EXPLAINER: Just how dangerous is mixing caffeine and alcohol?

Before 15-year-old Paris Kamper was found unconscious on her family’s Kenthurst property on Friday night, she had been drinking heavily.

Police told reporters on Tuesday that alcohol “led directly or indirectly” to her death in hospital a few days later, with her blood alcohol reading at the lethal level of 0.4.

But energy drinks were also found at her home and have been seized by police, who are also looking further into indications she had been looking up recipes for energy drink and alcohol mixes online.

So how much did energy drinks play a role in the Sydney teen’s death?

Well, while we can’t know until a coroner report has been released, experts have warned in the wake of the tragedy, that mixing alcohol and caffeine is a risky decision.

‘Caffeine increases your urge to drink’

Associate Professor Melissa Norberg is deputy director of the Centre for Emotional Health and head of the Behavioural Science Laboratory at Macquarie University.

Assoc Prof Norberg says that while there is no data on the two drugs causing a dangerous chemical reaction in the body, there is research that shows mixing caffeine and alcohol can cause you to drink more.

“Caffeine does nothing to reduce the effects of alcohol, but it does increase alertness and offset fatigue,” she says.

Assoc Prof Norberg says people are “notoriously poor” at judging how intoxicated they are, and a study showed a lot of caffeine (three or more drinks) could make it harder for people to determine just how drunk they are.

Naturally, when you don’t know how drunk you are, you tend to drink more.

“But even at one or two drinks, caffeine does increase your urge to drink. And that’s where the danger comes in. Because ultimately if you drink more alcohol, you’re going to have more negative effects.”

Knowing when to stop

So is there a safe level of espresso martinis or Jägerbombs to drink?

Well, Assoc Prof Norberg tells Mamamia that while there isn’t any data to “suggest where the cut off is”,  the more caffeine you drink with alcohol, the riskier it is.

“Combining caffeine and alcohol is not a great mix for anyone at any age. My heart breaks for these parents.”

Meanwhile, Dr David Caldicott, an emergency consultant and senior clinical lecturer in medicine at the Australian National University, reminds us that both alcohol and caffeine are legal drugs.

“Caffeine poisoning is rare, and deaths even rarer. Alcohol intoxication is an all-too-common cause of harm and death in Australia,” he points out.

Dr Caldicott believes deaths like Paris’ are preventable with better education.

“Certainly, better information about the general potential harms from alcohol… including the exacerbated harms from the combination with energy drinks, might help.”

He says we should be telling young people the same thing as we would about mixing other, illegal, recreational drugs with alcohol, “Don’t mix your drugs – and go low, and slow.”