From flat whites to energy drinks, Australian adolescents drink a surprising amount of caffeine. Here’s how it affects their health.

Lucy E Cousins
Updated September 2020

On average, 75% of Australians enjoy at least one cup of coffee a day. Picking up a coffee from your local café is a daily routine for many, so it’s no great surprise that our teenagers are starting to take part in our coffee culture.

Research suggests 15% of Australian teenagers are regularly drinking coffee and the average consumption of caffeinated tea among 14–17-year-olds is 5.5 cups a week. But caffeine intake isn’t limited to tea and coffee, with the consumption of energy drinks also rising.

The effects of caffeine on teenagers

How does caffeine intake affect teenagers’ minds and bodies, and should we be worried? As clinical psychologist Gemma Cribb explains: “Caffeine acts as a central nervous system stimulant to increase alertness and make you feel less worn out. It binds to the adenosine receptors in your brain, preventing the chemical from making you feel tired.”

And while feeling less tired may seem beneficial for overworked adults, the effects of caffeine in teenagers can be far reaching. Studies show caffeine consumption can affect a teenager’s concentration and ability to sleep, which in turn may slow the maturing process of their brains.

And because of their smaller body weight (on average), caffeine has more than twice the impact on children than it does on adults. This means children and young adolescents are more susceptible to caffeine-related symptoms such as anxiety, insomnia and nervousness.

Additionally, studies have suggested that the adolescent brain is more susceptible to stress and addiction due to the way the developing brain is wired. “During adolescence, the brain has the most neural connections it will ever have in your life,” Gemma explains. “Caffeine (with its effects on sleep) will disrupt your brain's ability to form these connections.”

In very rare cases, coffee could put pressure on the heart if consumed in very high doses, particularly where there could be an existing heart condition, reports the American Journal of Clinical Nutrition.

Coffee vs energy drinks for teens

Aside from coffee and tea, soft drinks, and in particular, energy drinks, can include high levels of both caffeine and sugar. Cancer Council’s research found that one in six Australian teenage boys drinks at least 52 litres of soft drink every year. Given some energy drinks can contain as much as 320mg of caffeine (equivalent to 2–3 cups of coffee), this is a reason for concern.

The mix of caffeine and sugar can also affect mood, according to dietitian Susie Burrell. She says that after drinking an energy drink, teenagers can “experience a ‘down’ period about 30-40 minutes afterwards”, which can lead to poor health choices. This correlates to research conducted by Cancer Council, which found teenagers who drink soft drinks and energy drinks are twice as likely to also be consuming more junk food.

“Consuming too much caffeine can stop a teenager from getting adequate nutrition,” says Gemma. “Especially if they choose to drink coffee and soda rather than consuming more nutrient-dense foods, for example.”

The pressure to perform

The rise in teenagers’ caffeine consumption could easily be put down to marketing and popular culture embracing coffee and performance drinks, but Gemma believes it might be societal pressures that make caffeine more attractive to teenagers.

“There’s a lot of pressure on teenagers to perform,” she says. “They feel the need to keep up with social media, their homework and the fast pace of modern life in general. And they see caffeine as giving them an edge.”

At what age is caffeine or coffee safe for teenagers?

Susie advises that adolescents under 14 should avoid caffeine where possible, and teenagers between 14 and 17 years of age should limit their intake to 100mg or less a day.

“That’s equivalent to a small milky coffee (60mg), or a couple of cups of tea (30mg each), or some [dark] chocolate (26mg/40g) a day,” she says.

“Some teenagers are drinking four large coffees, an energy drink plus a cola drink in a day. That could equate to as much as 500–600mg of caffeine. That’s why, as a rule, energy drinks that are high in sugar and stimulants should be avoided altogether.”

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