Energy drinks hold no benefit for children, and may not be safe for children's hearts, experts say.
The drinks can contain not only high amounts of caffeine but other compounds, and the possible effects of these chemicals — especially in combination — on children's health have not been well studied.
What is known is the drinks have no benefit for children who drink them, said Dr. Steven Lipshultz, professor of pediatrics at the University of Miami Miller School of Medicine. Kids may think the drinks will bring them more energy, or help them lose weight or perform better in sports, but there's no evidence the drinks help with any of these goals, and they may even interfere with sleep, which can make consumers more tired. If they contain high amounts of sugar, that could ultimately impede weight loss, he added.
"In the absence of a benefit, these drinks shouldn't be something that kids use," Lipshultz said. "There is no safe dose" of these drinks.
On Oct. 19, the parents of a Maryland girl who died in 2011 after reportedly drinking two 24-ounce cans of Monster Energy Drinks filed a wrongful-death lawsuit against the company, and the Food and Drug Administration is looking into several other deaths possibly linked to the drinks. A Monster Energy spokesperson has told reporters that the company is unaware of any fatalities caused by its drinks. It is unclear what other factors might have been involved in the deaths.
Lipshultz said the adverse effects of caffeine may strike children or teens after they have consumed one or two energy drinks.
What the compounds in energy drinks do to the heart
In addition to caffeine, energy drinks may contain chemicals such as guarana, taurine, L-carntiine, ginseng and yohimbine.
Caffeine and these other compounds generally increase heart rate and blood pressure, said Dr. John Higgins, associate professor of medicine at the University of Texas Medical School at Houston.
But at the same time, some evidence shows the compounds in energy drinks may slow the flow of blood through the coronary arteries, which bring oxygen and nutrients to the heart muscle, Higgins said.
"What you have is a situation where your heart rate and blood pressure go up, and the heart would need to dilate those arteries because it's working harder, but instead it's impaired — they don't dilate. It's sluggish, slower," he said.
Meanwhile, the caffeine also can cause a release of calcium in heart cells, affecting the electrical signaling that regulates the heartbeat and triggering an arrhythmia, he said. And there's evidence suggesting the drinks disrupt the normal balance of salts in the body. Changes in sodium or potassium levels also may be linked with arrhythmias, Higgins said.
However, more study of the compounds in energy drinks is needed to know how much a person can consume before negative effects are seen.
In a 2010 study, Higgins and other researchers looked at the compounds in energy drinks and their effects. They found four reports of caffeine-associated deaths and five separate cases of seizures linked with energy drinks.
"Our feeling is that it's probably the higher levels of caffeine, and also these other ingredients," that are involved in these cases, Higgins said. The compounds may be interacting and having a greater effect than any one chemical by itself, he said.
The drinks could be dangerous for a healthy person, and worse for people with heart conditions, Higgins said.
Heart palpitations, headache, vomiting, dizziness, anxiety, tremors, or a general feeling of not being well may be early signs of toxicity from a drink, and people with these symptoms should seek medical help, he said.
Children should limit their caffeine consumption to 100 milligrams a day, according to the American Academy of Pediatrics. An eight-ounce cup of coffee contains about 100 mg of caffeine; an eight-ounce Coca-Cola contains about 25 mg.
The AAP also says that "energy drinks are not appropriate for children and adolescents and should never be consumed."
Both Lipshultz and Higgins said the drinks should be regulated by the FDA. Because the drinks are classified as supplements, rather than food, they are not subject to the same regulations as, for example, cola.
"These are drugs — they are chemicals — and we don't know much about their interactions," Higgins said. For example, it's not clear whether the drinks affect girls differently than boys, or if there is an effect from having a smaller body size, he said.
It's also possible children and teens are more susceptible than adults to the drinks' effects, Lipshulz said.
"A lot of developing organs are more sensitive" to chemicals than adult organs are, but more research is needed to know whether this is the case with energy drinks, he said.
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