The Science Of Caffeine: America's Favorite DrugPlay
Let's talk about a drug that many people use every day. This particular drug, in its pure form, is a white powder that gives people energy and focus. One-sixteenth of a teaspoon is all you need to get that effect. But a full tablespoon will kill you. This drug is also highly addictive. So, what is it?
You might guess cocaine. But we're thinking of another drug that is virtually unregulated — that most of us take every day. Here are some big hints: it's in our coffee and tea. It's also in Coke, Pepsi, Dr. Pepper, Snapple and all those energy drinks, not to mention orange soda and chocolate.
The drug we're talking about is caffeine. Millions of us depend on it, need it — let's face it, we're addicted. But it's a drug that Murray Carpenter says we know surprisingly little about.
This conversation originally aired on March 18, 2014.
Murray Carpenter, author of "Caffeinated — How Our Daily Habit Helps, Hurts and Hooks Us." He lives in Belfast, Maine and tweets at @Murray_journo.
William "Scott" Killgore, associate professor of psychology at Harvard Medical School, director of the Social Cognitive and Affective Neuroscience (SCAN) Lab at McLean Hospital's Department of Psychiatry.
Ten Things To Know About Caffeine
- A Starbucks "grande" (16 ounces) can contain as much caffeine as seven cans of Red Bull.
- Most of the caffeine in soda and energy drinks is chemically synthesized in overseas pharmaceutical labs.
- The FDA doesn't require bottlers to label how much caffeine is in sodas and energy drinks.
- We now drink far less coffee than our grandparents did.
- One hundred years ago, the amount of caffeine in a Coke was equivalent to the caffeine levels in a Red Bull today.
- More than 10 million pounds of caffeine powder are put into sodas in the U.S. annually.
- Monsanto used to make caffeine for Coca-Cola by extracting it from waste tea leaves.
- Caffeine blocks a neurotransmitter that tells us we're tired.
- Caffeine has performance-enhancing effects and it's legal in nearly all athletic events.
- Caffeine decreases certain stages of sleep that make up 20 percent of our sleeping time.
On regulating caffeine:
Murray Carpenter: "We have to give FDA credit for this because there's really no parallel like this, in terms of a drug that FDA would be regulating that you and I and most Americans are taking every single day. For example, there's not even a requirement that bottlers who are blending caffeine into sodas and energy drinks list the quantity that they're blending into. And that's sort of the basic thing that we need to know to be able to be informed consumers... Coke, Pepsi and Dr. Pepper, Snapple, have started voluntarily doing this and it is listed in milligrams and it's small and it's on the back and most of us would have a hard time because, what's 35 milligrams of caffeine? It's hard for us to comprehend this. Some of the energy drink bottlers are starting to do this as well. So there is some movement afoot. As FDA is assessing, now, the safety of energy drinks, I think labeling is going to be one of the big issues they take on."
On thinking of caffeine as a drug:
MC: "You're not the first person to suggest that this really should belong in a whole different category other than drugs of abuse, but it does have the hallmarks of addiction, which is to say we develop tolerance, most of us — even with moderate caffeine use — we experience withdrawal symptoms upon cessation. And then there's a small portion of the population who would like to quit or moderate their caffeine use and find themselves unable to. The issue of addiction is a tough word for this substance."
On caffeine's withdrawal symptoms:
MC: "Caffeine is a vasoconstrictor so it's actually constricting those blood vessels in your head, in your brain, and as your caffeine levels are dropping after you've stopped, they're probably expanding and giving you a slight throbbing headache just where you gestured, on the outside of your head. This is a very characteristic headache for people who are going through caffeine withdrawal."
On drinking less coffee than our grandparents did:
MC: "Everyone in the industry understands this well — in the coffee industry — but our grandparents drank about twice as much coffee as we do. Coffee consumption peaked shortly after World War II in this country and declined pretty steadily, but what you're mentioning in terms of the specialty coffee boom has really helped coffee to regain some of that market share, maybe about 20 percent. We're getting back up there, but we're still way below the levels that people consumed 50 years ago."
On the levels of caffeine in "gourmet" coffee:
MC "A lot of people get a Starbucks grande, 16 ounces, that can pack a lot of caffeine. So we may not be drinking as much caffeine as a society as we used to but we are getting some pretty big, strong servings. One 16 ounce cup of Starbucks can have a lot of caffeine, and it varies so widely that it's really hard to know from day-to-day how much caffeine you're getting in your coffee... A Florida researcher, Bruce Goldberger, went into Starbucks and got the same 16 ounce Starbucks every day for six consecutive days and one day it had as little as 260 milligrams of caffeine. Another day it had 560 milligrams, as much as seven Red Bulls."
The Atlantic: How Athletes Strategically Use Caffeine
- "Caffeine has become the performance-enhancing drug of choice in competitive sports. Using it in precise ways, and not excessively, seems most effective."
Wired: Inside The Crazy Lab Where The Army Spikes Its Rations With Caffeine
- "One of the buildings at Natick has a brightly lit room called the Warfighter Cafe. That’s where Betty Davis, who leads the Performance Optimization Research Team, showed me a small table covered with snack foods—applesauce, beef jerky, energy bars, and nutritious “tube foods,” which taste like pudding but come in a package that looks like a large tube of Crest."
Salon: The Truth About Caffeine: Why We Know So Little About Our Favorite Addictive Drug
- "In a culture where we worry about unregulated chemicals and food additives, it’s shocking how little we know about one of the most common ones: caffeine."
This segment aired on October 6, 2015.