title: Role of familiarity on effects of caffeine- and glucose-containing soft drinks.
abstract: Familiarity, through conditioned responses and expectations, may play a significant role in the expression of liking for, and mood and performance effects of, food and drink constituents. The role of familiarity and the effects of caffeine and glucose in Lucozade Energy were investigated by testing this familiar soft drink, and its non-caffeine/non-CHO placebo match, against novel coloured/flavoured full and placebo drinks. Both the familiar drink and its placebo improved alertness, mental energy and mental performance compared to baseline and compared to the novel placebo drink. After repeated exposure, that is, after having gained familiarity with the novel drinks in addition to the already existing familiarity with Lucozade Energy, only the full (caffeine and CHO containing) drinks showed sustained beneficial effects compared to placebo drinks and baseline measures, as well as an increase in liking compared to placebo drinks. Therefore, participants appeared to have learned that beneficial effects were mainly linked to the full products. The results illustrate the restorative combination of caffeine and CHO in the drink, and emphasises the need to implement the appropriate placebo(s) in any study design employing familiar foods or drinks.
authors.affiliation: Department of Experimental Psychology, University of Bristol, UK. henk.smit@bristol.ac.uk
authors.forename: Hendrik J
authors.initials: HJ
authors.lastname: Smit
authors.forename: Melanie L
authors.initials: ML
authors.lastname: Grady
authors.forename: Yvonne E
authors.initials: YE
authors.lastname: Finnegan
authors.forename: Sally-Anne C
authors.initials: SA
authors.lastname: Hughes
authors.forename: Jacqui R
authors.initials: JR
authors.lastname: Cotton
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Rogers
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect / Q000187:drug effects; D001288:Attention / Q000187:drug effects; D001628:Beverages; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003071:Cognition / Q000187:drug effects; D003627:Data Interpretation, Statistical; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects; D008875:Middle Aged; D025341:Principal Component Analysis; D011597:Psychomotor Performance / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects; D013649:Taste / Q000187:drug effects
chemical_list: D000697:Central Nervous System Stimulants; D002110:Caffeine; D005947:Glucose