What does alcohol really do to your body?

Natalie Louise Burrows, Nutritionist and Clinic Director at Integral Wellness

A glass of wine at dinner. A cocktail with friends. Alcohol is one of the most socially accepted drugs in the world, often used to relax, celebrate, or simply mark the end of a long day (or the middle of a tough one). But beneath its cultural charm, alcohol has a wide-ranging impact on the body, and many of these effects begin long before a hangover sets in.

From the brain to the gut, from your mood to your metabolism, alcohol interacts with nearly every system in the body. This blog is going to be a #sorrynotsorry kinda blog, as I share what alcohol really does, from occasional drinks to regular consumption, so you can make empowered, informed choices about how it features in your life.

Ready?

The liver

Your liver plays a central role in metabolising alcohol; prioritising its breakdown above food, nutrients, and even medications. One of alcohol’s byproducts, acetaldehyde, is highly toxic and contributes to inflammation and cell damage.

Long-term, frequent drinking can lead to fatty liver, hepatitis, and eventually cirrhosis. Even moderate consumption has been linked to increases in liver enzymes and fat accumulation. Importantly, the liver also plays a key role in regulating blood sugar, cholesterol, and hormone metabolism, functions that can all become impaired when alcohol is regularly in the mix.

The gut

Bloating? Changes in toilet habits? Alcohol disrupts the gut barrier, making it more permeable (often referred to as “leaky gut” but I prefer gut permeability, as it’s recognised medically). If the gut barrier is more permeable there is a greater chance of endotoxins and pathogens entering the bloodstream. This can trigger widespread inflammation, immune activation, and, you guessed it, digestive discomfort.

It also reduces the diversity of the gut microbiome, killing beneficial bacteria and encouraging the growth of less beneficial, more problematic, strains. These changes in the gut are increasingly being linked to mood disorders, metabolic issues, and immune dysfunction.

Metabolic health

Alcohol is metabolised as a priority fuel, which means fat burning, glucose metabolism, and nutrient absorption are temporarily sidelined. It’s the reasons blood sugars aren’t always affected with alcohol, because the liver stops releasing glycogen (stored sugar) and prioritises detoxifying alcohol instead. It also disrupts insulin sensitivity and increases fat storage, especially around the abdomen.

Need to eat more the day after a late night? That’s because alcohol interferes with appetite regulation, reducing leptin (satiety hormone) and increasing ghrelin (hunger hormone), leading to overeating. Over time, this contributes to weight gain, visceral fat accumulation, and a greater risk of type 2 diabetes and metabolic syndrome.

The heart

The idea that red wine is “good for the heart” comes from older studies suggesting moderate drinkers had better cardiovascular outcomes. But newer research, especially with better controls, shows that even low to moderate alcohol intake raises blood pressure, heart rate, and the risk of atrial fibrillation (approximately 1.4 million people have atrial fibrillation).

Alcohol also damages the lining of blood vessels and contributes to oxidative stress. Rather than protecting the heart, regular drinking may be placing it under silent strain.

The brain

Alcohol acts quickly on the brain, altering levels of neurotransmitters like GABA (which calms brain activity) and dopamine (which stimulates pleasure). These chemical shifts are why alcohol can initially feel relaxing or euphoric. But the effects are temporary and the aftermath is more complex.

In the short term, alcohol impairs coordination, reaction time, memory and decision-making. Over time, regular alcohol use may shrink brain volume and increase the risk of depression, anxiety, and cognitive decline. What’s often used to numb stress can actually worsen the body’s ability to handle it.

Cognitive decline

Newer studies have challenged the notion that only heavy drinking affects the brain. Even moderate alcohol use has been associated with reduced grey matter volume and increased risk of dementia.

The brain is particularly sensitive to inflammation and oxidative stress, both of which are amplified by alcohol. The cumulative impact over years can alter memory, learning, and emotional regulation.

Sleep, mood and mental health

Alcohol is often seen as a sleep aid but while it may help you fall asleep faster, it disrupts the quality and architecture of your sleep. It suppresses REM sleep (the most restorative phase) and increases nighttime wakefulness, dehydration, and cortisol release.

This leaves you feeling groggy, anxious, and irritable the next day, even after a modest amount of sleep. Over time, alcohol lowers serotonin levels and can fuel low mood, anxiety, and poor stress resilience.

So, should I stop drinking?

This isn’t about demonising alcohol or suggesting you should never drink. It’s about awareness. Alcohol’s effects are dose-dependent and cumulative, so even small reductions in intake can significantly benefit your long-term health.

If alcohol is part of your lifestyle, consider:

• Having alcohol-free days each week - or alcohol free weeks!
•  Drinking with food to slow absorption
•  Staying hydrated and nourishing your gut and liver through your diet
• Tuning into your mood and sleep patterns post-drinking to assess what’s right for you

Your body works hard to keep you going and remain in homeostasis (a state of biochemical balance). Understanding how alcohol interacts with your biology helps you make choices that support, and don’t sabotage, your health.

Although I’m #sorrynotsorry for this info reveal, I hope this helps you feel more in control of your health journey. Whatever decisions you make, own it!