Caffeine

What Kind of Drug Is It?

Caffeine is a natural stimulant. A stimulant is a substance that increases the activity of a living organism or one of its parts. Caffeine was named after the shrubby coffee plant, which is native to the eastern African nation of Ethiopia. Although coffee is an ancient drink, it was not until 1821 that German chemist Friedlieb Ferdinand Runge finally isolated caffeine from the coffee bean.

Chemically speaking, caffeine is a bitter white alkaloid. Its chemical formula is C₈H₁₀N₄O₂, and it is found especially in coffee and tea. Caffeine is considered both a drug and a psychoactive substance. Such substances alter the user's mental state or change behavior.

As a mild stimulant, it is often used medicinally to treat certain kinds of headache pain. Caffeine consumption speeds up the rate at which chemical reactions occur in the body. By increasing the heart and breathing rates, it helps more oxygen get to the brain. It also acts as a diuretic (pronounced die-er-EH-tik), a substance that reduces bodily fluids by increasing the production of urine.

Overview

Caffeine is said to be consumed on a regular basis by up to 90 percent of the world's people. Humankind's fascination with caffeine dates back to prehistoric times. Andrew Weil and Winifred Rosen retold the story of coffee's accidental discovery in From Chocolate to Morphine. "Legend has it that coffee was first discovered long ago by Ethiopian nomads [or wanderers] who noticed that their domestic animals became frisky" after eating the red fruit of a certain shrub. "When people tried eating the seeds," continued the authors, "they got frisky, too, and eventually they learned to make a flavorful drink from the roasted seeds." By the fifteenth century, just as the Middle Ages (c. 500–c. 1500) were coming to a close, coffee had become a popular drink in the Arab world.

Official Drug Name: Caffeine

Also Known As: None

Drug Classifications: Not scheduled; stimulant

Thousands of years earlier, the Chinese were already steeping and drinking tea as a beverage believed to lengthen life.

A Chinese myth about the discovery of tea dates back more than 4,000 years. According to the tale, a Chinese emperor brewed the first cup of tea after a mysterious leaf fell into the water his servant had boiled for him. The leaf, so the story goes, was from a wild tea tree.

The Road from Picking to Profits

Centuries of war, land-grabbing, oceanic explorations, and trading led to the arrival of coffee and tea in Europe by the 1500s. Coffee use spread throughout the continent and then to America. In the eighteenth century, coffee plantations were actively producing the bean in Indonesia and the West Indies.

Since then, caffeine has been credited with transforming the United States and countries in Europe from agricultural nations to industrial nations. This change has made "the modern world

possible," wrote T. R. Reidin National Geographic in 2005. "Boiling water to make coffee or tea helped decrease the incidence of disease among workers in crowded cities. And the caffeine in their systems kept them from falling asleep over the machinery."

Coffee farming in the South American nation of Colombiais done the old-fashioned way, noted Ruth Morris in Life in 2005. The process "still relies on strained back muscles, wooden tools, and traditional methods" such as mule power "that haven't changed much since coffee was first produced here in the early 1800s." After observing coffee farmers firsthand, Morris explained: "It's a long way from these Colombian hills to 'Skim latte, no foam, please."'

What Is It Made Of?

Caffeine, the active substance responsible for the stimulant effect of the coffee plant's berry, is a xanthine. Xanthines are compounds made of the elements carbon, hydrogen, nitrogen, and oxygen. Some xanthines occur in the blood, urine, and muscle tissue of animals; others are found in certain plants.

The caffeine xanthine is one of the family of stimulants present in more than sixty different species of plants. The pure chemical is a yellowish-white, bitter crystal. Other xanthines related to caffeine include theophylline and theobromine. The pods of cacao beans (better known in the United States as cocoa beans) are ground to make chocolate.

How Is It Taken?

The vast majority of caffeine is ingested in a beverage such as coffee, tea, or soft drinks. Beyond beverages, caffeine is also consumed in snacks such as chocolate candy bars. Pain relievers, including aspirin, acetaminophen, and ibuprofen, may contain some caffeine. The stimulant effects of the caffeine allow the pain relievers to act more quickly.

Caffeine is also found in nonprescription aids and herbal preparations for alertness and dieting. Pure caffeine in tablet form is available over-the-counter in substances such as No-Doz and Vivarin. The caffeine in these tablets has the same effect as the caffeine found in coffee or tea—it is just more concentrated. Many abused illegal drugs contain caffeine, either for added effect or as a "filler," used in powder form to cut the strength of street drugs.

