{"id":"1e8196ef-c49b-5af6-b4f3-1f8f0993f30b","stable_key":"56f1d914-e7da-595a-af69-c217b2b47407:l-phenylalanine-tyrosine-sparing","predicate":"changes_context_for","statement":"With excess tyrosine supplied, indicator-amino-acid oxidation in twelve older adults across 66 studies estimated mean phenylalanine requirement at 9.03 mg/kg/day and its upper 95% confidence limit at 15.9 mg/kg/day.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"7b598e7c-1151-59cf-a6a1-c34fbbea7e0b","mechanism_event_label":"Supplying tyrosine changes how much phenylalanine must be reserved for making it.","subject":{"id":"bcfef85f-831d-5439-ba51-1aef4b090441","slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"},"object":{"id":"af82b147-62ec-5dd8-ab4c-461e8a79ccff","slug":"human-phenylalanine-requirement","display_name":"Human dietary phenylalanine requirement estimate","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"7b598e7c-1151-59cf-a6a1-c34fbbea7e0b","stable_key":"56f1d914-e7da-595a-af69-c217b2b47407:l-phenylalanine-tyrosine-sparing-event","event_type":"observed_relationship","label":"Supplying tyrosine changes how much phenylalanine must be reserved for making it.","description":"With excess tyrosine supplied, indicator-amino-acid oxidation in twelve older adults across 66 studies estimated mean phenylalanine requirement at 9.03 mg/kg/day and its upper 95% confidence limit at 15.9 mg/kg/day.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"bcfef85f-831d-5439-ba51-1aef4b090441","slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"af82b147-62ec-5dd8-ab4c-461e8a79ccff","slug":"human-phenylalanine-requirement","display_name":"Human dietary phenylalanine requirement estimate","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"190407ad-0219-54b5-b05f-7c75f3895ca6","slug":"l-phenylalanine","display_name":"L-Phenylalanine","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":"Human tracer feeding study with phenylalanine intakes 7.2–40 mg/kg/day and excess tyrosine.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"This conditional estimate is not a universal intake target or evidence that tyrosine replaces phenylalanine in proteins.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Phenylalanine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-phenylalanine","display_name":"L-Phenylalanine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"Supplying tyrosine changes how much phenylalanine must be reserved for making it.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"The Phenylalanine Requirement of Elderly Men and Women Measured by Direct 13C Carbon Oxidation Method Is Similar to That of Young Adults. · 2019 · https://pubmed.ncbi.nlm.nih.gov/31271193/ · DOI 10.1093/jn/nxz137","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"3993b1df-4054-53bd-bb9e-351613643eab","evidence_kind":"source_excerpt","locator":"Lines 262-268","start_line":262,"end_line":268,"excerpt":"## l-phenylalanine-tyrosine-sparing\nSupplying tyrosine changes how much phenylalanine must be reserved for making it.\nWith excess tyrosine supplied, indicator-amino-acid oxidation in twelve older adults across 66 studies estimated mean phenylalanine requirement at 9.03 mg/kg/day and its upper 95% confidence limit at 15.9 mg/kg/day.\nModel: Human tracer feeding study with phenylalanine intakes 7.2–40 mg/kg/day and excess tyrosine.\nLimitations: This conditional estimate is not a universal intake target or evidence that tyrosine replaces phenylalanine in proteins.\nEvidence access: Primary abstract\nThe Phenylalanine Requirement of Elderly Men and Women Measured by Direct 13C Carbon Oxidation Method Is Similar to That of Young Adults. · 2019 · https://pubmed.ncbi.nlm.nih.gov/31271193/ · DOI 10.1093/jn/nxz137","model_system":"Human tracer feeding study with phenylalanine intakes 7.2–40 mg/kg/day and excess tyrosine.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; 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Not publisher full text.","file_path":"","sha256":"4d53adcd4acc7a9aecf44ccb2623ec540c9d221a0f7c00002585870b39b8ffb8","revision_id":"fd182a81-4ab7-559a-9c77-fb4cf72982ef","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}