Alcohol is a known carcinogen. This means that alcohol causes cancer. There is strong evidence that drinking alcohol increases people’s risk of cancers of the female breast, liver, mouth, throat (pharynx and larynx), oesophagus and bowel. Heavy drinking may also increase people’s risk of stomach cancer.
How does alcohol cause cancer?
- Alcohol causes 7 different types of cancer.
- It’s alcohol itself that causes damage to your body – the type of alcohol you drink doesn’t matter.
- Whatever your drinking habits, cutting down will reduce your risk of cancer.
What’s my cancer risk from drinking alcohol?
Drinking alcohol increases the risk of cancer. Drinking alcohol doesn’t mean that you’ll get cancer, but the risk is higher the more alcohol you drink.
People might talk about some alcoholic drinks being better or worse for you than others. But all types of alcohol increase the risk of cancer – as it’s the alcohol itself that causes damage, even in small amounts.
So the more you can cut down on alcohol the more you can reduce your risk of cancer.
Drinking less alcohol has lots of other health benefits, too. You can reduce your risk of accidents, high blood pressure and liver disease by cutting back.
There are many ways that alcohol can cause cancer. Some of the main ways are:
- Damage to cells. When we drink alcohol, our bodies turn it into a chemical, called acetaldehyde. Acetaldehyde can damage our cells and can also stop cells from repairing this damage.
- Changes to hormones. Alcohol can increase the levels of some hormones in our bodies such as oestrogen and insulin. Hormones are chemical messengers, and higher levels of oestrogen and insulin can make cells divide more often. This increases the chance that cancer will develop.
- Changes to cells in the mouth and throat. Alcohol can make it easier for cells in the mouth and throat to absorb harmful chemicals that cause damage.
Remember, it’s the alcohol itself that damages your body, even in small amounts. It doesn’t matter whether you drink beer, wine or spirits. All types of alcohol can cause cancer.
There are plenty of tricks that people claim ‘cure’ hangovers. But even if they work for your hangover, they don’t reverse the damage caused by drinking alcohol.
Alcohol and breast cancer
Breast cancer is the most common cancer and drinking alcohol is one of the biggest risk factors for breast cancer. Around 1 in 10 breast cancer cases are caused by drinking alcohol, that’s about 4,400 cases a year. The risk of breast cancer is increased even if you drink at low levels.
Head and neck cancer: Moderate to heavy alcohol consumption is associated with higher risks of certain head and neck cancers. Moderate drinkers have 1.8-fold higher risks of oral cavity (excluding the lips) and pharynx (throat) cancers and 1.4-fold higher risks of larynx (voice box) cancers than non-drinkers, and heavy drinkers have 5-fold higher risks of oral cavity and pharynx cancers and 2.6-fold higher risks of larynx cancers. Moreover, the risks of these cancers are substantially higher among persons who consume this amount of alcohol and also use tobacco.
Oesophagal cancer: Alcohol consumption at any level is associated with an increased risk of a type of oesophagal cancer called esophageal squamous cell carcinoma. The risks, compared with no alcohol consumption, range from 1.3-fold higher for light drinking to nearly 5-fold higher for heavy drinking. In addition, people who inherit a deficiency in an enzyme that metabolizes alcohol have been found to have substantially increased risks of oesophagal squamous cell carcinoma if they consume alcohol.
Liver cancer: Heavy alcohol consumption is associated with approximately 2-fold increased risks of two types of liver cancer (hepatocellular carcinoma and intrahepatic cholangiocarcinoma).
Colorectal cancer: Numerous studies have examined whether there is an association between alcohol consumption and the risk of other cancers. For cancers of the ovary, prostate, stomach, uterus, and bladder, either no association with alcohol use has been found or the evidence for an association is inconsistent. However, evidence is accumulating that alcohol consumption is associated with increased risks of melanoma and prostate and pancreatic cancers.
How does alcohol affect the risk of cancer?
Researchers have hypothesized multiple ways that alcohol may increase the risk of cancer, including
- metabolizing (breaking down) ethanol in alcoholic drinks to acetaldehyde, which is a toxic chemical and a probable human carcinogen; acetaldehyde can damage both DNA (the genetic material that makes up genes) and proteins
- generating reactive oxygen species (chemically reactive molecules that contain oxygen), which can damage DNA, proteins, and lipids (fats) in the body through a process called oxidation
- impairing the body’s ability to break down and absorb a variety of nutrients that may be associated with cancer risk, including vitamin A; nutrients in the vitamin B complex, such as folate; vitamin C; vitamin D; vitamin E; and carotenoids
- increasing blood levels of estrogen, a sex hormone linked to the risk of breast cancer
Alcoholic beverages may also contain a variety of carcinogenic contaminants that are introduced during fermentation and production, such as nitrosamines, asbestos fibres, phenols, and hydrocarbons.