As teenagers walk to school each morning, it’s not uncommon to see a huge can of energy drink being guzzled along the way. Over the past 10 years, the consumption of caffeinated beverages intended to “energise” has skyrocketed. Energy drinks have been found to comprise 20% of a total convenience store, but along with the increase in their consumption there has also been a rise in the incidence of toxicity from caffeine overdose. So are energy drinks safe and should our teens really be having them?
Energy drinks and their impact on health are never far from the headlines. Unsurprisingly, they have been thrown back into the spotlight again as a lawsuit against Monster Beverage (the manufacturer of Monster Energy) begins in the California Supreme Court, following the death of a fourteen year old US girl. In December 2011, the teen girl downed two 700ml cans of energy drink while hanging out with friends. By drinking two large energy drinks, the teen consumed 480mg of caffeine – that’s the caffeine equivalent of 14 cans of Coke! The next day she went into cardiac arrest. Six days later she died with the official cause of death being cited as cardiac arrhythmia due to caffeine toxicity. While the girl and her family knew she had a malfunction in a heart valve (a common heart condition called mitral valve prolapse), the teenager’s doctor felt that her case posed little health risk. But when you consider the amount of caffeine she consumed from those two energy drinks the day prior to the cardiac arrest – nearly five times the amount recommended by the American Academy of Pediatrics – questions need to be asked about the safety of energy drinks for not only teens but all of us.
What are energy drinks?
Energy drinks are beverages that contain caffeine, taurine, vitamins, herbal supplements and sugar or sweeteners, and are marketed to boost energy levels, stamina, concentration and athletic performance. Caffeine is the main ingredient in energy drinks with many energy drinks containing 70 to 80mg per 250ml. However, when packed as energy shots or as larger drinks, the caffeine content can be nearly five times greater than that found in 250ml of coke. Additional caffeine is also present in additives such as guarana, which are also found in energy drinks. Each gram of guarana contains 40-80mg of caffeine and potentially it has a longer half-life (length of time for caffeine the initial caffeine dose to still be in our system) due to the interactions with other plant compounds. In the US, manufacturers are not required to list the caffeine content from guarana and other ingredients. Therefore, the actual caffeine dose in a single serving may exceed that listed on the food label. This is not the case in Australia however, where the listing of caffeine on the label of energy drinks includes “all caffeine present from whatever source in a formulated caffeinated beverage” as stipulated by Food Standards Australia and New Zealand in Standard 2.6.4.
Energy drinks and health
Adverse reactions and toxicity from energy drinks stems primarily from their caffeine content. Caffeine is an adenosine receptor antagonist and central nervous system stimulant. In healthy adults, a caffeine is of 400mg or less per day is considered safe, while acute clinical toxicity begins at 1g, and 5 to 10g can be lethal. In children and teens, caffeine should be limited to no more than 100mg per day. Caffeine constricts blood vessels in the brain and heart, relaxes smooth muscle, stimulates skeletal muscle and improves insulin sensitivity. Large amounts of caffeine increase urine flow and sweat excretion and alter blood electrolyte levels. Consuming 4 to 12mg of caffeine per kilogram of body weight has been associated with undesirable symptoms including anxiety and jitteriness, while headaches and fatigue are common withdrawal symptoms after short-term, high-dose use. In children, caffeine increases blood pressure and sleep disturbances. Cessation in children who habitually consume caffeine leads to a decrease in attention, while reaction time increases.
Caffeine aside, energy drinks are also loaded with sugar, and just like other sweetened beverages contribute to obesity. A 500ml can of V energy drink contains almost 1000kJ, 155mg of caffeine and 53g of sugar – that’s 60 per cent of our total daily sugar allowance. While too many kilojoules is bad for the waistline, high consumption of sugar can raise levels of harmful blood fats called triglycerides and contribute to atherosclerosis by stiffening arteries, making it damaging for the heart. In addition, studies among American college students show that mixing energy drinks with alcohol is more dangerous than consuming alcohol alone. When combined the energy drink acts as a stimulant boosting alertness, while the alcohol works as a sedative. While the energy drink masks some of the sedative effect of alcohol making us more alert, the mixed drink can lead to negative physiological side effects associated with over stimulation such as heart palpitations, sleep difficulties, agitation, tremors, irritability and tension. Our perception of our level of intoxication is also decreased when we drink alcohol mixed with energy drinks, so people are getting more and more intoxicated because they’re a ‘wide-awake drunk’. This has all different types of consequences including risky behaviour.
Where to from here?
A new review published in The Medical Journal of Australia states that health authorities should increase awareness of the problem of energy drinks, as well as improve package labeling and regulate caffeine content. Health warnings and the national poisons hotline number (13 11 26 in Australia) should be included not only on packaging but also along side any marketing of energy drinks are also recommended by the authors. While the report doesn’t discuss placing an age-restriction on energy drinks, this is something that should be considered as teens and young adults are particularly attracted to energy drinks, yet often have a lack of knowledge about the potential harmful effects. Then again, are energy drinks necessary in the first place?
Do you think energy drinks should be restricted to people 18 and older?