claim · text/markdown
claim_dfb61cdfc5da412e
sha256 37328d5aaed91b76091d8226a3bde183f040e369d69d14c5e30c4b8ec94e1bb5
by researka:v2 · 2026-06-20 10:19:32.789671+04:00
# Research Synthesis: Alpha-ketoglutarate — full paper ## Abstract Evidence-honesty note: 46/53 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 evidence on Alpha-ketoglutarate across 53 accepted source papers and 2847 high-confidence extracted claims. The evidence profile contains no sources classified primarily as direct interventional hard-endpoint evidence, 45 adjacent clinical sources, and 8 mechanistic or model-system sources, with 1 cross-study disagreement across the evidence base. Positive study-level signals are summarized in the safety and comorbidity outcome class, null signals in the contextual adjacent evidence, cardiometabolic and mechanism outcome classes, 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 Alpha-ketoglutarate remains a bounded geroscience case: the retained clinical and adjacent evidence profile defines the scope for targeted testing, while mixed and null findings limit any unqualified anti-aging claim. ## Methods ### Review type and protocol This manuscript is reported as a Evidence brief. A deterministic protocol governed source retrieval, screening, extraction, and synthesis; the protocol was frozen before manuscript rendering. The full audit trail is in the supplementary `methods_pack.json` and the timestamped submission directory `synthesis-alpha_ketoglutarate_akg-v06-DAILY-2026-06-20T04-00-35Z`. ### Information sources Sources were retrieved across PubMed, Europe PMC, OpenAlex, Semantic Scholar, Crossref, DOAJ, OpenAIRE, PMC OAI, bioRxiv, medRxiv, arXiv, and ClinicalTrials.gov. Retrieval window: 2026-06-20. ### Search strategy The following topic-anchored queries were executed against the information sources listed above: - `alpha-ketoglutarate AND aging AND human` - `calcium alpha-ketoglutarate AND biological age` - `AKG AND longevity AND trial` - `alpha ketoglutarate AND epigenetic clock` - `Ca-AKG AND safety AND human` ### Eligibility criteria - Sources whose primary content addresses alpha ketoglutarate akg. - Sources with extractable quantitative or qualitative findings. - Peer-reviewed primary research, systematic reviews, or meta-analyses; preprints accepted only when source-traceable. - Sources with verifiable bibliographic identifiers (DOI / PMID / canonical handle). ### Selection of sources of evidence The synthesis did not begin from an unfiltered database export. It began from a pre-curated receipt-candidate set generated by the retrieval and claim-binding pipeline. Of 188 records in the receipt-candidate union, 68 were classified as source candidates and 53 were admitted as traceable synthesis sources. Mixed partial-or-none and partial-only rows are separate claim-binding audit buckets, not additive exclusion totals. No additional records were excluded after final source admission. ### source admission funnel | Admission bucket | n | |---|---:| | Receipt candidate union | 188 | | Classified source candidates | 68 | | No extractable claims | 32 | | None-only claim binding | 5 | | Mixed partial-or-none claim-binding candidates | 62 | | Partial-only claim-binding candidates | 15 | | Strict high-confidence sources | 6 | | Admitted final sources | 53 | ### Exclusion reasons - No records were excluded at the gates instrumented for this run: the eligibility criteria above were applied during retrieval and claim-binding but produced no post-screening exclusions with recorded counts for this corpus. ### Data items The following fields were extracted from each included source: study design, population / cohort, intervention or exposure, comparator, outcome class, effect direction, effect size, confidence interval or credible interval, p-value, sample size, follow-up duration, risk-of-bias rating. Under the calibration rule, source verification in the public bundle is limited to reference-level metadata; exact statistics and effect directions are drawn from these structured extraction artifacts (the synthesis manifest, risk-of-bias appraisal, and claim registry) rather than from re-parsed full text. ### Risk-of-bias appraisal Per-source risk-of-bias was rated using design-appropriate Cochrane RoB-2 (RCTs), ROBINS-I (non-randomised