Energy Drinks--Good, Bad or Ugly?
Stimulants from a Can...What are the Risks and Benefits?
Aug 14, 2008
Americans are paying big bucks to feel “energized.” We spend nearly $3.5 billion annually on drinks named Rockstar, Red Bull, Power House, Adrenaline Rush, Monster, Spike, and Venom. Eight million adolescents guzzle these beverages on a daily basis, and both casual and dedicated athletes use them to get an extra “push.”
Exactly what is it that makes energy drinks so popular? Caffeine is the primary ingredient that gives these liquids their zing. The average cup of coffee contains about 75 milligrams of caffeine; Red Bull—an energy drink at the lower end of the jitter scale—contains 80 mg. In contrast, an 8.4 oz can of Spike Shotgun houses a whopping 350 mg of caffeine.
A multitude of other ingredients are added to energy drinks, including sweeteners, vitamins, amino acids, antioxidants, and assorted herbs. With new and improved versions of energy drinks appearing worldwide—seemingly with the primary goal of ramping up the dosages of stimulants—it’s time to reevaluate the benefits and potential problems associated with these beverages.
Benefits
- Caffeine, in conjunction with physical training, enhances performance in single bouts of endurance exercise (long distance running, for example); it may also improve strength and speed during shorter-duration exertion. When ingested before exercise, caffeine accelerates the burning of fat.
- In moderate doses, caffeine has been shown to improve performance on certain cognitive tests, and it may help to protect memory in elderly women. Other health benefits attributed to caffeine are the subject of ongoing research.
- Amino acids are the building blocks for proteins. Taurine, a derivative of the amino acid cysteine and a common energy drink ingredient, has not been shown to directly increase energy levels. However, it appears to decrease muscular fatigue and improve exercise capacity. Taurine may also favorably affect nerve transmission and fat metabolism.
- Most energy drinks contain an array of B vitamins; doses vary from 100% to 8,000% of daily recommendations. B vitamins are necessary for building proteins and energy molecules; they are needed in higher doses during times of stress.
- Herbs like ginseng, guarana (a natural source of caffeine), astragalus, and schisandra have their advocates, and some of these plants have been used for centuries in certain cultures. However, relatively few controlled studies have been done to support claims that many of them significantly increase energy levels.
- Sugar, in one form or another, is the sweetener found in most energy drinks. And most energy drinks have a lot of sugar. Since glucose is the body’s preferred source of fuel, and since most natural sugars are converted to glucose, the reason for adding sugar to an energy drink seems clear: sugar is glucose, glucose is fuel, and fuel is good.
Risks
It is possible, although rare, to fatally overdose on caffeine. While it would take about 70 cups of coffee to administer a lethal dose, one must remember that energy drinks typically contain more caffeine than a cup of coffee.
- High doses of caffeine can cause palpitations and cardiac dysrhythmias. The most common abnormal heart rhythm is tachycardia (rapid heart rate), but other, potentially deadly rhythms are possible, particularly for those with pre-existing heart problems—or those using recreational drugs.
- Caffeine, particularly in larger doses, is a mild diuretic, perhaps because one of its metabolites (theobromine) increases renal blood flow, or because it decreases sodium and water reabsorption in the renal tubules. In addition, the high sugar concentrations found in most energy drinks inhibit the absorption of water from the gut. In the absence of adequate fluid intake (during exercise, for example), energy drinks can contribute to dehydration.
- For pregnant women, experts recommend a maximum daily caffeine dose of 200 mg (many energy drinks contain more). Higher doses increase the risk of miscarriage. Additionally, fetuses can’t efficiently metabolize caffeine.
- High doses of caffeine (500 to 600 mg) will raise systolic blood pressure to a small degree; this may be pertinent for those who already have hypertension.
- Regular use of caffeine leads to tolerance; in order to maintain the same level of central nervous system stimulation over time, higher doses must be ingested.
- The increasingly popular practice of mixing energy drinks with alcohol simply aggravates these beverages’ ill effects.
Since individuals who regularly use energy drinks tend to exist on the “extreme” edge of life, moderation is not a concept they’re likely to embrace. For the rest of us, a bit of restraint in the use of these products seems wise.
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