Alcohol is a drug with two stories. There’s one story of feeling relaxed after a glass of wine and another of being unconscious after a bottle. There’s one story of feeling social after a margarita and another of feeling reckless after tequila shots. There’s one story of feeling alive and in the moment at sunset and another of feeling nothing at all by sunrise.“Alcohol is an interesting drug because the distance between the dose that causes a small buzz and the dose that can kill you is not very big,” says Aaron White, a neuroscientist with the National Institute on Alcohol Abuse and Alcoholism. “A little bit can be good for your heart, relaxing and part of a healthy lifestyle … but as soon as you go past those few drinks, it’s a different drug. The risk of cancer goes up, the risk of injuries goes up, and of course, blackouts and overdose deaths go up.”
Drinking too much can be dangerous. When you reach .08 blood alcohol content you cannot legally drive anywhere in the U.S. and .1 BAC is the point when people start throwing up.
Blood Alcohol Content Levels
Let’s stumble through that short span between buzzed and blitzed by looking at the amount of alcohol present in your blood stream, which is referred to as your blood alcohol content.
- .05 BAC: This is about the point at which you actually feel the effects of alcohol, or as White puts it, when you have “a nice little buzz.” Typically after a drink or two is when you feel more relaxed, social and maybe disinhibited. “These are the things most people seem to look for in the effects of alcohol,” White says.
- .08 BAC: At this point, it’s illegal to drive in all 50 states. “Not a single skill you use to drive is still functioning at 100 percent” White says. According to the U.S. Centers for Disease Control and Prevention, this is the point when it gets tougher to balance and your reaction time slows.
- .1 BAC Here’s where some people begin vomiting and become emotional, perhaps by getting combative, White says. You also might start to slur your speech around .1, according to the CDC. Get ready for a rough night or early morning.
- .15 BAC: This is around when you experience major loss in muscle control and balance, states the CDC. Blackouts tend to happen at this point, too, White says, “and beyond that, it’s just everything getting worse until you die.”
- .35 BAC: This point is referred to as the “lethal dose 50,” White says, meaning that about half the people who get this drunk will die. About 10 drinks in two hours would get a 140-pound female to around .35, while about 13 drinks in two hours would do the same for a 160-pound male.
Your Brain on Booze
Another way of looking at the effects of alcohol is by examining the parts of your brain it suppresses as you progress from happy hour to party to after-party:
- Frontal lobes: These parts of your brain, which “help you make decisions – good decisions – and control your urges,” become increasingly suppressed as you drink, White says. So after a few drinks, you might tell a co-worker how you really feel about him, or indulge in a midnight slice of pizza (or five). As you continue to drink, the effects may become more serious. “If you suppress [the frontal lobes] enough, then it becomes risky sex, jumping off a roof into a swimming pool and drinking more alcohol,” White says.
- Amygdala: This part of the brain warns us of danger and makes us feel afraid, worried and anxious. “One of the reasons that people seem to like alcohol is that it takes the volume of the amygdala and cranks it down,” White says. He gives the example of planning to have only a drink or two, because you have class or work in the morning. “But then you have your two drinks, and you’re like, ‘Hey, I’m not so worried about work anymore,’” he says. The hushing of the amygdala turns more dangerous as people become really drunk; they can feel fearless as their abilities to make decisions and control impulses weaken.
- Hippocampus: Here’s the part of your brain that makes memories. If you become really drunk really fast – say, with concentrated alcohol on an empty stomach – the alcohol can swamp the memory circuits before your brain has time to adjust. The result? A blackout, when the hippocampus is shut off or significantly suppressed. “In essence, you’re going through life, but it’s not being recorded, because those circuits have been knocked offline,” White says.
These three parts of the brain become “seriously suppressed” at about .15 BAC, White says. Then, “death happens when areas of the brainstem deep down in the base of your skull get turned off.” These “kill switches” are the reflexes that control breathing, keep the heart beating and recognize when something is clogging the airway. White explains why alcohol is so deadly: “Even if you don’t get killed in an accident or hurt somebody, if you go too drunk, you can just drop dead.”
Warning Signs of an Overdose
While there may seem like relatively few steps between tipsy and totaled, there are often plenty of warning signs of danger along the way. Look out for these clues in yourself and among your friends:
- Slurred speech, impaired balance and trouble focusing: At this point, someone is in the “danger zone,” White says. “If you can, cut them off, get them home and separate them from alcohol.” Monitor your friend for more severe signs, too, because you don’t know if his or her alcohol level is on its way up or down. White also says it’s a “recipe for disaster” to continue drinking after vomiting, which is your body’s way to reject a poison.
- Vomiting, slowed or irregular breathing, trouble remaining conscious or bluish skin color: “Once you’ve gotten to these signs, you should really stop even considering how to help your friend and get help,” White says. Call 911. For more information on alcohol overdose, see the National Institute on Alcohol Abuse and Alcoholism website.
Preventive Measures
Of course, it doesn’t have to get to these terrifying levels. You can still have a good time at the bar without later feeling miserable (or worse) at the hospital. White suggests a few tried-and-true steps for staying safe:
- Eat before your drink: “The amount of alcohol that hits your brain after you drink will be almost a third lower if you’ve got a meal in your stomach,” White says.
- Snack while you drink, and alternate nonalcoholic drinks with alcoholic beverages: These are two more ways to slow the alcohol absorption process.
- Know how much you’re drinking. Review this chart of what constitutes one drink, and downing a dozen in two hours to get to that “death zone” of .35 BAC may not seem so crazy. One shot, for example, is one drink’s worth of alcohol. Do the math, and three mixed drinks with a few shots in each, and you’re chipping away toward a near-deadly dose of alcohol.
- Make a plan, and share it: Before drinking, decide how much you plan to drink and commit to taking these safety steps. White suggests sharing the plan with the other people you’re going out with and agreeing to look out for each other.