Energy drinks are becoming increasingly popular among those needing a boost to keep going through a late-night session of study or work. With attractive names such as Red Bull, Shark and Red Dragon, these products promise to keep you energetic and alert.

But before you stock up on Red Bull to get you through RRSP season, nutritional experts say, energy drinks should be taken with caution — preferably, not at all.

These beverages rely on caffeine and sugar to provide stimulation. You should never consume more than 500 millilitres of energy drinks in one day; reported side effects include rapid heart rate and increases in blood pressure, according to the Dietitians of Canada, the professional association for dietitians.

In addition to caffeine and sugar, energy drinks typically contain other ingredients, such as ginseng, guarana, taurine and green tea, says Nicole Springle, a registered dietician and sports nutritionist with the Cleveland Clinic Canada in Toronto. The effects of mixing such substances and supplements have not been studied.

While a cup of coffee usually has about 80 milligrams of caffeine, some energy drinks can have more than three times that amount — up to 250 mg, according to Springle. The caffeine in energy drinks may be listed on the label as the ingredient guarana, a tropical bean that is a source of caffeine.

Another ingredient, taurine, is a compound similar to amino acids that occurs naturally in foods such as meat and dairy products. Claims that taurine improves alertness have not been substantiated.

The herbs gingko biloba and ginseng, and other common ingredients in energy drinks, can interact with some prescription drugs.

Sarah Mahdavi, a registered dietician and nutrition therapist (www.balanced-nutrition.ca) in Toronto, suggests a small cup of coffee as a more healthy alternative to energy drinks if you need a boost. Although energy drinks contain pure caffeine, coffee also contains antioxidants, which can prevent disease.

The high sugar content in energy drinks is also a problem. Too much sugar in the body can lead to obesity and illnesses, Springle says, such as heart disease and diabetes.

And you should never take energy drinks before exercising, says Springle, who is also an official provider of nutrition services for the Ontario chapter of the Canadian Sport Centre and the Coaching Association of Canada. The caffeine in energy drinks makes them act as a diuretic, which makes you lose body fluids through urine.

Using energy drinks before or during long periods of exercise can lead to other complications. After about 90 minutes of exercise, the body needs a source of carbohydrates that can be quickly absorbed, says Springle. The high concentration of carbohydrates in energy drinks can cause cramping in the stomach. She recommends sports drinks, such as Gatorade or PowerAde, which have less sugar.

Additionally, the effects of the stimulants in energy drinks combined with the physical activity can overstimulate the central nervous system, which can withstand such stimulation for no more than two or three hours in a 24-hour period.

Consuming energy drinks throughout the day — with or without exercise — will overstimulate your body, resulting in chronic fatigue. Says Springle: “After the body is overstimulated, energy levels tend to drop.”

There are many healthy and effective alternatives to energy drinks when you want to battle fatigue. Have some water, a glass of milk or real fruit juice (not a fruit drink), dieticians advise. Fruit juice provides the natural vitamins and minerals that are in the fruit.

Or try a balanced snack with high fibre and a source of protein. A whole-grain granola bar accompanied by some protein will help the energy last longer. Cheese and crackers, fruit and yogurt, or trail mix with dried fruit and nuts are all good alternatives, Springle says.

Drinking water is always the best way to hydrate when exercising — particularly, when weight training or on a half-hour run. If you plan to exercise for a longer period, try making your own sports drink: equal amounts of fruit juice and water plus a pinch of salt.

Most energy drinks are classified as supplements and fall under Health Canada’s “natural health product” regulations. Not all energy drinks on the market have been approved under those regulations. If you can find the letters DIN or NPN followed by an eight-digit number on the can, the drink has been approved for sale. But that does not mean it is safe in large doses or for everyone. IE

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