{"id":"065af958-7e3d-584c-bb80-f81196a77d53","stable_key":"41a89233-da9a-5b7b-9c18-e19bbadcfe2d:methionine-rat-lifespan-growth","predicate":"has_mixed_outcomes_in","statement":"Reducing dietary methionine from 0.86% to 0.17% extended male F344 rat lifespan by about 30% while abolishing growth in the original experiment.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"7bb272b0-5378-5552-9b08-1d4e823b9591","mechanism_event_label":"The longevity observation came with a substantial growth cost.","subject":{"id":"2fa490e6-50cc-5a22-b1ea-af5e128666e4","slug":"experimental-methionine-restriction","display_name":"Experimentally methionine-restricted diet","entity_type_key":"cellular_process"},"object":{"id":"034f9b66-9a10-5578-b95c-9fe80876395a","slug":"rat-methionine-restriction-lifespan-growth","display_name":"Lifespan and growth in methionine-restricted male F344 rats","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"7bb272b0-5378-5552-9b08-1d4e823b9591","stable_key":"41a89233-da9a-5b7b-9c18-e19bbadcfe2d:methionine-rat-lifespan-growth-event","event_type":"observed_relationship","label":"The longevity observation came with a substantial growth cost.","description":"Reducing dietary methionine from 0.86% to 0.17% extended male F344 rat lifespan by about 30% while abolishing growth in the original experiment.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"2fa490e6-50cc-5a22-b1ea-af5e128666e4","slug":"experimental-methionine-restriction","display_name":"Experimentally methionine-restricted diet","entity_type_key":"cellular_process"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"034f9b66-9a10-5578-b95c-9fe80876395a","slug":"rat-methionine-restriction-lifespan-growth","display_name":"Lifespan and growth in methionine-restricted male F344 rats","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"9d39f561-740b-5f67-bba7-8a72ef612a99","slug":"methionine","display_name":"L-Methionine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Lifelong controlled feeding of male Fischer 344 rats.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Not human lifespan evidence or a nutritionally appropriate target for children.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Methionine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"methionine","display_name":"L-Methionine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"The longevity observation came with a substantial growth cost.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Low methionine ingestion by rats extends life span. · 1993 · https://pubmed.ncbi.nlm.nih.gov/8429371/ · DOI 10.1093/jn/123.2.269","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"5f286212-777a-546b-89d8-39a77cd8f5ce","evidence_kind":"source_excerpt","locator":"Lines 356-362","start_line":356,"end_line":362,"excerpt":"## methionine-rat-lifespan-growth\nThe longevity observation came with a substantial growth cost.\nReducing dietary methionine from 0.86% to 0.17% extended male F344 rat lifespan by about 30% while abolishing growth in the original experiment.\nModel: Lifelong controlled feeding of male Fischer 344 rats.\nLimitations: Not human lifespan evidence or a nutritionally appropriate target for children.\nEvidence access: Primary abstract\nLow methionine ingestion by rats extends life span. · 1993 · https://pubmed.ncbi.nlm.nih.gov/8429371/ · DOI 10.1093/jn/123.2.269","model_system":"Lifelong controlled feeding of male Fischer 344 rats.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access and experimental limitations specified.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"d969b004-ccc2-5bb4-9109-8ac649137ad1","stable_key":"import-41a89233-da9a-5b7b-9c18-e19bbadcfe2d","title":"L-Methionine: transport, methylation, sulfur metabolism and cross-nutrient mechanisms (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary references, access levels and experimental limitations individually identified. 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