Kate Heddleston

For some unknown reason (I was hungover) I decided to research how alcohol affects the body. I wanted to know exactly what happens from the moment you drink the alcohol to the moment (22 hours later) when the alcohol is gone. There's some good news and some bad news. First, the good news: alcohol is good for you, just like broccoli! The bad news: alcohol can kill you. For all you hungover souls out there wondering exactly what you did to your body last night, last weekend, or all four years of college here it is. If you manage to make it through the article, you even get some helpful tips on what not to mix with alcohol and how to cure a hangover.

You drink alcohol

That's a stomach tennis court, in case you were wondering. You'll understand in a minute.

Let's start at the beginning: for those of you unaware of how to consume alcohol, you drink it. You should only DRINK alcohol, not try to put it into your body through any other method than your digestive system. I can’t believe I have to say this but emergency room stories seem to warrant a clarification. Alcohol is a poison and your digestive system is really the only part of your body even remotely prepared to handle it.

Once you’ve poured your favorite concoction of poisonous liquids into your stomach it’s absorbed through the stomach lining and small intestines. The small intestine absorbs alcohol much faster than the stomach because it has 250 square meters of surface area (about the size of a tennis court) whereas your stomach only has about 800 square centimeters of surface area. So you have an entire tennis court tucked and folded into the bottom part of your abdomen. Crazy.

Your stomach has a valve

There’s a valve between your stomach and the small intestine that closes whenever food is present so that your body absorbs the nutrients you're digesting more slowly. This is why eating a meal with your drink slows down the absorption of alcohol - it closes that valve so alcohol is absorbed through the stomach rather than the small intestine and your BAC rises more slowly [12].

Whenever people talk about something “getting you drunk faster” it usually has to do with whether this valve is open or closed. When food is in your stomach the valve closes and slows down absorption. Carbonation forces food and liquid out of the stomach into the small intestine [1]. Alcohol mixed with sugar, like a rum and coke, is treated like food so the valve closes [6]. Alcohol mixed with artificial sweeteners, like rum and diet coke, is not recognized as food so unless other food is present the valve stays open and alcohol is absorbed faster.

It goes to your liver

Jaques from Finding Nemo. Best line: "Voila, he is clean!"

Your liver is your body’s personal OCD crustacean (if you don’t get the reference, watch this clip here). Among other things your liver cleans the things you digest and is on high alert for poisons that come through your system. So when it sees alcohol it hits the emergency alarm button and drops everything else that's going on. Specifically it halts glucose production in order to deal with the alcohol poison apocalypse you just ingested.

Stopping glucose production means that while your body is detoxing from alcohol your blood sugar levels are slowly dropping. If you have one or two drinks and eat a meal this is no problem since the liver returns to glucose production once it’s done processing the alcohol. However, a night out binge drinking means that for the five or six or however many hours you’re drunk your blood sugar is slowly, steadily dropping. Low blood sugar the morning after drinking is the part of the hangover that makes you feel nauseous, and it’s way worse than the headache from dehydration [4]. This is why eating that box of macaroni and cheese on the kitchen floor at 2am actually makes you feel better the next day. Once your body finishes with the alcohol it can use that food to replenish blood sugar and stave off hangover nausea [6].

Alcohol Dehydrogenase (ADH)

The metabolic process the body uses to deal with alcohol is oxidation, which is the extent of my understanding of organic chemistry. The first enzyme needed for this process is alcohol dehydrogenase (ADH); this is the enzyme that breaks down alcohol into acetaldehyde by removing a hydrogen molecule from the alcohol. ADH is present in your body starting in the stomach, but most of the work gets done in the liver. Depending on your weight, size, race, gender, or religion (JK) you may have more or less ADH naturally occurring in your body. For example, women have less ADH than men regardless of weight, size, or race [3]. People of Native Northern American descent can have very low to no ADH, which slows down alcohol metabolization and increases the risk of alcoholism.

Alcohol Something Dehydrogenase 2 (ALDH2)

The second step requires ALDH2, which turns acetaldehyde into NADH. Some people have a harder time metabolizing alcohol even though they have an abundance of ADH because they have less than normal amounts of ALDH2. What happens is this: the ADH works as it should and turns the alcohol into acetaldehyde. However, since there's less ALDH2 to process the acetaldehyde it builds up in the body. This sucks because acetaldehyde makes you feel way sicker than alcohol. Insufficient ALDH2 is more common among people of Chinese or Japanese descent, and it's marked by a characteristic physical manifestation which is redness in the face [9].

Some fun facts about ADH production: As men age they tend to produce less ADH than when they are younger, meaning that older men have less of a tolerance for alcohol than their younger selves [4]. Age doesn’t seem to affect women’s production of ADH. Frequent or heavy drinkers produce more ADH (this is how you build a tolerance to alcohol) and therefore don’t get drunk as quickly on the same amount of alcohol. However, people with liver damage produce less ADH than normal, impairing the ability to process alcohol.

Most people know the general rule of thumb that your body can process one drink an hour, which is .5oz of pure alcohol, 6-12oz of beer, 5oz of wine, or 1oz of hard alcohol. However, when you drink more than that per hour here’s where the alcohol goes next.

It goes to your heart

Once alcohol in the blood stream reaches the heart (about 5 minutes after consumption) it reduces the amount of force behind each pump [3]. Thus, each heartbeat pushes less blood through your body. Your blood vessels relax and your blood pressure goes down for a little while. Alcohol also thins the blood making it easier to pump. Thinning the blood and lowering blood pressure is actually a good thing for a lot of people and drinking moderately is linked with significant decreases in heart disease.

