In the first investigation of the frequency of this behaviour in an Australian community, University of Tasmania PhD student Amy Peacock has found that it is associated with heart palpitations, sleep difficulties, agitation and tremors.
Having surveyed 403 Australians aged 18 to 35, Amy and her colleagues also found significantly increased odds of irritability and tension, associated with over-stimulation, as well as 'jolt and crash' episodes where drinkers experience increased stimulation followed by a sharp, sudden drop in energy.
The research will be published later this year in the journal 'Alcoholism: Clinical and Experimental Research'.
Peacock and her colleagues collected data from across the country in an online survey. All participants had consumed alcohol/energy drinks and alcohol-only drinks in the preceding six months.
The survey showed consumers are six times more likely to have heart palpitations and four times more likely to have sleep difficulties when drinking alcohol/energy drinks compared with drinking alcohol only.
However, energy drinks appeared to counter some of the sedative effects of alcohol, including reducing the odds of slurred speech, impaired walking and vision, and nausea.
Psychologically, mixing the drinks produced significantly higher odds of feeling 'on edge' and irritable, and significantly lower odds of feeling sociable and content. While drinkers had similar rates of feeling more impulsive and novelty-seeking they had significantly lower odds of feeling disinhibited behaving than alcohol-only drinkers.
But on 26 risk-taking behaviours the drinkers reported more surprising results.
“People reported engaging in risk-taking behaviour such as driving while intoxicated, casual sex, using illicit drugs and engaging in verbal or physical aggression during both alcohol drinking sessions and mixed alcohol and energy drink sessions,” Peacock said.
“But the odds of these risk behaviours were lower when using the mixed drinks.”
However, the researchers are not suggesting that alcohol consumers should mix alcohol with energy drinks to reduce these risks associated with drinking. This finding regarding risk-taking contradicts the limited international research available.
Peacock said more research was needed to examine the potential mechanisms explaining the effects of mixing drinks on risk-taking.
