Negative & Positive Effects on People Who Drink Energy Drinks

Energy drinks have become increasingly popular since they were first introduced into the European market in 1987 and then in the U.S. about 10 years later. Manufacturers of these products claim to increase energy, endurance, burn fat and improve athletic performance. The medical community has begun to question the amount of sugars, and safety of caffeine levels and other supplements in these beverages 2.


Energy drinks contain high levels of caffeine, at 80 to 500 mg per can when compared to 65 to 100 mg for a cup of coffee. Caffeine is a central nervous system stimulant and diuretic. Three cups of coffee -- about 3 -- offer a maximum recommended daily amount of 250 mg of caffeine. Another ingredient often found in these types of drinks is guarana seed extract, from a plant that is native to the Amazon. Guarana is high in caffeine content 1.

Positive Effects

Caffeine is the main supplement in most energy drinks 2. It is an appetite suppressant, and has been used effectively in the treatment of migraine headaches and to combat short-term drowsiness and fatigue. According to a UC Davis publication, Guarana has been scientifically linked to increased energy, appetite suppression and athletic performance enhancement.

Negative Effects

Caffeine or guarana consumption can result in increased heart rate, sleeplessness, nausea, anxiety, depression, nervousness, irritability, abnormal heart rhythms -- arrhythmia and late-term miscarriage. Some drugs can interact with either supplement and should be considered prior to consuming energy drinks. A study by the American Heart Association showed significant increases in heart rate and blood pressure with energy drink consumption during sedentary activities. A concern was raised that combining energy drinks with higher levels of physical activity could pose a risk for people with high blood pressure or heart disease.

Safe Energy Drink Consumption

While the FDA has set a caffeine maximum level at 71 mg for a 12-oz. soda, According to "The Journal of The American Medical Association," it has not set maximums for energy drinks. Further studies on caffeine’s effects are under way with many medical organizations advising adults to consume energy drinks in moderation; and for children and teens to abstain altogether until their safety can be established. New studies have also been concerned with alcohol-based cocktails that include energy drinks. A study published in the February 2011 issue of "Alcoholism: Clinical and Experimental Research" indicates that energy drink-laced cocktails spur continued alcohol consumption because of the stimulating effects of these beverages.