When you take the first sip of alcohol, it goes straight to your stomach. It skips digestion to be directly absorbed into the bloodstream. Your body is 55-60% water and being soluble in water, alcohol can travel to different parts of the body quickly. The rate of absorption depends on the alcohol content of the drink- higher the content, faster is the absorption and the presence of food in the stomach- alcohol absorbs faster on an empty stomach. It travels to your kidneys, lungs, heart, muscles, skin, and liver. The liver breaks it down into a toxic material called acetaldehyde  which is subsequently cleared away by the body. Once it reaches the kidneys, it makes them produce more urine, leading to dehydration .
How does alcohol affect the brain?
Your brain receives a rich supply of blood. Alcohol from the blood can easily enter the brain within 6 minutes of consumption .
- It affects all areas of the brain  starting from the front part which is responsible for judgement, reasoning, and self-control. Thus, lowering your inhibition, giving you “liquid courage.” This happens after you have had 1-2 drinks.
- Once you have had 3-4 drinks, heightened emotions like pleasure, sadness, euphoria, etc are experienced. This is because it affects the emotion and memory areas of the brain, increasing emotional responses and making it hard to remember information. Alcohol prevents the transfer of information from short term storage to long term storage in the brain. After a night out, you might struggle to remember the events of the prior night.
- After 4-6 drinks, the brain area responsible for movement, coordination, and balance, is affected causing you to stumble and mumble.
- It further affects the part of the brain that maintains your heartbeat and body temperature, lowering both.
- By the time you have had 6 drinks, your entire brain is affected by alcohol. Depending on the amount and frequency of intake, alcohol can induce long term and short term effects.
Alcohol disrupts your brain chemicals
The connection of alcohol and mental health stems from its effect on brain structures and chemicals. Alcohol affects the excitatory and inhibitory brain chemicals. These brain chemicals need to be maintained in the perfect balance to ensure optimal transport of brain signals. Alcohol affects functioning of the relaxing brain chemical called GABA. When GABA is released, it prolongs its effect in the brain, adding to the drowsiness effect [5,6]. It also blocks the excitatory brain chemical called glutamate, preventing the activation of brain cells. This also affects learning and memory .
Alcohol promotes release of dopamine, the pleasure and reward chemical. Dopamine plays a major role in motivation and contributes to encouraging further drinking to experience the initial “feel good” effect of alcohol. Even a small volume of alcohol can trigger dopamine release and induce persistent intake .
Hangover: what happens the morning after
Intake of 3-8 drinks can induce a hangover the next morning, which can last up to 3 days. The number of drinks that can cause a hangover vary with gender, ethnicity, medication, tolerance, body weight, speed of drinking etc . Symptoms like headaches, nausea, fatigue start when the alcohol level in the body diminishes. Hangovers are a result of complex reactions in the body, including dehydration, brain chemical balance disruption, inflammation . The severity of a hangover can be eased by consuming less and spacing out your drinks.
Alcohol’s end product, acetaldehyde promotes oxidative stress in the body. When acetaldehyde accumulates faster than it can be cleared, more harmful products are created that are part of the oxidative stress process. Protective compounds that neutralise these are called antioxidants and can be found in berries, nuts, dark chocolate and green tea. These can help reduce the effects of a hangover .
Other ways to ease your hangover is to get sufficient good quality sleep and increase hydration levels. The only sure way to avoid a hangover is to abstain from drinking. Even among heavy drinkers, brain repair and blood flow improved within 2 weeks of abstinence .
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