A study with 19 female undergraduates revealed that caffeine alone had a facilitative effect on reaction times, but taurine alone had no effects on performance.
In addition, taurine was found to attenuate the facilitative effects of caffeine in stimulus degradation tasks, researchers from the University of Tasmania and the University of Newcastle report in Appetite .
“The present findings of a potential antagonistic relationship between taurine and caffeine may encourage further research into the interactive effects of the ingredients and the performance-benefits conferred by energy drink relative to alternative caffeinated beverages, allowing for a more informed consumer choice,” wrote Amy Peacock, Frances Heritage Martin, and Andrea Carr.
There is increased attention on the energy drinks and shot sector, with some politicians pointing fingers at the caffeine content of the beverages, and raising questions about the other ingredients used in the formulations.
Taurine is commonly included in energy drink and shot formulations, but only one other study has assessed the “independent and combined effects of caffeine and taurine on behavioral performance”, said Peacock, Martin, and Carr.
Moreover, the other study (Pharmacology Biochemistry and Behavior , Oct 2012, Vol. 102, pp. 569–577) used doses that were not typical for energy beverages, and the Australia-based researchers used more typical doses: Approximately 80 mg of caffeine and 1,000 mg of taurine per 250 mL serving.
Nineteen young women were recruited to participate in the double-blind, placebo-controlled, crossover trial. The women were asked to perform a visual oddball task and a stimulus degradation task 45 minutes after consuming capsules containing 80 mg caffeine, or 1,000 mg taurine, or caffeine and taurine combined, or placebo. Two day washout periods separated the interventions.
Results showed that there were no significant effects on the visual oddball task for any of the interventions. For the stimulus degradation task, caffeine was associated with a significantly faster reaction time.
“Caution should be employed when using the present results to inform beverage choice for peak performance, not only because the paired comparison trended towards significance,” wrote the researchers.
“Energy drinks commonly contain other ingredients (e.g., glucose) which may exert independent and interactive effects on performance. Furthermore, energy drinks’ effects on performance may not be purely pharmacologically-dependent.”
Published online ahead of print, doi: 10.1016/j.appet.2012.12.021
“Energy drink ingredients. Contribution of caffeine and taurine to performance outcomes”
Authors: A. Peacock, F. Heritage Martin, A. Carr