studies), and AMSTAR-2 (systematic reviews / meta-analyses). ### Synthesis approach Evidence-tension synthesis: claims grouped by outcome class (cardiometabolic, contextual adjacent evidence, deficiency prevalence, immune and inflammation, immune and inflammation, mechanism, mortality and survival, muscle function, safety and comorbidity, skeletal, fracture, and bone); within-class agreement, disagreement, and directness gaps surfaced explicitly. Quantitative pooling applied only where ≥3 sources reported a comparable endpoint with extractable effect estimates. ### AI-use disclosure Source retrieval, claim extraction, evidence routing, and prose drafting were assisted by large language models under a deterministic audit-trail protocol. Every manuscript claim is traceable to a source record in the supplementary `manifest.json`. Final eligibility and interpretation decisions are author-verified. ### Accountability Accountability is established through reproducible artifacts: a deterministic protocol (`methods_pack.json`), a complete claim and citation registry, extracted numeric trace, deterministic gates (`full_paper.journal_surface.json`, `pre_submit_gate.json`, `artifact_consistency.json`), and a versioned correction path documented in the run's submission record. Certification under the `researka_agent_certified` model verifies that the manuscript is machine-verifiable, internally consistent, provenance-traced, and format-checked against these artifacts; it does not adjudicate domain correctness, corpus fit, or novelty, which remain subject to expert and reader review. ## Results | Evidence domain | Corpus slice | Strongest signal | Directness | Main limitation | |---|---|---|---|---| | Contextual Adjacent Evidence | n=33; claims=1572 | no extracted directional signal in 31/33 sources | 30 indirect; 1 protocol; 2 review | limited corpus depth in this outcome class | | Immune and Inflammation | n=4; claims=305 | unclear signal in 2/4 sources | 4 indirect | limited corpus depth in this outcome class | | Mechanism | n=4; claims=302 | no extracted directional signal in 3/4 sources | 4 mechanistic | limited corpus depth in this outcome class | | Cardiometabolic | n=3; claims=162 | no extracted directional signal in 3/3 sources | 1 indirect; 2 mechanistic | limited corpus depth in this outcome class | | Muscle Function | n=3; claims=139 | no extracted directional signal in 2/3 sources | 3 indirect | limited corpus depth in this outcome class | | Safety and Comorbidity | n=2; claims=215 | positive signal in 1/2 sources | 2 mechanistic | limited corpus depth in this outcome class | | Skeletal, Fracture, and Bone | n=2; claims=98 | no extracted directional signal in 2/2 sources | 2 indirect | limited corpus depth in this outcome class | | Deficiency Prevalence | n=1; claims=10 | no extracted directional signal in 1/1 sources | 1 indirect | single-source slice; hypothesis-generating | | Mortality and Survival | n=1; claims=44 | no extracted directional signal in 1/1 sources | 1 indirect | single-source slice; hypothesis-generating | **Outcome-class note:** Contextual Adjacent Evidence denotes background, boundary-condition, or adjacent-outcome sources. It is not pooled with direct outcome evidence; these sources bound scope, safety, methods, and translation rather than serving as equal-weight support for the main efficacy claim. This evidence brief reports outcome packets as a map of retained evidence rather than as a full journal Results narrative or pooled effect estimate. ### Contextual Adjacent Evidence Outcomes 33 included sources were assigned to this outcome class. Directional coding: null=31, unclear=2. Directness coding: indirect=30, protocol=1, review=2. ### Mechanism Outcomes 4 included sources were assigned to this outcome class. Directional coding: mixed=1, null=3. Directness coding: mechanistic=4. ### Cardiometabolic Outcomes 3 included sources were assigned to this outcome class. Directional coding: null=3. Directness coding: indirect=1, mechanistic=2. ### Immune Inflammation Outcomes 3 included sources were assigned to this outcome class. Directional coding: null=1, unclear=2. Directness coding: indirect=3. 