About one in five Canadian students say they have mixed alcohol with energy drinks, which researchers call a public health concern.

Doctors say energy drinks mask the symptoms of intoxication and can lead to more risk-taking behaviour, such as drunk driving. That in turn increases the likelihood of injury, compared with drinking alcohol alone in the short term.

Mark Ashbridge of Dalhousie University in Halifax used nationally representative data from 36,155 students who were in grades 7 to 12 in 2010-2011 to determine how commonly alcohol is consumed together with energy drinks or in premixes sold in a bottle or can.

About 20 per cent of participants said they did mix energy drinks and alcohol, which is in line with previous studies of university students in Canada, the U.S. and Europe.

Use was highest in British Columba (26 per cent) and Nova Scotia (26 per cent) and lowest in Prince Edward Island (16 per cent).

"Consumption of these drinks is substantial among Canadian high school students and can lead to many potential harms," the study's authors concluded in this week's issue of the journal CMAJ Open.

"Given that youth continue to drink alcohol illegally, alternative strategies may be more effective than top-down, abstinence-based programs."

The main concern should be underage drinking, the researchers said.

They suggest a flat tax on energy drinks or a variable tax that reflects caffeine content, such as Saskatchewan's, as well as harm-reduction campaigns to encourage young people not to mix alcohol with energy drinks.

While there were provincial differences in consumption, it's not known if variations in the availability of energy drinks, prices or provincial taxes made a difference.

Use of alcohol mixed with energy drinks was higher among students were who younger, marijuana users, and those who were frequently absent from school, involved in sports and had more spending money.

Doing well in school and feeling more connected to school seemed to be protective.

The researchers noted that the students were reporting on their own use of the substances, which is a sensitive subject.

The team did not have demographic data such as family income or the students' mental health that could influence consumption.

Students from all provinces except New Brunswick were included.

In January, researchers in the U.S. said the number of people seeking emergency treatment after consuming energy drinks has doubled across the country over the past four years. Most of the cases involved teens or young adults.

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  • Risk: Caffeine Overload

    Many energy drinks and other products feature very large amounts of caffeine -- approximately three times the amount found in a regular cup of coffee -- often along with other stimulants. The problem with consuming large amounts of caffeine is two-fold, explains K. Steven Whiting, Ph.D., of Phoenix Nutritionals in San Diego and author of "Healthy Living Made Easy". One, it targets the central nervous system directly. Two, it can lead to dehydration and loss of water-soluble nutrients that have a calming effect on the central nervous system. This combined effect can cause agitation and sleep problems and potentially lead to the development of long-term anxiety issues.

  • Risk: Too Many 'Energy-Boosting' Ingredients

    Caffeine may not be the only stimulant in your energy drink. Many of these products contain similar ingredients, from various forms of caffeine to guarana, acai berry, taurine, ginseng, arnitine, creatine, inositol and ginkgo biloba -- all of which have stimulating effects. "Taurine has been shown to improve athletic performance so this may be the reason why it is added to many of these drinks -- and mixing taurine with caffeine may increase mental performance, but this research remains inconclusive," says Amy Shapiro, R.D., C.D.N., of Real Nutrition in New York City.

  • Risk: Sugar Overload

    Other dangers of energy drinks can be traced to the fact that they're also loaded with sugar, a particular health risk for children and people at risk for diabetes. Even for non-diabetics, all the sugar causes a crash a few hours later, leaving the drinker more exhausted than before they had the drink. Keep in mind that while sugar-free energy drinks may be a better option, sugar-free versions of Red Bull, Amp, Rockstar, NOS and Crunk still carry serious risks because of their high caffeine content and artificial ingredients, including artificial sweeteners like aspartame.

  • Beware of Energy Drinks for Kids

    With endorsements from cartoon characters and famous athletes, many energy drinks are marketed directly to kids and teens. "Young people really need to be careful with these energy products because their central nervous system is not full developed and [the drinks] can lead to longer-term health problems," Whiting warns. Talk to your child's doctor about whether any amount of caffeine is acceptable, and make sure your teen knows the possible dangers of drinking these products. <br><br> In the lawsuit against Monster, Fournier's mother says that the caffeine in energy drinks should be regulated, particularly because the drinks are heavily marketed to teens and children.

  • Do Not Mix: Energy Drinks And Alcohol

    Some energy drinks not only contain high amounts of caffeine and sugar but also high amounts of alcohol and have been associated with serious side effects, including death. Some states, including New York, have banned drinks that combine alcohol and caffeine, but many people continue to mix them through Red Bull-vodka cocktails, among others. "The combination of alcohol and caffeine may lead to adverse effects, as the presence of caffeine increases the absorption of alcohol, which can increase intoxication," Shapiro says. Although many people may think that the caffeine in these drinks can prevent the drowsiness associated with drinking alcohol, it cannot prevent the effects that alcohol has on the brain.

  • The Problem With Energy Shots

    Energy shots, including 5-Hour Energy and 6-Hour Energy, provide a burst of energy to help you get through the day and typically do not contain large amounts of sugar, but the amount of caffeine they contain is unclear. "The problem with these energy products is no one really knows how much is too much," says Whiting. "The manufacturers have not done any studies to determine the appropriate amount, as caffeine is an uncontrolled substance. They don't put any warnings or precautions on these products either."

  • Energy Strips Caution

    Energy strips, including LeBron James's Caffeine Strips, are packaged like breath strips and are marketed to teens and tweens. They have the same dangers as energy drinks. "Energy strips are likely absorbed much quicker than other energy products as they are absorbed directly into the bloodstream through the tongue," Shapiro explains.

  • The Dangers Of Caffeine Pills

    Caffeine or energy pills carry a greater risk for adverse effects when used in combination with other energy products. "The problem is that many people probably use more than one form of these products to stay awake," Whiting says. "They take an energy or caffeine pill in the morning, have a cup of coffee, and in the middle of the afternoon have an energy drink -- it can be very harmful to have this excess of caffeine."