Another study involving the cognitive effects of the popular energy supplement, 5-hour Energy, suggests water with a caffeine additive is better at improving reaction time and neural capacity. Researchers from Centre College in Kentucky set out to answer the question: is the energy blend contained in energy drinks more effective at increasing a person's P300 amplitude and latency time on visual attention tasks than caffeine alone?

P300 is an event-related potential (ERP) brain wave that directly influences our decision making. P300 amplitude is marked by electroencephalography (EEG) used for electrically tracking cognitive activity.

"It's been used quite a bit in other studies looking at caffeine, as an indicator showing that caffeine does increase arousal and alertness levels," explained lead researcher KatieAnn Skogsberg, professor of psychology and behavioral neuroscience at Centre College.

Skogsberg and her associates tracked caffeine and artificial sweetener sensitivity, vision and attention disorders, and history of caffeine consumption in 31 Centre College undergraduates, Food Navigator reported.

Participants were asked to consume either water, water with caffeine, or a 5-hour Energy, and then perform a range of cognitive tasks that involved clicking on a number when it appeared on a computer screen. Although preliminary results showed that caffeine led to a quicker response time compared to water, there was no difference between water with caffeine and a 5-hour Energy.

"This is a preliminary study using a small sample size, so the first and most important step is to replicate it, using more participants, and even more labs replicate our research. We need more research, more 'takes' on it," Skogsberg added.

"We're collecting the data, replicating the experiment and might add the placebo aspect to it before we publish. It just depends on how much excitement there is."

A similar study conducted in January 2012 by researchers from Spain probed the effects of a caffeine-containing energy drink on simulated soccer performance. Instead of cognitive ability, researchers were more focused on the participants' physical output.

Nineteen semiprofessional soccer players were asked to drink 3 mg of caffeine from a sugar-free Red Bull or a placebo noncaffeinated beverage. After participants consumed their beverages, the research team tracked each player's physical performance through a range of fitness tests.

In their findings, the researchers stated, "A caffeine-containing energy drink in a dose equivalent to 3 mg/kg increased the ability to repeatedly sprint and the distance covered at high intensity during a simulated soccer game. In addition, the caffeinated energy drink increased jump height which may represent a meaningful improvement for headers or when players are competing for a ball."

Source: Skogsberg KA, Stevenson K, Blaine L, Rose G, Oberst L, Benham C. The Effect of Energy Drinks on Visual Attention Task Performance. Annual Meeting of the Association for Psychological Science. 2013.