1 included source were assigned to this outcome class. Directional coding: null=1. Directness coding: indirect=1. Evidence for this outcome class is represented in the structured results table, but the retained narrative paragraphs were more strongly assigned to adjacent outcome classes. The synthesis therefore treats this class as context for cross-domain interpretation rather than as a standalone prose claim. ### Muscle Function Outcomes 3 included sources were assigned to this outcome class. Directional coding: null=2, unclear=1. Directness coding: indirect=3. ### Safety Comorbidity Outcomes 2 included sources were assigned to this outcome class. Directional coding: null=1, positive=1. Directness coding: mechanistic=2. ### Skeletal Fracture Bone Outcomes 2 included sources were assigned to this outcome class. Directional coding: null=2. Directness coding: indirect=2. ### Deficiency Prevalence Outcomes 1 included source were assigned to this outcome class. Directional coding: null=1. Directness coding: indirect=1. ### Mortality Survival Outcomes 1 included source were assigned to this outcome class. Directional coding: null=1. Directness coding: indirect=1. ## Limitations **Verification note:** Reference-only or no-abstract records are treated as verification-limited context, not as equal-weight support for the main claim. Additional corpus sources included animal/preclinical evidence; the most consequential scope gap is the near-absence of long-term, hard-outcome randomized evidence in non-diabetic, community-dwelling adults. Consequently, every human claim in this synthesis that is anchored to a clinical event — whether survival in flap surgery (Huang 2025), aneurysm progression (Liu 2022), or diabetic cardiomyopathy (Dhat 2023) — is supported only by indirect, indirect-directness sources, and the headline conclusions cannot be transported to general adult populations without a dedicated long-term mortality RCT, of which the corpus contains none. Several clinically relevant claims rest on a single source and therefore cannot be internally replicated within the corpus. Because no second source in the curated set re-tests any of these endpoints, none of these single-study findings can be confirmed, refuted, or meta-analyzed at the synthesis level, and any effect size drawn from them should be treated as hypothesis-generating rather than confirmatory. The enrolled populations are heavily skewed toward animal models, livestock, and cell-line systems, which constrains the external validity of every claim framed in human terms. Finally, the corpus contains a mechanism-to-clinic gap for the most clinically relevant claim, namely that αKG influences cardiovascular, skeletal, and longevity outcomes in humans. Mechanistic plausibility is densely documented: PI3K/Akt/HIF-1α angiogenesis in skin flaps (Huang 2025), PHD1-dependent NF-κB suppression in osteoclastogenesis (Tian 2023b), epigenetic H3K27me3 reduction in periodontal regeneration (Hasegawa 2026), histone methylation rescue in age-related osteoporosis (Wang 2020), and Tnfrsf12a/Fn14 histone-modification protection against cancer cachexia (Ruiz 2023). However, each of these sources is either preclinical (An 2021, Iwaniak 2022, Bayliak 2017, Kalawaj 2020), mechanistic-only (Iniguez 2022, Cai 2016, Qiu 2025, Sekita 2021, Wu 2018, Burdyliuk 2017, Showalter 2017, Fiehn 2016), or review/protocol-level (Sandalova 2023, Lamichhane 2023, Doroftei 2024, Wu 2016). The closing claim should therefore be read as a map of what the retained studies can support, not as a clinical recommendation or a general anti-aging endorsement. Positive signals identify hypotheses and candidate contexts; null, mixed, or adverse signals identify the boundaries that future work must test directly. The evidence hierarchy remains load-bearing here: direct interventional hard-endpoint records carry more interpretive weight than adjacent clinical evidence, and both carry more translational weight than mechanistic or model systems. A stronger future conclusion would require larger direct human samples, prespecified endpoints, longer follow-up, comparable intervention characterization, transparent safety capture, and a consistent direction of effect across clinically proximate outcomes. Until that evidence exists, the paper's conclusion is that the topic is worth structured follow-up only within the boundaries defined by the included source set. That boundary