Reading improvement

THE 

WORLD’S 

FAVORITE DRUG!

RITE DRUG 

Over two billion cups  

of coffee are consumed  

worldwide every day. 

It’s 1:45 a.m., and 21-year-old Thomas  

Murphy is burning the midnight oil, 

studying for an important engineering exam  

he has at 2:00 in the afternoon later today.  

To stay awake and alert, he’s had two cups  

of coffee in the last three hours and is now  

downing a popular energy drink—one that  

has two to three times the amount of caffeine  

as a similar sized can of soda. Many students  

like Murphy, as well as marathon runners,  

airline pilots, and long-distance travelers, owe  

their energy to one of humankind’s oldest  

stimulants: 

 caffeine. 

The power to counter 

 physical fatigue 

 and  

increase alertness is part of the reason caffeine  

ranks as the world’s most popular mood-altering 

drug. It is found not only in sodas, energy drinks, coffee, and tea, but in diet  

pills, pain relievers (like aspirin), and chocolate bars. Many societies around the  

world have also created entire rituals around the use of caffeine. For example,  

there’s the café culture of France, the tea ceremony in Japan, and the morning  

cup of coffee or tea that marks the start of the day in many cultures. 

Caffeine is present in many of the foods and drinks we consume, but is  

it good for us? Charles Czeisler, a scientist and sleep expert at Harvard  

Medical School, believes that caffeine causes us to lose sleep, which he says  

is unhealthy. “Without adequate sleep—the typical eight hours—the human  

body will not function at its best, physically, mentally, or emotionally.” Too  

often, Czeisler says, we consume caffeine to stay awake, which later makes it  

impossible for us to get the rest we need. 

Health risks have also been tied to caffeine consumption. Over the years,  

studies have attributed higher rates of certain types of cancer and bone disease  

to caffeine consumption. To date, however, there is no proof that caffeine  

actually causes these diseases. 

A number of scientists, including Roland Griffiths—a professor at the Johns Hopkins  

School of Medicine in the United States—believe that regular caffeine use causes  

physical dependence. Heavy caffeine users, Griffiths says, exhibit similar behaviors.  

For example, their moods fluctuate from high to low, they get mild to severe  

headaches, or they feel tired or sad when they can’t have a caffeinated drink. To  

minimize or stop these feelings, users must consume caffeine—a behavior Griffiths  

says is characteristic of drug addiction. 

Despite these concerns, the general opinion in the scientific community is that  

caffeine is not dangerous when consumed in moderation.6 

 This means having one  

or two small cups of coffee (about 300 milligrams of caffeine) per day, for example.  

Furthermore, a lot of current research contradicts long-held negative beliefs about  

caffeine, and suggests that it may, in fact, have health benefits. For instance, studies  

have shown that caffeine can help ease muscle pain. Because it is a stimulant, caffeine  

can also help improve one’s mood. Research has also shown that some caffeinated  

drinks—specifically certain teas—have disease-fighting chemicals that can help the  

body fight a number of illnesses, including certain types of cancer. 

In addition, as a type of mental stimulant, caffeine increases alertness, memory, and  

reaction speed. Because it fights fatigue, it facilitates performance on tasks like  

driving, flying, and solving simple math problems. And while it is true that caffeine can  

increase blood pressure, the effect is usually temporary and therefore not likely to cause  

heart trouble. This is especially true if caffeine is consumed in moderation. Moreover,  

despite its nearly universal use, caffeine has rarely been abused. “With caffeine, overuse

tends to stop itself,” says Jack Bergman, a specialist at Harvard Medical School. If you  

consume too much, “you get . . . uncomfortable, and you don’t want to continue.” 

Caffeine’s behavioral effects are real, but most often mild. Getting that burst of  

energy, of course, is why many of the world’s most popular drinks contain caffeine.  

Whether it’s a student drinking coffee before class or a businessperson enjoying tea  

with lunch, humankind’s favorite stimulant is at work every day, all over the world.