Almost everyone knows that the U.S. legal drinking age is 21. However, according to the National Center on Addiction and Substance Abuse, about 80 percent of high school students have tried alcohol and report easy access to it, with 69 percent saying they got alcohol from their family members or friends.

"Deciding whether to drink is a personal choice that teens eventually have to face," explained Pediatrician Richelle Keleman, M.D. "Evidence suggests that the most reliable predictor of a youth's choice to drink or not drink is the drinkingbehavior of his or her friends. Alcohol is the number one drug of choice among our nation's youth and it can have serious, lifelong consequences."

How Does Alcohol Affect the Body?

"Alcohol is a depressant, which means that it slows the function of the central nervous system," Dr. Keleman added. "It actually blocks some of the messages trying to get to the brain, which can alter a person's perceptions, emotions, movement, vision, and hearing.In larger amounts, alcohol can cause greater changes in the brain and result in intoxication. People who have overused alcohol may stagger, lose their coordination, slur their speech and become confused or disoriented. Depending on the person, intoxication can also make someone very friendly and talkative or very aggressive and angry. When large amounts of alcohol are consumed in a short period of time, such as in the case of binge drinking, alcohol poisoning can result. Violent vomiting is usually the first symptom of alcohol poisoning, followed by extreme sleepiness, unconsciousness, difficulty breathing, dangerously low blood sugar, seizures or even death.

"Adolescents are also vulnerable to alcoholinduced brain damage, which could contribute to poor performance at school or work," she advised. "During the time of adolescence, significant changes occur in the body's hormones and the formation of new networks in the brain. Exposing the brain to alcohol during this period may interrupt key processes of brain development. In addition, youthful drinking is also associated with an increased likelihood of the development of alcohol abuse or dependence later in life. People who begin drinking before the age of 15 are four times more likely to develop alcohol dependence at some time in their lives compared with those who have their first drink at age 20 or older."

Teen drinkers are more likely to have weight and other health problems, too. One study by the University of Washington found that those who regularly had five or more drinks in a row starting at age 13 were much more likely to be overweight or have high blood pressure by age 24 than their non-drinking peers. People who continue drinking heavily well into adulthood risk damaging their organs, such as the liver, heart, and brain.

Consequences of Underage Drinking

"Underage alcohol use is more likely to kill young people than all illegal drugs combined," stated Dr. Keleman. "The immediate consequences of teen drinking are well known, including the risk of motor vehicle accidents, inappropriate sexual behavior, other substance abuse, and physical injury."

Drinking and Driving:Motor vehicle crashes are the leading cause of death among youth ages 15 to 20. "Drivers younger than 21 are more susceptible to impaired driving due to alcohol use than older drivers," said Dr. Keleman. "The rate of fatal crashes among drivers between 16 and 20 years old when alcohol is involved is more than twice the rate for those 21 and older."

Suicide: Alcohol use negatively impacts depression and stress, which contribute to suicide, the third leading cause of death among people between the ages of 14 and 25.

Sexual Assault: Sexual assault, including rape, occurs most commonly among women in late adolescence and early adulthood, usually within the context of a date. Research suggests that alcohol use by the offender, the victim, or both, increases the likelihoodof sexual assault by a male acquaintance.

HighRisk Sex: "Studies have shown that alcohol use by teens is associated with highrisk sexual behavior," added Dr. Keleman. "For example, adolescents using alcohol have a greater risk of having multiple sexual partners, sexually-transmitted diseases or unwanted pregnancy."

Teaching Kids to Say "No"

"Communicating with teenagers about their decision making is a critical aspect of parenting," Dr. Keleman said. "Talk openly with your teens about the pressures they are under to drink. If all their friends drink, it can be hard to say no, without feeling left out."

Teach kids a variety ofapproaches to deal with offers of alcohol:

- If a drink of any kindis offered, they shouldask, "What is it and where did you get it?"

- Teach themto say "no, thanks" when an alcoholic drink is offered.

- Remind them to leave an uncomfortablesituation, and make sure they havemoney for transportation or leave a phone number where a responsible adult can be reached.

- Some parents find that offering to pick up their kids from anuncomfortable situation - no questions asked - helps encourage kids to be honest and call when they need help.

Take Steps at Home

"If you drink as an adult, keep track of the alcohol in your home," Dr. Keleman concluded. "Make sure that teens don't have access to it. In addition, let your child know that underage drinking can cause not only serious health consequences for teens, but legal consequences for the person who provides the alcohol. Lastly, be a good role model. Consider how your use of alcohol or medications may influence your children. Consider offering only nonalcoholic beverages at parties and other social events to show your kids thatyou don't need to drink to have fun."