Caffeinated: How Our Daily Habit Helps, Hurts, and Hooks Us (Book Review)


I could tell a story of my life, back to childhood, through coffee. At five, drinking the lukewarm dregs of milked-and-sugared coffee from my father’s cup after he left for work. At ten, learning how to make coffee for my mother in a percolator. At 15, drinking black coffee for the first time at a university chemistry conference with my high school teacher, Mr. Koury, and my friend, Eddie, and realizing, “Coffee is about being an adult.” I started my daily habit then. It supported my schoolwork, friendships, and even self-image.

Caffeinated: How Our Daily Habit Helps, Hurts, and Hooks Us - book cover

In college, I would walk with my friend Lisa, whom I considered my first grownup friend (she was a law student with her own apartment), to the renowned Coffee Connection in Harvard Square. Our coffee was served, still brewing, in a French press. At my first job, at a peace studies institute, the only other non-scholar employee, Judy, introduced me to cappuccino and sent me every day with a few dollars to the café next door to get us each one.

When I was 26 and in the hospital after my diagnosis with Type 1 diabetes, my meal trays appeared on schedule with plain, salt-free food (typical of the diabetes diet in 1992), unsweetened applesauce for dessert, and decaffeinated coffee. I tolerated this for a couple of days and finally beseeched the nutritionist, “I can stand it all, but not the decaf. Could I please drink real coffee?” She said, “Yes, we all need a vice, and coffee can be yours.” Since then, as a person with diabetes, I have viewed coffee as The Thing I Can Have. I only drink the good stuff — it’s my treat — and I don’t skip a day.

Caffeinated (Hudson Street Press, 2014), Murray Carpenter’s new nonfiction book on the key ingredient in coffee, tea, soda, and energy drinks, asserts that the pleasure in drinking one’s favorite beverage is inextricable from the psychomotor effects of methylated xanthine, the chemical we know as “caffeine.” It increases alertness, boosts mood, and improves physical performance in sports and exercise. As long as I hit the “sweet spot” with my daily caffeine consumption, the taste and the drug improve my life. While I might think of myself as a coffee lover, Carpenter would put me in the same category he puts himself into: “omnivorous and enthusiastic caffeine user.”

Carpenter traces the world history of caffeine, which is foundation for his argument that we have been hooked for a long, long time. The first documented habitual use has been traced to the Soconusco region of Mexico, a sweltering, rainy plain region along the Pacific coast. Archaeological evidence 3,500 years old indicates that the Izapans, Mayans, and Aztecs relied on chocolate in ceremonies (including human sacrifice), as currency, and in warfare. The cacao drink imbibed in the Izapan era, unlike today’s Hershey bars, was unadulterated and may have provided, Carpenter speculates, as much caffeine as a single shot of espresso. “That,” the author writes, “is a good, solid bump.”

Tea drinking in Asia and coffee agriculture in Africa and later Latin America are not as well documented archaeologically. However, folklore accounts claim that the Chinese have been ritualistically brewing caffeine-rich tea for 5,000 years and that North Africans long ago adopted the practice of chewing on coffee berries after goats “nibbled on the plant and suddenly started dancing.” Carpenter explores the tea’s reputation as “mellower” than coffee’s “angry buzz” and, citing scientific studies, concludes that tea simply has less caffeine.

Although he is interested in the roots of caffeine use and habituation, Carpenter always brings his narrative back to “Americans’ collective caffeine dose.” About tea, he reports that it only provides about one-tenth of our total caffeine consumption. “We get nearly twice as much caffeine from soft drinks and six times as much from coffee.”

Interestingly, even though caffeine is more highly concentrated in coffee, Americans drink more soft drinks than cups of java. In 1975, “soft drinks passed coffee as America’s favorite beverage.” Even though we Americans think we are just enjoying a soda, eight of the top 10 soft drinks in the U.S. are caffeinated.

The centerpiece of Carpenter’s analysis of caffeine’s reach into our daily lives is the story of Coca-Cola, its early formulation (which in 1909 included a dose of caffeine equal to half a cup of coffee), and strategic marketing of the cola as a fatigue reliever. The drama at the heart of the story is provided by a court case that pitted Coca-Cola’s owner Asa Candler against Harvey Washington Wiley, chairman of the USDA’s Bureau of Chemistry, which later became the FDA. In 1909, Wiley was determined to alert Americans to the dangers of caffeine as “addictive poison,” especially inappropriate for children. Testimony in the first two weeks of the trial was “strong on emotion, anecdotal evidence, and pseudoscience.” In the third week, Coca-Cola’s lawyers brought out “their secret weapon” – results from human trials, conducted by psychologist Harry Levi Hollingworth, on 16 subjects who were regular caffeine users. The cognitive, sensory, and motor tests showed that caffeine had a noticeable, positive effect on users. This evidence, paradoxically, led Judge Edward Sanford to rule that Coca-Cola, without caffeine, “would lack one of its essential elements.”

