Hypothesis

Core idea: Routine use of common analgesics (NSAIDs, acetaminophen) during intermittent metabolic stressors such as fasting or exercise inhibits the neuronal TRPV1‑Ca2+‑AMPK axis that normally drives autophagy and HSP70 induction, thereby converting a hormetic signal into a blank.

Mechanistic rationale: Transient stressors activate sensory neurons expressing TRPV1, leading to calcium influx, AMPK activation, and downstream upregulation of Beclin‑1, LC3‑II and HSP70 via HSF1 2, 3. Analgesics that blunt neuronal excitability—particularly NSAIDs that reduce prostaglandin‑sensitization of TRPV1 and acetaminophen that modulates serotonergic tone—can diminish this calcium signal without affecting peripheral metabolic changes 4. Consequently, the cellular repair program is inadequately engaged despite intact nutrient deprivation.

Testable predictions:

1. Mice undergoing a 24‑hour fast will show a ~2‑fold increase in hepatic LC3‑II/I ratio and HSP70 expression; pretreatment with ibuprofen (10 mg/kg) or acetaminophen (5 mg/kg) will reduce these markers by ≥40 % while leaving plasma β‑hydroxybutyrate unchanged.
2. In humans, a crossover trial where participants consume a 16‑hour fast with or without a single dose of naproxen will exhibit lower circulating LC3‑II‑positive extracellular vesicles and reduced phospho‑AMPK in peripheral blood mononuclear cells.
3. Genetic ablation of TRPV1 in sensory neurons will phenocopy the analgesic effect, confirming neuronal specificity.

Falsifiability: If analgesic administration fails to alter autophagy or stress‑protein markers despite verified target engagement (e.g., reduced prostaglandin levels), the hypothesis is refuted. Conversely, a rescue experiment where optogenetic activation of TRPV1‑expressing neurons restores autophagy in the presence of NSAIDs would support the mechanistic link.

Broader implication: This reframes analgesic use not merely as pain suppression but as a potential modulator of hormetic signaling, suggesting that timing and dosage relative to stressors could determine whether these drugs accelerate or decelerate biological aging.

Potential confounders: Changes in gut microbiota or systemic inflammation induced by analgesics could independently affect autophagy; therefore, experiments should include germ‑free or antibiotic‑treated controls to isolate neuronal effects.

Alternative pathways: While the TRPV1‑AMPK axis is a primary focus, analgesics may also influence mitochondrial ROS production or NAD+ levels, which intersect with sirtuin‑dependent stress responses; future work could probe these nodes to assess compensatory mechanisms.

By linking a well‑characterized neuronal pain pathway to the effector machinery of hormesis, this hypothesis offers a concrete, falsifiable framework for evaluating whether the widespread pharmacological quieting of discomfort inadvertently undermines a conserved longevity signal.