ALCOHOL

About 90% of high school seniors have tried alcohol. Nearly a third report drinking heavily (more than 5 drinks in a night) in the past 2 weeks.

Found in: Beer, wine, liquor.

Source: A variety of organic substances including grapes, berries, potatoes, sugars, corn, and grains-all left to ferment.

Legal code: Legal if you are over 21.

History: Alcohol has been around for thousands of years, used both recreationally and as part of religious ceremonies. Some of the earliest known writings include references to drinking. In the Middle Ages, alcohol was thought to be able to cure almost every health problem.

Effects: Many people feel a sense of well-being, self-confidence, and stimulation while drinking. This feeling is often replaced by drowsiness and sedation as the alcohol leaves the body. Alcohol dulls awareness, reflexes, and judgment. Alcohol is absorbed very quickly into the blood from the stomach, in as short a time as 5 to 10 minutes. The effects can last for several hours depending on the amount, how quickly it was drunk, and the body size of the drinker. A few studies have reported that drinking in moderation (a glass of wine a day) can actually be healthy.

Risks: Dangerous overdoses are possible when people drink a lot of alcohol very quickly. This type of overdose is most common in younger (especially college-age) drinkers. Drinking on an empty stomach is particularly dangerous. If someone passes out and can't be woken up or seems to have trouble breathing, call for help immediately. An unconscious person may literally choke on his or her own vomit. Moderate drinking can cause hangovers, including headaches and nausea. Excessive drinking can compromise memory, abstract thinking, problem solving, attention, and concentration. It can also cause loss of appetite, vitamin deficiencies, stomach ailments, skin problems, sexual impotence, liver damage, and damage to the heart and central nervous system. Alcoholism and drunk driving ruin many lives every year.

Risks for women: Women get drunk faster than men: after drinking the same amount of alcohol, a woman's blood alcohol level may be 25 to 30 percent higher. This is in part because women are smaller. More significantly, women produce less of the enzyme that metabolizes alcohol, alcohol dehydrogenase, so a greater percentage of the alcohol consumed goes directly into a woman's bloodstream. This means that women are more vulnerable to the negative effects of alcohol, in both the short and the long term. Women are more prone to liver damage from excessive alcohol. After drinking the same amount as a man, a woman's ability to determine the safety of a situation (Can I drive? Should I have sex with him? Do I have to use a rubber?) is also more compromised. The more alcohol a woman drinks, the higher her chances are of being sexually assaulted. Birth control pills slow down the rate at which alcohol leaves the body. Alcohol can cause serious and permanent damage to an unborn fetus. If you think you may be pregnant, do not drink! Some studies suggest that women who have three to nine drinks per week are more likely to develop breast cancer than women who don't drink at all. This research is very preliminary, but women who do decide to drink should pay attention to it and any forthcoming breast cancer studies.

Risks for teens: Since your brain does not finish developing until you are 20, it may be more vulnerable to alcohol's damaging effects than mature brains. Genetic risks: Children and siblings of alcoholics are estimated to have a seven times greater chance of becoming alcoholics than children and siblings of nonalcoholics. (The males in a family are more prone to these genetic risks.) If you have a close relative who is an alcoholic, it is extra-important to make smart decisions about drinking.

Do not combine with: Any other downers. Each downer increases the other's effects. Two or more downers taken together can be extremely dangerous and even deadly.

Addiction rating: Medium (high if you have a genetic predisposition toward alcoholism).

Drinking and driving: If you decide to drink, be responsible and don't ever drive drunk! Legally, if you're caught driving with a .08--.10% blood alcohol concentration (the exact percentage differs by state), you may be arrested and charged with DWI (driving while intoxicated). You also jeopardize your own life, and the lives of anyone else on the road.