER CYTOPLASMIC ORGANELLES, MITOCHONDRIA CONTAIN THEIR OWN GENOME. MOST RESEARCH TO DATE, THROUGH INVESTIGATING MITOCHONDRIAL DNA COPY NUMBER, HAS FOCUSED ON LARGER STRUCTURAL CHANGES OR ALTERATIONS TO THE ENTIRE MITOCHONDRIAL GENOME AND THEIR ROLE IN HUMAN DISEASE. USING THESE METHODS, MITOCHONDRIAL DYSFUNCTION HAS BEEN LINKED TO CANCERS, CARDIOVASCULAR DISEASE, AND METABOLIC HEALTH. HOWEVER, LIKE THE NUCLEAR GENOME, THE MITOCHONDRIAL GENOME MAY EXPERIENCE EPIGENETIC ALTERATIONS, INCLUDING DNA METHYLATION THAT MAY PARTIALLY EXPLAIN SOME OF THE HEALTH EFFECTS OF VARIOUS EXPOSURES. RECENTLY, THERE HAS BEEN A MOVEMENT TO UNDERSTAND HUMAN HEALTH AND DISEASE WITHIN THE CONTEXT OF THE EXPOSOME, WHICH AIMS TO DESCRIBE AND QUANTIFY THE ENTIRETY OF ALL EXPOSURES PEOPLE ENCOUNTER THROUGHOUT THEIR LIVES. THESE INCLUDE, AMONG OTHERS, ENVIRONMENTAL POLLUTANTS, OCCUPATIONAL EXPOSURES, HEAVY METALS, AND LIFESTYLE AND BEHAVIORAL FACTORS. IN THIS CHAPTER, WE SUMMARIZE THE CURRENT RESEARCH ON MITOCHONDRIA AND HUMAN HEALTH, PROVIDE AN OVERVIEW OF THE CURRENT KNOWLEDGE ON MITOCHONDRIAL EPIGENETICS, AND DESCRIBE THE EXPERIMENTAL AND EPIDEMIOLOGIC STUDIES THAT HAVE INVESTIGATED PARTICULAR EXPOSURES AND THEIR RELATIONSHIPS WITH MITOCHONDRIAL EPIGENETIC MODIFICATIONS. WE CONCLUDE THE CHAPTER WITH SUGGESTIONS FOR FUTURE DIRECTIONS IN EPIDEMIOLOGIC AND EXPERIMENTAL RESEARCH THAT IS NEEDED TO ADVANCE THE GROWING FIELD OF MITOCHONDRIAL EPIGENETICS. 2023 20 5945 25 TARGETING THE "HALLMARKS OF AGING" TO SLOW AGING AND TREAT AGE-RELATED DISEASE: FACT OR FICTION? AGING IS A MAJOR RISK FACTOR FOR A NUMBER OF CHRONIC DISEASES, INCLUDING NEURODEGENERATIVE AND CEREBROVASCULAR DISORDERS. AGING PROCESSES HAVE THEREFORE BEEN DISCUSSED AS POTENTIAL TARGETS FOR THE DEVELOPMENT OF NOVEL AND BROADLY EFFECTIVE PREVENTATIVES OR THERAPEUTICS FOR AGE-RELATED DISEASES, INCLUDING THOSE AFFECTING THE BRAIN. MECHANISMS THOUGHT TO CONTRIBUTE TO AGING HAVE BEEN SUMMARIZED UNDER THE TERM THE "HALLMARKS OF AGING" AND INCLUDE A LOSS OF PROTEOSTASIS, MITOCHONDRIAL DYSFUNCTION, ALTERED NUTRIENT SENSING, TELOMERE ATTRITION, GENOMIC INSTABILITY, CELLULAR SENESCENCE, STEM CELL EXHAUSTION, EPIGENETIC ALTERATIONS AND ALTERED INTERCELLULAR COMMUNICATION. WE HERE EXAMINE KEY CLAIMS ABOUT THE "HALLMARKS OF AGING". OUR ANALYSIS REVEALS IMPORTANT WEAKNESSES THAT PRECLUDE STRONG AND DEFINITIVE CONCLUSIONS CONCERNING A POSSIBLE ROLE OF THESE PROCESSES IN SHAPING ORGANISMAL AGING RATE. SIGNIFICANT AMBIGUITY ARISES FROM THE OVERRELIANCE ON LIFESPAN AS A PROXY MARKER FOR AGING, THE USE OF MODELS WITH UNCLEAR RELEVANCE FOR ORGANISMAL AGING, AND THE USE OF STUDY DESIGNS THAT DO NOT ALLOW TO PROPERLY ESTIMATE INTERVENTION EFFECTS ON AGING RATE. WE ALSO DISCUSS FUTURE RESEARCH DIRECTIONS THAT SHOULD BE TAKEN TO CLARIFY IF AND TO WHAT EXTENT PUTATIVE AGING REGULATORS DO IN FACT INTERACT WITH AGING. THESE INCLUDE MULTIDIMENSIONAL ANALYTICAL FRAMEWORKS AS WELL AS DESIGNS THAT FACILITATE THE PROPER ASSESSMENT OF INTERVENTION EFFECTS ON AGING RATE. 2023