You breathe it out

After reaching the heart alcohol travels through your pulmonary vein into your lungs where a small bit of it leaves your body every time you exhale [3]. Thus the effectiveness of the breathalyzer test in determining blood alcohol levels.

You sweat it out

After reaching your lungs the alcohol goes back to your heart and out through the aorta. As it permeates your blood stream it causes blood vessels to open up along the way. This makes you look flushed and feel warmer. At this point tiny amounts of alcohol start to ooze out your pores so your sweat smells like whatever you’ve been drinking. Delightful. There’s nothing like the smell of last night’s alcohol coming out your pores at the gym the next morning. So ladies trying to deter men at the bar from hitting on you - there’s no need for a fake wedding ring. Just drink a lot of beer and eat a lot of garlic (which also sweats out your pores), then build up a nice musk and you’ll be left alone all night.

It floods your brain

Now that alcohol has caused a ruckus in the rest of your body it floods your brain. Alcohol slows down your brain by altering levels of neurotransmitters [2]. It does this in two ways. First, alcohol suppresses the release of glutamate; glutamate increases brain activity and energy levels. Second, it amplifies the effects of an inhibitory neurotransmitter called GABA, which slows things down in your body and reduces energy levels. Valium and Xanax increase the production of GABA which results in sedation, and alcohol has a slightly similar effect in this regard. The result of reducing glutamate and amplifying GABA is that you slow down; your thought process, speech, coordination, and texting abilities all suffer.

Next up alcohol causes your brain to unleash its stores of dopamine, the feel good hormone that is released when good things happen (or when you do drugs like coke or meth). This is the root cause of all the excessive “wooh-ing” and dancing during your night out. However, when a neurotransmitter/hormone like dopamine is artificially released by drugs or alcohol it depletes your body’s stores and you can feel more depressed the morning after drinking. For most people this isn’t a problem, but for anyone who has issues with depression, drinking can trigger low or depressed states that are hard to recover from.

Alcohol affects four parts of your brain: the cerebral cortex (thought processing and judgement), cerebellum (movement and balance), hypothalamus and pituitary (hormone release, sex drive and sexual performance), and the medulla (breathing, consciousness, and body temperature) [13]. It also reduces your brain’s production of antidiuretic hormones, which causes your body to slough more water making you pee more. This is what generally leads to dehydration [3].

Hangovers

By the time you wake up the next morning, you’ve spent an entire evening with your body in emergency poison control mode. Glycogen production has been halted so your blood sugar levels are very low. You’ve been peeing like crazy all night so you’re dehydrated [5]. Alcohol interrupts REM sleep [11] so you wake up feeling tired. Your dopamine is depleted so you’re a little bit sad. And to top it all off you’re probably a little embarrassed that you danced on the bar last night or told your least favorite family member exactly what you think of them. At this point you need a high carb, high fat meal, tons of water, a nap, and some friend therapy and reassurance that everyone else was too drunk to notice your embarrassing behavior. Why do we do this to ourselves again?

Mixing Drugs

A few fun facts about mixing drugs with alcohol [4]. For unknown reasons, Aspirin prevents ADH from working effectively so you stay drunk longer and can’t process as much alcohol. Cayenne pepper dilates the blood vessels which leads to a higher BAC and more alcohol reaching the brain, so you feel drunker and act dumber. Tylenol is really rough on your liver, so taking tylenol with alcohol is like a one-two punch to your liver - not a great idea and you don’t have any more fun so you should probably just skip that combo. Mixing alcohol with any other depressants, like antihistamines or sleeping pills, is always a bad idea because depressant plus depressant equals double depressant and potentially eternal sleep. Finally, mixing alcohol with caffeine has the effect of making people feel more sober so they drink more alcohol than they would have otherwise [7].

Physical Dependence

Should you drink significant amounts of alcohol regularly you can become physically addicted. Because of the way that alcohol affects your brain a cold-turkey withdrawal can actually kill you, which is relatively rare for drugs. It’s the reason why ERs need alcohol IVs but not heroin IVs for addicts going through withdrawal [14].

Remember GABAs and how alcohol amplifies their sedative effects? Your body adapts to prolonged use of alcohol by altering the regulation of GABA receptors which changes your overall brain chemistry. When someone physically addicted to alcohol stops drinking the brain freaks out. This can lead to seizures, tremors, hallucinations, insomnia, nausea, anxiety, and autonomic instability (yeah, that’s the part of the nervous system that controls automatic things like breathing).

Alcohol is like Broccoli!

Now that you know the depressing ways alcohol can affect your body (pun intended), here's the great news about our favorite little poison. Alcohol is actually good for you, just like broccoli. One of the reasons that broccoli is good for you is because it contains a little bit of cyanide, which is poisonous to the human body. Crazy, right, that broccoli is healthy because it's poisonous! This little bit of cyanide works to keep our liver and other poison removal systems on their toes. It's a little bit like scaring your cat to make sure he remains alert and vigilant for predators. This is only true, however, if you drink alcohol in moderation. Drowning your body with poison just exhausts and ruins it, but a little bit every day or every week is good.

Additionally, in the long term, moderate drinking can decrease the risk of heart disease in men and women because of how it thins blood and lowers blood pressure. About one drink per week for women and one drink a day for men greatly reduces the risk of heart disease [7]. Finally, if that isn’t enough good news, red wine can also help keep you skinny by preventing the creation of fat cells [8]. Red wine consumption is one of the reasons scientists think French people can eat more fatty foods and stay slimmer than Americans. In conclusion, drinking in moderation keeps your body functioning properly, staves off heart disease, and keeps you skinny.

What happens when you drink alcohol?

AKA What exactly did I do to my body last night?

January 02, 2015