Energy drinks have become a popular way to get a quick boost when people are tired or trying to power through a workout or busy day.
But some energy drinks contain significantly more caffeine than a typical cup of coffee, and the effects can be more concerning for people who are already predisposed to certain heart, neurological or behavioral conditions.
Dr. Stacy Chronister, an internal medicine specialist with OSU Medicine, explained what consumers should know about energy drinks, caffeine levels and potential side effects.
Q: How much caffeine is in an energy drink compared with coffee or tea?
The amount of caffeine can vary significantly depending on the drink.
Black tea and green tea typically contain around 30-50 milligrams of caffeine. An 8-ounce cup of coffee generally has about 80 to 100 milligrams.
Energy drinks can contain considerably more. Chronister said some contain around 160 milligrams of caffeine, while some popular products have 200 to 300 milligrams in a single drink.
That means one energy drink can contain the equivalent of several cups of coffee.
Q: Why can energy drinks cause side effects?
The high caffeine content can affect the cardiovascular and nervous systems.
Chronister said people may experience high blood pressure, a rapid heart rate, anxiety and other behavioral changes. In more serious cases, neurological effects such as seizures can occur.
Those effects can be more concerning for people who already have a predisposition to certain conditions, even if they are not aware they have one.
The effects may also be more noticeable when someone is already depleted, such as when they are tired, dehydrated, sick or have been exercising.
Q: What should people know about the other ingredients in energy drinks?
Caffeine is not necessarily the only consideration when looking at an energy drink’s ingredients.
Chronister discussed ingredients including guarana and other additives that can contribute to the overall stimulant effect of a drink.
Consumers should look closely at the ingredient list and caffeine content rather than assuming an energy drink is safe simply because it contains vitamins or other ingredients that sound beneficial.
Q: Can energy drinks interfere with medical tests?
Another concern involves biotin, a B vitamin found in some energy drinks and supplements.
Chronister said biotin can interfere with certain laboratory tests, including thyroid tests and some tests used to evaluate the heart.
That can become particularly important if someone consumes an energy drink and later seeks emergency medical care for symptoms such as chest pain or heart palpitations.
Patients should tell medical providers about supplements and energy drinks they have consumed so doctors can take that information into account when evaluating their symptoms and test results.
Q: How much caffeine is too much?
Chronister recommends keeping caffeine below 200 milligrams in a single drink and, ideally, below 400 milligrams per day for adults.
That means consumers should pay attention to both the amount of caffeine in an individual energy drink and how much caffeine they consume from other sources throughout the day.
Someone who drinks an energy drink containing 200 to 300 milligrams of caffeine may already be consuming a substantial portion of the recommended daily limit before accounting for coffee, tea or other caffeinated products.
Q: Should children and teenagers drink energy drinks?
Chronister recommends that adolescents avoid energy drinks completely.
Teenagers are among the people who frequently consume these products, but the high caffeine content can be particularly concerning because of the potential cardiovascular, neurological and behavioral effects.
Parents should pay attention to how much caffeine children and teenagers are consuming and remember that energy drinks can contain substantially more caffeine than a typical serving of coffee or tea.
What should consumers remember?
Energy drinks may provide a temporary boost, but the amount of caffeine can vary widely between products.
Consumers should check the caffeine content before drinking an energy drink, avoid frequent consumption and be especially cautious if they have conditions that could make them more vulnerable to caffeine’s effects.
