Health Effects

Energy Drinks,Common ingredients

Although energy drinks manufacturers claim that ginseng can improve physical performance, studies generally have not shown a significant benefit. Therapeutic doses for ginseng commonly range between 100 and 200 mg/day, with doses as high as 2,000 mg daily. A review of several popular energy drinks revealed sub therapeutic quantities of ginseng. For instance, SoBe Adrenaline Rush contains 25 mg, Full Throttle 90 mg, and Rockstar Juiced 25 mg.  To get the lowest therapeutic dose, a consumer would have to drink a minimum of two to four cans per day.

Taurine

Another ingredient often found in energy drinks is the beta-amino acid taurine.  Taurine is the most abundant intracellular amino acid in the human body.  The scientific name of taurine is 2-aminoethane sulfonic acid.  It is a conditionally essential nutrient; in other words, healthy adults can manufacture taurine from other amino acids, but infants and ill adults must obtain it via foods or supplements.

 Many important physiological functions are associated with taurine, the most common of which is its role in the formation of taurine bile acid conjugates in the liver, which are essential for micelle formation and fat absorption.

Drinks containing taurine and caffeine (1,000 mg and 80 mg/240 mℓ, respectively) were evaluated for effects on mood, memory, and information processing in healthy volunteers. Whether the effects resulted from the individual taurine or caffeine components could not be determined.

Energy drinks containing taurine and caffeine have been linked with athlete deaths in Europe, and some countries have banned or limited their sales. It is worth to mention that the European Food Safety Authority has refused to approve claims that “Taurine helps maintain mental function and heart health and reduces muscle fatigue”.

 Bitter orange

Bitter orange was used in many reformulated products. The active components of bitter orange are synephrine and octopamine, which are structurally related to epinephrine and norepinephrine, respectively. Bitter orange is used as a treatment for nasal congestion, chronic fatigue syndrome, and stimulation of heart and circulation, while topical uses include inflammation, retinal hemorrhage, bruises, and bedsores.

Several case reports document adverse events associated with use of dietary supplements containing bitter orange, including ischemic stroke, possible myocardial infarction, increase diastolic and systolic blood pressure and heart rate for up to 5 hours after a single 900-mg oral dose in young healthy adults.

Not all energy drinks contain bitter orange. Two energy drinks currently on the market that contain bitter orange are Extreme Ripped Force and Piranha. Bitter orange combined with other stimulants such as caffeine and guarana may produce additive stimulant effects. This could result in adverse events at lower doses than required for any of the components alone.

 Guarana/Caffeine

Another ingredient found in most energy drinks is guarana, also known as Brazilian cocoa or zoom. The active component in guarana is caffeine in concentrations of 3.6% to 5.8%.  The uses for guarana are virtually the same as those for caffeine.

Caffeine has many physiologic effects, including stimulation of the central nervous system, heart, and skeletal muscles and possibly the presser centers that control blood pressure. Caffeine is also associated with insomnia, nervousness, restlessness, gastric irritation, nausea, vomiting, tremors, and anxiety. These adverse effects have occurred at doses as low as 250 to 300 mg. Fatal caffeine overdose usually results from ventricular tachycardia and occurs at doses of 10 to 14 grams (150-200 mg/kg).

 Caffeine is found in nearly all commercially available energy drinks at a concentration of approximately 75 to 80 mg per 8-ounce serving, although some products contain up to 300 mg per 8 ounces. Depending on the product size and average amount consumed, this could lead to a daily ingestion of up to 720 mg caffeine.

Glucose

Except for sugar-free versions, all energy drinks contain sugars in the form of sucrose, glucose, and/or high-fructose corn syrup. The sugar content varies among energy drinks but ranges from 21 to 34 grams per 8-ounce can.

Glucose is a major source of energy for the brain, red blood cells, muscles, and other cells of the body and is essential to the normal functioning of the central nervous system and the entire human body. However, relatively little glucose can be stored. Consequently, the body relies on a continuous supply of glucose as its primary fuel delivered via the bloodstream.

The amount of glucose found in most energy drinks (approximately 30 grams/8 ounces) is similar to that found in other soft drinks such as colas and fruit drinks. Official U.S. guidelines recommend a maximum sugar intake of 32 grams for every 2,000 calories, which equates to approximately 7% to 8% of the total daily caloric intake. A 16- or 24-ounce energy drink contains approximately 60 to 90 grams of sugar, which is two to three times the maximum recommended daily intake.