That caffeine rush can give a kick in the stomach too

Special to The Times

Recently, one of my colleagues, a pediatric gastroenterologist, told me about a teenage boy who had come to see him because of severe stomach pain he’d had for about two months. The boy had been referred by his primary care doctor, who had evaluated him for several possible causes, including infections and ulcers. That doctor had also recommended or prescribed a variety of medications to relieve the pain, but to no avail.

The specialist performed an endoscopy, in which a camera is inserted into a patient’s esophagus and down into the stomach and upper part of the small intestine.

The findings were impressive: severe inflammation, bleeding and ulcerations in a part of the small intestine called the duodenum, the portion of the intestine closest to the stomach.


When the medical team’s members went back and got further history, they learned that the teen had been drinking several Redline energy drinks a day. Energy drinks, including Red Bull, Rockstar and Full Throttle, have become extremely popular over the last decade because they can give lift when needed, such as when studying for finals or partying into the wee hours. The energy drink industry is worth about $2.5 billion in the United States, according to a 2006 report in Fortune magazine, and it has grown 700% since 2000, earning manufacturers millions of dollars, primarily by marketing to teens and young adults.

The staple ingredient in energy drinks is caffeine -- lots of it. If you’re wondering how much caffeine energy drinks have compared with other beverages, here’s your answer, according to the caffeine database at

8 ounces of tea (brewed): 47 milligrams

12 ounces Coca-Cola: 34 milligrams

12 ounces Sunkist: 41 milligrams

8 ounces coffee: 108 milligrams

8 ounces Red Bull: 80 milligrams

8 ounces Redline RTD: 250 milligrams

Those who love caffeinated beverages such as coffee probably, at one time or another, have experienced the heartburn they can cause. This is a known effect of caffeine. In excess, such drinks can irritate the lining of the gut, leading to severe pain. As with this teenager, they can tear you up on the inside.

Though his situation is probably a rarity, reports of serious medical events because of caffeine are increasing. A recent three-year study of calls to a Chicago poison center found more than 250 cases of caffeine-supplement overdose, with 12% of those requiring hospitalization. Nearly two-thirds of the hospitalizations involved the intensive care unit. Symptoms included insomnia, palpitations, tremors, sweating, nausea, vomiting, diarrhea and chest pains. The average age of patients was 21. Another poison center study focused on Redline. Nine cases requiring hospitalization related to this specific drink were reported in the California Poison Control System database in a two-year period, with severe symptoms involved.

Besides traditional forms of caffeine, many energy drinks include caffeine-containing substances such as guarana, a South American plant whose seeds are crushed and added as a stimulant. Other common ingredients include ginseng (thought to increase endurance, although studies have never proved it), carnitine (a protein thought to improve muscle performance, but again, that claim remains unproved) and other snake oil we don’t know a whole lot about. All of these ingredients are classified as nutritional supplements by the Food and Drug Administration, meaning they can be sold over-the-counter without any trials to demonstrate their effectiveness or safety.

The label on Redline recommends consuming no more than one a day. Clearly, though, few consumers seem to notice the small print (and there’s little motivation to make it larger, because a four-bottle pack of Redline can cost about $15).


There seem to be two lessons here. For starters, getting high on energy drinks can be hazardous to your health. Second, parents and those of us who work with children need to be aware of how popular the drinks have become. As with other high-risk behaviors such as drinking alcohol and smoking, we may need to clearly ask and counsel young people about their risks.

As for the Redline-guzzling teenager, he was given medication to relieve his gastritis -- and strictly forbidden to consume caffeinated products.


Dr. Rahul K. Parikh is a physician and writer in Walnut Creek. He writes the Vital Signs medical column for and can be reached at