Crazy for Coffee

How much do you know about coffee? Ruth Morris' article "America's Bottomless Cup" in Life magazine and the Web site www.coffeekids.org offer many interesting facts about growing, producing, and drinking coffee. For example, did you know that:

• It takes 4,000 coffee beans to produce one pound of coffee; that is more beans than the average coffee tree yields in a year.
• Americans consume 3 billion pounds of coffee each year.
• Worldwide coffee consumption is estimated at 11 billion pounds per year.
• The average coffee farm in the poverty-stricken nation of Colombia makes about $1,900 each year.
• The female Colombian farm workers who pick out flawed coffee beans—by hand—from enormous troughs of beans make only $5 per day.
• In the coffee-growing regions of Mexico, Guatemala, Nicaragua, and Costa Rica, most coffee farmers earn just a few pennies per pound for their harvest.

CNN medical correspondent Dr. Sanjay Gupta told interviewer Daryn Kagan that people need to be more informed about the "hidden" caffeine content in the foods they eat. "Half a cup of … coffee ice cream from Häagen-Dazs has actually more caffeine than a Coke," remarked Gupta. "Most people are surprised by that." Another example cited by Gupta involved carbonated soft drinks. Ounce for ounce, Sunkist orange soda—a beverage not often thought of as a high source of caffeine—has nearly the same caffeine content as a Coke.

Many people think that dark-colored soft drinks contain caffeine and the light-colored ones do not. However, many popular root beers contain no caffeine while the light-colored Mountain Dew contains more caffeine than a regular Coke. Some manufacturers now offer their popular products in caffeine-free versions as well. If in doubt, check the ingredients on the can or bottle. It will note if the beverage contains caffeine or not.

MSNBC.com reported in 2004 that "in North America, 80 percent to 90 percent of adults drink caffeine regularly." Each day in the United States, the average person consumes about 280 milligrams of caffeine, which equals roughly a mug or two of coffee or three to five cans of soft drinks.

How Much Caffeine Is in That?

Ever wonder how much caffeine is in a certain product? Various Web sites list the caffeine content of many of the most popular products containing caffeine. Among those Web sites are: American Beverage Association <http://www.ameribev.org/health/caffeinecontent.asp> and Center for Science in the Public Interest <http://cspinet.org/new/cafchart.htm>. Here are some examples of popular products and their caffeine content:

Soft Drinks

• 12 oz. A&W Root Beer: 0 mg
• 12 oz. Coca-Cola: 34 mg
• 12 oz. Diet Coke: 45 mg
• 12 oz. Mountain Dew: 55 mg
• 12 oz. Sunkist Orange: 42 mg

Energy Drinks

• 12 oz. Red Bull: 115 mg

Coffee, Tea, Hot Chocolate

• 8 oz. coffee (brewed): 80-135 mg
• 8 oz. decaffeinated coffee (brewed): 3-5 mg
• 8 oz. tea (brewed): 40-60 mg
• 8 oz. iced tea: 15-40 mg (depending on brand)
• 8 oz. hot chocolate: 5-14 mg

Candy Bars

• 1.5 oz. milk chocolate bar: 10 mg
• 1.5 oz. dark chocolate bar: 31 mg

Over-the-Counter Pills

• 1 tablet No-Doz: 100 mg
• 1 tablet Excedrin: 65 mg
• 1 tablet Midol: 32.4 mg

Are There Any Medical Reasons for Taking This Substance?

Many headache medications contain caffeine, which helps speed up the action of analgesics. Because caffeine cuts blood flow in the brain, it should not be used by people at risk for or recovering from a stroke. By slowing blood flow through the brain, caffeine could starve already struggling nerve cells. Rumors of caffeine's effectiveness and safety as a weight loss agent have persisted for years, but they have never been medically proven.

Breathing rates increase in response to caffeine. Theophylline has an especially strong effect on respiration, affecting the smooth muscle of the bronchial tree in the lungs. This is why theophylline is sometimes used as a treatment for asthma. Doctors may recommend weak tea for their asthmatic patients with colds, as the tea will aid in clearing mucus from the respiratory tract.

Usage Trends

Ninety-five percent of all caffeine is consumed in the form of tea and coffee. In the United States and Scandinavian countries, coffee is the main source of total caffeine consumption. In the United Kingdom, tea accounts for about three-quarters of the total caffeine intake. Following water, tea is the most popular beverage in the world.

"People generally take caffeine in forms so diluted as to make it highly unlikely that excessive doses—more than 300 or 400 milligrams at a sitting—will be ingested," noted Edward M. Brecher in The Consumers Union Report on Licit and Illicit Drugs. "People have also developed the custom of drinking coffee and tea after a meal," he added, offering "further protection for the stomach lining."