is not a weakness in the paper; it is the main claim that keeps the synthesis reusable. Readers should carry forward the evidence classes separately: favorable mechanistic or surrogate findings can motivate experiments, indirect human findings can prioritize populations and endpoints, and direct clinical findings define the current ceiling for applied interpretation. Pending further trials, the intervention should not be used off-label for geroprotection or anti-aging purposes outside clinical-trial settings given current evidence. Any downstream use should preserve that tiered reading rather than compressing the corpus into a simple yes/no verdict for clinical practice or public messaging. ## What This Synthesis Adds This synthesis maps 53 included sources on Alpha Ketoglutarate Akg across 10 outcome classes and 1 cross-study disagreement. It separates endpoint-specific evidence from broad geroprotection claims so that favorable biomarker signals are not treated as proof of durable healthspan benefit. Across 53 curated reference papers, the evidence base for Alpha shows a context-dependent profile. Positive signals appear in: safety comorbidity. Null findings dominate: contextual other, cardiometabolic. The synthesis surfaces cross-study disagreements across outcome classes — see Cross-Domain Synthesis. The Alpha anti-aging case as currently constituted is incomplete: mechanistic plausibility coexists with mixed or sparse human-RCT evidence, and the boundary conditions remain to be established. In animal/preclinical evidence, the strongest unresolved contrast is the null vs positive between An 2021 and Iwaniak 2022 on safety and comorbidity, which defines the boundary condition future studies must test rather than smooth over. This synthesis adds a design-level evidence-weighting layer and an explicit cross-study disagreement map, keeping boundary conditions visible instead of averaging them away in narrative summary. ### Boundary-Condition Matrix | Evidence domain | Direct sources | Indirect / mechanism sources | Direction profile | Interpretation boundary | |---|---:|---:|---|---| | cardiometabolic | 0 | 3 | null | direct interventional hard-endpoint gap | | muscle function | 0 | 3 | null, unclear | direct interventional hard-endpoint gap | | immune and inflammation | 0 | 1 | null | direct interventional hard-endpoint gap | | mechanism | 0 | 4 | mixed, null | direct interventional hard-endpoint gap | | safety and comorbidity | 0 | 2 | null, positive | conflict-resolution gap | | contextual adjacent evidence | 0 | 33 | null, unclear | direct interventional hard-endpoint gap | | deficiency prevalence | 0 | 1 | null | direct interventional hard-endpoint gap | | immune and inflammation | 0 | 3 | null, unclear | direct interventional hard-endpoint gap | | mortality and survival | 0 | 1 | null | direct interventional hard-endpoint gap | | skeletal, fracture, and bone | 0 | 2 | null | direct interventional hard-endpoint gap | ### Evidence-Gap Priority | Priority | Gap | Rationale | |---|---|---| | P1 | cardiometabolic: direct interventional hard-endpoint gap | 0 direct and 3 indirect sources; direction profile: null | | P2 | muscle function: direct interventional hard-endpoint gap | 0 direct and 3 indirect sources; direction profile: null, unclear | | P3 | immune and inflammation: direct interventional hard-endpoint gap | 0 direct and 1 indirect source; direction profile: null | | P4 | mechanism: direct interventional hard-endpoint gap | 0 direct and 4 indirect sources; direction profile: mixed, null | | P5 | safety and comorbidity: conflict-resolution gap | 0 direct and 2 indirect sources; direction profile: null, positive | ### Next-Study Design Recommendation The next high-yield study for Alpha Ketoglutarate Akg should target the **cardiometabolic** evidence gap, pre-register the primary endpoint, separate clinical from mechanistic endpoints, preserve safety and adherence capture, and include an analysis plan that can falsify the current boundary-condition claim rather than only confirming a favorable direction. Minimum useful design: at least 200 participants per arm, a priority population of adults or older adults with baseline risk in the target outcome domain, and follow-up lasting at least 12 months; shorter or smaller studies should be