KNOXVILLE (WATE) - The Food and Drug Administration is investigating reports of five deaths and a nonfatal heart attack in people who consumed high-energy drinks.
The drinks were made by the Monster Energy Company.
A Maryland couple has filed suit against the company, blaming Monster energy drink for their daughter's death.
Fourteen-year-old Anais Fournier collapsed after drinking two 24-ounce Monster Energy drinks in two days. She died six days later.
While the reports don't prove that the drinks caused the deaths, the FDA is looking into whether ingredients in the energy drinks, mainly caffeine, are the culprit.
Because energy drinks are sold as nutritional supplements, they are not regulated by the FDA.
6 News took a look at several energy drinks, including Monster. All contain a high amount of sugar, -- up to 200 grams in larger cans -- which is more than two Snickers candy bars.
When it comes to caffeine, experts say the energy drinks contain more than the amount recommended on a daily basis.
Dr. Anthony Wilson, of UT Medical Center's Family Medicine Department, has treated patients suffering heart palpitations after ingesting too much caffeine. He says caffeine poisoning can lead to serious problems.
"It can lead to palpitations and elevations in blood pressure," Dr. Wilson said.
Dr. Wilson also says people should limit their caffeine intake.
"I recommend that people take in no more than one or two cups of coffee or the equivalent per day. Once you get beyond that, " he said, "you're probably getting a little too much caffeine."
People who guzzle energy drinks for the caffeine fix, then embark on a strenuous workout, are at even greater risk of serious heart trouble.
"It can lead to scarring of the heart tissue, nd that can lead to rhythm abnormalities," Dr. Wilson explained . "Obviously if one is prone to rhythm abnormalities, that can lead to death."
The problem is, some of the energy drinks we checked, like Monster, don't list exactly how much caffeine each serving contains.
There are also a lot of other ingredients not regulated by the FDA that make up what some call a chemical soup.
"You still have the other additives..and so you don't know what you're getting, really," Dr. Wilson said
It's clear that you are getting a lot of sugar in these drinks. Dr. Wilson says too much can lead to obesity and diabetes.
He advises healthy people to limit sugar to one moderately sized sweet treat per day.
Remember, one large energy drink is not one serving. There are two-and-a-half to three servings in each 18 to 24-ounce can.