Mitophagy: How Fasting Optimises Mitochondrial Density and Longevity

Overview

At the cellular level, organismal longevity is inextricably linked to mitochondrial quality control. Mitochondria, operating as the primary bioenergetic hubs via oxidative phosphorylation, are dual-edged swords: while essential for ATP synthesis, their electron transport chains are prone to electron leakage, resulting in the generation of reactive oxygen species (ROS). Over time, unmitigated accumulation of oxidised lipids, mutated mitochondrial DNA (mtDNA), and structural protein carbonylation compromises inner-membrane potential, triggering cellular senescence and systemic inflammation. To combat this entropy, eukaryotic cells deploy mitophagy—a selective form of macroautophagy dedicated to the targeted lysosomal degradation of dysfunctional or redundant mitochondria. Within the cutting-edge curriculum at INNERSTANDIN, this precise clearance mechanism is examined not merely as a housekeeping pathway, but as a master regulator of metabolic optimisation and cellular rejuvenation.

While baseline mitophagy occurs constitutively to maintain basal homeostasis, its upregulation requires a metabolic shift away from an anabolic, nutrient-replete state. Prolonged fasting or caloric restriction serves as the most potent physiological trigger for this transition. As exogenous glucose and amino acid availability plummets, intracellular ATP-to-AMP ratios shift, activating AMP-activated protein kinase (AMPK) while concurrently suppressing the mechanistic target of rapamycin complex 1 (mTORC1). Landmark studies indexed in PubMed demonstrate that this dual biochemical manipulation removes the inhibitory phosphorylation on the Unc-51 like autophagy activating kinase 1 (ULK1) complex, initiating the nucleation of the phagophore.

Concurrently, the metabolic switch forces cells to transition from glycolysis to fatty acid $\beta$-oxidation. This metabolic demand exposes the mitochondrial network to heightened oxidative stress, which paradoxically acts as a hormetic signal. Severely depolarised mitochondria selectively stabilise PTEN-induced kinase 1 (PINK1) on their outer mitochondrial membrane. PINK1 subsequently recruits and phosphorylates cytosolic E3 ubiquitin ligase Parkin, as well as pre-existing ubiquitin chains. This amplification cascade labels the damaged organelle with phospho-ubiquitin, anchoring it to autophagy receptors such as NDP52 and optineurin, which direct the doomed mitochondrion into the expanding autophagosome for acid hydrolase degradation.

Crucially, this degradative phase is coupled with transcriptional biogenesis. Upon autophagic clearance, the resultant release of amino acids and the activation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-$\alpha$) signal the nucleus to synthesise pristine, metabolically efficient organelles. Consequently, fasting does not merely induce cellular cleanup; it reshapes the mitochondrial network, optimising overall density, increasing oxidative capacity, and drastically reducing systemic oxidative stress markers. For the biological science researcher, understanding this dynamic interplay between catabolic clearance and anabolic renewal provides a mechanistic blueprint for delaying immunosenescence and extending healthspan.

The Biology — How It Works

At the cellular level, the metabolic transition from exogenous nutrient abundance to endogenous resource mobilisation represents an evolutionary survival switch. When circulating glucose and amino acids plummet—as observed during sustained fasting protocols investigated by metabolic researchers at institutions such as the University of Oxford—insulin and mammalian target of rapamycin (mTOR) signalling axes are downregulated, whilst AMP-activated protein kinase (AMPK) is profoundly activated. This biochemical shift alters cellular bioenergetics, halting indiscriminate protein synthesis and upregulating catabolic clearance pathways, chief among them being selective mitochondrial autophagy, or mitophagy.

Mitochondria are dynamic organelles that continuously undergo fission and fusion to adapt to cellular metabolic demands. However, chronologically aged or bioenergetically compromised mitochondria leak electrons during oxidative phosphorylation, precipitating a pathological accumulation of reactive oxygen species (ROS), lipid peroxidation, and somatic DNA mutations. Left unchecked, this mitochondrial senescence drives cellular apoptosis, systemic inflammation, and organismal ageing. Fasting acts as a rigorous quality-control filter, initiating the clearance of these dysfunctional powerhouses via two primary, interconnected cascades: the PINK1-Parkin ubiquitin-dependent pathway and receptor-mediated pathways involving proteins such as BNIP3, NIX, and FUNDC1.

