The World of Caffeine (57 page)

Another psychiatric problem associated with excessive caffeine consumption is delirium, which is sometimes present in cases of extreme caffeine intoxication. For example, caffeine-induced delirium has been reported in a man who chugged down large amounts of coffee, cola, and 800 mg of caffeine tablets while competing in the Iditarod sled dog race held between Anchorage
and Nome, Alaska. He experienced tremor and alteration in his level of consciousness, anxiety, visual illusions and hallucinations, vertigo, and impaired memory consistent with an episode of delirium. While in this case and others delirium has been attributed to excessive caffeine use, the degree to which factors such as fatigue and sleep deprivation may have contributed to the delirium is not readily determinable. However, even though the redoubtable
DSM-IV,
the bible of psychiatric diagnosis, does not yet officially recognize caffeine as one of the agents that can produce a “substance intoxication delirium,” it seems probable that caffeine, like other psychoactive substances, should produce delirium if taken in sufficiently high doses.

If you take enough caffeine, it can kill you. The value generally accepted for a fatal overdose, and one given by pharmacology texts for fifty years, is about 10 grams for the average adult, about as much as in one hundred cups of coffee. In more precise clinical terms, the LD-50 of caffeine, that is, the lethal dosage for 50 percent of the population, is estimated at 10 grams for oral administration. However, the lethal dosage for any individual varies directly with body weight, and about 150 mg/kg to 200 mg/kg of caffeine is the usual estimate for the LD-50 for adult human beings. That is, those who weigh 150 pounds will have an LD-50 of at least 10 grams. However, because fatalities are very rare, and deaths have occurred at 5 to 50 grams, it is impossible to have confidence in this exact figure.

Acute toxic symptoms occur at levels as low as 50 mg/kg, equivalent to about 3.5 grams for a 150-pound person, about as much as in 35 cups of coffee. Even these levels are not usually attainable from dietary sources.
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Milder caffeine intoxication symptoms, including anxiety, insomnia, and gastrointestinal disturbances, can occur after a 150-pound man ingests as little as 250 mg, or about 3 mg/kg.

Researcher Jack James cites what may be the first account of caffeine poisoning, dating from 1883. In this description, a sixty-three-year-old man “survived an oral overdose of caffeine after developing various cardiovascular, CNS, and gastrointestinal symptoms.”
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Others have not been so fortunate. An account published in 1959 of a thirty-five-year-old woman who, after arriving at the hospital in a state of insulin shock, was accidentally injected with a caffeine solution instead of glucose,
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died after experiencing convulsions and respiratory arrest. Subsequent investigation determined that she had received 3.2 grams, raising her serum concentration of caffeine to 57 mg/kg.

Most of the cases where caffeine was the cause of death were the result of the accidental administration of caffeine by hospital staff. Typical examples are those of a fifteen-month-old boy and a sixty-one-year-old man, each given about 18 grams of caffeine orally. Another is a forty-five-year-old woman who was given 50 grams of caffeine instead of 50 grams of glucose.

In “A Fatal Ingestion of Caffeine,” a 1977 article in
Clinical Toxicology,
written by J.E.Turner and R.H.Cravey, of the Office of the Sheriff-Coroner, Toxicology Laboratory, Santa Ana, presents one of the rare caffeine-associated deaths. According to the authors, the thirty-four-year-old woman who was to die from a massive overdose of caffeine

Toxicological Findings after a Fatal Caffeine Overdose

Turner and Cravey, “A Fatal Ingestion of Caffeine,” Clinical Toxicology 10 (3): 341–44 (1977).

To comprehend the blood values of the deceased, consider that a 300 mg dose of caffeine, about as much as in two strong cups of coffee, result in a maximum blood concentration of about .5 mg/100 ml in a 200-pound adult, or less than 5 percent of the level found in this autopsy.