From Beans and Leaves to Power Drinks

Both health claims and controversies have followed caffeine through the centuries. Studies warning of the harmful effects of caffeine began surfacing in the 1960s. By the early 2000s, though, most follow-ups to those studies failed to duplicate the initial findings. Around the same time, youth culture began to thrive on the excessive use of caffeine. New drinks such as Red Bull, Jolt, and Adrenaline Rush purposely contained large amounts of the stimulant.

Although moderate use of caffeine has been deemed safe by medical researchers, the "power drinks" of the twenty-first century increased the risk of possible negative effects on users. While doing research in London, Reid interviewed several young users of Red Bull. "I've had eight.… I'm flying," reported one. Another compared drinking two tins of the energy drink to "drinking a pint of speed."

Critics of popular beverages such as Red Bull and Adrenaline Rush suggest that the caffeine content, along with the massive doses of sugar in each can, pose a significant health risk. These drinks do provide users with an energy boost. But some researchers think they also increase the chance of dehydration among athletes and all-night dancers. The high sugar content of the drinks impairs the body's ability to replenish fluids lost through sweat.

Energy drinks are also used as mixers for alcoholic drinks. The combination of the two can cause heart damage. In addition, "people who ingest a lot of caffeine, a stimulant, along with a lot of alcohol … won't realize how drunk they really are," warned Elizabeth Cohen on the CNN.com/HEALTH Web site. This could lead people to believe they are capable of driving when they really are not.

Effects on the Body

"The reasons for the attraction" to caffeine, wrote Jennie Kim in The Hoya, "lie in the short-term effects … often referred to as a caffeine 'lift."' Within about fifteen minutes of consumption, a caffeinated beverage will cause the drinker to feel more alert. But, according to Reid, "the instant surge is mostly placebo"—the belief that the substance will produce a desired effect in the user, even if the substance itself is not capable of producing that effect. Reid added: "[C]affeine's effects don't peak for up to an hour after it hits the bloodstream."

Caffeine Consumption

Many people throughout the world consume caffeine every day. Caffeine is found in coffee, tea, soft drinks, chocolate, and even over-the-counter drugs, among other products. Here are more facts about this popular natural stimulant.

• Medical experts recommend that the caffeine intake for children be limited to 100 milligrams daily.
• The average daily consumption of caffeine for adults in the United States is about 280 milligrams.
• Approximately 600 milligrams of caffeine have the same stimulating effect as 20 milligrams of amphetamines (am-FETT-uh-meens). (Prescription-only stimulant drugs, amphetamines increase mental alertness, reduce appetite, and help keep users awake.)
• About 1.5 billion cups of coffee are consumed every day throughout the world.
• Most of the caffeine in soft drinks is added by the manufacturers. The kola nut, the source of some of the flavoring of cola drinks, has only a bit of caffeine, providing about 5 percent of the total amount in a standard serving.

Whether it takes fifteen minutes or sixty minutes after consumption for a "caffeine buzz" to kick in, the stimulant effects of this substance are very real. Simple intellectual tasks are performed more readily, as are physical jobs that require endurance. However, fine motor movements may become more difficult to carry out, perhaps due to the slight hand tremors

that become more pronounced with higher doses of caffeine. Larger doses of caffeine, especially in people who do not use it regularly, typically cause headache and nervousness.

The effects of caffeine last for about five hours after it is ingested. Taken near bedtime, caffeine will delay the time it takes for the user to fall asleep. It will also reduce the depth and quality of sleep. These effects are evident with the amount of caffeine present in a cup or two of coffee, approximately 80 to 250 milligrams. People who have consumed caffeine shortly before trying to sleep tend to move around in bed more and wake up more easily than sleepers who have not consumed caffeine prior to bedtime.

More Harmful Side Effects

After being taken by mouth, caffeine dissolves easily in body fats. It does not encounter any barrier as it spreads throughout the body, so it rapidly crosses the mucosa (the mucus membrane) of the stomach and soaks through the blood-brain barrier. Caffeine affects the brain, the digestive system, heart and breathing rates, and the kidneys. When consumed in very large amounts, it can cause users to experience an increase in muscle activity, a rise in body temperature, a decrease in appetite, and problems sleeping.

In addition to increased heartbeat and rate of respiration, stomach acid production rises, sometimes causing indigestion. Urination is also stimulated. Caffeine directly affects the kidneys, cutting their ability to reabsorb electrolytes and water. For every single cup of coffee or two to three cans of caffeinated soft drink consumed, about five milligrams of calcium, an important electrolyte, are lost in the urine.

