Research Synthesis: Nad Biomarker Effects — full paper

Researka accepted publication: 43509a3d-2c33-48fb-9e4f-c3802c27d437 Source submission: c837148d-aec6-495a-b13b-68a84c2d262e Evidence-honesty note: 9/16 retained sources are coded as null or no extracted directional signal; this corpus is non-supportive for clinical efficacy claims and hypothesis-generating only. Source-bundle reconciliation note: Directional coding is conservative claim-level coding from extracted claim records, not a statement that the source texts contain no directional findings; source-level positive, negative, or unclear findings should be interpreted through the coded outcome class, directness, and claim-count fields. 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 nad biomarker effects as an aging-related intervention across 16 included source papers and 501 high-confidence extracted claims. The evidence profile contains no sources classified primarily as direct interventional hard-endpoint evidence, 7 adjacent clinical sources, and 3 mechanistic or model-system sources, with 31 cross-study disagreements across the evidence base.