EVIDENCE LIBRARY
Did Mixing an Energy Drink With Alcohol Raise Plasma Ethanol in a 16-Man Trial?
One crossover trial found higher plasma ethanol exposure with an energy-drink mixer, while peak breath readings did not differ significantly. The result cannot be generalized to every mixer or interpreted as faster alcohol elimination.
Yes. One 16-man crossover trial found higher plasma ethanol peaks and integrated exposure when an energy drink accompanied alcohol. Peak breath readings, however, were not significantly different between the alcohol conditions. The study did not establish a universal mixer effect or a reliable correction for an individual’s BAC.
The same participants completed four conditions
Pérez-Mañá and colleagues compared alcohol plus energy drink, alcohol plus mixer placebo, energy drink plus alcohol placebo, and both placebos. The randomized, double-blind sessions used a balanced crossover sequence.
The total alcohol dose was sixty grams, divided into two doses an hour apart. The energy-drink condition supplied 750 milliliters of Red Bull, containing 240 milligrams of caffeine. Its mixer placebo had similar carbohydrate content. The participants were healthy young men accustomed to alcohol and caffeine.
The protocol collected breath and venous samples over time. Plasma ethanol was measured with an enzymatic assay; caffeine and taurine were measured separately. Plasma results should not be silently relabeled as forensic whole-blood ethanol.
Plasma peaks increased; elimination rate did not
The table reported mean peak plasma ethanol values equivalent to approximately 83.5 milligrams per deciliter with the combined drink and 70.5 with alcohol plus mixer placebo. Integrated plasma ethanol exposure over eight hours was also significantly higher with the combination.
The reported elimination rates did not differ significantly. A higher peak or exposure area therefore was not evidence of faster alcohol removal. The study also did not establish a precise mechanism for the concentration increase.
The authors discussed possible effects on absorption and the contribution of different ingredients. Because a complete energy drink was tested, the result cannot be attributed solely to caffeine, taurine or any other single component.
Breath and plasma gave different statistical comparisons
Mean peak breath concentrations were approximately 0.40 milligrams per liter with the combined drink and 0.38 with alcohol alone. That comparison was not significant, despite the significant plasma findings.
Breath and plasma concentration curves were strongly correlated, with reported correlations around .96 in both alcohol conditions. Strong correlation describes how measurements vary together; it does not prove identical values, interchangeable specimens or identical sensitivity to a treatment difference.
The null breath comparison also does not establish equivalence. Sample size, measurement variation, sampling schedule and the endpoint being compared all affect the ability to detect a difference.
Higher exposure coexisted with less sedation
The combined condition reduced reported drowsiness and some sedation scores relative to alcohol alone. Reported drunkenness did not significantly change. Participants also expressed greater willingness to drive under some comparisons.
Selected tracking and reaction-time comparisons improved at particular times, but the main factorial analyses did not find an energy-drink interaction for the principal performance outcomes. No driving simulator or on-road test established restored driving ability.
These functional and subjective findings do not explain away the plasma result. Feeling less sleepy, performing a selected task better and having a lower alcohol concentration are different claims.
Limits for DUI reconstruction
The trial used one formulation, one dosing pattern and only sixteen men. Some outcomes had fewer observations, and several later subjective measurements were obtained from only half the sample. The findings cannot supply a fixed percentage adjustment for another drinker or mixer.
The site’s 28-person energy-drink analysis concerns a separate trial and performance question. Its findings should not be merged with this study’s plasma data as if they came from the same participants or design.
Primary source
Pérez-Mañá C and colleagues. Effects of Mixing Energy Drinks With Alcohol on Driving-Related Skills. International Journal of Neuropsychopharmacology. 2022;25:13–25; first published online in 2021. https://doi.org/10.1093/ijnp/pyab051.