What Alcohol Actually Does to Your Body

### Your Liver

Your liver is the organ that processes alcohol, and it takes the brunt of the damage. Every drink you have passes through your liver, which breaks down the ethanol into acetaldehyde — a toxic compound — before converting it into less harmful substances. This process generates oxidative stress and inflammation every single time.

Drink regularly and your liver never fully recovers between sessions. Fatty liver disease — where fat builds up in liver cells — can develop within just a few years of regular heavy drinking. It's often symptomless, which means you won't know you have it until something more serious develops. Left unchecked, fatty liver progresses to alcoholic hepatitis — inflammation and scarring — and eventually to cirrhosis, where the liver is so scarred it can no longer function properly. Cirrhosis is irreversible and can be fatal.

The insidious thing about liver damage is the silence. Your liver doesn't hurt. It doesn't send you warning signals until it's already in serious trouble. People drink for decades feeling perfectly fine, and then discover at a routine check-up that their liver is in a state that would have been entirely preventable.

### Cancer

This is the one that shocks people. Alcohol is a Group 1 carcinogen — the same classification as tobacco and asbestos. That's not a precautionary label. It means there is sufficient evidence in humans that alcohol causes cancer.

The cancers linked to alcohol consumption include:

• Mouth and throat (oral cavity, pharynx, larynx)
• Oesophagus (food pipe)
• Liver
• Bowel (colorectal)
• Breast
• Stomach

The risk increases with the amount consumed — there is no threshold below which the cancer risk is zero. Even moderate drinking increases the risk of breast cancer and oesophageal cancer. According to Cancer Research UK, alcohol causes around 11,900 cases of cancer in the UK each year. That's roughly 4% of all cancer cases, and most of them are preventable.

The mechanism is straightforward: when your body breaks down alcohol, it produces acetaldehyde, which damages DNA and prevents cells from repairing that damage. Damaged DNA is how cancers start. It's not complicated, and it's not controversial — it's basic biochemistry.

### Your Heart

For decades, people believed moderate drinking was good for the heart. That belief is now considered outdated at best and dangerous at worst. We'll deal with the "red wine" myth specifically below, but the cardiac picture is clear.

Regular alcohol consumption raises blood pressure. Sustained high blood pressure is one of the leading risk factors for heart attack and stroke. Even moderate drinking is associated with an increased risk of atrial fibrillation — an irregular heartbeat that significantly raises the risk of stroke and heart failure. Heavy drinking can cause alcoholic cardiomyopathy, where the heart muscle weakens and can no longer pump blood effectively.

The British Heart Foundation's position is straightforward: if you don't drink, don't start for any supposed heart benefits. If you do drink, stay within the 14-unit guideline.

### Your Brain

Alcohol is a neurotoxin. It crosses the blood-brain barrier and directly affects brain cells. In the short term, that's why you feel drunk — impaired judgement, slowed reactions, reduced inhibitions. In the long term, the effects are more concerning.

Regular heavy drinking causes measurable brain shrinkage, particularly in the frontal cortex — the area responsible for decision-making, planning, and impulse control. A major 2022 study published in Nature Communications found that even moderate drinking — one to two drinks per day — was associated with reductions in overall brain volume, and the relationship was dose-dependent: the more you drink, the more brain volume you lose.

Cognitive decline, memory problems, and increased risk of dementia are all associated with long-term alcohol use. The effects are cumulative and may not be fully reversible, even if you stop drinking.

### Your Gut

Alcohol disrupts the gut microbiome — the community of bacteria in your digestive system that plays a crucial role in immunity, digestion, and even mental health. Regular drinking reduces the diversity of beneficial gut bacteria and increases intestinal permeability — sometimes called "leaky gut" — where the lining of the intestine becomes more permeable, allowing toxins and bacteria to pass into the bloodstream. This triggers systemic inflammation, which is linked to a wide range of chronic health conditions.

Alcohol also irritates the stomach lining directly, increasing the risk of gastritis and acid reflux. Heavy drinkers are at significantly higher risk of stomach ulcers and inflammation of the pancreas (pancreatitis), which can be acutely dangerous.

### Your Weight

Here's a number that surprises people: a pint of average-strength beer contains roughly 180–220 calories. A stronger IPA or stout can be 250–350 calories per pint. These are what nutritionists call "empty calories" — they provide energy but virtually no nutritional value.

Three pints of beer is roughly equivalent in calories to a cheeseburger. Drink three pints five nights a week and you're adding around 3,000 calories to your weekly intake — enough to gain nearly a pound of body fat per week if you're not burning it off elsewhere. Over a year, that's the kind of weight gain that transforms your health profile.

The "beer belly" isn't a joke — it's visceral fat, the most dangerous type of fat, stored around your internal organs. Visceral fat is strongly associated with type 2 diabetes, cardiovascular disease, and certain cancers. It's the fat that kills, and alcohol is one of the most efficient ways to accumulate it.