From Medscape Internal Medicine > Medicine Matters

Sandra A. Fryhofer, MD

Posted: 06/03/2011

The topic is caffeinated energy drinks from a new report in the Journal of the American Medical Association.  Here is why it matters.

How Much Caffeine Is In Your Drink?
A lot of a good thing is not necessarily better; one of those things is caffeine, and the amount can vary widely depending on the source.

• A 6-oz cup of homemade coffee has about 75-100 mg of caffeine;
• A 6-oz cup of coffee from a coffeehouse can be as high as 150 mg (although no more than 25 mg caffeine per oz);
• A 12-oz can of soda contains about 35-50 mg of caffeine;
• The caffeine in energy drinks can be as high as 500 mg per serving; and
• So-called energy shots contain 100-350 mg/oz of caffeine.

In addition, one usually drinks coffee hot, so one sips it slowly. On the other hand, energy drinks are usually chugged cold and quickly.
Excess caffeine, especially from energy drinks, can have the following effects: anxiety, nervousness, sleep problems, elevated blood pressure, and heart palpitations.
 
Caffeine Plus Alcohol: Wide-Awake Drunkenness
There is a trend among college students and some adults of mixing energy drinks with alcohol in order to drink more and drink longer. The consequences can be dangerous and deadly. Caffeine does not counteract alcohol. The high caffeine content stimulant effect can prevent a person from becoming sleepy and experiencing drunkenness, but it does not prevent impairment, including in judgment, reaction time, and motor skills. The general report calls this "wide awake drunkenness," and it can lead to bad choices, risky behaviors, and worse.
 
The FDA Response
In 2006, 4 billion dollars worth of energy drinks were sold in the United States alone. Fortunately, on November 17, 2010, the US Food and Drug Administration (FDA) sent warning letters to 4 companies that caffeine added to malt alcohols is an unsafe food additive.^[2] The companies included the following:

• Charge Beverages Corporations (maker of Core High Gravity);
• New Century Brewing Company (maker of Moonshot);
• Fusion Products (maker of 4Loko); and
• United Brands Company (maker of Joose and Max).

The FDA limit for caffeine in cola drinks is set at 0.02%, a max of 71 mg per 12-oz serving. Why doesn't this also apply to energy drinks? Scientists and health professionals cannot wait for further FDA action. Available scientific evidence indicates that action is needed now. Warn your patients. Tell your children about the danger of mixing alcohol with energy drinks. I told mine.