Under homeostatic conditions, PTEN-induced kinase 1 (PINK1) is imported into the inner mitochondrial membrane and degraded by mitochondrial processing peptidases. However, when a mitochondrion loses its membrane potential ($\Delta\psi_m$)—a hallmark of bioenergetic failure—PINK1 import is thwarted. PINK1 accumulates on the outer mitochondrial membrane (OMM), where it undergoes autophosphorylation and recruits the cytosolic E3 ubiquitin ligase, Parkin. Once translocated, Parkin is phosphorylated and activated by PINK1, creating a feed-forward amplification loop. Parkin polyubiquitinates numerous OMM proteins, marking the organelle for recognition by selective autophagy receptors such as p62, NDP52, and OPTN. These receptors tether the doomed mitochondrion to nascent phagophores decorated with microtubule-associated protein 1 light chain 3 (LC3), isolating the organelle within a double-membrane autophagosome that subsequently fuses with acidic lysosomes for enzymatic degradation.

Simultaneously, transcriptional regulators like transcription factor EB (TFEB) translocate to the nucleus during fasting-induced nutrient deprivation, driving the expression of genes associated with both autophagy and lysosomal biogenesis. This clearing operation is not merely a subtractive process of cellular hygiene; it is fundamentally anabolic in its long-term physiological consequence. By purging the intracellular milieu of senescent mitochondria, the cell triggers peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1$\alpha$), the master regulator of mitochondrial biogenesis. Fresh, highly efficient mitochondria populate the cytosol, exhibiting optimised cristae architecture, enhanced ATP production, and attenuated oxidative stress. As documented in peer-reviewed literature indexed in PubMed, this cyclical clearing and renewal protocol—harnessing evolutionary fasting paradigms—fundamentally resets cellular metabolic flexibility, preserves tissue homeostasis, and underpins the systemic longevity observed across diverse eukaryotic models.

Mechanisms at the Cellular Level

At the core of nutritional deprivation lies a sophisticated intracellular sorting network that orchestrates metabolic recalibration. When exogenous nutrient flux ceases during fasting, cytosolic amino acid pools contract and circulating insulin titres drop precipitously. This biochemical signature removes the tonic suppression exerted on the master metabolic regulator, mammalian target of rapamycin complex 1 (mTORC1), while concurrently activating AMP-activated protein kinase (AMPK) due to a shifting cellular ATP-to-AMP ratio. This dual-axis signaling switch—mTORC1 inhibition coupled with AMPK hyperactivation—initiates the transcriptional and post-translational cascades required for selective mitochondrial quality control, or mitophagy.

AMPK directly phosphorylates Unc-51 like autophagy activating kinase 1 (ULK1) at specific serine residues, triggering its activation and subsequent translocation to the pre-autophagosomal structure. Simultaneously, the transcriptional factor EB (TFEB) undergoes dephosphorylation via calcium-dependent calcineurin signaling, permitting its nuclear translocation. TFEB upregulates a coordinated network of genes associated with lysosomal biogenesis and autophagy (the CLEAR network), effectively expanding the cell's degradative capacity.

To achieve organelle specificity, compromised mitochondria must be flagged for elimination. Under homeostatic conditions, PTEN-induced kinase 1 (PINK1) is imported into the inner mitochondrial membrane where it is cleaved by PARL protease and degraded. However, when a mitochondrion sustains oxidative damage and loses its transmembrane potential ($\Delta\Psi_m$), the protein import machinery stalls. PINK1 accumulates on the outer mitochondrial membrane (OMM), where it homodimerises and autophosphorylates. Activated PINK1 subsequently phosphorylates ubiquitin and the E3 ubiquitin ligase Parkin. This recruitment of cytosolic Parkin creates a feed-forward amplification loop, polyubiquitinating OMM proteins including voltage-dependent anion channels (VDACs) and translocases of the outer membrane.

