The Biology of a Night Out: Alcohol and Your Body.
Have you ever been out and had a bartender say something along the lines of , “pick your poison” when you order a drink? Well, they’re not kidding; when we drink, our bodies actually think we are being poisoned.
The active ingredient in most alcohols is this little chemical, ethanol: . A small chemical with widespread effects on different parts of our bodies.
Brain: When you’re drinking, alcohol travels up and into your brain, causing two main effects…
GABA | Alcohol
Ethanol mimics a natural brain chemical, GABA, and fits right into the receptors made for GABA. Since GABA is a chemical that sends signals to block certain brain processes, when ethanol binds to those receptors, it also sends signals to block some brain
processes — just like GABA.
Ethanol also blocks a different natural brain chemical, Glutamate, which makes the brain more active. Ethanol fits into the receptor for Glutamate, but this time, instead of sending the same signals, it prevents any signal from being sent at all, so the brain can’t become more active.
Glutamate | Alcohol
GABA is also involved in the brain’s reward pathway, which is the way the brain high-fives itself after something fun happens. The high-five occurs when dopamine is deposited into a part of the brain called the nucleus accumbens (NA). Normally, GABA can block some dopamine from being deposited. But when alcohol enters the brain, it prevents GABA from doing that job, meaning that more dopamine can be deposited onto the nucleus accumbens. Read: high-five after high-five after high-five.
Why is reward important? While it contributes to the happy, light feeling that is associated with drinking, if that high-five happens too often, the brain starts to feel like it deserves the high-five, and can’t function as well without it. This is called addiction.
Body: When you’re drinking, alcohol affects the body several ways. The riskiest of these are…
Byproducts. In the stomach, small intestine and liver, natural enzyme called ADH breaks ethanol down into a toxic chemical called acetaldehyde. During binge drinking, there is an acetaldehyde “backup” because the enzyme that neutralizes acetaldehyde works slower than ADH.
Why are byproducts important? This “backup” causes high body levels of toxic acetaldehyde, which is to blame for some hangover symptoms. Women and younger people are especially vulnerable to an acetaldehyde “backup” because they naturally have less neutralizing enzyme than men and older people do. Acetaldehyde also causes some of the poor coordination, memory impairment, and sleepiness that are associated with drinking.
Spread. Ethanol is also unique because it literally floods the body. Ethanol can cross cell membranes, so during drinking, alcohol doesn’t stay just in your digestive organs. It leaches out of the digestive tract, cell by cell, and spreads across the body.
Why is spread important? This means that nearly every cell in the body has some amount of alcohol in it during drinking, and is exposed to toxic acetaldehyde. In this respect, men also tend to fare better. This is because men tend to have more muscle tissue than women. Muscle has more water than fat, so the acetaldehyde from ethanol will be diluted more in a person with more muscle tissue.
Dehydration. Ethanol also interacts with an enzyme that controls the amount of water in the body. When ethanol levels increase, they block the enzyme from being released, and the kidneys don’t get the signal to retain water.
Why is dehydration important? This is why drinking is correlated with frequent urination and the dehydration/electrolyte imbalance that is the culprit for some hangover symptoms.
For these reasons, and a few more, it is a good idea to avoid binge drinking. Most research has shown that reaching a blood alcohol concentration of 0.1% is all it takes for most people to experience these brain and body functions to a degree that causes a hangover the following day.
If you or someone you know is struggling with alcohol dependence or abuse, please reach out! Student Wellness provides free consultations to students who have concerns about themselves or a friend. The Center for Health and Wellness Promotion can support and guide you in helping yourself or a friend. Helping others and/or asking for help can be stressful and we want you to know that you are NOT alone. Call (619) 260-4618 to set up an appointment or visit University Center Room 161.