The easy availability and virtual ubiquity of the beverages might lull drinkers into thinking they pose no risk.

“People think that if something is available over the counter, [then] it’s safe. That’s not necessarily true,” said Milazzo. “Any product with caffeine will increase respiration and heart rate, and its diuretic effects can cause dehydration.”

More critically, “there is a potential link between energy drinks and deaths related to arrhythmias,” he added.

In November, the Food and Drug Administration (FDA) released data showing 18 deaths associated with Monster Energy and 5-hour Energy from 2004 to late 2012. The deaths were reported by healthcare providers and patient families, and the FDA noted that no causal relationship had been established.

Part of the problem, according to Milazzo, is that drinkers may inadvertently consume more caffeine than they intend.

“Many people think of the drinks as being more like a soda or flavored drink than a cup of coffee. They may actually be supplementing them with other caffeinated drinks such as coffee, tea and soda,” he said, noting that younger people might be particularly at risk.

“If they are caffeine naïve, their bodies don’t have a chance to slowly adjust, and it can be a shock to the system,” he explained.

FDA Investigating

According to a November letter from FDA Acting Associate Commissioner for Legislation Michele Mital to Sen. Richard “Dick” Durbin (D-IL), the agency is “looking at whether products that may be safe for most individuals under labeled-use conditions may pose significant risks, arising from direct toxic effects, when the products are consumed in excess or by vulnerable groups, including young people and those with pre-existing cardiac or other conditions. … Areas of particular focus would include such matters as the vulnerability of certain populations to stimulants and the consequences of excessive consumption of ‘energy drinks,’ especially by young people.” ²

In addition, the labeling on energy drinks and the smaller, more concentrated energy shots, can be confusing or provide little information, according to the letter released by Durbin’s office.

Energy drinks typically include herbal supplements such as guarana, ginkgo, or taurine, which allow them to be marketed as dietary supplements, rather than as conventional food or beverages, and exempt them from FDA regulation. Those marketed as dietary supplements, including Monster and 5-hour Energy, do not need to disclose the amount of caffeine in the products.

Mital’s letter noted that “within the bounds of our authority, FDA will consider taking appropriate action with respect to the labeling of these products, such as requiring disclosure of the amount of caffeine in food products, limitations on intended use or warnings about possible adverse effects.”

Energy drinks sold as beverages already disclose the amount of caffeine they contain, but a consumer might not be clear on the amount in each can they drink.

“If you flip the can around, it may say it contains two servings. But the amount of caffeine and other ingredients in the table applies to just one serving, so it looks like less than it is,” Milazzo said. “It’s a little alarming when you don’t know the amount you’re consuming in some of these products.”

1.  The DAWN Report. Update on Emergency Department Visits Involving Energy Drinks: A Continuing Public Health Concern. Substance Abuse and Mental Health Services Administration. Jan. 10, 2013.