Many of us are going on trips to see family and old friends for spring break. In the process, many of you will probably be drinking alcohol.
This column is going to be half science, half public service announcement. Knowing what happens to the body and brain when you consume alcohol can inform you when the drunkenness has gone from having a good time to needing a trip to the hospital.
The kind of alcohol that you drink is more specifically called ethanol, also commonly known as grain alcohol. There are many different types of alcohol, such as wood alcohol (methanol), but most are not safe to drink.
Alcoholic drinks can be very broadly classified by whether they are fermented or distilled. When yeast metabolizes some kind of food source, ethanol is one of the byproducts. Beers come from fermented cereal grains and other starches, wines and ciders come from fermented fruit juices and meads come from fermented honey. When fermented products are distilled (making the ethanol more concentrated), the result can be whiskey, brandy, rum or vodka, depending on what the starting product was.
So, you drink alcohol and it goes down the esophagus into the stomach. The alcohol then goes into the bloodstream. How does that make you drunk, and how much alcohol does it take? The very simplified answer is that if you drink alcohol faster than your liver can process it into other compounds, you will feel the effects of drunkenness.
Let’s slow down a bit. Once ethanol is in the bloodstream, it travels through the body and eventually reaches the brain. Exactly what it does in the brain is still not fully understood, but in general it is considered a central nervous system depressant.
Blood alcohol content (BAC) is measured by the percentage of blood, by volume, that is alcohol. For example, a BAC of 0.08 percent means that 0.08 percent of that person’s blood is alcohol. If someone is driving with that BAC, they will receive a citation for driving under the influence (DUI).
Part of the problem with alcohol is that there is such a wide variation between people in how well it’s metabolized, and thus how quickly they can get drunk and how quickly they will then recover.
Body weight is usually a good indicator (it tends to take more alcohol for a heavy person to get drunk compared to a lighter weight person) but other factors include gender, other drugs that the person is taking and even how much they have eaten beforehand.
The first skills to go when people get drunk are their reasoning, depth perception and concentration. This can happen after about one to two drinks within an hour for a 120 pound individual (again, keeping in mind that I’m using very rough estimates; the amount of alcohol to reach these points can vary widely).
A BAC of 0.1 to 0.19 percent, which for a 120 pound person is between four and six drinks in about an hour, often results in slurred speech, loss of motor control, slowed reflexes and temporary erectile dysfunction. A BAC of 0.2 to 0.29 percent is when a person can have a memory blackout; 0.3 to 0.39 percent is when people tend to completely lose consciousness. At 0.4 percent and beyond, the drinker is risking coma or death.
The most important thing to remember is that falling asleep is not the same thing as passing out. A person who has merely fallen asleep will wake up if they have to vomit; a person who is unconscious will not. If a friend has passed out and doesn’t respond to you lightly shaking them, refrain from drawing penises on their faces. Instead, turn them over onto their side so that they won’t inhale any vomit. Next, call an ambulance and tell them that your friend may have alcohol poisoning: other signs to watch for include slow breathing (fewer than eight breaths per minute), cold or clammy skin and confusion.
Assuming no one has experienced alcohol poisoning, you can wake up the morning after a fun party with the last souvenir — the dreaded hangover. Hangovers are caused by a combination of factors, including the byproducts of alcohol metabolism in the liver as well as dehydration. Most hangover “cures” don’t really work other than through the placebo effect. Get some rest, drink plenty of fluids (especially if you were vomiting the night before) and lay off the booze for a few nights.
AMY STEWART can be reached at science@theaggie.org.