The survivor of what is probably the largest dose of caffeine on record is a twenty-one-year-old woman, estimated to have ingested a total of 106 grams, taken in the form of more than four hundred tablets, each containing 250 mg of caffeine. Despite an astonishing serum caffeine concentration of nearly 300 mg/100 ml, the patient was said to have shown “no residual neurological deficit” when discharged from the hospital four days later.
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Although people who consume caffeine are less likely to commit suicide than nonconsumers, there are outstandingly rare suicide attempts utilizing high doses of the drug, which, under extreme circumstances, may in fact prove fatal, and there have been at least two reports of suicides by caffeine overdose.
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Caffeine may be used to commit suicide so infrequently partially because few people know if it could kill them or how much it would take to kill them. The infrequency of accidental death may be a result of the emetic (purgative) effect of the drug. If there is evidence that a patient has significantly overdosed on caffeine, it should be treated as a medical emergency requiring intensive monitoring, symptomatic treatment for rapid or irregular heartbeat and seizures, aspiration of the stomach, and assessment of the serum caffeine level. Serum readings of more than 1 milligram per milliliter are generally considered toxic. Caffeine overdose has also been treated successfully with hemoperfusion, or flushing the blood supply clean with fluids.

Because infants and young children are much more vulnerable to the toxic effects of caffeine than adults, even when the discrepancies in their body weights have been factored out, researchers say that in infants 40 mg/ml is probably toxic.
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There is a case of a child who died from orally ingesting less than 5.5 grams, or the equivalent of about five cups of coffee.
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Finally, the habit of smoking cigarettes must be mentioned again in relation to caffeine toxicity. There is an unholy bond between the habits of smoking cigarettes and drinking coffee. Although the precise figures vary, every survey indicates that a higher percentage of smokers drink coffee regularly than do non-smokers and that of regular coffee drinkers, smokers drink more of it than do non-smokers. We have noted repeatedly how variable the kinetic profile, or speed of metabolic passage, of caffeine can be among different people or in the same person at different times. Most people do not realize, however, that giving up cigarettes causes a profound slowing of caffeine’s half-life, creating a toxic hazard for people who continue their previous levels of caffeine intake, unaware that, if they are no longer smoking, their coffee or tea will have a greater and more sustained effect on them than they had become accustomed to.

In the course of its relatively brief history, caffeine has become the world’s most popular drug. Its most common sources, coffee, tea, and chocolate, have been celebrated and promoted as productive of health, stamina, and creativity and have been condemned and banned as the corrupters of the body and mind and subverters of social propriety and civil order. Through coffee and the coffeehouse, caffeine has altered society and culture from the Middle East to Europe, America, and beyond, justifying the fears of Islamic clerics and sultans and Western kings and police chiefs that the institutions purveying caffeine would undermine the stability and insularity of social and political order and religious practice. Through tea, teaism, and the afternoon tea, caffeine has subtly shaped the spiritual and aesthetic ideals of the Orient and given the British Empire, the most extensive imperial realm the world has ever seen, a universal symbol of civility, restraint, refinement, and social order. Through caffeinated soft drinks, caffeine has perfected its conquest of humanity, extending its community of users to children.

What powers or properties of caffeine have enabled it to exert such a broad influence on human history?

For one thing, caffeine is an intoxicant. As Freud observes in
Civilization and Its Discontents
(1930), man averts suffering by means of the enjoyment of four things: the enjoyment of illusions, or what Coleridge called “the willing suspension of disbelief”; the enjoyment of beauty, which beauty, we have been told by Keats, is “a joy forever”; the enjoyment of what we can have instead of the pursuit of the unattainable, which is called “displacement”; and, lastly, the enjoyment of intoxicants, or chemical intoxication. Freud might therefore have responded to the question “Why do people take drugs?” with the reply “Why not?” For it should come as no surprise that if caffeine, as an intoxicant, answers essentially to man’s quest for happiness, it should be among the general pleasures of mankind.

