What Does Alcohol Do?


How does alcohol affect people?


Physiologically, alcohol affects people in very similar ways. However, mood, expectations, and environment can all have a significant effect on how people react to drinking alcohol.  We’ll start with the physiology:

The intoxicating chemical in alcoholic beverages is ethanol.  Yes, you read that right- the same thing you put in your car’s gas tank.  It is absorbed into the bloodstream as it passes through the stomach and small intestine.  Alcohol is a depressant, and acts on the central nervous system to effectively slow down the body’s ability to function.  At lower levels, this results in a “buzzed” feeling.  As levels increase, the ability to make decisions, react, see clearly, remember things, or even breathe will be impaired.  A blood alcohol concentration (BAC) of 0.08 is the legal limit for intoxication, as most people will begin to see significant functional impairment at this level. To promote healthy behaviors, as well as safety, it is recommended that individuals stay under a BAC of .06 when drinking.

Alcohol is metabolized in the liver at a fairly constant rate of 0.5-0.6 oz. of ethanol per hour, or about one standard drink per hour (a standard drink is a 12 oz. beer, 4-5 oz. wine, or 1.5 oz. liquor).  Intoxication occurs when the liver is unable to keep up with the amount of alcohol consumed.  The liver will continue to work on getting rid of any alcohol in the system after an individual stops drinking.  This process may take anywhere from a couple of hours to more than a full day depending on the level of intoxication.  

If used in moderation, alcohol can be part of a healthy lifestyle.  The CDC recommends no more than two drinks per day for men, and no more than one drink per day for women to avoid the risks associated with higher levels of alcohol use. The National Institute on Alcohol Abuse and Alcoholism defines high-risk (binge) drinking as more than four drinks on any one occasion for women, and more than five drinks on any one occasion for men.

High-risk alcohol use is associated with the following:

  • Increased risk for a myriad of diseases, including cancer and liver cirrhosis
  • Injuries resulting from impaired judgment, reaction time, and motor skills
  • Increased risk for violence
  • Birth defects and fetal alcohol syndrome
  • Addiction

Psychologically, alcohol can affect people very differently.  Research has shown that expectations play a large part in how an individual will react to drinking alcohol.  In a nutshell, what you expect out of a situation has a lot more to do with how much fun you have than how much you drink.  Additionally, alcohol tends to amplify mood, so you may be able to avoid potential issues just by reflecting on your mood (and your reasons for drinking) before you start drinking alcohol.

Student Health & Wellness has a substance abuse counselor on staff if you have concerns regarding your alcohol use, or have further questions regarding alcohol and other drugs.  To make an appointment with a substance abuse counselor, call (319) 335-8394.

Student Health & Wellness Staff

Written 06/14/10

Updated 05/20/13

Source: Centers for Disease Control and Prevention: Alcohol: Frequently asked questions.