Q. I love coffee but have heard caffeine is bad for me. Is caffeine really detrimental? What's the healthiest way to get my buzz?

A. You're not the only one keeping Starbucks in business: More than 80 percent of Americans consume caffeine daily. While it's true that the stimulant can have many unpleasant side effects, it does enhance cognitive abilities, increase feelings of well-being, and boost exercise performance and motivation to work.

But those perks come at a cost, which varies by individual and the amount of caffeine consumed. As a result of your daily fix, you may suffer from increased urination, dehydration, diarrhea, insomnia, anxiety, heartburn, irritability, increased blood pressure, and withdrawal symptoms (headache, nervousness, nausea, and tension) after 24 hours without caffeine. If consumed in excess, caffeine may also increase your risk of developing osteoporosis. Pregnant women, or those planning to conceive, should steer clear of caffeine, because it slightly increases the risk of miscarriage, preterm labor, and low birth weight—and may even make it more difficult to conceive.

If you aren't eager to give up caffeine, a small cup of coffee plain or with low-fat milk is better than caffeinated sodas or syrupy, flavored espresso drinks, which are packed with high fructose corn syrup or artificial sweeteners. Choose organic beans or brew to avoid the numerous pesticides used on conventional coffee crops. In addition, buy unbleached filters for your drip coffeemaker; otherwise chlorine will leach into your coffee.

Keep in mind the wide variations in reactions to caffeine: For most people, one to two cups daily is fine, but for others, unpleasant side effects manifest after even small amounts. As you may know, it's a good idea to skip coffee after lunch to avoid insomnia. Better yet, consider switching to tea—or use it in place of some of your daily java. Tea contains health-enhancing antioxidants as well as a modest caffeine kick (90 mg or less per cup, compared with 160 mg or less in coffee). For the most antioxidants, go with white or green tea, as both contain higher levels than black or oolong varieties. Or try yerba maté, another increasingly popular, antioxidant-rich coffee alternative, for a quick (though still caffeinated) pick-me-up.

This Q&A was written by Victoria Dolby Toews, MPH, author of the The Soy Sensation (McGraw-Hill, 2002) and The Green Tea Book (Avery, 1998).