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What you should know about caffeine

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Peace Coffee
In this file photo, Peace Coffee Shop head barista Jackson O'Brien pours an example of "latte art" Wednesday, Nov. 21, 2012 in Minneapolis.
MPR Photo/Jennifer Simonson

Most of us take in caffeine every day, one way or another. A study in the Journal of the American Dietetic Association found that nearly 90 percent of adults and 76 percent of children ingest caffeine daily. 

But Americans may not realize how much caffeine they're getting because manufacturers are only required to list caffeine as an ingredient on the food or drink label -- not the amount of caffeine in the product. 

After the FDA received reports last month that 13 deaths were possibly linked to the 5 Hour Energy drink, the New York Times wrote:

The fast-growing energy drink industry is facing increasing scrutiny over issues like labeling disclosures and possible health risks. Some lawmakers are calling on the F.D.A. to increase its regulation of the products and the New York State attorney general is investigating the practices of several producers.

Unlike Red Bull, Monster Energy and some other energy drinks that look like beverages, 5-Hour Energy is sold in a two-ounce bottle referred to as a shot. The company does not disclose the amount of caffeine in each bottle, but a recent article published by Consumer Reports placed that level at about 215 milligrams.

An eight-ounce cup of coffee, depending on how it is made, can contain from 100 to 150 milligrams of caffeine.

The F.D.A. has stated that it does not have sufficient scientific evidence to justify changing how it regulates caffeine or other ingredients in energy products. The issue of how to do so is complicated by the fact that some high-caffeine drinks, like Red Bull, are sold under agency rules governing beverages, while others, like 5-Hour Energy and Monster Energy, are marketed as dietary supplements. The categories have differing ingredient rules and reporting requirements.

How much do we really know about the chemical compound so many of us rely on for a pick-me-up?  We learned some new things about caffeine from two experts on The Daily Circuit Wednesday, Dec. 19.

Abraham Palmer is associate professor in the University of Chicago's Department of Human Genetics.  

Bennett Alan Weinberg is co-author of "The World of Caffeine: The Science and Culture of the World's Most Popular Drug," and "The Caffeine Advantage: How to Sharpen Your Mind, Improve Your Physical Performance, and Achieve Your Goals--the Healthy Way."

Here are a few questions and answers about caffeine:

How many cups of caffeinated coffee is too many?

Palmer says that depends on the strength of your brew, with a cup containing anywhere from 100 to 300 mg of caffeine.  

"I think people start to feel uncomfortable and have toxic effects that are mostly just unpleasant, not so much dangerous, around 600 to 900 mg of caffeine," Palmer said.  "So if you drink two or three big cups of Starbucks coffee, you probably know you're going to wish you didn't."

Weinberg believes discomfort from too much caffeine is the proper measure, more than danger.

"If you are a person who is very sensitive to it, you may have to moderate your use of it," he said. "But as far as how much is safe for you to use, basically whatever you're comfortable using is probably a decent amount for you."

What are some of caffeine's benefits?

"Caffeine has a wide panoply of effects and it really is a very interesting and actually confusing topic," Weinberg said. "It has benefits for your mood, it has benefits for your performance and it has benefits for your health. It really is a very beneficial substance and it is a drug."

But caffeine will only take a person so far, Weinberg said. "A little more caffeine might help you run ... faster and longer. But if you take more than the optimal amount, it starts to erode your ability to run faster and longer. So for example if you're an athlete there really is no motivation to take super doses of caffeine because it's going to hurt your performance."

Should policy makers be concerning themselves with caffeine?

"The main thing on my worry list is a lot of the irresponsible criticisms of caffeine we're hearing," Weinberg said. "Politicians, lawyers who are trying to launch frivolous lawsuits, people who call themselves caffeine experts are issuing a lot of warnings about caffeine and even saying it causes death and other serious adverse health effects. The FDA has not only said that there's no basis for further regulation at this point. But they've said more than that. They've said caffeine has a long history of safe use and there really is no other drug that has been field tested the way caffeine has."

But could caffeine labeling be better?

Palmer argues that beverages containing caffeine should list amounts, saying that would help parents regulate the amount of caffeine their children consumer.

Weinberg said labeling could provide a warning when a drink contains less caffeine than consumers might guess.

"A lot of these energy drinks don't want you to know how little caffeine they contain," Weinberg said. "They tout it as having some super-charged benefit for you or harm to you and the truth is that coffee contains between 25 mg and 50 mg of caffeine per ounce, while the popular energy drinks typically contain only about 10 mg per ounce."

What are some caffeine cautions?

Withdrawal is one issue. "A minority of people ... experience these withdrawal effects, but some people do," Weinberg said. "They can range from mild discomfort, little irritability, to being serious, pretty bad headaches... If you're going to stop using caffeine, then it makes sense to do it on a graded basis. If you're having five cups of coffee a day, try to have four, then three, then two, then one. You'll minimize and perhaps eliminate your withdrawal problems."

Weinberg's serious warning about caffeine? Pregnant women should not consume it. "Enough caffeine can increase the number of miscarriages and things like that," he said. "Small amounts don't ... Pregnant women don't metabolize caffeeine like other people do. When a pregnant woman consumes caffeine, it stays in her system far, far, far, longer than a person who isn't pregnant and the fetus is bathed in this caffeine."

READ MORE ABOUT CAFFEINE AND HEALTH

Caffeine: How much is too much? (Mayo Clinic)

A close look at energy drinks (CBS News)

The case for drinking as much coffee as you like (The Atlantic)

FDA Dismisses Concerns about Caffeine and Energy Drinks (World of Caffeine)