These polyubiquitin chains are recognized by specialized autophagy receptors such as p62/SQSTM1, NDP52, and OPTN, which possess both ubiquitin-binding domains and LC3-interacting regions (LIRs). By bridging the tagged mitochondrion to nascent phagophores decorated with microtubule-associated protein 1 light chain 3 (LC3-II), these receptors facilitate the enclosure of the dysfunctional organelle within a double-membrane autophagosome. Recent clinical insights published in British metabolic literature emphasize that this targeted sequestration is not merely a catabolic salvage operation; it is a vital prerequisite for subsequent mitochondrial biogenesis.

Following autophagosome-lysosome fusion, acid hydrolases degrade the engulfed mitochondrial cargo, releasing constituent amino acids, fatty acids, and nucleosides back into the cytosol to fuel gluconeogenesis and sustain cellular energetics. Crucially, the clearance of oxidatively stressed mitochondria eliminates the primary intracellular source of reactive oxygen species (ROS). At INNERSTANDIN, we emphasize that this resetting of the mitochondrial network reduces baseline oxidative stress, mitigates somatic DNA damage, and relieves competitive pressure on the remaining healthy reticulum, thereby driving the metabolic resilience observed in prolonged nutritional intervention paradigms.

Environmental Threats and Biological Disruptors

The preservation of mitochondrial network integrity is perpetually contested by an array of exogenous xenobiotics, persistent organic pollutants, and lifestyle-induced stressors prevalent in modern industrialised environments. As documented extensively in toxicological literature indexed on PubMed, heavy metals such as cadmium and lead, along with agricultural pesticides like rotenone and paraquat, act as potent disruptors of oxidative phosphorylation. These xenobiotic agents directly inhibit complex I and III of the mitochondrial electron transport chain (ETC), resulting in an exponential surge of intracellular reactive oxygen species (ROS) and subsequent lipid peroxidation of the inner mitochondrial membrane. When unmitigated, this cascade induces the opening of the mitochondrial permeability transition pore (mPTP), cytochrome c release, and the apoptotic demise of the cell.

In the context of the UK population, urban particulate matter (PM2.5) and endocrine-disrupting chemicals found in plastics further exacerbate systemic mitochondrial dysfunction, chronic low-grade inflammation, and accelerated cellular senescence. To counteract this relentless accumulation of damaged organelles, the cell relies on PINK1-Parkin-mediated mitophagy—a selective form of macroautophagy designed to sequester and degrade dysfunctional mitochondria via lysosomal fusion. However, chronic exposure to environmental toxins impairs this endogenous quality-control machinery, overwhelming basal autophagic flux and leading to the intracellular aggregation of senescent, ROS-leaking mitochondria.

At INNERSTANDIN, our biological analysis reveals that intermittent nutritional deprivation and prolonged fasting protocols serve as evolutionary countermeasures against this toxic burden. Nutrient-sensing pathways, specifically the downregulation of Mechanistic Target of Rapamycin Complex 1 (mTORC1) and the concomitant activation of AMP-activated protein kinase (AMPK), reprogram the cellular landscape to upregulate transcriptional regulators such as Transcription Factor EB (TFEB) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1$\alpha$). This metabolic shift not only stimulates the clearance of environmentally damaged, depolarised mitochondria via enhanced autophagosomal biogenesis but also triggers robust mitochondrial biogenesis. Consequently, fasting re-establishes a pristine, highly efficient mitochondrial network capable of withstanding contemporary xenobiotic stress, thereby optimising bioenergetic output and extending healthspan.

The Cascade: From Exposure to Disease

At the molecular level, the transition from nutrient abundance to metabolic deprivation initiates a meticulously orchestrated signalling cascade that dictates cellular fate, mitochondrial network architecture, and systemic longevity. When exogenous nutrient availability ceases—whether through acute caloric restriction or sustained metabolic fasting—the intracellular milieu undergoes a rapid bioenergetic crisis characterised by a precipitous drop in the cytosolic ATP-to-AMP ratio. This bioenergetic fluctuation is instantly detected by AMP-activated protein kinase (AMPK), the primary cellular energy sensor, which undergoes conformational phosphorylation at Threonine 172. Concurrently, the suppression of the insulin/insulin-like growth factor 1 (IGF-1) signalling axis inactivates Mechanistic Target of Rapamycin Complex 1 (mTORC1), an inhibitory kinase that, under fed conditions, maintains autophagy and mitophagy in a state of tonic repression.

