Caffeine: the bitter truth
It can boost your mood and energy level -- if you don't mind being mildly addicted.

About 80% of all adult Americans take in caffeine every day, usually in coffee. Caffeine is the most popular psychoactive drug in the world. "Caffeine is a classic stimulant, producing feelings of increased energy and well-being, decreased sleepiness, more talkativeness and sociability, and a better ability to concentrate," says Roland Griffiths, Ph.D., a prominent caffeine researcher at Johns Hopkins University School of Medicine.

Caffeine also is mildly addictive. If you take in caffeine regularly, you're apt to feel lousy if you don't get your fix. Here's the latest scientific word on caffeine:

It's OK for most. For most people, as drugs go, caffeine is relatively benign, says Griffiths. It's certainly not life-threatening, as are excessive alcohol, cocaine and smoking. But its effects vary with individual biology, and some people are more sensitive. Restrict caffeine if you have anxiety, insomnia, panic disorder, heart arrhythmias, tachycardias or palpitations, or if you are pregnant, Griffiths advises. Some experts also say avoiding caffeine can lower blood pressure.

Small-dose impact. One mere cup of tea can speed up mental functioning, according to British research. Subjects showed faster response times on mental tests within minutes of drinking a cup of caffeinated tea, compared with drinking decaffeinated tea. In other British research, a cup of tea (or coffee) in the morning, early afternoon and early evening preserved alertness and good mental functioning throughout the day, compared with drinking plain water.

Addiction risk. More than half of regular caffeine users are apt to suffer withdrawal symptoms if they quit abruptly, says Griffiths. Surprisingly, he finds, you can experience withdrawal after giving up only one cup of coffee a day. His new research also finds that you can get hooked after only three consecutive days of consuming 300mg a day.

Children are vulnerable, too, declare researchers at the University of Minnesota. For two weeks, every day, 8- to 12-year-olds were given the caffeine in three to five soft drinks. Then the caffeine was suddenly cut off. Within 24 hours, the children had a deterioration in mood and mental performance. They had slower reaction times and shorter attention spans. The withdrawal symptoms lasted two weeks.

Withdrawal headaches. Without a caffeine fix, most regular users suffer mild to severe withdrawal headaches within 12 to 36 hours. Also common: sleepiness, depression, even nausea and flulike symptoms. Some people, says Griffiths, become "crippled" without caffeine. Withdrawal symptoms generally last a few days to a couple of weeks. If you cut down on caffeine, do it gradually over a week or so, Griffiths advises. Taking in as little as 25mg daily can ward off withdrawal headaches, he finds.

Caffeine vs. cancer? There's little evidence that caffeine promotes cancer, except possibly bladder cancer. On the contrary, recent Japanese research suggests that caffeine alters hormones in ways that may reduce the odds of breast cancer. New research in Switzerland has found coffee drinkers have a 27% lower risk of developing colon cancer. A study at Harvard suggested four to five cups of coffee a day reduced the risk of colorectal cancer by 24%.

TIPS

Surprise
Coffee ice cream and coffee yogurt also contain caffeine ranging from 30mg to 85mg per cup, says the Center for Science in the Public Interest.

Gallstones: Coffee reduces risk in women

Good news for coffee lovers: Researchers report that women who drank four cups of coffee a day reduced their risk of needing gallstone surgery by 25%. And women who drank five or more cups were even less likely to need gallstone surgery.

The brewing method made no difference, researchers say, but the coffee had to be the real thing, with caffeine. Decaf didn't cut gallstone risk at all for participants in the long-term Harvard Nurses Study. And coffee didn't have the same gallstone effect on men.

Caution: Experts aren't encouraging women who don't already drink coffee to start, nor are they giving a license to drink it by the quart. Past studies on coffee's health effects have been inconclusive, but the American Medical Association has concluded that moderate coffee drinking is OK.

Coffee: A new health drink?

Are you ready? Coffee, not known as a health tonic, is now hailed for its wide-ranging health benefits.

Here's what you need to know:

Heart Saver: A large new Harvard study found no increased heart attacks in longtime coffee drinkers. More remarkable: Coffee may save lives. Women ages 55 to 69 who drank 1 to 3 cups a day were 24% less likely to die of heart disease than non-coffee drinkers, says a new analysis of the Iowa Women's Health Study of 27,000 women. Indeed, their odds of dying from any cause during the study decreased about 15%.

Liver Protector: Coffee, even in very low doses, appears to protect the liver. Kaiser Permanente researchers found less cirrhosis in heavy alcohol users who also consumed coffee. Drinking less than a cup a day cut risk of cirrhosis by 30%, and 4 or more cups cut it by a remarkable 80%, compared with drinking none.

Diabetes foe: Drinking lots of coffee slashed risk of type 2 diabetes in recent studies. At Harvard, men drinking 6 or more cups of caffeinated coffee every day had half the risk of type 2 diabetes as non-coffee drinkers. In women, 6 or more cups daily cut risk by 30%. Even decaf cut odds somewhat.

Parkinson's fighter: Coffee drinkers are about one-third less likely to develop Parkinson's disease, say Harvard investigators. Italian research found a steeper drop of 80%.

Still, researchers don't recommend guzzling more coffee, because it can be harmful to some, promoting headaches, insomnia, anxiety and even heart attacks in individuals who are especially suspectible to caffeine. For specific advice, consult your doctor.