Alcohol is a carcinogen. This means it causes cancer. Alcohol is one of the most preventable causes of cancer after smoking. The less you drink, the lower your risk of developing alcohol-related cancer.

Each year in Ireland:

• 1,000 people are diagnosed with alcohol-related cancers.
• Alcohol causes almost 400 bowel cancers.
• Alcohol causes at least 260 female breast cancers.

Types of cancer caused by alcohol
Alcohol causes at least 7 types of cancer, including:

• Breast
• Liver
• Bowel
• Mouth
• Upper throat
• Larynx
• Oesophagus (foodpipe)

How alcohol increases your risk of cancer
Any type of alcoholic drink can increase your risk of cancer. What matters is the amount of pure alcohol you drink, not the type of drink. When alcohol is broken down in your body it can damage your body’s cells. Alcohol is converted in our bodies into a toxic chemical called acetaldehyde. This can cause cancer by damaging our DNA and stopping cells from repairing the damage.

• Alcohol can also increase the levels of some hormones, such as oestrogen. This increases the risk of breast cancer.
• Alcohol also impairs the body’s ability to absorb important nutrients that may protect you against cancer.
• Alcohol helps cancer-causing substances from tobacco to move into the body, especially to the cells lining the mouth, head and neck, and oesophagus (food pipe).

How much alcohol increases your risk
People are more likely to get cancer if they drink a lot of alcohol. How much alcohol increases your risk depends on the type of cancer.

Heavy drinking increases the risk for all the cancers caused by alcohol. The more you drink, the greater the risk.

For breast cancer, even light regular drinking increases the risk.

Cancer risk from alcohol varies for different parts of the body. The strongest association is for tissues that come into direct contact with alcohol, such as the mouth, head and neck.

The amount of alcohol you drink across your life affects your cancer risk. The younger you start drinking, the more years you drink and the heavier you drink, all matter.

Drinking in your teens and 20s does not result in a diagnosis of cancer immediately. But it increases the risk 10 to 20 years later. It will depend on how much and how often you drink.

Alcohol, smoking and cancer
If you smoke as well as drink alcohol, your risk of certain cancers is even higher. Cigarette smoke contains over 70 cancer-causing chemicals.

Alcohol makes it easier for these harmful chemicals to enter the cells lining the:

• mouth
• throat
• larynx (voicebox)
• oesophagus (foodpipe)

This greatly increases the risk of cancer developing in these areas.

People who drink and smoke are 5 times more at risk of these cancers.

Reduce the risk
Alcohol is one of the most preventable causes of cancer after smoking. You can reduce your risk of cancer if you do not drink alcohol. The less you drink, the lower your risk of cancer.

More in Alcohol and physical health

• Alcohol and blackouts
• Alcohol and older people
• Alcohol and diabetes
• Alcohol and cancer
• Avoiding alcohol-related accidents and injuries
• How alcohol affects your ability to drive
• Alcohol poisoning
• Drug interactions with alcohol
• Signs alcohol is affecting physical health
• How alcohol affects the pancreas
• Sports performance