An evaluation of a caffeinated taurine drink on mood, memory and information processing in healthy volunteers without caffeine abstinence

Rationale: Caffeine is present in a wide variety of beverages, often togeth er with a number of other ingredients, such as sugars, taurine, glucuronola ctone and vitamins. However, the majority of psychopharmacological studies have used pure caffeine tablets or drinks with doses in excess of those nor mally consumed in daily life. In addition, all the participants are usually deprived of caffeine for 10 h or more before the study. Consequently, it h as been argued that any improvement in performance is only due to a reversa l of caffeine withdrawal. Objective: The present two studies tested partici pants who had minimal deprivation from caffeine (an hour or less) with an 8 0-mg caffeinated (80 mg/250 ml), taurine-containing beverage (commercially available) verum, which also contained sugars, glucuronolactone and vitamin s. The placebos in the two studies were a sugar-free and a sugar-containing drink, in order to examine the effects of the sugar. Methods: In total, 42 participants were tested with a rapid visual information test, a verbal re asoning test, a verbal and non-verbal memory test and a set of mood measure s. Prior to testing, they were allowed ad libitum caffeinated beverages unt il I h before testing (study 1) and unrestricted caffeine use before testin g (study 2). Results: In both studies, the caffeinated, taurine-containing beverage produced improved attention and verbal reasoning, in comparison wi th a sugar-free and the sugar-containing drinks. The improvement with the v erum drink was manifested in terms of both the mean number correct and the reaction times. Another important finding was the reduction in the variabil ity of attentional performance between participants. No effects on memory w ere found. There were no differences in performance between the glucose and sugar-free drinks. Conclusions: Moderate doses of caffeine and taurine can improve information processing in individuals who could not have been in c affeine withdrawal.