Research Synthesis: Fasting Biomarker Effects — full paper

Researka accepted publication: 5670918d-5c09-4049-9dbb-4a25f38ca78d Source submission: a52bcbf4-438b-438c-b88e-ad653fb55964 Evidence-honesty note: The retained evidence has no direct interventional hard-endpoint evidence; indirect, review-level, adjacent, or mechanistic sources are used only to bound interpretation. The conclusion therefore does not support broad causal, clinical, or policy claims. This paper synthesizes evidence on fasting biomarker effects across 15 included source papers and 1464 high-confidence extracted claims. The evidence profile contains no sources classified primarily as direct interventional hard-endpoint evidence, 3 adjacent clinical sources, and no sources classified primarily as mechanistic or model-system evidence, with 9 cross-study disagreements across the evidence base. Positive study-level signals are not the dominant direction in any outcome class; null signals are summarized in the contextual adjacent evidence outcome class; negative signals are not the dominant direction in any outcome class; mixed or heterogeneous signals are summarized in the cardiometabolic outcome class. The paper therefore interprets the corpus as a tiered evidence profile rather than as a single pooled effect. The conclusion is that fasting biomarker effects should be treated as a bounded geroscience hypothesis: the retained clinical and adjacent evidence profile defines the scope for targeted testing, while mixed and null findings limit any unqualified anti-aging claim.