What this observation leaves unaddressed is why caffeine should have emerged so recently from the large, diverse collection of available intoxicants to become both the most popular drug on earth, used regularly by more than 90 percent of everyone alive, and the most inconspicuous as well. For caffeine is as unnoticed as it is ubiquitous, suffusing our systems unremarked, despite its presence in our bodies from birth (and even before birth) through childhood, adulthood, and old age.
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Because the nature and extent of caffeine’s effects are widely variable among different people and in the same person at different times, different people use caffeine for different reasons, and the same person uses caffeine for different reasons at different times. This diversity of effects and purposes may be one reason caffeine is the most popular drug on earth. But this same diversity also suggests that a complete understanding of caffeine will elude us until we have fully disentangled the complexities of human life itself.

Of course, caffeine comes to us accompanied by delights beyond its power to intoxicate: the sensual appeal of its most commonly enjoyed vehicles, coffee, tea, and chocolate. And caffeine itself should not be overlooked as an important component of their taste. The taste threshold for caffeine, that is, the minimum concentration at which it can be detected by the tongue (about .02 mM/L [millimole per liter]), is the same order of magnitude as actually found in a cup of coffee. However, caffeine’s contribution to the taste of coffee and other beverages is greater than this number suggests, because, at levels far below the threshold of perception, caffeine affects the taste of sweet, bitter, and salty foods or drinks, and therefore affects the overall taste mix of coffee’s and tea’s many flavoring components. In this book we have not discussed the art of beverage preparation, except as an aside, preferring to follow the disclaimer found in
A Compleat History of DRUGGS,
in which the early-eighteenth-century author, speaking of recipes for chocolate, explains:

We have discussed what we think constitutes the most important reason for caffeine’s prominence in the modern world: It gives men the power to regulate their biological systems so as to make them more conformable with the demands of exacting and highly integrated schedules. Perhaps another reason for caffeine’s enduring appeal is that, as compared with many other intoxicants, it is mild and benign. Although it can produce undesirable effects, from jitteriness and insomnia to withdrawal headaches and sleepiness, few people, as far as we know, find their health broken by caffeine use, and few lose their jobs, families, or fortunes because of excessive caffeine consumption. Of course part of the difference between caffeine and stronger, more
dangerous drugs is simply a legal artifact. No one really knows to what extent caffeine use would follow the patterns of the abuse of other drugs if it were to join them as a controlled or illegal substance, or, conversely, to what extent the patterns of abuse of other drugs would abate if they, like caffeine, were obtainable legally.

What is the future of the coffeehouse? All we can be certain of is that it has one and will continue to have one. We recently read of two high school alumnae from Philadelphia’s Main Line who met, for the first time in a decade, by chance in the Pumpernickel Café in Kathmandu, Nepal. Can there be any doubt that, if and when there are settlements on Mars, coffeehouses will be among the first amenities available to the émigrés? The coffeehouse, which changes, adapts, and diversifies, merits recognition as the most protean institution in history. In coffeehouses, men met and plotted the American, French, Russian, and Chinese revolutions, dissected dolphins, invented and wrote newspapers, underwrote international commerce, conducted love affairs, and bandied and exchanged every sort of idea. In seventeenth- and eighteenthcentury London, quack doctors treated patients and sold patent medicines at the coffeehouses. In Los Angeles at the end of the millennium a young lawyer has opened a coffeehouse in hope of practicing law there. To the concept of the
tabula rasa,
the blank slate of the mind on which experience writes, an idea of Locke’s so favored by the generation of Addison and Steele, who worked and played in the coffeehouses, might be added the
mensa rasa,
the cleared table of the coffeehouse, across which every sort of opinion might be sounded and every sort of person faced.

Chemical intoxicants have been widely enjoyed since the remotest prehistoric times. We know that the production and consumption of alcohol from fermented plant matter are universal practices and have either arisen independently or been adopted into every place where human beings have lived. Yet the use of caffeine began to assert itself only within historical times, emerging as a relatively localized practice, first documented as coffee drinking in the Yemen, or as tea drinking in China and Japan, before suddenly exploding over the entire surface of the globe within the last few hundred years. Most cultivars, such as wheat, have been raised as long as they have been known, generally long before the time of written records. Yet the caffeinated plants, which are by far the largest cash crops on earth today, were still unknown within historical times, even in the regions in which they are today often mistakenly imagined to have originated.

