Waking up to the facts about caffeine
No, we aren’t going to tell you to give up that morning cup of coffee, so keep reading.
You’re tired, so you grab a cup of tea or coffee. Or you’re working the late shift, so you drink an energy drink to stay awake.
On average, Americans consume about 300 mg. of caffeine every day, or the equivalent of three cups of coffee. At that level, caffeine is not a health problem for most people, and it might even have some benefits: mental stimulation, increased physical performance, and easing headaches, just to name a few.
The problem is that consumption of caffeine is rising, and many people who are consuming unsafe levels may not even realize it. We expect to find caffeine in coffee, tea, soft drinks, energy drinks, and chocolate. But today you also can find it in some surprising places: gum (45 mg.), candy (up to 600 mg.), almonds (25 mg.), waffles (200 mg.), ice cream (up to 125 mg.), and bottled water (up to 90 mg.), for example.
Not every brand of these products contains caffeine, of course; those that do usually tip you off with words related to increased energy like wild, jolt, bang, or perky. You can find out how much caffeine is hiding in the products you consume at Caffeine Informer and the Center for Science in the Public Interest.
When you consume too much
High daily consumption of caffeine, especially more than 500 mg. per day, is considered a significant health risk. Even above 400 mg. a day, caffeine can begin to cause insomnia, breathing problems, diarrhea, dizziness, fever, and increased thirst and urination. High consumption has also been linked to anxiety, cardiovascular symptoms, and gastrointestinal complaints. At a high enough level, it can even cause delusions, hallucinations, seizures, cardiac arrest, coma, and death. And, if this convinces you to cut back, withdrawal can cause fatigue, muscle pain, headache, lack of focus, and nausea.
Because the caffeine that most of us consume is diluted in coffee, tea, and soft drinks, fatal overdoses have historically been rare. It would be almost impossible to drink a lethal amount of coffee, which could be close to 50 cups in a day. The hidden (and not-so-hidden sources) of caffeine mentioned above can quickly get someone to 500 mg. a day. Add a couple of energy drinks or one-eighth teaspoon of caffeine powder, and you rocket past a safe level.
Energy drinks
A total of 34 deaths have been linked to energy drinks since 2004, according to Food and Drug Administration (FDA) adverse event reports. Other recorded effects of energy drinks include high blood pressure, convulsions, and heart attacks.
The Substance Abuse and Mental Health Services Administration (SAMHSA) reported an increase in the number of energy drink-related emergency room visits from 1,128 in 2005 to more than 16,000 in 2008. By 2011, the number had grown to more than 20,000.
SAMHSA has issued a report calling energy drinks “a continuing public health concern,” and, in 2014, the Center for Science in the Public Interest (CSPI) asked the FDA to notify consumers of the “risk of heart attack, convulsion, and other adverse reaction to energy drinks.”
CSPI also asked that the FDA require manufacturers to lower caffeine levels in the drinks to 0.02 percent, or 71 milligrams per 12 ounces—the maximum amount the FDA considers safe in cola-style beverages. And it called for more studies on the other chemical and herbal ingredients found in energy drinks—examples include taurine, glucuronolactone, ginseng, and guarana—and the effects of their interaction with caffeine.
What about powdered caffeine?
With 400 mg. of caffeine in one-quarter teaspoon, the risk of an overdose using powdered caffeine is high, and it has been the cause of a majority of caffeine-related poisonings. Powdered caffeine has contributed to at least two deaths. Ten grams, about a tablespoon, is a lethal dose for an adult.
In December 2014, CSPI petitioned the FDA to ban retail sales of powdered caffeine. Laura MacCleery, a CSPI attorney, said, “It’s the public misperception and familiarity with caffeine, which is something we think we know, that makes this product so dangerous in its current form.”
The FDA advises consumers to avoid pure powdered caffeine. Accurately measuring the powder with common kitchen utensils is nearly impossible, making it easy to accidentally consume a lethal amount.
The bottom line
Before you reach for that energy drink or fourth cup of coffee, consider better ways to increase your energy. Drink a glass of water instead. Get enough sleep, be more active, and eat a healthy diet.
Some interesting numbers
20,000 Number of hospital emergency room visits in 2011 involving energy drinks
One teaspoon Amount of powdered caffeine that can result in heart failure
400 mg. Amount caffeine per day that is a safe amount for most adults—the equivalent of about three 8-oz. cups of coffee.
Five to seven hours. The half-life of caffeine, meaning if you drink 240 mg. for dinner, you could still have 120 mg. in your body at midnight, when you are wondering why you can’t get to sleep.
71 mg. FDA official limit for the amount of caffeine in 12-ounce soft drinks.
ONLINE RESOURCES
Medscape’s site on caffeine has detailed information.
You can learn how caffeine interacts with vitamins and supplements and guarana on WebMD.
“How Much Caffeine Before I End Up in the E.R.?”, The Atlantic, January 15, 2013.
“Tragic Deaths Highlight the Dangers of Powdered Pure Caffeine,” FDA Voice, Michael M. Landa, posted December 16, 2014.
The FDA has a number of sites related to caffeine. Three are listed below.