{"id":"4f232ed1-cdcc-5320-bdb3-c5f774385906","stable_key":"63ce713e-6aea-59f6-9896-ca30e010b2ce:l-tyrosine-cold-performance","predicate":"improves","statement":"In 19 volunteers, tyrosine-containing food bars improved selected working-memory measures during repeated cold-water immersion relative to cold/placebo.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"c8ae9264-6255-588d-9159-0029f83c254f","mechanism_event_label":"A benefit was observed under a specific severe stressor.","subject":{"id":"bcfef85f-831d-5439-ba51-1aef4b090441","slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"},"object":{"id":"010784da-606e-565b-a6bc-68e2e56634df","slug":"human-cold-exposure-working-memory","display_name":"Human working memory during experimental cold-water exposure","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"c8ae9264-6255-588d-9159-0029f83c254f","stable_key":"63ce713e-6aea-59f6-9896-ca30e010b2ce:l-tyrosine-cold-performance-event","event_type":"observed_relationship","label":"A benefit was observed under a specific severe stressor.","description":"In 19 volunteers, tyrosine-containing food bars improved selected working-memory measures during repeated cold-water immersion relative to cold/placebo.","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":"010784da-606e-565b-a6bc-68e2e56634df","slug":"human-cold-exposure-working-memory","display_name":"Human working memory during experimental cold-water exposure","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Double-blind within-subject design; two 150 mg/kg doses, total 300 mg/kg; two 90-minute approximately 10-degree-C immersions.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"This was a high experimental dose, not routine dietary exposure; dopamine mediation was not directly measured.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Tyrosine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"A benefit was observed under a specific severe stressor.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Tyrosine supplementation mitigates working memory decrements during cold exposure. · 2007 · https://pubmed.ncbi.nlm.nih.gov/17585971/ · DOI 10.1016/j.physbeh.2007.05.003","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"1ff3de0e-bab5-5e96-9c41-709c0d594d8f","evidence_kind":"source_excerpt","locator":"Lines 396-402","start_line":396,"end_line":402,"excerpt":"## l-tyrosine-cold-performance\nA benefit was observed under a specific severe stressor.\nIn 19 volunteers, tyrosine-containing food bars improved selected working-memory measures during repeated cold-water immersion relative to cold/placebo.\nModel: Double-blind within-subject design; two 150 mg/kg doses, total 300 mg/kg; two 90-minute approximately 10-degree-C immersions.\nLimitations: This was a high experimental dose, not routine dietary exposure; dopamine mediation was not directly measured.\nEvidence access: Primary abstract\nTyrosine supplementation mitigates working memory decrements during cold exposure. · 2007 · https://pubmed.ncbi.nlm.nih.gov/17585971/ · DOI 10.1016/j.physbeh.2007.05.003","model_system":"Double-blind within-subject design; two 150 mg/kg doses, total 300 mg/kg; two 90-minute approximately 10-degree-C immersions.","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":"12917df2-c6e0-5b61-850f-dbff6d4b4d30","stable_key":"import-63ce713e-6aea-59f6-9896-ca30e010b2ce","title":"L-Tyrosine: catecholamines, thyroid chemistry, pigment, 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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