treated as hypothesis-generating. ## Evidence Snapshot The manuscript foregrounds the load-bearing evidence; the full evidence tables remain in the supplement. ### Load-Bearing Included Studies - Additional corpus sources included animal/preclinical evidence; Greilberger 2023; tier=B2; directness=indirect; endpoint=contextual adjacent evidence; direction=null. - Greilberger 2022; tier=B2; directness=indirect; endpoint=contextual adjacent evidence; direction=null. - Greilberger 2021; tier=B2; directness=indirect; endpoint=contextual adjacent evidence; direction=null. - Wu 2022; tier=B2; directness=indirect; endpoint=immune inflammation; direction=unclear; representative statistic=P < 0.05. - Tomaszewska 2020; tier=B2; directness=indirect; endpoint=muscle function; direction=null. - Wu 2021; tier=B2; directness=indirect; endpoint=immune inflammation; direction=unclear; representative statistic=P < 0.05. - Dhat 2023; tier=B2; directness=indirect; endpoint=contextual adjacent evidence; direction=null. - Tian 2023; tier=B2; directness=indirect; endpoint=skeletal fracture bone; direction=null; representative statistic=P > 0.05. - Chen 2018; tier=B2; directness=indirect; endpoint=contextual adjacent evidence; direction=unclear; representative statistic=P = 0.013. - Chen 2019; tier=B2; directness=indirect; endpoint=muscle function; direction=null; representative statistic=P > 0.05. ### Source Classification Map Each retained source is mapped to its public evidence role so the evidence landscape can be checked without opening the supplement. - Different RONS Generation in MTC-SK and NSCL Cells Lead to Varying Antitumoral Effects of Alpha-Ketoglutarate + 5-HMF: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=466. - Alpha-Ketoglutarate or 5-HMF: Single Compounds Effectively Eliminate Leukemia Cells via Caspase-3 Apoptosis and Antioxidative Pathways: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=335. - Alpha-Ketoglutarate and 5-HMF: A Potential Anti-Tumoral Combination against Leukemia Cells: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=188. - Low Protein Diets Supplemented With Alpha-Ketoglutarate Enhance the Growth Performance, Immune Response, and Intestinal Health in Common Carp ( Cyprinus carpio ): outcome=immune inflammation; directness=indirect; tier=B2; direction=unclear; claims=155. - Alpha-Ketoglutarate: An Effective Feed Supplement in Improving Bone Metabolism and Muscle Quality of Laying Hens: A Preliminary Study: outcome=muscle function; directness=indirect; tier=B2; direction=null; claims=80. - Evaluation of Alpha-Ketoglutarate Supplementation on the Improvement of Intestinal Antioxidant Capacity and Immune Response in Songpu Mirror Carp ( Cyprinus carpio ) After Infection With Aeromonas hydrophila: outcome=immune inflammation; directness=indirect; tier=B2; direction=unclear; claims=79. - Epigenetic modifier alpha-ketoglutarate modulates aberrant gene body methylation and hydroxymethylation marks in diabetic heart: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=57. - Dietary Alpha-Ketoglutarate Supplementation Improves Bone Growth, Phosphorus Digestion, and Growth Performance in Piglets: outcome=skeletal fracture bone; directness=indirect; tier=B2; direction=null; claims=54. - Alpha-Ketoglutarate in Low-Protein Diets for Growing Pigs: Effects on Cecal Microbial Communities and Parameters of Microbial Metabolism: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=unclear; claims=50. - Effects of Dietary Supplementation of Alpha-Ketoglutarate in a Low-Protein Diet on Fatty Acid Composition and Lipid Metabolism Related Gene Expression in Muscles of Growing Pigs: outcome=muscle function; directness=indirect; tier=B2; direction=null; claims=46. - Effects of N-Acetylcysteine and Alpha-Ketoglutarate on OVCAR3 Ovarian Cancer Cells: Insights from Integrative Bioinformatics and Experimental Validation: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=46. - Effects of Long-Term Cultivation on Medium with Alpha-Ketoglutarate Supplementation on Metabolic Processes of Saccharomyces cerevisiae: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=45. - Alpha-ketoglutarate promotes random-pattern skin flap survival by enhancing angiogenesis via PI3K/Akt/HIF-1α signaling pathway: outcome=mortality