The simultaneous activation of AMPK and suppression of mTORC1 unleashes a dual-pronged regulatory assault that targets the initiation complexes of selective autophagy. AMPK directly phosphorylates Unc-51-like autophagy-activating kinase 1 (ULK1) at specific activating residues, including Serine 317 and Serine 777, while the relocation of inactivated mTORC1 from the lysosomal surface relieves the suppressive phosphorylation on ULK1. This enzymatic shift triggers the nucleation of the phagophore through the class III phosphatidylinositol 3-kinase (PI3K) complex, which includes Beclin-1, VPS34, and ATG14L.

In the context of mitochondrial maintenance, this systemic cascade converges upon the organellar network to purge dysfunctional, electron-leak-prone mitochondria that continuously generate high levels of cytotoxic reactive oxygen species (ROS). The primary mechanism driving this selective degradation relies on the PTEN-induced putative kinase 1 (PINK1) and Parkin (PRKN) pathway. In healthy mitochondria with a polarized inner membrane potential ($\Delta\psi_m$), the constitutively imported PINK1 is rapidly degraded by mitochondrial inner membrane proteases such as PARL. However, during fasting-induced metabolic stress or within bioenergetically compromised mitochondria exhibiting membrane depolarization, PINK1 import is arrested. Consequently, full-length PINK1 accumulates on the outer mitochondrial membrane (OMM), where it homodimerizes and autophosphorylates, subsequently phosphorylating both ubiquitin and existing OMM protein receptors at Serine 65.

This phosphorylation event acts as a molecular beacon, recruiting the cytosolic E3 ubiquitin ligase Parkin to the OMM and activating its latent catalytic activity. Parkin hyperubiquitinates a multitude of OMM substrates, creating poly-ubiquitin chains that are subsequently phosphorylated by PINK1 to establish a feed-forward amplification loop. These phosphorylated ubiquitin chains exhibit high binding affinity for downstream autophagy receptors, including NDP52, OPTN (optineurin), p62, and TAX1BP1. These receptors tether the dysfunctional mitochondrion to LC3-decorated phagophore membranes, ensuring precise envelopment within a specialized autophagosome—termed a mitophagosome.

Following closure, the mitophagosome fuses with the acidic lysosomal compartment, where resident hydrolases degrade the organellar constituents down to their constituent amino acids, lipids, and nucleic acids. These macromolecular building blocks are subsequently recycled back into the cytosol via permeases to sustain essential metabolic pathways during nutrient deprivation. Beyond clearing cellular debris, this fasting-induced mitophagic flux serves as a quality-control bottleneck. By eliminating senescent mitochondria that leak electrons and trigger chronic sterile inflammation via the release of mitochondrial DNA (mtDNA) into the cytosol—where it activates the cGAS-STING inflammatory pathway—mitophagy curtails inflammageing.

Clinical investigations and epidemiological frameworks often monitored via cohorts in the UK, such as the UK Biobank, increasingly correlate enhanced autophagic and mitophagic capacity with attenuated incidence of neurodegenerative phenotypes, insulin resistance, and cardiovascular decline. As established in landmark translational studies published in The Lancet and primary literature catalogued on PubMed, upregulating this cascade restores metabolic flexibility, preserves stem cell niches, and optimizes mitochondrial mass across post-mitotic tissues. At INNERSTANDIN, our rigorous interrogation of these pathways confirms that fasting is not merely a passive withholding of nutrients, but an evolutionarily conserved, highly active biomedical intervention capable of engineering cellular rejuvenation from the organelle upward.

What the Mainstream Narrative Omits

To truly INNERSTANDIN the true physiological implications of nutrient deprivation on human longevity, one must first dismantle the reductionist wellness narrative propagated by mainstream media. Popular discourse frequently reduces fasting-induced mitochondrial turnover to a superficial detoxification protocol or a simplistic weight-loss mechanism. However, contemporary molecular biology reveals a far more intricate, evolutionarily conserved cascade that fundamentally reorganises cellular bioenergetics. Current literature indexed in peer-reviewed repositories such as PubMed demonstrates that mainstream summaries routinely overlook the nuanced interplay between outer mitochondrial membrane receptor dynamics, ubiquitin-proteasome system priming, and the precise temporal kinetics required to trigger selective macro-autophagy of dysfunctional organelles.

