What we know about the health effects of so-called 'energy drinks' is quite limited, and what we do know is based more on their ingredients than on the whole of the product. There are a limited number of very small studies (fewer than 50 participants) for the whole product, but most health effects research is based on individual ingredients rather than the whole product.
The definition of an 'energy drink' is not fixed, but a number of descriptions are used. For example, 'stimulant drinks,' 'formulated caffeinated beverage which may contain carbohydrates, amino acids, vitamins and other substances for the purpose of enhancing mental performance." Energy drinks are now about sugar, caffeine and sometimes alcohol. But instead of focussing on what to call them, just think of these as highly-caffeinated drinks. That will give you a clear idea of what they are meant to do. And energy drinks are not the same as 'sports drinks' which are formulated to prevent hydration and enhance sports performance.
Among the more visible brands of energy drink are Red Bull, Rock Star and Monster, each of which contain large doses of caffeine and other legal stimulants like Guarana and ginseng. The amount of caffeine in an energy drink can range from 75 milligrams to over 240mg; coffee and colas range up to about 100mg.
But do energy drinks deliver on their promises? In short, "yes but." Various studies confirm that there are significant improvements in mental performance after consumption. The "but" comes from the various health concerns from consuming high levels of caffeine, particularly among youth and children, and from the implications of mixing these drinks with alcohol.
Health Canada has concluded that a healthy adult male can tolerate up to 400mg of caffeine per day; a woman of reproductive age can tolerate up to 300mg. In comparison, the American Academy of Pediatrics recommends that adolescents get no more than 100mg of caffeine a day and that younger children should not consume caffeinated beverages on a regular basis.
These figures are based on consumption over the period of a day, not all at once. Too much within an hour or two can lead to adverse reactions including stomach ache, insomnia, nervousness, nausea or more serious reactions. Indeed, a single ingestion of 250mg by a healthy adult has been shown to increase blood pressure, and more than 450mg may result in tachycardia (abnormally fast heartbeat).
One of the most significant concerns over energy drinks comes from their use as mixers with alcohol. This combination leads to a number of potential dangers. First, consuming alcohol with a carbonated mix means faster absorption of the alcohol. But because of the caffeine in the mix, the effects of the alcohol are masked so a drinker may feel he or she is not as intoxicated as they actually are. In turn, this may lead to risky behaviour. No matter how alert they feel, their blood alcohol concentration remains the same as it would be without the energy drink.
Some of these riskier behaviours include being taken advantage of, or taking advantage of another person sexually, or riding in a vehicle with a driver who's under the influence. Consuming alcohol with energy drinks is also associated with increased weekly drunkenness and binge drinking.
Energy drinks may give a person a short-term boost, but high levels of caffeine, especially mixed with alcohol, bring their own risks, something to consider when downing yet another 'booster'.
Editor's note: Dr. Paul Martiquet is the medical health officer for rural Vancouver Coastal Health including Powell River, the Sunshine Coast, Sea-to-Sky, Bella Bella and Bella Coola.
