A major review of previous health studies discovered “strong evidence that alcohol causes cancer at seven sites [in the body]”.
Researchers found a particularly strong link between alcohol consumption and cancers of the mouth and throat, which they believe is caused by a compound called acetaldehyde.
Experts concluded that the more alcohol a person drinks, the more likely they are to develop cancer. However they added that even people who drink low to moderate amounts are still at risk.
It is estimated that alcohol consumption was responsible for half a million cancer deaths worldwide in 2012 alone.
For the review, published in the journal Addiction, researchers analysed a wide range of studies focused on alcohol and cancer.
They found strong evidence that alcohol causes cancer in seven areas of the body, including the:
Oropharynx (a part of the throat)
Larynx (an air passage to the lungs which holds the vocal cords)
Oesophagus (also know as the food pipe or gullet)
“The highest risks are associated with the heaviest drinking but a considerable burden is experienced by drinkers with low to moderate consumption, due to the distribution of drinking in the population,” said lead researcher Dr Jennie Connor, from the University of Otago in New Zealand, according to The Guardian.
Researchers said there was growing evidence to suggest that alcohol could cause other types of cancer too, such as prostate and pancreatic cancer, and melanoma. However they couldn’t conclude that there was a cause-and-effect relationship for these cancers.
The research found that those who drank more than 50 grams of alcohol per day (approximately six bottles of beer or two-thirds of a bottle of wine) had a four to seven times greater risk of developing mouth, throat or oesophagus cancer, compared to those who didn’t drink.
It was also associated with a 1.5 times greater risk of developing colorectal, liver or breast cancer.
It is unclear exactly how alcohol causes cancer in the different parts of the body.
Researchers do, however, have a theory that a compound which forms when alcohol is broken down by saliva, called acetaldehyde, is responsible for mouth, throat and liver cancers.
Alcohol might also be responsible for increasing levels of oestrogen in the body, which has been linked to breast cancer.
At the beginning of the year, health officials reduced the recommended level of alcohol consumption after a study suggested there was a strong link between drinking and increased cancer risk.
The new recommendations suggested that men should drink no more than 14 units of alcohol per week, bringing them in line with women’s recommended drinking levels.
Previously men were advised to consume no more than 21 units per week.
Elaine Hindal, chief executive officer of independent alcohol education charity Drinkaware, told The Huffington Post UK that roughly 3.5 million middle-aged men are drinking more than the low risk guidance of 14 units (or six pints of 4% beer) per week.
“Regularly drinking more than the government’s low risk guidelines puts you at increased risk of some types of cancer, and can also increase your risk of heart and liver disease, strokes and pancreatitis,” she warned.
“Smoking and drinking together increases your risk of developing throat and mouth cancer more than doing either on their own.”