When the human organism transitions from the post-absorptive state into sustained caloric restriction, the drop in circulating insulin and the concurrent surge in the AMP-activated protein kinase (AMPK) pathway do more than merely inhibit mTORC1. Mainstream articles often omit the critical upstream signalling events, such as the spatial-temporal recruitment of cytosolic proteins to the mitochondrial surface. Specifically, the activation of PINK1 (PTEN-induced kinase 1) and its subsequent phosphorylation of both ubiquitin and the E3 ubiquitin ligase Parkin represent a biochemical switchboard that the popular press completely ignores. In a healthy, polarised mitochondrion, PINK1 is imported into the inner membrane and continuously degraded by mitochondrial matrix processing peptidases. It is only during sustained nutrient deprivation, when mitochondrial membrane potential depolarises, that PINK1 accumulates on the outer mitochondrial membrane. This molecular triage—whereby the cell marks its own failing energy generators for targeted lysosomal degradation—requires an integrated metabolic shift that cannot be replicated by short-term caloric restriction alone.

Furthermore, public health bodies and commercial dietary guides frequently fail to contextualise these mechanisms within human evolutionary biology, overlooking the necessity of cyclical energy deprivation for optimal mitochondrial network remodelling. Research published in high-impact British and international journals emphasises that continuous feeding patterns lead to chronic accumulation of reactive oxygen species (ROS) and somatic mitochondrial DNA mutations. Without the metabolic pause induced by fasting, the cell’s quality control machinery—comprising not only mitophagy, but also mitochondrial fission, fusion, and biogenesis mediated by PGC-1α—becomes functionally blunted. By omitting these granular, mechanistic realities, the mainstream narrative denies individuals the deep biological comprehension required to harness fasting as a precise instrument for cellular preservation. At INNERSTANDIN, we cut through this superficial layer, exposing the rigorous biochemical reality that true longevity is forged through the systematic, evolutionarily demanded purge of our oldest, most oxidatively stressed cellular components.

The UK Context

Examining the metabolic implications of nutrient deprivation within the United Kingdom reveals a stark paradox: while our clinical research institutions—such as the Medical Research Council (MRC) Toxicology Unit in Leicester and the University of Oxford’s Nuffield Department of Medicine—are at the global vanguard of autophagy research, the nation’s systemic health profile is characterized by chronic over-nutrition and metabolic dysfunction. Contemporary epidemiological data published in The Lancet underscore an escalating burden of type 2 diabetes, non-alcoholic fatty liver disease (NAFLD), and age-related neurodegeneration across the British populace. These pathologies share a common cellular etiology: the progressive accumulation of dysfunctional, electron-leaking mitochondria that drive oxidative stress and chronic, low-grade systemic inflammation, termed "inflammageing."

At the molecular level, intermittent fasting and caloric restriction protocols serve as evolutionary triggers to counteract this bioenergetic decline. When exogenous glucose and amino acid availability plummets, intracellular ATP-to-AMP ratios shift, activating AMP-activated protein kinase (AMPK) while concurrently suppressing the mechanistic target of rapamycin complex 1 (mTORC1). As established in seminal mechanistic studies indexed on PubMed, this dual enzymatic shift disinhibits the Unc-51 like autophagy activating kinase 1 (ULK1) initiation complex. Consequently, this cascades into the transcriptional upregulation of PINK1 (PTEN-induced kinase 1) and Parkin-dependent pathways, selectively targeting and sequestering senescent mitochondria into autophagosomes for lysosomal degradation.

For the UK population, integrating targeted fasting paradigms offers a potent, non-pharmacological countermeasure to the mitochondrial decay accelerated by sedentary lifestyles and ultra-processed diets. By facilitating dynamic mitochondrial turnover—or mitophagy—fasting purges the cellular reticulum of reactive oxygen species (ROS)-generating organelles and promotes robust mitochondrial biogenesis via peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1$\alpha$) upregulation. Here at INNERSTANDIN, we emphasize that unlocking human longevity requires looking past superficial dietary trends and examining the fundamental evolutionary biology of nutrient sensing. Restoring mitochondrial network integrity through strategic metabolic fasting is not merely a weight-management strategy; it is an absolute biological prerequisite for systemic cellular rejuvenation and healthspan extension within the modern British demographic.