survival; directness=indirect; tier=B2; direction=null; claims=44. - Alpha-ketoglutarate ameliorates age-related osteoporosis via regulating histone methylations: outcome=skeletal fracture bone; directness=indirect; tier=B2; direction=null; claims=44. - Glutaminase 1 regulates the release of extracellular vesicles during neuroinflammation through key metabolic intermediate alpha-ketoglutarate: outcome=immune inflammation; directness=indirect; tier=B2; direction=null; claims=42. - Replication Study: The common feature of leukemia-associated IDH1 and IDH2 mutations is a neomorphic enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutarate: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=41. - Alpha-ketoglutarate ameliorates abdominal aortic aneurysm via inhibiting PXDN/HOCL/ERK signaling pathways: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=36. - Elevation of Intracellular Alpha-Ketoglutarate Levels Inhibits Osteoclastogenesis by Suppressing the NF-κB Signaling Pathway in a PHD1-Dependent Manner: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=unclear; claims=30. - Alpha-ketoglutarate enhances adipose-derived stem cells survival in wound healing by hypoxia-inducible factor 1-alpha-mediated redox homeostasis and glycogen-dependent bioenergetics: outcome=immune; directness=indirect; tier=B2; direction=null; claims=29. - Alpha-ketoglutarate suppresses the NF-κB-mediated inflammatory pathway and enhances the PXR-regulated detoxification pathway: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=28. - Administration of alpha-ketoglutarate improves epithelial restitution under stress injury in early-weaning piglets: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=26. - Development and First-in-Human Translation of Hyperpolarized [1- 13 C]Alpha-Ketoglutarate MR Spectroscopy in the Brain: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=26. - Effects of Alpha-Ketoglutarate Supplementation on Growth Performance, Diarrhea Incidence, Plasma Amino Acid, and Nutrient Digestibility in Weaned Piglets: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=25. - Alpha-Ketoglutarate Regulates Tnfrsf12a/Fn14 Expression via Histone Modification and Prevents Cancer-Induced Cachexia: outcome=cardiometabolic; directness=indirect; tier=B2; direction=null; claims=21. - Cholesterol Content, Fatty Acid Profile and Health Lipid Indices in the Egg Yolk of Eggs from Hens at the End of the Laying Cycle, Following Alpha-Ketoglutarate Supplementation: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=18. - Effects of Dietary Alpha-Ketoglutarate Supplementation on Diarrhea Incidence and Nutrient Digestibility in Weaned Piglets Fed Low-Protein Diets: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=14. - Alpha-ketoglutarate promotes skeletal muscle hypertrophy and protein synthesis through Akt/mTOR signaling pathways: outcome=muscle function; directness=indirect; tier=B2; direction=unclear; claims=13. - Rejuvant®, a potential life-extending compound formulation with alpha-ketoglutarate and vitamins, conferred an average 8 year reduction in biological aging, after an average of 7 months of use, in the TruAge DNA methylation test: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=13. - Alpha-Ketoglutarate: A Potential Inner Mitochondrial and Cytosolic Protector against Peroxynitrite and Peroxynitrite-Induced Nitration?: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=12. - Lack of association of the alpha-ketoglutarate-dependent dioxygenase (FTO) gene polymorphisms with pulmonary tuberculosis risk: a systematic review and meta-analysis: outcome=contextual adjacent evidence; directness=review; tier=B2; direction=null; claims=11. - AKT signaling is associated with epigenetic reprogramming via the upregulation of TET and its cofactor, alpha-ketoglutarate during iPSC generation: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=11. - The Role of the Rare Variants in the Genes Encoding the Alpha-Ketoglutarate Dehydrogenase in Alzheimer’s Disease: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=10. - Mutations in human lipoyltransferase gene LIPT1 cause a Leigh disease with secondary deficiency for pyruvate and alpha-ketoglutarate dehydrogenase: outcome=deficiency prevalence; directness=indirect; tier=B2; direction=null; claims=10. - Foliar application of