The Science of the Sauce: What Happens to Your Brain When You Drink Alcohol?

The consumption of alcohol directly influences specific processes of the brain, the command center of the body, which results in feeling inebriated. Breaking down the science of being buzzed, Regina Krel, M.D., headache medicine specialist at the Headache Center at the Neuroscience Institute at Hackensack University Medical Center, shares an inside look at what happens to your brain when you drink, as well as the side effects afterwards.

Scientifically speaking, what’s happening in your body as you’re getting “drunk?”

“Once you start consuming alcohol, your liver begins breaking it down. An enzyme called alcohol dehydrogenase is responsible for breaking down alcohol to acetaldehyde and that is then further broken down to acetic acid,” notes Dr. Krel. “Getting drunk occurs when you consume alcohol faster than you can break it down.”

What are the effects of consuming alcohol?

“Alcohol is a depressant to our bodies. Some of the visible symptoms you are used to seeing in someone who’s drunk – slurred speech, loss of coordination, falling, loss of inhibition, passing out – all of these side effects are a result of our brain cells communicating at a slower rate,” explains Dr. Krel.

Dopamine Release

The initial euphoric effects of alcohol are a result of dopamine being released from the reward center in the brain.

• Dopamine is known as the “feel good” neurotransmitter and it is involved in feeling pleasure.
• Dopamine release is also thought to be one of the mechanisms that drive addiction. 
• In addition to dopamine, drinking alcohol initially releases serotonin which is another neurotransmitter involved in feeling happy and calm.

Slower Brain Response

“Alcohol also increases the effects of GABA, an inhibitory neurotransmitter. By increasing the effects of GABA, responses in the brain are decreased – this slowed neurotransmission results in slurred speech,” identifies Dr. Krel. “Our limbic system is involved in emotional responses, which is also slowed by alcohol, resulting in the loss of inhibition experienced while getting drunk.”

Lack of Coordination

You may notice an inebriated person stumbling, or having difficulty walking straight – this is because the part of your brain that controls coordination, the cerebellum, is very sensitive to alcohol. Passing out or sleepiness is also another side effect. The reticular activating system is an area in the brainstem that controls consciousness, alcohol can dampen this system.

Increased Urination & Dehydration

Alcohol also blocks vasopressin, a hormone that prevents our kidneys from eliminating too much fluid. This can increase the need to urinate and precipitate dehydration. Dr. Krel also mentions, “Contrary to popular belief, getting drunk reduces sexual responses.”

What is a hangover?

A hangover occurs during and after the overconsumption of alcohol.

Dr. Krel notes, “The actual mechanism of what happens during a hangover is still not clear but is thought to be a result of the toxicity of acetaldehyde on the body, changes in electrolytes, dehydration, and low blood sugar. The most common symptoms during a hangover include headache, nausea, dizziness, feeling sleepy or sluggish.”

What are the short and long-term effects of alcohol use on your brain and body?

The short-term effects of consuming excess alcohol can result in:

• lapse of judgment
• loss of coordination
• nausea
• vomiting
• blacking out
• slurred speech
• impaired memory

Prolonged use of alcohol is toxic to neurons and can result in neuron death.

• Continued use of alcohol can cause atrophy of the cerebellum – a shrinkage of the brain. This results in ataxia, a degenerative disease of the nervous system, which is irreversible.

“Since alcohol consumption impacts the hippocampus, the part of the brain involved in memory formation, overuse can result in memory impairment,” Dr. Krel warns. “Alcohol is also toxic to the nerves outside of the brain and the nervous system which can result in the loss of sensation of your hands and feet, known as neuropathy.”

Outside of the nervous system, alcohol can permanently damage the liver and result in liver cirrhosis.

• This will prevent the body from clearing toxins.
• The liver also produces clotting factors which is responsible for bleeding cessation. With a damaged liver, clotting factors are decreased and bleeding risk is increased.

If you have a dependency on alcohol, it is important to seek professional help.

• Abrupt withdrawal from alcohol can cause seizures.
• Wernicke- Korsakoff syndrome can occur in patients with prolonged alcohol use and is a result of Vitamin B1 (Thiamine) deficiency.  The syndrome is characterized by confusion/encephalopathy, abnormal eye movements/changes in vision, and ataxia or loss of coordination; Korsakoff syndrome is a psychosis that can ensue and if left untreated, can be fatal.

How do we know if it is a hangover, or something more serious?

“Medical attention should be sought during prolonged periods of vomiting because that can result in dangerous electrolyte abnormalities and severe dehydration. You should also seek help if there are signs of alcohol poisoning; symptoms include decreased or irregular breathing, decreased heart rate, decreased body temperature, stupor, or seizures,” recommends Dr. Krel.

For non-emergent situations, most hangovers will pass with time, rest, hydration and Advil for headache relief. Dr. Krel warns that Tylenol is not recommended to treat headaches related to alcohol use, “It also metabolizes in the liver and can result in liver toxicity/failure which can be serious.”

“To mitigate some of the effects of alcohol and prevent or lessen your hangovers, it’s recommended to limit your alcohol intake, drink water in between drinks, and try to eat foods with a high fat content to decrease alcohol absorption,” guides Dr. Krel.

Next Steps & Resources:

• Meet our source: Regina Krel, M.D.
• To make an appointment with Dr. Krel or a headache specialist near you, call 800-822-8905 or visit our website.
• Learn more about headache and migraine treatments available throughout Hackensack Meridian Health. 

The material provided through Health Hub is intended to be used as general information only and should not replace the advice of your physician. Always consult your physician for individual care.