Whether, like coffee, which was brought by Gabriel as a medicinal gift for Solomon or Mohammed, like tea, which was discovered by Shen Nung or carried by the missionary Bodhidharma, or, like chocolate, which was brought by Quetzalcoatl from heaven for the enjoyment of his people, the great caffeine-bearing plants were described as gifts from the gods in the earliest cultures into which they are known to have been introduced. The religious of many faiths have been repeatedly associated with the early uses of caffeine and the cultivation and propagation of the plants in which it occurs, as illustrated in examples such as the Sufis with coffee, the Buddhist monks with tea, the Aztec god-king with chocolate, and the Jesuits with all three and maté as well.

The seeds or leaves of the caffeine-bearing plants have been recurringly used as money, as cacao beans were by the Maya and Aztecs, cassine leaves by the North American Indians, cola nuts by the Africans, coffee beans by the Arabs, and bricks of tea by the Chinese and the Russians, a use that places them in the very small class of negotiable substances such as gold, silver, and precious jewels.

Today, more than any time before, caffeine is the dominant, nearly universal drug of the human race. It was in the steaming cups of coffee or tea that sat alongside the men who created the first newspapers. It is in the steaming cups of coffee or . tea or, nearly as often, in the cold colas or other carbonated soft drinks that sit by those who design and use the Internet software and websites that are taking us into the third millennium.

Other drugs have had their days, for the use of many intoxicants is cyclic, rising and falling over the decades and centuries. Certainly caffeine use has not remained constant, nor can it be absolutely asserted that its use has demonstrated an unbroken increase in every nation in every decade. Yet, during the five centuries since word of the caffeinated beverages reached Europe, the coffee bean alone has come to account for a greater share of international trade than any other agricultural commodity, and these beverages have reached every quarter of every country on the earth. We can be fairly certain that this ubiety is unlikely to be compromised in the new millennium. Indeed, if our observations about the attractions of caffeine as a benign intoxicant and conversational stimulant and its uses to help us conform to our schedules, increase our physical and mental endurance, even spark our creative imaginations are correct, then this strange crystal, which may have evolved as a natural insecticide, has a shining future in the centuries ahead.

Selling the caffeinated beverages is and is likely to remain a great business. The cost of the imported green beans in a cup of coffee, sold retail at between seventyfive cents and five dollars, depending on where you buy it, is about seven cents. The cost of the roasted, ground coffee in a cup is less than twenty cents.
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Few people, however, are ever likely to shun the café because of the big markup in price.

Is caffeine safe? The answers given in
part 5
—“Nobody knows” or “It depends”— are still the most accurate. As of this writing, caffeine appears to be remarkably nontoxic and to have been associated with few, if any, large-scale health problems. Unfortunately, in proportion to the extent of our exposure to caffeine, too little is yet known about its health effects for smugness. For example, questions have recently arisen again about whether caffeine increases the risk for developing high blood
pressure. And there is no question that more work must be done to determine its effects on the fetus, in light of the fact that more than 75 percent of infants are born with detectable amounts of caffeine in their blood.

Caffeine has played a part in medicine, religion, painting, poetry, learning, love, life, and death. It figures prominently in the accords and enmities and the exchanges of trade and intelligence that constitute the history and intercourse of nations; and it is also a vitalizing and nearly indispensable agent in the singular lives of the overwhelming majority of the world’s six billion people. Caffeine propels both idleness and industry. In the coffeehouse, it feeds idleness, whether it is the productive idleness of talk of politics, art, or social engagement, or the useless or even inimical idleness of gaming and gossip; in the workplace, it fuels the mental and physical stimulation that make possible long hours, punctuality, alertness, and alacrity; and in the studio, it stirs the artist’s imagination and creative energies. And it does these things with little or no harm to the prudent user. Of no other drug, nor any other agency known to man, can we say the same.