alpha-ketoglutarate plus nitrogen improves drought resistance in soybean ( Glycine max L. Merr. ): outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=9. - Alpha Ketoglutarate Downregulates the Neutral Endopeptidase and Enhances the Growth Inhibitory Activity of Thiorphan in Highly Aggressive Osteosarcoma Cells: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=8. - Repurposing FDA-approved drugs to find a novel inhibitor of alpha-ketoglutarate-dependent dioxygenase FTO to treat esophageal cancer: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=8. - A strategically designed small molecule attacks alpha-ketoglutarate dehydrogenase in tumor cells through a redox process: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=8. - D2HGDH regulates alpha-ketoglutarate levels and dioxygenase function by modulating IDH2: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=6. - Comparative Study of Various Delivery Methods for the Supply of Alpha-Ketoglutarate to the Neural Cells for Tissue Engineering: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=5. - Alpha-Ketoglutarate Drives an Osteogenic and Extracellular Matrix Gene Program in Periodontal Ligament Fibroblasts via Selective Reduction of H3K27me3: outcome=contextual adjacent evidence; directness=indirect; tier=B2; direction=null; claims=2. ### Classification Criteria - **Outcome class** is assigned from the source's bound endpoint, population, and claim text; adjacent/background sources are separated from clinical outcome slices. - **Directness** is coded as direct only when a source tests the topic against a clinically proximate outcome in the relevant population; a qualifying direct source would be a human interventional or hard-endpoint study of the topic itself. Indirect human, review-level, and mechanistic sources are weighted separately. - **Directional signal** is counted within the assigned outcome class only. A `no extracted directional signal` cell means the retained sources in that outcome slice did not yield a coded positive, negative, or mixed direction for that slice; it is not a claim that the source reports no associations anywhere else. - **Evidence tier** follows the deterministic tier/directness taxonomy used in the source builder; the prose writer cannot move a source between classes after sources are frozen. ### Load-Bearing Tensions - In animal/preclinical evidence, severity 4 null vs positive: An 2021 vs Iwaniak 2022; An 2021 (positive on safety comorbidity) vs Iwaniak 2022 (null on safety comorbidity) — partial conflict ## Conclusion Additional corpus sources included animal/preclinical evidence; additional corpus sources informed the synthesis without anchoring a foregrounded quantitative claim and are catalogued for completeness: Takemura 2025, Sun 2025, Khamineh 2026, Dilimulati 2026, He 2017, Kim 2026, He 2017b, Sun 2025b, Tomaszewska 2021, Sun 2025c, Demidenko 2021, Greilberger 2021b, Soreze 2013, Csaban 2021, Gai 2022, Mohammadi 2025, Stuart 2014, Mizerska-Kowalska 2022, Lin 2015, Vishnoi 2013, Zhang 2020, Studenski 2011, Perera 2006, ADA 2024, WHO 2000, Cruz-Jentoft 2019, Ioannidis 2005. ## References - **Greilberger 2023.** _Different RONS Generation in MTC-SK and NSCL Cells Lead to Varying Antitumoral Effects of Alpha-Ketoglutarate + 5-HMF._ Current Issues in Molecular Biology, 2023. DOI: 10.3390/cimb45080410. PMID: 37623229. - **Greilberger 2022.** _Alpha-Ketoglutarate or 5-HMF: Single Compounds Effectively Eliminate Leukemia Cells via Caspase-3 Apoptosis and Antioxidative Pathways._ International Journal of Molecular Sciences, 2022. DOI: 10.3390/ijms23169034. PMID: 36012295. - **Qiu 2025.** _Alpha-ketoglutarate rescues impaired endothelial progenitor cell-mediated angiogenesis in diabetic mice._ Frontiers in Pharmacology, 2025. DOI: 10.3389/fphar.2025.1656473. PMID: 41181587. - **Greilberger 2021.** _Alpha-Ketoglutarate and 5-HMF: A Potential Anti-Tumoral Combination against Leukemia Cells._ Antioxidants, 2021. DOI: 10.3390/antiox10111804. PMID: 34829675. - **Wu 2022.** _Low Protein Diets Supplemented With Alpha-Ketoglutarate Enhance the Growth Performance, Immune Response, and Intestinal Health in Common Carp ( Cyprinus carpio )._ Frontiers in Immunology, 2022. DOI: 10.3389/fimmu.2022.915657. 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