Caffeine temporarily increases blood pressure. In healthy users, the body is able to compensate for this increase and adjust back to its normal blood pressure rate. However, people with hypertension or who are at high risk for heart attacks may have a more sensitive response to the drug and are advised to minimize their caffeine intake. Even in people without heart disease, the effects of caffeine on the heart can be considerable. Rapid or irregular heartbeats can result from ingesting the substance in very large amounts.

For migraine headache sufferers, the effect of caffeine on the blood vessels around the brain is beneficial. It constricts both the inner and outer vessels, relieving pain. Also, because caffeine-containing drinks such as coffee increase the acidity in the stomach, they speed the absorption of pain medications. Some people, however, find that caffeine irritates their stomachs and intestinal tracts. It is still unclear if the effect is from the caffeine itself, or from another asyet-undetermined substance that could be in coffee. Large amounts of caffeine may also contribute to osteoporosis, particularly in elderly women.

Caffeine Can Be Toxic

Toxic or poisonous effects, such as persistent insomnia and anxiety, only become evident when people drink more than eight or nine cups of coffee or tea a day. Insomnia is when someone has difficulty falling asleep or an inability to sleep. Anxiety is a feeling of being extremely overwhelmed, restless, fearful, and worried.

Convulsions and delirium can follow enormous doses. Morris noted that the amount of caffeine in forty-nine eight-ounce cups of coffee can actually be fatal to a human being if consumed by mouth in a short period of time. That works out to about 4,000 to 6,600 milligrams of caffeine in a sitting.

Dangers can occur when caffeine-containing beverages are mixed with caffeine tablets such as No-Doz or Vivarin, both of which are sold without a prescription at drugstores. These tablets have high concentrations of caffeine in them. Taking them at higher than recommended doses, especially along with coffee, tea, or other caffeinated drinks, can cause toxic results.

Women and Caffeine, 1969

In 1969, Dr. Avram Goldstein and Dr. Sophia Kaizer, both of the Stanford University School of Medicine, decided to examine why so many people drink coffee. They focused their study on the coffee-drinking habits of 239 young women.

The women were asked a series of questions. A full 60 percent of them claimed that they drank their first cup of coffee in the morning "because they needed it." Heavier users reported symptoms of withdrawal when they skipped their morning coffee. These symptoms ranged from "headache" and "irritability" to an "inability to work effectively."

The next phase of the experiment produced interesting results. Some of the women agreed to brew and drink nine unmarked vials of coffee—one each morning over the course of nine days. Three of the vials contained no caffeine, three contained 150 milligrams of caffeine, and three contained 300 milligrams of caffeine. Each day, the group was asked to record their moods every half hour for two hours after drinking whatever vial they brewed that day. None of them knew who was drinking what each morning.

The Goldstein–Kaizer study is credited with proving that caffeine is indeed a mind-affecting drug. Heavy coffee drinkers reported feeling nervous, sluggish, and irritable on the mornings they drank the caffeine-free coffee. Among light coffee drinkers, jittery feelings and stomach problems plagued them on mornings when they drank the highly caffeinated coffee.

The results of the Goldstein–Kaizer study were first published in the July 8, 1969, issue of Clinical Pharmacology and Therapeutics. The information was adapted by Edward M. Brecher for use in The Consumers Union Report on Licit and Illicit Drugs, 1972.

Babies born to women who consume extremely large amounts of caffeine during pregnancy have demonstrated delayed growth and problems with mental or physical development. As of 2005, doctors were advising pregnant women to keep their caffeine consumption within the bounds of a cup or two of coffee per day to ensure the good health of their babies. Pregnant women who have miscarried in the past are advised to avoid caffeine totally.

Reactions with Other Drugs or Substances

Caffeine cannot sober up someone who is drunk or save someone who is overdosing on a sedative. It can, however, alter the rate of absorption in the digestive system. Consuming caffeine in combination with drugs such as oral contraceptives and alcohol can delay the body's ability to rid itself of the caffeine.

Treatment for Habitual Users

Legally, caffeine is not regulated as a dangerously addictive substance. Yet, withdrawal from caffeine is documented in medical literature as a recognized set of symptoms. Physical and psychological dependence on coffee, for instance, tends to occur at rates of five or more cups per day. Many people who regularly consume caffeine and then suddenly stop will experience headaches, irritability, muscle aches, extreme tiredness, and impaired concentration.

A major symptom of quitting caffeine abruptly is a moderate to severe headache that generally begins within eighteen hours of the last dose. The feeling has been described as a fullness in the head that turns into a throbbing pain and is worsened by physical activity. Sadness and mild nausea are also reported by a quarter of those individuals who get the withdrawal headache. Those who chronically consume 500 to 600 mg of caffeine per day are more likely to experience withdrawal if they suddenly cease their habit. MSNBC.com reported that 13 percent of coffee addicts "were sick enough to lose time at work" when the source of their caffeine was taken away. Withdrawal symptoms can last as long as nine days.

