Energy Drinks: What are they really doing to your health?

Energy Drinks: What are they really doing to your health?

Energy drinks boost energy, increase alertness and reduce fatigue but this may come at a cost to your health.


Teenagers sip them as they walk to school, athletes scull them before a training session and office workers drink them at their desks. Over the last decade, the consumption of caffeinated beverages intended to “energise” has skyrocketed with Australians spending more than $500 million a year on energy drinks. Touted as a convenient way to increase alertness and reduce fatigue, energy drinks are big business is today’s fast-paced society. But do these drinks really contain, how do they work and are they in fact safe?

What are energy drinks?

Energy drinks are beverages that contain caffeine in combination with other ingredients such as taurine, B vitamins, guarana 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. However, this is not the case in Australia 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: their impact on health

According to a new report by the World Health Organization, adverse reactions and toxicity from energy drinks stem primarily from their caffeine content. Caffeine is an adenosine receptor antagonist and central nervous system stimulant. 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.

In healthy adults, a daily caffeine intake of 400mg or less is considered safe. Toxicity begins at 1g, while 5 to 10g can be lethal. Consuming 4 to 12mg of caffeine per kilogram of body weight has been associated with anxiety and jitteriness, while headaches and fatigue are common withdrawal symptoms after short-term, high-dose use. Increasingly, toxicity from caffeine overdose is being reported to hospitals and poisons centres.

Caffeine aside, energy drinks are also loaded with empty kilojoules and sugar. A 500ml can of V contains almost 1000kJ and 53g of sugar – 60% of the total recommended daily sugar intake. High sugar consumption contributes to weight gain, raises levels of harmful blood fats called triglycerides and contributes 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 alcohol’s sedative effect making us more alert, the mixed drink can lead to negative 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 are a ‘wide-awake drunk’. The short consequences of this are endless, while we still do not know about the long-term impact.

Image Credit: BigStock


CAITLIN (53 of 58)About the author
Caitlin Reid is a unique health professional with qualifications as an accredited nutritionist, accredited exercise physiologist and yoga teacher. Caitlin is passionate about all things health and wellness, and keeps up-to-date with the latest health research, which she uses when contributing expert advice to health, fitness, lifestyle and food companies. She is also the nutrition expert for the Women’s Fitness magazine, the dietitian for the South Sydney Rabbitohs and ambassador for Papaya Australia. Follow Caitlin on Instagram @caitlinareid or visit her website.

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