Because the drug is linked to the production of adrenaline and cortisol, hormones which are in turn associated with the fight-or-flight response, says Duke’s James Lane, “for someone with a busy, stressful job, little stresses elicit big responses on caffeine, and big stresses elicit huge responses.” Lane once did a study in which he compared caffeine’s effects on type-A versus type-B personalities. “Caffeine tended to make type Bs into type As,” he says. “Their blood pressure went up. They rose to challenges.” The type As didn’t get any more ambitious; they just became more excitableread more
Photographs by Mitchell Feinberg. Food styling by Sara Jane.
Caffeine is the world’s most widely used psychoactive substance because it works, and quickly. Caffeine enters the bloodstream almost instantaneously upon ingestion. Within 30 to 45 minutes it has permeated nearly every cell in the body. Because it slips effortlessly across the blood-brain barrier—a sort of filter that prevents bacteria, viruses, and most drugs from entering the brain—it penetrates the cerebral cortex unimpeded. Once inside the central nervous system, caffeine is believed to plug up the receptors of adenosine, a neuromodulator that acts like a brake on nerve cells firing their messages across synapses. With the neural sluice gates open, more messages flood through, resulting, it’s said, in a sense of heightened mental quickness. “It makes people feel good, it increases their arousal and alertness, and makes them more friendly and sociable and talkative,” says Laura Juliano, an American University psychology professor, coffee researcher, and substance-dependence expert. Adenosine is also linked to the onset of sleep; rats injected with it have been observed to keel over unconscious, then wake up a few minutes later. When we pull a coffee-fueled all-nighter, “we’re blocking the adenosine telling us to go to sleep because we’re tired,” says James Lane, a professor of psychology at Duke University Medical Center who has been studying the effects of caffeine since the eighties. Caffeine also greatly aids physical endurance and athletic performance, allowing one to go longer and stronger to such an extent that the International Olympic Committee once limited its use as a performance enhancer, though it lifted the restriction in 2004.
Caffeine is classified pharmacologically as a stimulant, a cousin of cocaine and amphetamines, including Adderall and other substances in the increasingly popular cognitive-improvement prescription-drug toolbox. ... The difference between caffeine and other stimulants is, in part, a matter of degree. Like its pharmacological cousins, caffeine signals the body to release adrenaline (hence the heightened sense of energy). Caffeine also slightly raises levels of dopamine, the brain’s feel-good hormone. Cocaine and amphetamines essentially do the same thing, only they create not just a pleasant feeling but outright euphoria. Methamphetamine and crack, because they’re highly concentrated, create an even more intense feeling. But the higher a drug’s highs, the lower its lows, which is why a crack user needing a fix might rob an elderly neighbor at gunpoint while a coffee drinker might simply get snippy with co-workers.
... a more substantive difference between caffeine and related stimulants. Because the brain develops a tolerance to all of these drugs, ever-increasing quantities are required to achieve the same high. What makes caffeine more desirable, or less potentially dangerous, than other stimulants is its built-in restraining mechanism. Technically called caffeinism, it’s the state in which an overcaffeinated user hits the drug’s “dysphoric” range and is overcome by the shakes, anxiety, tension, and nausea. Caffeine, that is, is self-regulating. “That’s one of the secrets of caffeine and probably why it’s accepted worldwide,” says Roland Griffiths, professor of psychiatry and neuroscience at Johns Hopkins and the unofficial dean of caffeine researchers. “With cocaine and amphetamines, when you increase the doses, you generally get increased stimulation and well-being.” Too much cocaine makes you feel invincible; too much coffee makes you think you’re having a nervous breakdown.
Studies touting newly discovered benefits of coffee and caffeine are published every few weeks. (April 8, 2008, bulletin: Caffeine may help prevent autoimmune diseases such as multiple sclerosis.) Drinking moderate amounts of coffee is believed to slash rates of Parkinson’s disease, inhibit the formation of gallstones, and ward off cirrhosis. It may help prevent Alzheimer’s. Caffeine relieves asthma symptoms by acting as a bronchodilator. Researchers who fed mice caffeinated water found that the animals were less likely to develop skin cancer... One large-scale study showed that a person’s suicide risk decreased with each cup of coffee consumed per day, up to seven cups (notably, though, eight cups or more was shown in a separate study to increase the risk substantially). Caffeine is probably not as bad a diuretic as it’s reputed to be; many nutritionists now believe that a cup of coffee hydrates people about as well as a cup of water... Another study showed that a serving of coffee has more antioxidants than a serving of either grape juice or blueberries.
... And now the bad. A study published earlier this year demonstrated that pregnant women who consume 200 milligrams of caffeine or more per day (that’s less than one Tall Starbucks drip coffee or three six-ounce cups of traditional coffee) are more than twice as likely to have a miscarriage as those who don’t use any. Too much caffeine during gestation may also contribute to low birth weights in children and result in babies born with a caffeine dependence. Large daily doses may also be a factor in female infertility. A study released in late May found that drinking coffee before breakfast could cause blood-glucose levels to rise sharply, which can be dangerous for people with type 2 diabetes. Drinking large amounts of caffeine has been found to exacerbate osteoporosis. And despite the popular idea that caffeine can relieve migraines, doctors say it more often causes them (Caffeine withdrawal seems to be the trigger).
The most serious negative effects of hypercaffeination involve stress and sleeplessness. Because the drug is linked to the production of adrenaline and cortisol, hormones which are in turn associated with the fight-or-flight response, says Duke’s James Lane, “for someone with a busy, stressful job, little stresses elicit big responses on caffeine, and big stresses elicit huge responses.” Lane once did a study in which he compared caffeine’s effects on type-A versus type-B personalities. “Caffeine tended to make type Bs into type As,” he says. “Their blood pressure went up. They rose to challenges.” The type As didn’t get any more ambitious; they just became more excitable. Stress has been linked to everything from cancer to sexual dysfunction to depression. Before she prescribes an antianxiety drug like Xanax, Juliano advises her patients to quit coffee.
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