In "Decreasing Your Caffeine Intake," registered dietician Karen Schroeder advises users who want to cut back on their caffeine intake to do so gradually. "Decreasing over a period of time" rather than going "cold turkey" may help minimize the symptoms of withdrawal. For starters, Schroeder suggests "mixing half regular and half decaffeinated coffee" or brewing tea "for a shorter time," since "a one-minute brew contains about half of the caffeine that a three-minute brew contains."

Consequences

As of 2005, there was no evidence that caffeine use alone was linked to the socially damaging behaviors that characterize drugs of abuse. Kim noted, however, that students who consume large amounts of caffeine to "enhance mental capacity" should be cautioned. Excessive caffeine consumption may actually bring on "symptoms unfavorable to studying, such as restlessness, anxiety, and heart palpitations. The student may struggle and would have better study habits without the caffeine."

The Law

There are no legal consequences for caffeine sale, use, or possession, since caffeine is not a scheduled substance. In 1997, the U.S. Food and Drug Administration (FDA) required labeling of the caffeine content of foods and drinks. Soft drink manufacturers are allowed to add a maximum of 6 milligrams of caffeine per ounce of beverage, which adds up to a limit of 72 milligrams per 12-ounce serving. Coffee and tea, containing caffeine naturally rather than as an additive, are not regulated for caffeine content.

For More Information

Books

Braun, Stephen. Buzz: The Science and Lore of Alcohol and Caffeine. New York: Oxford University Press, 1996.

Brecher, Edward M., and others. The Consumers Union Report on Licit and Illicit Drugs. Boston: Little Brown & Co., 1972.

Gahlinger, Paul M. Illegal Drugs: A Complete Guide to Their History, Chemistry, Use, and Abuse. Las Vegas, NV: Sagebrush Press, 2001.

Kuhn, Cynthia, Scott Swartzwelder, Wilkie Wilson, and others. Buzzed: The Straight Facts about the Most Used and Abused Drugs from Alcohol to Ecstasy, 2nd ed. New York: W.W. Norton, 2003.

Pendergrast, Mark. Uncommon Grounds. New York: Basic Books, 1999.

Weil, Andrew, and Winifred Rosen. From Chocolate to Morphine. New York: Houghton Mifflin, 1993, rev. 2004.

Weinberg, Bennett Alan, and Bonnie K. Bealer. The World of Caffeine: The Science and Culture of the World's Most Popular Drug. New York: Routledge, 2001.

Periodicals

Kim, Jennie. "The Buzz on Caffeine." The Hoya (February 8, 2000).

Morris, Ruth. "America's Bottomless Cup." Life (January 14, 2005): pp. 4-9.

Reid, T. R. "Caffeine." National Geographic (January, 2005): pp. 3-33.

Sparano, Nicole. "Is the Combination of Ibuprofen Plus Caffeine Effective for the Treatment of Tension-type Headache?" Journal of Family Practice (January, 2001): pp. 312-319.

Web Sites

"Coffee Kids." Coffee Kids: Grounds for Hope.http://www.coffeekids.org/ (accessed June 30, 2005).

Cohen, Elizabeth. "Energy Drinks Pack a Punch, But Is It Too Much?" CNN.com/HEALTH, May 29, 2001. http://archives.cnn.com/2001/HEALTH/diet.fitness/05/29/energy.drinks.02/index.html (accessed June 30, 2005).

Kagan, Daryn. "Dr. Sanjay Gupta: Caffeine Hidden in Many Foods." CNN.com/HEALTH, June 27, 2003. http://www.cnn.com/2003/HEALTH/diet.fitness/06/27/otsc.gupta/index.html (accessed June 30, 2005).

Schroeder, Karen. "Decreasing Your Caffeine Intake." St. John Health.http://www.stjohn.org/healthinfolib/ (accessed June 30, 2005).

"Tea and Caffeine." Holy Mountain Trading Company.http://www.holymtn.com/tea/caffeine.htm (accessed June 30, 2005).

"Too Much Caffeine." Information for Health Professionals: Medsafe Prescriber Update Articles, August 1999. http://www.medsafe.govt.nz/profs/PUarticles/caffeine.htm (accessed June 30, 2005).

"Yes, You Really Do Need That Coffee." MSNBC.com, September 30, 2004. http://www.msnbc.msn.com/id/6140162/ (accessed June 30, 2005).

See also: Amphetamines; Ephedra; Herbal Drugs