Do you need an extra jolt in the morning to get going? Does a quick midafternoon pick-me-up seem necessary to get you through the rest of the day?
If so, you probably turn to coffee. Every day, almost 130 million Americans reach for a cup of caffeinated java, according to the National Coffee Assn., a trade organization for the coffee industry.
But it's the caffeine that perks you up, not the coffee. An alkaloid found in the leaves, seeds or fruits of more than 60 plants, caffeine stimulates the central nervous system, cardiac muscles and respiratory system. Just 50 to 100 milligrams (less than the amount found in one cup of coffee) can produce a temporary increase in mental clarity and energy.
Caffeine can also open breathing passages, improve muscular coordination for routine tasks such as typing, and increase muscle strength and endurance even as it increases the body's ability to burn fat as fuel.
*
But there are risks as well as benefits. Although the Food and Drug Administration classifies it as "generally recognized as safe," caffeine is mildly addictive. Excessive amounts can produce irritability, fatigue, headaches, heart palpitations, feelings of anxiety and sleeplessness.
And it can be found, often unexpectedly, in a variety of common foods.
Michael Jacobsen, executive director of Center for Science in the Public Interest, has petitioned the FDA to require the declaration of caffeine content on food and beverage labels. "Labeling just helps people control the amount of caffeine they consume," he says, "and also can help guide people who want more caffeine."
Especially of concern is the amount of caffeine that children and young adults are consuming. Two Cokes a day, a cup of coffee-flavored yogurt or coffee ice cream and a couple of chocolate chip cookies could bring a child's caffeine intake to over 200 milligrams--possibly starting them on the way to a caffeine addiction.
*
"While soft drink companies contend that they add caffeine to their products for flavor," Jacobsen says, "it's a great way to get them [kids] hooked on the product."
Dr. Harvey Wolinsky, clinical professor of medicine at Mount Sinai School of Medicine in New York, says sensitivity to caffeine varies, but that an adult can exhibit symptoms of caffeine dependence or habituation with regular use of 350 milligrams a day.
