I learned this today. Alcohol gets people drunk because it is a depressant and slows down the speed at which the brain can send signals.
Most alcoholic drinks contain ethanol which is produced when sugars are fermented. It naturally occurs in nature.
Humans have drunk alcoholic drinks for thousands of years. They probably started by eating fermented fruit, then graduated to making alcohol themselves. The earliest evidence of making alcohol has been found in a burial site in Israel. The site has been dated to 13,000 years ago. There is a brewery where traces of a wheat and barley-based beer have been found. Some experts have theorized that humans turned to agriculture because they wanted a way of making alcohol. They domesticated cereal crops because they wanted to make beer, not because they wanted a reliable food source. I like that idea, but I don’t know if it’s true.
What happens when you drink alcohol? Well, the ethanol is water soluble, and the molecules are small enough to pass through cell walls. At first, the ethanol is absorbed into your blood stream. This happens through the lining of your mouth and your tongue, then through your stomach and finally through your small intestines.
When the alcohol is in your blood stream, it widens your blood vessels. This causes flushes (the red face), and a feeling of warmth.
The alcohol heads to the liver where the liver does what it is supposed to do and tries to metabolize the alcohol. It uses an enzyme called alcohol dehydrogenase that breaks the alcohol down into acetaldehyde. Another enzyme, aldehyde dehydrogenase, then breaks that acetaldehyde down into acetate. The acetate is then metabolized into carbon dioxide and water. So, that is three steps to get the alcohol out of your body.
It take the liver about one hour to metabolize one unit of alcohol. There are two units of alcohol in a regular can of beer, so your liver needs two hours to clean your body of one beer. If you are drinking alcohol faster than one unit an hour, then the ethanol in your blood starts to build up faster than the liver can remove it. This is when you get drunk. The ethanol builds up in your blood and finds its way to your brain.
Your brain controls your whole body by sending electrical signals through your central nervous system. These signals pass around the brain over the neurons. Neurons have a small gap between them called a synapse and that gap is filled by neurotransmitters. There are two types of transmitters: a chemical called glutamate and an acid called gamma-aminobutyric (GABA). Glutamate basically speeds your brain up and GABA slows it down. They balance each other out. Ethanol binds with both neurotransmitters. It stops the glutamate from working, but it stimulates the GABA. This means your brain slows down and you get slurred speech, loss of coordination, loss of inhibition, blurred vision, and dizziness.
Your brain has to fire stronger signals to overcome the interference. This can last when the alcohol has left the system, causing the DTs. Prolonged heavy drinking can cause damage in the brain because the neurons end up only being able to fire at the new rate, and they burn out.
The ethanol also causes the release of dopamine. This is one of the problems with alcohol because this is the chemical your brain associates with reward and pleasure. This makes us want to drink more, causing a vicious circle.
The ethanol also suppresses vasopressin, a hormone which tells your kidneys how much water to keep or release. It causes your kidneys to release far more water and you end up having to go to the toilet a lot. You also end up dehydrated after a night of drinking.
So, alcohol makes us drunk because the ethanol in it interferes with the neurotransmitters between the neurons in our brains, slowing down the signals it can send. It also causes the release of dopamine, making us feel pleasure. And this is what I learned today.
Sources
https://www.livescience.com/10221-beer-lubricated-rise-civilization-study-suggests.html
https://www.theguardian.com/commentisfree/2018/may/16/why-does-alcohol-make-us-drunk-google
https://www.mydr.com.au/liver-and-alcohol-breakdown/
https://en.wikipedia.org/wiki/History_of_alcoholic_drinks
https://en.wikipedia.org/wiki/Ethanol
https://www.scripps.edu/newsandviews/e_20020225/koob2.html