Coke won the trial. So did caffeine. Since then, the FDA has periodically made attempts to regulate the use of caffeine as an additive, especially as concerns about energy drinks have risen. Drinks like Monster and Red Bull have even been implicated in the deaths of a few teenagers who overdosed on caffeine by consuming more than a serving of these extra-caffeinated beverages. (Two 24-ounce Monster cans, the cause of one death, total almost 500 milligrams of caffeine, the equivalent to almost seven espressos.) Carpenter points to a 2012 article in the New York Times that reported 93 events, over eight years, of adverse effects from energy drinks and energy shots; 13 deaths were included on the list. Still, he writes, “It is hard to unravel the health problems attributed to energy drinks. Caffeine is not as powerful as cocaine… But neither is it weak.”

After reading Caffeinated, my pleasure in my daily coffee is no longer so innocent. Carpenter writes about the downside, which has been reported anecdotally and studied scientifically: Too much caffeine disrupts the heart rhythm, causes headaches, prompts nausea and sometimes vomiting, and depresses mood. Ten grams (a tablespoon) of caffeine is a lethal dose. People who quit caffeine experience measurable withdrawal symptoms that affect daily life.

And even though coffee companies like Starbucks and Green Mountain support Fair Trade and provide customers with pleasurable coffee experiences, they also calibrate brews and beverages, situate their restaurants or coffee stations, and strategize coffee culture so that their customers, like me, always have access to caffeine when they need it. Green Mountain’s subsidiary Keurig produces the ubiquitous, single-serving-sized K-Cups, introduced in 2003, so that “people could pop their own pods on demand.” Most of Green Mountain’s recent growth has been driven by the K-Cups, and Starbucks got into the single-serving game in 2009 with Via instant coffee. Carpenter writes, “The whole model is based on making it quick and easy to get a tasty caffeine jolt.”

So much for my sepia-toned memories of drinking my father’s coffee dregs or meeting a new friend for a coffee date in Harvard Square. While I am not worried that coffee-drinking – or diet Coke or tea drinking – will harm my health, Carpenter summarizes legitimate studies and talks to scientists about caffeine’s health effects, and the findings are mixed. In particular, while some research on coffee and Type 2 diabetes “found a strong association between habitual coffee drinking and a substantially lower risk of type 2 diabetes,” another study linked caffeine to insulin resistance. Carpenter scrolls through caffeine-related studies on depression (caffeine may help), birth defects and miscarriages (moderate coffee drinking is okay), osteoporosis (no effect), and cognitive function (extroverts may get more cognitive enhancement than introverts do). The “highly varied effects… make caffeine so hard to pigeonhole,” he concludes, explaining why the FDA may have so far failed to define limits for its use.

Caffeine “is the most popular, least regulated drug in the United States,” insists Carpenter, and his thorough investigation is convincing. He describes how athletes in the Ironman World Championships use caffeine for endurance. Researchers studying the effect of caffeine on the athlete admit, “It is a performance-enhancing substance.” Another chapter, on the military, describes research and engineering that includes the development of snack foods and rations with added caffeine formulated for soldiers. If the drug alleviates the stress and improves performance of the world’s strongest people at their physical limits (and research shows it does), how does it affect the world’s average people, like me, at the limits of their patience, concentration, and stamina?

Caffeinated ends in 2013 with caffeine in the crossfire between the FDA — gearing up to study and possibly regulate caffeine in gum (that happened), energy drinks, bottled teas, and instant coffee – and companies like Starbucks, which continually innovate new products that provide “a boost of natural energy.” As Carpenter’s book has revealed, it seems as though we are so far down the caffeine path that a reversal would be intolerable. A couple of years ago, my teenage daughter commented on my coffee drinking and suggested I minimize it. “But Lydia,” I responded, “How would I live my life and do all the things I need to do?” She looked at me; there was no answer. We both knew I couldn’t.

Caffeinated is available on Amazon.

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8 years ago

Thanks for this, Jane – so interesting! As a side note, I recently read Gary Taubes’ book, Why We Get Fat (fascinating in and of itself – it’s all about insulin) and he goes into further detail about the correlation between caffeine consumption and insulin resistance. (This resulted in an ah-hah moment for me: occasionally, especially in the morning, I find that I have to take insulin with my coffee even if I’m not eating anything else.) I’m not sure how deep Carpenter gets into that particular issue, but if anyone out there wants more, I recommend checking out Taubes’… Read more »

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