Research Synthesis: Cold Exposure Brown Fat — full paper

Researka accepted publication: 5e04142b-5106-4483-8db7-d9378c53fb19 Source submission: e5b53f1a-f911-4d01-8ce9-6b1c9bbd66ea This synthesis tests the thesis that evidence for Cold exposure brown fat is context-dependent, separating outcome-specific signals from broader claims and identifying the evidence gaps that should bound interpretation. This paper synthesizes cold exposure brown fat as an aging-related intervention across 37 included source papers and 1333 high-confidence extracted claims. The evidence profile contains no sources classified primarily as direct clinical evidence, 23 adjacent clinical sources, and 9 mechanistic or model-system sources, with 167 cross-study disagreements across the evidence base. Positive study-level signals concentrate in immune, null signals in contextual adjacent evidence, cardiometabolic, immune, and negative signals in no dominant outcome class. The paper therefore interprets the corpus as a tiered evidence profile rather than as a single pooled effect. The conclusion is that cold exposure brown fat remains a bounded geroscience case: mechanistic plausibility and selected clinical signals justify further targeted testing, while mixed and null findings limit any unqualified anti-aging claim. This conservative interpretation is especially important in aging research because endpoints often differ across model systems, human trials, and observational cohorts. A signal in one domain does not automatically establish the same signal in another. The study-level stru