Facebook Pixel

The Truth About Caffeine

Rate This
Diet & Nutrition related image Photo: Getty Images

Let’s face it. In today’s busy world, juggling work, kids and who-knows-what-else, sometimes a caffeine mainline sounds like an appealing support system. But while about 90 percent of adults use caffeine daily — yes, “use,” as you would a drug! — many of us know little about the nitty-gritty of caffeine.

According to MedicineNet.com, “Caffeine is considered the most commonly used psychoactive drug in the world.” Scientifically known as 1,3,7-trimethylxanthine, caffeine earned its common name from the German kaffee and the French café, both of which mean “coffee.”

It’s no surprise, then, that so many of us turn to coffee for our caffeine fix. An 8-ounce cup of plain, brewed Joe contains 135 mg of caffeine, almost four times as much as a 1-ounce pour of espresso (40 mg) and more than twice as much as an 8-ounce cup of brewed tea (25-40 mg for green tea, 40-70 mg for black tea). Diet Coke contains more caffeine than regular Coke (47 mg vs. 35 mg). (Diet Pepsi contains 36 mg of caffeine, whereas regular Pepsi packs 38 mg.) Even chocolate and many over-the-counter medications contain substantial amounts of caffeine.

A moderate daily intake of caffeine — anywhere from 200 to 300 mg/day — is considered safe for most adults. A quarter to one-third of American adults consume twice that every day. “Heavy” caffeine consumption is classified as more than 6000 mg/day. (Picture 85 cans of Mountain Dew!)

Health nuts and purists often eschew caffeine usage altogether, though sometimes they might not be able to say why. Perhaps it’s how caffeine can induce over-stimulation or jitters. In any case, understanding how caffeine works in the body can help anyone make a mindful decision about whether to order that next cup of coffee — or maybe to make it a decaf (though even “decaf” coffee contains 5 mg of caffeine per 8-ounce pour).

Interestingly, nutrition labels on foods and beverages don’t list caffeine content. And more products keep popping up on the market touting their energy-boosting effects, often due to high levels of caffeine. Don’t be fooled into believing that caffeine is risk-free.

On the contrary, the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) calls caffeine intoxication a clinical syndrome. Caffeine intoxication occurs when, during or soon after caffeine consumption, at least five of these symptoms occur: restlessness, nervousness, excitement, insomnia, flushed face, diuresis, gastrointestinal complaints.

Even more severe is the risk of death from excessive caffeine intake. Of course, ingesting over 10 grams of caffeine—the equivalent of 80 to 100 cups of coffee—sounds impossible, but a death was reported of a man who imbibed too many spoonfuls of caffeine powder at a party. While risk of death is slim, it is certainly a reminder that caffeine intake is not benign.

Caffeine is absorbed by the body within 30 to 45 minutes and has a half-life of four to eight hours. Caffeine users will argue that their morning coffee or cola helps them concentrate better, makes them more alert and clear-headed, and allows them to be more social. (When I was in college, I knew better than to speak to my roommate before she’d had her first cup of coffee!) Caffeine has been shown to improve memory and selective attention. Regular use of caffeine, though, can make a person more tolerant and less affected by its effects. Quitting cold-turkey can also induce symptoms such as headache and fatigue.

Limited research has suggested reduced risk of many diseases with caffeine usage, including asthma, colorectal cancer, liver and Parkinson’s diseases, type 2 diabetes and dementia. Naturally, these reduced risks need to be balanced with the potential adverse effects of caffeine, especially until further research is completed.

As with any health concern, dietary or otherwise, a risk-benefit analysis is advisable in order to make a conscious, educated decision whether to include caffeine in your diet.


Kovacs, Betty, MS, RD. “Caffeine.” MedicineNet.com. Web. 31 Aug. 2011. http://www.medicinenet.com/caffeine/article.htm

Lewis, Kristyn Kusek. "Caffeine Facts: Addiction, Insomnia, Pregnancy Effects, and More." WebMD - Better information. Better health. Web. 31 Aug. 2011. http://www.webmd.com/balance/caffeine-myths-and-facts.

Addicott, Merideth A. & Laurienti, Paul J. "A comparison of the effects of caffeine following abstinence and normal caffeine use." Psychopharmacology (Berl). 2009 December; 207(3): 423-431. National Center for Biotechnology Information. Web. 31 Aug. 2011.

Reviewed September 1, 2011
by Michele Blacksberg R.N.
Edited by Jody Smith

Add a Comment1 Comments

EmpowHER Guest

Even when you try not to consume caffeine, it's really difficult. A whole lot of products have caffeine as an ingredient -- from chewing gum, candy and potato chips to energy drinks and medicines:


Additionally, research has shown that there is a gender-effect with caffeine and that it is more addictive for boys than for girls:


September 1, 2011 - 10:59am
Enter the characters shown in the image.
By submitting this form, you agree to EmpowHER's terms of service and privacy policy
Add a Comment

We value and respect our HERWriters' experiences, but everyone is different. Many of our writers are speaking from personal experience, and what's worked for them may not work for you. Their articles are not a substitute for medical advice, although we hope you can gain knowledge from their insight.

Diet & Nutrition

Get Email Updates

Diet & Nutrition Guide

Have a question? We're here to help. Ask the Community.


Health Newsletter

Receive the latest and greatest in women's health and wellness from EmpowHER - for free!