These are the hidden risks in energy drinks, according to one expert

Energy drinks are shown in a store on July 26, 2010 in Montreal. (Paul Chiasson / The Canadian Press)

Energy drinks have become a go-to choice for students, shift workers and gym goers looking for a quick boost. Registered dietitian Nishta Saxena says the appeal lies in the promise of instant performance.

“It feels like a hack. You want to kind of do multiple things at once. You want to feel energized. You kind of want to create this sort of superhuman version of yourself,” Saxena told CTV’s Your Morning Tuesday.

For this reason, Saxena says people opt for energy drinks over coffee.

What’s inside the can

Most energy drinks are built around four major components, Saxena said.

The first is caffeine, typically around 160 milligrams per serving, just under Canada’s legal limit of 180 milligrams set by Health Canada.

Saxena said caffeine sources may vary from traditional coffee or green tea extract, guarana or yerba mate, which are natural sources of caffeine — all of which deliver sightly different effects.

These drinks also contain amino acids, such as L-taurine or L-carnitine, which Saxena says are meant to enhance brain and cellular energy.

Many drinks also include B vitamins, which help covert food into energy. Lastly, herbal ingredients like ginkgo biloba or ginseng — which Saxena refers to as the “biohacking piece” — are marketed to improve mood, memory or mental clarity.

“Each of these substances has clinically effective doses and benefit. The problem is we’re not studying these doses together. They’re not regulated,” Saxena said.

“We don’t know exactly how much is in each drink, and how they work together when they’re layered with other things you may have through the day,” she added.

Hidden risks

Saxena cautioned that energy drinks can carry serious health risks, especially for people on blood pressure, heart, diabetes or thyroid medications. These drinks can cause dehydration, digestive upset and appetite suppression, leading to nutrient deficiencies.

“They have a huge impact on mood. If you’re sensitive to things like depressive feelings or anxious feelings, these drinks can push you right into an area of having like arrhythmias, anxiety attacks,” Saxena explained.

A 2024 study published in Heart Rhythm found that energy drink consumption had been linked to sudden cardiac arrest in individuals with underlying heart conditions. Researchers reviewed 144 cases of cardiac arrest survivors and discovered seven of them — about five per cent — experienced their episodes shortly after consuming energy drinks.

The study highlighted that many of these individuals had genetic heart disorders suggesting that the combination of high caffeine and stimulants found in energy drinks could trigger arrhythmias in susceptible people.

Whose it for?

Saxena emphasized that no one under 21 should be consuming energy drinks, echoing international efforts like the U.K.’s push to restrict sales to minors.

Saxena said for certain groups of people, an energy drink would be a benefit.

“If you were a shift worker working long shifts ... some of our frontline workers may be using these to get through really difficult shifts,“ she said, adding that older university students may also use energy drinks for long study sessions and exams.

Saxena also listed gym goers and athletes who may use them as performance enhancers, depending on the type of workout.

“For most people, they’re really unnecessary.” Saxena said, adding that stacking an energy drink with other additives, like a morning coffee, can be risky.

In 2024, Health Canada warned Canadians over 18 that exceeding 400 milligrams of caffeine per day - roughly two strong energy drinks - can increase insomnia, nervousness, rapid heart rate and dehydration.