title: L-theanine and caffeine improve task switching but not intersensory attention or subjective alertness.
abstract: Tea ingredients L-theanine and caffeine have repeatedly been shown to deliver unique cognitive benefits when consumed in combination. The current randomized, placebo-controlled, double-blind, cross-over study compared a combination of L-theanine (97 mg) and caffeine (40 mg) to a placebo on two attention tasks and a self-report questionnaire before, and 10 and 60 min after consumption. The combination of L-theanine and caffeine significantly improved attention on a switch task as compared to the placebo, while subjective alertness and intersensory attention were not improved significantly. The results support previous evidence that L-theanine and caffeine in combination can improve attention.
authors.affiliation: Sensation, Perception & Behaviour, Unilever R&D Vlaardingen, Vlaardingen, The Netherlands. Suzanne.Einother@Unilever.com
authors.forename: Suzanne J L
authors.initials: SJ
authors.lastname: Einöther
authors.forename: Vanessa E G
authors.initials: VE
authors.lastname: Martens
authors.forename: Jane A
authors.initials: JA
authors.lastname: Rycroft
authors.forename: Eveline A
authors.initials: EA
authors.lastname: De Bruin
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect / Q000187:drug effects / Q000502:physiology; D000704:Analysis of Variance; D001288:Attention / Q000187:drug effects / Q000502:physiology; D001628:Beverages; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003071:Cognition / Q000187:drug effects* / Q000502:physiology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005971:Glutamates / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012677:Sensation / Q000187:drug effects; D013647:Task Performance and Analysis; D013662:Tea / Q000737:chemistry*; D013997:Time Factors; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D005971:Glutamates; D013662:Tea; D002110:Caffeine; C026166:theanine