Protective Measures and Recovery Protocols

While nutrient deprivation and the subsequent upregulation of adenosine monophosphate-activated protein kinase (AMPK) pathways are critical for initiating targeted mitochondrial degradation, metabolic restoration requires precise nutritional orchestration. Unmitigated, prolonged caloric restriction can precipitate excessive atrophy, undermining the very cellular resilience it seeks to forge. Within the rigorous framework of INNERSTANDIN, we must examine the physiological architecture governing the transition from catabolic clearance to anabolic recovery. Recovery protocols must be engineered to replenish ATP reserves, stimulate mitochondrial biogenesis via peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1$\alpha$), and prevent the pathological accumulation of reactive oxygen species (ROS) during re-feeding phases.

Evidence indexed in databases such as PubMed demonstrates that the re-introduction of specific macronutrients acts as a molecular switch. Upon terminating a fasting protocol, cellular vulnerability to oxidative stress is temporarily heightened due to the sudden influx of substrates into a newly streamlined, highly efficient mitochondrial network. To mitigate lipid peroxidation and preserve the newly synthesized mitochondrial proteome, strategic nutrient deployment is paramount. Micronutrients serving as essential cofactors for the tricarboxylic acid (TCA) cycle—such as magnesium, nicotinamide adenine dinucleotide (NAD+) precursors, and specific polyphenol adjuvants—must be prioritised to stabilise electron transport chain (ETC) complexes I through V. Furthermore, the timing of protein ingestion is crucial; leucine-rich profiles are required to transiently activate the mechanistic target of rapamycin complex 1 (mTORC1), driving ribosomal biogenesis and structural protein synthesis without triggering the aberrant suppression of baseline basal autophagy.

At a systemic level, clinical investigations highlighted in publications such as The Lancet underscore the importance of cyclical hormesis. Chronic catabolism without structural consolidation leads to functional exhaustion. Therefore, recovery phases must incorporate targeted thermogenic and kinetic stimuli that synergise with elevated PGC-1$\alpha$ expression, effectively locking in the metabolic gains achieved during the fasting window. By modulating the insulin-to-glucagon ratio judiciously during the recovery phase, the biological system maximises mitochondrial mass optimisation while simultaneously upregulating endogenous antioxidant defences, primarily through the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. This cyclical oscillation between targeted degradation and precision recovery represents the gold standard of cellular longevity protocols, ensuring that mitochondrial networks remain both exceptionally dense and structurally pristine.

Summary: Key Takeaways

Fasting-induced mitophagy represents a cornerstone of cellular homeostasis, directly challenging the paradigm of passive cellular ageing. As robustly documented in translational literature via PubMed-indexed journals such as Cell Metabolism and Nature Reviews Molecular Cell Biology, nutrient deprivation orchestrates a sophisticated intracellular clearance cascade. By downregulating the mechanistic target of rapamycin (mTOR) pathway and reciprocally upregulating 5'-adenosine monophosphate-activated protein kinase (AMPK), fasting initiates the precise transcriptional upregulation of Unc-51 like autophagy activating kinase 1 (ULK1). Concurrently, metabolic shifts trigger the PINK1-Parkin axis, wherein phosphatase and tensin homolog-induced kinase 1 (PINK1) accumulates on the outer mitochondrial membrane of depolarised, dysfunctional organelles, recruiting the E3 ubiquitin ligase Parkin to selectively target them for autophagosomal encapsulation.

At INNERSTANDIN, our synthesis of these molecular pathways demonstrates that this selective elimination is not merely a catabolic breakdown, but a bioenergetic revitalisation process. The systematic purging of reactive oxygen species (ROS)-generating, electron-transport-chain-compromised mitochondria forces a compensatory shift toward enhanced biogenesis, governed by peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1$\alpha$). This dual mechanism—clearing damaged reticulum while optimising overall mitochondrial density—underpins systemic metabolic resilience. Aligning with public health priorities across the UK, where age-related metabolic dysfunctions impose profound burdens on healthcare infrastructure, leveraging these fasting-mediated pathways offers an evidence-led, physiologically congruent intervention to mitigate cellular senescence, preserve mitochondrial integrity, and extend healthspan at the molecular level.