Caffeine's unseen effects

If it seems to you that just about everyone you know uses some form of caffeine to jump-start their day, you're probably right: The average American consumes about 200 milligrams of caffeine daily.

While regularly drinking coffee, tea, or caffeinated soft drinks may seem like an innocuous habit, it can actually have significant long-term effects on health.

A study led by James Lane, PhD, of Duke's Department of Psychiatry and Behavioral Sciences revealed that caffeine taken in the morning raises blood pressure, heart rate, and adrenaline levels throughout the day and into the evening. In addition, says Lane, caffeine amplifies the biochemical effects of stress.

The research built on Lane's earlier findings that the caffeine contained in four to five cups of coffee sends blood pressure levels about five points higher than only one cup does. While an occasional five-point spike in blood pressure is not excessive, maintaining these elevated levels over several years is associated with a 34 percent increase in stroke and a 21 percent increase in coronary artery disease.

"Many people don't believe that there could be a health downside to caffeine consumption," says Lane. "But our evidence -- and that of other studies -- shows that this downside exists. Eliminating caffeine from the diet, or at least decreasing it substantially, could be a helpful way to decrease blood pressure and minimize long-term risk for cardiovascular illness."

Interested in easing up on caffeine? Since abruptly reducing intake can cause headaches and sleepiness, Lane suggests cutting back gradually. Lower the octane in your regular brew by mixing in decaf, or use more milk for a latte-style brew; replace your customary afternoon cola with herbal tea or juice; and don't forget to drink plenty of water.

After all, even if you have to wean yourself off your daily buzz, you may reap more days of life in the bargain.