{"id":"5cda5aca-9066-5b74-b3ac-b730b0cfdf21","stable_key":"63ce713e-6aea-59f6-9896-ca30e010b2ce:l-tyrosine-cognitive-load","predicate":"reduces","statement":"In a randomized double-blind trial of 70 healthy volunteers, 2 g tyrosine worsened cognitive flexibility under the high-load condition.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"7ec23f08-8377-5401-9b40-eb12388f9ed6","mechanism_event_label":"The effect depends on the task and the kind of stress.","subject":{"id":"bcfef85f-831d-5439-ba51-1aef4b090441","slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"},"object":{"id":"248e2ea0-0478-5282-8fe1-c90962236c75","slug":"human-high-load-cognitive-flexibility","display_name":"Human cognitive flexibility after high cognitive load","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"7ec23f08-8377-5401-9b40-eb12388f9ed6","stable_key":"63ce713e-6aea-59f6-9896-ca30e010b2ce:l-tyrosine-cognitive-load-event","event_type":"observed_relationship","label":"The effect depends on the task and the kind of stress.","description":"In a randomized double-blind trial of 70 healthy volunteers, 2 g tyrosine worsened cognitive flexibility under the high-load condition.","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":"248e2ea0-0478-5282-8fe1-c90962236c75","slug":"human-high-load-cognitive-flexibility","display_name":"Human cognitive flexibility after high cognitive load","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":"Tyrosine versus cellulose, high/low cognitive load and Wisconsin Card Sorting Test.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Physiological stress markers were not measured; catecholamine mediation remained unmeasured.","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":"The effect depends on the task and the kind of stress.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Tyrosine negatively affects flexible-like behaviour under cognitively demanding conditions. · 2020 · https://pubmed.ncbi.nlm.nih.gov/31521870/ · DOI 10.1016/j.jad.2019.09.031","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"ca75613d-e3ac-50b3-b0b7-b59b49ad3185","evidence_kind":"source_excerpt","locator":"Lines 420-426","start_line":420,"end_line":426,"excerpt":"## l-tyrosine-cognitive-load\nThe effect depends on the task and the kind of stress.\nIn a randomized double-blind trial of 70 healthy volunteers, 2 g tyrosine worsened cognitive flexibility under the high-load condition.\nModel: Tyrosine versus cellulose, high/low cognitive load and Wisconsin Card Sorting Test.\nLimitations: Physiological stress markers were not measured; catecholamine mediation remained unmeasured.\nEvidence access: Primary abstract\nTyrosine negatively affects flexible-like behaviour under cognitively demanding conditions. · 2020 · https://pubmed.ncbi.nlm.nih.gov/31521870/ · DOI 10.1016/j.jad.2019.09.031","model_system":"Tyrosine versus cellulose, high/low cognitive load and Wisconsin Card Sorting Test.","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. Not publisher full text.","file_path":"","sha256":"7777f4440a8bfb14a04ff73e73392ccc45d8ee89f7853ecbcc0027d6f563b8a0","revision_id":"e1206111-3a75-5809-b8e9-231ff809ff1e","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}