FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

CAFFEINE IS POWERFUL STIMULANT; READER NEEDS GRADUAL WITHDRAWAL

Question: My wife complains that I drink too much coffee. I drink about 10 cups a day, which I think is fine. Is this amount of caffeine harmful to my health?

Answer: Caffeine is a ubiquitous substance. It has a chemical formula of C8H10N4O2 and is found in many foods derived from plants, particularly coffee beans, tea, chocolate and most nuts. It is also an important component of many soft drinks, pain medications, as well as NoDoz and similar stimulant prepartions.

Caffeine a strong stimulant of the central nervous system is the most commonly used psychoactive drug in the world. This drug is generally safe and useful as a stimulant, and in fact, it is usually consumed principally to get that caffeine "buzz," which some think of as a "pick-me-up" or increase in mental alertness. Heavy consumption can cause nervousness, anxiety, headaches, muscle twitching, sleeplessness, diarrhea, stomach irritation, palpitations, fast heart rate and irregular heart beats. And withdrawal usually causes headache and drowsiness. Yes, it is a powerful drug! Most who consume a modest amount about 200 milligrams (mg) of caffeine a day -- only experience the mild stimulant effect and avoid the more severe symptoms.

Regardless of the food, drink, or medication that delivers it to the digestive system, caffeine is rapidly absorbed. The most intense period of stimulation occurs about one hour later, but the chemical lasts in the body a much longer time. It takes four to six hours for the body to use up half of the amount that is absorbed into the blood from that first cup of coffee, and most of a day to eliminate the rest of it, assuming that one doesn't consume more.

The average American adult consumes about 200 mg of caffeine a day. That is equal to about two eight ounce cups of regular coffee, six 12-ounce colas, or four cups of regular tea. Despite many research studies designed to find possible health risks associated with this level of use, none have been found. I guess this makes 200 mg per day a reasonable definition of "modest" consumption.

So, do you drink too much coffee? Probably. For most people, ingesting a large amount of caffeine in a short period of time, such as 400 mg in one hour, causes the symptoms excess consumption I described earlier. A constant intake, such as 100 mg every hour for 10 hours two cups of coffee to get going in the morning followed by one each hour until work is over produces more subtle symptoms. Nonetheless, 10 cups of coffee means you are ingesting quite a significant amount of this stimulant drug. I'd suggest cutting back by a rate of one cup each day until you get to no more than 400 mg of caffeine each day and preferably 200 mg. Gradually cutting back like this avoids the headache, drowsiness, and grouchy disposition that go with acute withdrawal from the drug.

The following is a brief list of the caffeine levels in common products. Use it to help judge your daily consumption.

8 oz. regular coffee. 110-135 8 oz. gourmet coffee 250

8 oz. decaf coffee 10 one bag tea 50

green tea or instant 30 1 oz. expresso 35

12 oz. cola 35 8 oz. hot chocolate 5

1 oz. dark chocolate 20 1 oz. milk chocolate 5

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.