Alcohol is the third leading cause of cancer in the United States, yet less than half of US citizens polled are aware of its link to cancer, according to the US Surgeon General.

To mitigate this, the warning labels on alcoholic beverages should be updated to include the risk of cancer, advised Surgeon General Dr Vivek Murthy this week.

By 2019, almost 100,000 cancer cases in the country “were related to alcohol consumption including 42,400 in men and 54,330 in women”, according to the Surgeon General’s advisory on alcohol and cancer issued this week. 

Breast cancer accounted for the “largest burden of alcohol-related cancer in the US”, with an estimated 44,180 cases in 2019, according to the advisory. This was 16.4% of the total breast cancer cases for women that year.

Cancer of the colorectum, oesophagus, liver, mouth (oral cavity), throat (pharynx), and voice box (larynx) are also linked to alcohol consumption. 

There are around 20,000 annual alcohol-related cancer deaths – significantly higher than the approximately 13,500 alcohol-associated traffic crash deaths. Only tobacco consumption and obesity cause more cancer than alcohol.

“The more alcohol consumed, the greater the risk of cancer. For certain cancers, like breast, mouth, and throat cancers, evidence shows that this risk may start to increase around one or fewer drinks per day,” the advisory notes.

Almost three-quarters of US citizens (72%) reported having at least one alcoholic drink a week (2019-2020).

According to the World Health Organization’s (WHO) global status report on alcohol and substance use disorders, based on 2019 data from 154 countries, in the region of the Americas, Canada (21.5) and the USA (20.8) topped the list of alcohol consumption.

Those living in the vast WHO European region, which includes Russia, consumed the most alcohol – 9.2 litres of pure alcohol per person annually. The Region of the Americas, which includes North and South America and the Caribbean, followed with 7.5 litres.

But in a 2019 survey, only 45% of people in the US were aware of the relationship between alcohol consumption and cancer risk.

‘Extensive evidence’

There is extensive evidence from biological studies that ethanol (the pure alcohol found in all alcohol-containing beverages) causes cancer in at least four distinct ways, according to the advisory.

First, alcohol breaks down into acetaldehyde in the body. This causes cancer by binding to DNA and damaging it. 

Alcohol also generates “reactive oxygen specie”s, which increase inflammation and can damage DNA, proteins, and lipids in the body through a process called oxidation. 

Third, alcohol alters hormone levels (including estrogen), which can play a role in the development of breast cancer. 

Fourth, carcinogens from other sources, especially particles of tobacco smoke, can dissolve in alcohol, making it easier for them to be absorbed into the body, increasing the risk for mouth and throat cancers. 

The World Health Organization (WHO) has said that there is no safe level of alcohol consumption, calling for global action to combat the consumption of alcohol and and narcotic drugs.

Mitigation of risk

In  order to reduce alcohol-related cancers in the US, the Surgeon General recommends updating the warning labels on alcoholic beverages to include the risk of cancer and making the labels “more visible, prominent, and effective”.

He also suggests reassessing recommended limits for alcohol consumption based on the latest evidence on alcohol consumption and cancer risk.

Other suggestions include stronger and more educational efforts to increase general awareness that alcohol consumption causes cancer, informing patients of their risks and promoting alcohol screening, intervention and treatment referral.

Image Credits: Stanislav Ivanitskiy/ Unsplash, US Surgeon General, US Surgeon-General.