The Effects Of Commercially Available Energy Drink On Cognitive Performance

Abstract

Energy drinks are frequently purported as a non-alcoholic beverage food commodity to im-prove cognitive function and concentration and as such is marketed especially on vulnerable populations such as professional drivers, students, managers. We aimed to explore the acute dose-effect of commercially available multi-ingredient beverage on cognitive performance. Twenty adult university students, caffeine-deprived received two 500 ml non-alcoholic, glucose-free, multi-herbal extract drinks differing in ingredients dose: DRINK100, threefold higher concentration dosage (DRINK300) and ingredients-free, flavored-matched placebo (PLA) in a double-blind, three-way cross over, randomized order, separated by a 7-day wash-out period. Cognitive functions, autonomous nervous system activity, and specific mental performance were assessed. Drinks were consumed in the late evening (20 p.m.). Standardized psychomotor vigilance task (PVT) to detect reaction time, lapses and the total score and spectral analysis of heart rate variability (software-driven, standing/lying down with ~300 beats recorded in each position, relative change in total power score be-tween consecutive measurements was used) took place immediately prior and 60, 120 and 180 min post-drink consumption (post-drink). Thirty minutes of the cognitively demanding task (continuous manual text transcription) was commenced immediately and in 90, and 150 min post-drink. Total word counts were used in assessing mental performance chang-es. The ecologically valid methodology was used to mimic typical students time of drink consumption. During the 60min post-drink, the level of alertness decreased independently of the drink category, however, DRINK300 increased correct: lapsus ratio in 120 min and this remained elevated until the end of testing. No significant effect of DRINK100 over PLA on vigilance was present. DRINK300 led to an increase in autonomic nervous system activity after drink admin-istration in 60–90 minutes post-drink with a clear decline observed in PLA. This corresponds with a significant increase in the number of words transcripted in the corresponding time in DRINK300, however, not sustained in 180 min post-drink. We demonstrate an acute and transitional dose-effect of multi-herbal caffeine-containing non-energetic beverage on cognitive and autonomous nervous system performance. The effect appears to be evident immediately ( < 30 min) post-drink. A beverage containing guar-ana equivalent to 120 mg of caffeine reduce cognitive performance impairment and this is sustained over ~180 min.