Energy drinks could act as a ‘gateway’ to cocaine for young people, say scientists.
A study found 21 to 25 year-olds who consumed high amounts of the sugar and caffeine-fuelled beverages were much more likely to become hooked on the party drug.
They were also at greater risk of alcohol abuse and being on amphetamines and other non-medically prescribed stimulants (NPS) within the next five years.
Professor Amelia Arria, of Maryland University, said: “The results suggest energy drink users might be at heightened risk for other substance use - particularly stimulants.
“Because of the longitudinal design of this study - and the fact we were able to take into account other factors that would be related to risk for substance use - this study provides evidence of a specific contribution of energy drink consumption to subsequent substance use.”
The findings published in Drug and Alcohol Dependence suggest the drinks - which have been linked to obesity among young people - could present another danger.
Prof Arria said it is the first time patterns of energy drink consumption and drug use have been explored for such a long time - and there is reason for concern.
Regular consumers over the whole period were significantly more likely to be abusing drugs by the age of 25.
Previous research by Prof Arria’s team at the university’s Centre on Young Adult Health and Development (CYAHD) has suggested the drinks can lead to high-risk alcohol and drug use.
But this study is the first to examine the unique effect of different levels of consumption on the likelihood of later substance abuse.
Notably more than half (51.4%) of the 1,099 participants fell into the group with a “persistent trajectory” - meaning they sustained it over time.
They were much more likely to end up using cocaine, amphetamines and other stimulants - and be at risk for alcohol use disorder.
The researchers single out energy drinks because they took into account other factors that could have had a possible influence.
This included demographics, sensation-seeking behaviours, other caffeine consumption such as coffee and prior substance use before 21.
Those in the “intermediate trajectory” group (17.4%) were also at increased risk for using cocaine and other stimulants.
This was compared to those in the “non-use trajectory” who never consumed energy drinks (20.6%).
Members of the “desisting trajectory” group - those whose consumption declined steadily over time - and the non-use group were not at higher risk for any substance use.
The biological mechanism that might explain how someone who persistently consumes energy drinks might go on to use other stimulant drugs remains unclear.
But the researchers said it’s a cause for concern that should be further investigated.
Prof Arria’s research group has previously examined the health risks from consuming energy drinks.
She has been a leader in efforts to protect teenagers and children from them. These include heart damage and even death.
She has also joined with other medical and public health experts who urged the US food and Drink Administration to regulate them.
Unlike soft drinks energy drinks remain unregulated and are not subject to government labelling requirements to list caffeine content or additional ingredients that are not well understood.
Prof Arria said: “Future studies should focus on younger people, because we know that they too are regularly consuming energy drinks.
“We want to know whether or not adolescents are similarly at risk for future substance use.”
Energy drinks are flavoured beverages that contain extra caffeine as well as other additives such as taurine, guarana and ginseng.
Sales of energy drinks in the UK increased by 155% between 2006 and 2014 - from 235 to 600 million litres.
About seven-in-ten 11 to 18 year-olds in the UK and a fifth of children aged 10 and under consume THEM.
A single can of popular brands can contain around 160mg of caffeine. the European Food Safety Authority recommends an intake of no more than 105mg per day for an average 11-year-old.
Five years ago a study found young people who love drinking coffee or other high-energy drinks are more likely to become cocaine or amphetamine users.
Those who responded favourably to caffeine also enjoyed the effects of the drugs - especially in high doses.
This could suggest a vulnerability to the stimulating effects of cocaine or amphetamines among some people who enjoy caffeine.
But Gavin Partington, Director General at British Soft Drinks Association commented: “It’s important to note that a study of this sort cannot prove cause and effect.
“The European Food Safety Authority (EFSA) latest opinion confirms the safety of energy drinks and their ingredients and therefore does not provide any scientific justification to treat energy drinks differently to other caffeine-based drinks such as coffee.”