It seems that everywhere you look these days – on television, at the grocery store, vending machines, and sporting events – you see claims made about the benefits of energy drinks. But are these caffeine-laden beverages really providing energy, improved performance, or mental alertness as many of them claim? Let’s take a look.

Depending on the brand, energy drinks contain mostly carbonated water in combination with caffeine and a host of other ingredients and flavorings, which can include sugar, ginseng, taurine, carnitine, guarana, and one or more added vitamins.

While a normal 8-oz serving of coffee contains between 134 and 240 mg of caffeine, the caffeine content of an 8-oz serving of an energy drink can range between 72 and 150 mg. The catch, however, is that most energy drinks come in bottles containing two to three servings, bringing the potential caffeine content in one bottle to 450 mg. Sugar content of these beverages ranges from 0 to 30 g per serving.

Many of the claims made by manufacturers of these beverages, such as promoting weight loss or improving athletic performance, have not been proven to be true. For that reason and because of the potentially high caffeine content, it is not recommended that children and youth use energy drinks and that healthy adults limit their use. Large amounts of caffeine can increase heart rate and blood pressure and interfere with normal sleeping patterns.

So next time you reach for an energy drink, remember that you are really drinking a highly caffeinated beverage, probably containing sugar and other ingredients, that may or may not live up to claims made about it and may or may not be safe for consumption.