The Negative Effects of Caffeine

Dr. Tom Ferguson spelled out the many negative effects of caffeine in this installment of his regular column.

067 negatives effects of caffeine - Fotolia

An apparently innocent fresh cup of coffee betrays nothing about the many negative effects of caffeine. 


Content Tools

Millions of law-abiding North Americans are physically addicted to caffeine—a potent central nervous system (CNS ) stimulant—and aren't even aware of it. When deprived of their "fix," such addicts often experience severe withdrawal symptoms. These may include depression, throbbing headaches, disorientation, constipation, nausea, sluggishness, and irritability. And, as with other addictive drugs, heavy users often develop a tolerance, and require even higher doses to obtain the desired effects.

Other negative effects of caffeine include a dramatic increase in the rate of oxygen use by cells, muscle tension , stomach acid secretion,  and blood pressure—as much as 14% when taken in the form of two to three cups of coffee.  Caffeine has also been implicated as a possible contributing factor in birth defects and fibrocystic breast disease. (In fact, extremely large doses are potentially fatal.)

In spite of its potency, caffeine has only one medical use: the treatment of poisoning by CNS depressants. In fact, if caffeine were a newly synthesized drug, its manufacturers would have great difficulty getting it licensed for sale. And if it were licensed, it would certainly be available only by prescription.

Yet more than two billion pounds of coffee are consumed in this country each year. And caffeine is also found in teas, cola drinks, chocolate, and many over-the-counter "medicines."

A Case of Caffeinism

People's reactions to caffeine differ greatly, but an intake above one's Individual limit—whatever that may be—produces "caffeinism," a condition with symptoms indistinguishable from those of anxiety neurosis: extreme nervousness, irritability, tremulousness, chronic muscle tension, difficulty falling asleep, trouble sleeping soundly, sensory disturbances, increased frequency of urination, frequent loose stools, gastrointestinal upsets, and those alarmingly strong and rapid heartbeats that are known as palpitations.

However, in spite of caffeine's harmful effects, a researcher who recently reviewed the medical records of 100 randomly selected psychiatric outpatients found that not a single form contained any information about the person's tea or coffee habits, although 42% of the records made mention of anxiety symptoms. (One wonders just how many tranquilizer prescriptions have been handed out to clients suffering from undiagnosed caffeinism ... a condition that's estimated to affect up to 15% of all Americans.)

Most surveys of U.S. coffee drinkers agree that about 25% consume at least five cups of coffee per day, a caffeine dose of 500-600 milligrams (mg.). Various researchers have used values ranging from 200 mg. to 750 mg. of caffeine per day as presumed "danger points," above which one is assumed to be at a high risk of caffeinism. (Since the drug's effects depend on both dose and body weight, a young child who drinks one cola may experience the same problems—irritability, irregular heartbeats, insomnia—as does an adult who has four cups of coffee.)

A lethal dose of caffeine for a healthy, adult male is approximately 10 grams, the equivalent of 80-100 cups of coffee, but—because our bodies can break down caffeine and excrete it rapidly—deaths from overdoses of the stimulant are virtually unknown.

However, both moderate and heavy coffee drinkers can experience withdrawal symptoms if they go without caffeine for 24 hours. For most people, the first sign of deprivation is a headache that may develop as early as 18 hours after their last "fix." It typically begins with a feeling of cerebral fullness and progresses to a diffused, painful throbbing that's frequently made worse by exercise ... but is, of course, relieved by drinking coffee or tea, or taking a caffeine-containing pain remedy such as Anacin, Vanquish, Excedrin, etc.

Special Caffeine Risks

The caffeine equivalent of five to six cups of coffee per day has been shown to increase the risk of birth defects in laboratory animals. One recent study showed that, among women who exceeded 600 mg. of caffeine per day, only one in 16 had a normal delivery. The other 15 pregnancies ended in spontaneous abortion, stillbirth, or premature birth.

An Ohio State researcher found that many women with fibrocystic breast disease (benign breast lumps) could shrink or eliminate the cysts by cutting caffeine from their diets. In fact, in 65% of the women observed, these problems disappeared completely within two to six months after giving up the drug.

Studies on the correlation between caffeine and heart problems are in conflict, but until this controversy is settled, it would seem wise for people with heart disease or high blood pressure to confine their caffeine intake to low levels.

Watch Your Habit

Though caffeine can be a useful tool at times, many people who decide to reduce or eliminate this substance altogether experience an improvement in the quality of their lives. Here are some things to keep in mind when trying to determine just how great a role caffeine plays in your life:

Most folks tend to substantially underestimate their caffeine intake ... so try maintaining a log to learn how much you really consume.

Remember that reactions to this drug are extremely variable. Some people can't touch it, while others ingest substantial amounts without undesired results. Also, an individual's response can change over time.

If you decide to eliminate caffeine, consider tapering off. If you stop "cold turkey," you may experience a headache or morning drowsiness for as long as a week. (One way to cut back is to mix decaffeinated coffee half and half with your regular brew. Tea can also help a heavy addict taper down, as the average cup of the beverage contains less than half the caffeine of brewed coffee.)

Consider, too, using nonliquid coffee substitutes. Many say that caffeine helps "get them going" ... but a short morning run, 15 minutes of yoga, or a brief meditation session may have the same positive effect without any of the negative ones.

At any rate, experiment with your caffeine intake. Consider, perhaps, going for a week without coffee to see how it feels. One friend who recently did just that decided afterward to use caffeine only occasionally.

"I feel I'm so much more in control of my life ... even emotionally! " she explained. "Before, I was always rushing. Now I'm moving at my proper pace. It's so nice to wake up in the morning without the need to drink something in order to function."

In 1976, Tom Ferguson—then a fourth-year medical student at Yale—launched a magazine called Medical Self-Care, which he hoped would serve as "a Whole Earth Catalog of the best medical books, tools, and resources." 

Tom spoke of his plans for the publication and of his conviction that self-care could raise the general level of health in this country and lower our inflated levels of medical spending in a MOTHER EARTH NEWS interview, and left no doubt that he would work toward making those "dreams"come true.

Well, Tom Ferguson is Doctor Ferguson now, and the medical self-care "movement" has flourished. People are beginning to assume more responsibility for their own well-being and are eager for information that will help them take better care of their bodies.

So in an effort to provide just such very necessary data, MOTHER EARTH NEWS offers this regular feature by Tom Ferguson, M.D.