Effects of caffeine on alcohol reinforcement: beverage choice, self-administration, and subjective ratings

Abstract

Rationale Combining alcohol and caffeine is associated with increased alcohol consumption, but no prospective experimental studies have examined whether added caffeine increases alcohol consumption. Objectives This study examined how caffeine alters alcohol self-administration and subjective reinforcing effects in healthy adults. Methods Thirty-one participants completed six double-blind alcohol self-administration sessions: three sessions with alcohol only (e.g., Beverage A) and three sessions with alcohol and caffeine (e.g., Beverage B). Participants chose which beverage to consume on a subsequent session (e.g., Beverage A or B). Effects of caffeine on overall beverage choice, number of self-administered drinks, subjective ratings (e.g., Biphasic Alcohol Effects Scale), and psychomotor performance were examined. Results A majority of participants (65%) chose to drink the alcohol beverage containing caffeine on their final self-administration session. Caffeine did not increase the number of self-administered drinks. Caffeine significantly increased stimulant effects, decreased sedative effects, and attenuated decreases in psychomotor performance attributable to alcohol. Relative to nonchoosers, caffeine choosers reported overall lower stimulant ratings, and reported greater drinking behavior prior to the study. Conclusions Although caffeine did not increase the number of self-administered drinks, most participants chose the alcohol beverage containing caffeine. Given the differences in subjective ratings and pre-existing differences in self-reported alcohol consumption for caffeine choosers and nonchoosers, these data suggest decreased stimulant effects of alcohol and heavier self-reported drinking may predict subsequent choice of combined caffeine and alcohol beverages. These predictors may identify individuals who would benefit from efforts to reduce risk behaviors associated with combining alcohol and caffeine.

Alcohol mixed with energy drink (AMED): A critical review and meta‐analysis

“…It should be taken into account that the urge or desire to drink does not automatically imply that this results in greater alcohol intake. For example, in a recent study, participants could choose their preferred beverage of choice, and the subsequent number of self‐administered drinks were recorded (Sweeney, Meredith, Evatt, & Griffiths, ). The alcoholic drinks each contained 14 g alcohol, with added caffeine (60 mg) or placebo.…”

“…For example, in a recent study, participants could choose their preferred beverage of choice, and the subsequent number of selfadministered drinks were recorded (Sweeney, Meredith, Evatt, & Griffiths, 2017). The alcoholic drinks each contained 14 g alcohol, with added caffeine (60 mg) or placebo.…”

Caffeine Potentiates Ethanol-Induced Neurotoxicity Through mTOR/p70S6K/4E-BP1 Inhibition in SH-SY5Y Cells

“…Since blood alcohol levels at higher than 100 mg/dL can suppress human brain activity 45 and caffeine is a brain stimulant, the popular opinion is that caffeine can antagonize or at least reduce the neuropsychiatric and motor deficits induced by alcohol intoxication. 25,26 However, only some animal experiments supported the benefits of caffeine on neuronal functions. In a rat model of ischemic stroke, a combination of low-dose ethanol and caffeine protected the brain from damage only when treated immediately before or for 2 hours after focal stroke 28 but not for chronic daily oral ethanol plus caffeine prior to ischemia.…”

“…[21][22][23] Caffeine and ethanol act on the adenosinergic system in distinct ways resulting in opposing physiological effects. 24 Some studies suggested that caffeine antagonized the cognitive and behavioral effects caused by ethanol intoxication, 25,26 while neuroprotective effects of caffeine on ethanol-induced neuronal cell death have also been reported. Previous studies in rats showed that low doses of ethanol, which singularly aggravates cerebral ischemia, reduced ischemic damage when applied with caffeine, 27,28 while another study in a rat model of alcoholism showed that the simultaneous ingestion of ethanol and caffeine reversed ethanol-induced neuronal and glial cell death in the cerebellar tissue.…”

Current perspectives of caffeinated energy drinks on exercise performance and safety assessment

“…[61][62][63][64] This includes concern about the use of EDs to counteract the depressive effects of alcohol, which, may lead to excessive alcohol intake and/or intoxication. 59,[65][66][67][68][69] For example, several studies suggest that individuals who mix alcohol with EDs are more likely to consume more alcohol and/or engage in risky behaviors. [70][71][72][73][74][75][76][77][78][79][80][81] While discussing the effects of concomitant use of EDs with alcohol goes beyond the scope of this paper, it is clear that consumption of EDs with alcohol may increase the likelihood of intoxication and risky behavior, and should therefore be discouraged.…”