Energy Boost or Energy Bust?
What are energy drinks?
The term “energy drinks” was coined by companies in the beverage industry and refers to beverages that contain caffeine in combination with other ingredients, such as taurine, guarana, ginseng, and B vitamins. Taurine is not an “upper” and has no known stimulatory effect on the body. It is unclear why taurine is added to energy drinks though it may reduce the jittery effect of high caffeine dosages or offset the dehydration effects of high levels of caffeine, typical in energy drinks. Substances such as guarana and ginseng are herbal stimulants that are often added to enhance the effects of caffeine. For example, 1g of guarana ≈ 40 mg caffeine and may substantially increase the total caffeine in an energy drink. B vitamins may be added to make the drinks appear “healthy” or because of their role in converting food into energy or in supporting or increasing the rate of metabolism. Overall, these beverages claim to provide their consumers with extra energy.
Is there evidence that these energy drinks increase energy?There is limited evidence that consumption of energy drinks can significantly improve physical and mental performance, driving ability when tired, and decrease mental fatigue during long periods of concentration. However, the research around these claims is limited, and it is not clear if these improvements are due to the caffeine, the other herbal ingredients, or the combination of caffeine and the other ingredients.
How much caffeine is in these drinks?A variety of numbers are quoted in different sources as to the caffeine content of popular beverages. Within a general range, a twelve-ounce can of carbonated soda, such as regular or diet Coca-Cola® or Pepsi® has 30-45mg of caffeine. Mountain Dew® comes in higher at 45-60mg. An eight-ounce serving of brewed coffee has almost three times the amount as soda at about 135mg of caffeine, and eight-ounces of brewed tea has similar to a twelve-ounce soda at 50mg.
A twelve-ounce serving of an energy drink has a caffeine content similar to that of the eight-ounce coffee – at around 120mg. Comparing these numbers can be deceiving because the amounts for the energy drinks are often quoted in eight-ounce servings, whereas sodas are more often seen in 12-ounce servings. Red Bull is sold in a smaller, one-serving can, but other energy drinks such as Rockstar or Monster are sold in large cans – so that the consumer is actually taking in 2-3 servings if he drinks the whole can – thus bringing the caffeine intake even higher.
Many people report anxious, jittery feelings of uneasiness after the consumption of more than 200mg of caffeine, and certainly by 400mg. Adverse effects associated with caffeine consumption close to 400 mg include nervousness, irritability, sleeplessness, increased urination, abnormal heart rhythms, and upset stomach.
Tracking your daily dose of caffeine can be tricky, as it is hard to know how much caffeine is in a given beverage, or even from one cup of coffee or tea to the next. But studies suggest just 100mg of caffeine, or the amount in a 6-ounce cup of coffee, are all that is needed for the average person to get a little boost.
What about us?A study in 2004 found caffeine consumption in adolescents to be associated with elevated blood pressure. Therefore, the consumption of energy drinks by children and adolescents is not recommended. Furthermore, energy drinks, like soda, contain added sugar, which also causes energy levels to rapidly rise and then fall and should be limited in a well-balanced diet.
Research has found consumption of caffeine prior to heavy exercise to be safe; however, the
safety of consuming caffeine in combination with other herbal supplements found in energy drinks prior to or during exercise has yet to be established. Until the safety of this practice can be established, consumption of energy drinks prior to exercise by individuals of any age is not recommended.