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Caffeine culture

Can't stay away from the coffee maker? Here are tips on how to limit your intake.

Not long ago I called my brother, and his wife said he was down at "that crack house" (her name for the local coffee establishment he frequents). She was speaking in jest, but it's worth examining: Can we actually become addicted to caffeine like we can to other drugs?

According to research from Johns Hopkins University published a few years ago, that may be the case for some folks. In the study, which appeared in the journal Psychopharmacology in October 2004, psychiatry and neuroscience professor Roland Griffiths led an analysis of more than 60 studies that had been published on caffeine withdrawal. And Griffiths and his colleagues made some interesting observations.

But first, what do we know about caffeine? Medical literature is filled with contradictory information regarding its effect on health. Some studies suggest that large amounts of coffee may reduce the risk of conditions such as gall bladder disease. Others show it to have a detrimental effect on things like sleep, blood pressure and bone density.

Suffice it to say, there is no clear-cut answer on what effects caffeine may have on the body's health. For now, let's look at some of the evidence on caffeine's addictive potential.

We know that caffeine is a stimulant. Stimulants elevate heart rate and blood pressure, can make us more alert and may even improve performance in certain sports. In fact, the International Olympic Committee, in its doping regulations, has in the past included caffeine on its list of restricted agents. What's more, like other stimulants, caffeine may cause a physiological dependency. That's what the Johns Hopkins researchers suggested with their study.

In their report, the researchers found five main withdrawal symptoms: headaches (the most common), fatigue, changes in mood (including depression), inability to concentrate and even flu-like symptoms. Many people had withdrawal symptoms (50% had headaches), but for most, the symptoms weren't overwhelming. However, one in eight (13%) were substantially impaired, experiencing headaches and/or other withdrawal symptoms severe enough to keep them from their normal routines.

Most withdrawal symptoms started within 24 hours of the last serving of caffeine. The symptoms peaked within the first two days and then trailed off, sometimes lingering for more than a week. A daily dose of caffeine did matter (i.e., more caffeine, more withdrawal), but some folks had symptoms when withdrawing from even small amounts.

Withdrawal headaches from caffeine make it difficult for people to quit. It's not fun to suffer when you know that a jolt of caffeine will fix the problem. Nonetheless, studies like this one reinforce the age-old adage that moderation is key.

Aim to find that happy medium when consuming any product containing caffeine. A general rule of thumb is to limit caffeinated beverages to no more than two servings daily. Still, an 8-ounce cup of coffee may contain twice as much caffeine as a 12-ounce cola, so two cups of coffee would have much more caffeine than two sodas. In spite of this discrepancy, I think it's a worthwhile rule to follow. For most folks, applying this limit to their routines will keep them from the headaches and hung-over feeling that can come with caffeinated drinks.

Tedd Mitchell, M.D., president and medical director of Dallas' Cooper Clinic, writes HealthSmart every week.

This week, Dr. Tedd appears on Laura McKenzie's "Traveler." Check your local TV listings for airtimes.