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Ways alcohol causes cancer

Alcohol causes at least 7 types of cancer

You probably know that smoking or spending too long in the sun can cause cancer, but it's less well known that alcohol use can increase the risk of at least seven types of cancer. Across Australia, alcohol causes nearly 3,500 cancer cases every year.

his link was first found more than 30 years ago. Yet Australian research has found the majority of Australians are unaware that alcohol causes cancer, with fewer than one in five of us aware it could cause breast cancer.

There is strong evidence that alcohol increases the risk of at least seven types of cancer, including:

  • Mouth
  • Pharynx (throat)
  • Larynx (throat)
  • Oesophagus
  • Liver
  • Breast (female)
  • Bowel

Ways alcohol causes cancer

Inside your body, ethanol (pure alcohol) is broken down into a toxic by-product called acetaldehyde. Ethanol and acetaldehyde damage cells by binding with DNA, leading to incorrect cell replication.


Acetaldehyde is toxic and can cause permanent DNA damage, which can lead to cancer (for example, in the bowel) .

  1. The liver converts most of the ethanol in alcoholic beverages we consume into acetaldeyde. Small amounts of ethanol are also broken down in the mouth and stomach.

Ethanol converts to acetaldehyde

  1. If too much alcohol is consumed the body cannot process the acetaldehyde fast enough. Acetaldehyde then builds up in the body.

Acetaldehyde build-up causes DNA damage

  1. Acetaldehyde build up can cause irreversible DNA damage, which can lead to cancer (for example, in the bowel).

DNA damage can cause cancer of the bowel, oesophagues, liver, breast, mouth, pharynx, larynx


Drinking a lot of alcohol can increase circulating oestrogen levels


Increased circulating levels of oestrogen alters structural development of mammary glands

This increase could lead to breast cancer in women through:

  1. Abnormal development of breast tissue
  2. Increased cell production and rearrangement
  3. Increased DNA damage

Increased DNA damage in mammary glands

The changes may also affect some trans and gender diverse people in terms of their cancer risk. Please talk with your GP or gender specialist for personalised advice.


  1. Consuming a large amount of alcohol alters the cells in the mouth and throat (pharynx, larynx).

Alters cells in mouth and throat

  1. Alcohol can act as a solvent, making it easier for other carcinogens such as tobacco to be absorbed into cells, leading to cancers of the mouth, throat and oesophagus.

Other carcinogens more easily absorbed

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