Surgeon general warns of link between alcohol consumption and cancer risk

The U.S. Surgeon General issued an advisory on Friday warning of a link between alcohol consumption and cancer risk.

Consuming any type of alcohol, including beer, wine or spirits, increases the risk for at least seven different types of cancer, including breast cancer for women, as well as cancers of the colorectum, esophagus, larynx, liver, mouth, and throat, U.S. Surgeon General Dr. Vivek Murthy wrote in a post on X, announcing the release of the advisory.

Alcohol consumption is the third leading preventable cause of cancer in the United States, after tobacco and obesity, according to the surgeon general's advisory.

For some cancers, including breast, mouth, and throat cancers, the risk of developing cancer may increase at one or fewer drinks per day, the advisory states.

A person's risk of developing cancer due to alcohol consumption is also determined by other factors, including biological, economic, environmental and social.

"Alcohol is a well-established, preventable cause of cancer responsible for about 100,000 cases of cancer and 20,000 cancer deaths annually in the United States - greater than the 13,500 alcohol-associated traffic crash fatalities per year in the U.S. - yet the majority of Americans are unaware of this risk," Murthy said in a statement. "This Advisory lays out steps we can all take to increase awareness of alcohol's cancer risk and minimize harm."

Despite a growing body of evidence, fewer than half of American adults aged 18 and older recognize alcohol consumption as a risk factor for cancer, according to the advisory.

"I think that it's been better popularized in the lay press and publications with regard to smoking's effects on cancer, but the effect of alcohol's risk becomes more better known, based on the [advisory] of the surgeon general," Dr. Howard Ross, a colorectal cancer surgeon and chair of surgery at Hackensack Meridian Health North in New Jersey, told ABC News.

Ross pointed to past articles that have suggested one glass of red wine a day can help protect against certain types of heart disease.

"The data that came out and is increasingly coming out, and is now being popularized, flies in the face of that," he said. "So, it's very challenging for people to know what to do."

About five more women out of 100 and three more men out of 100 would develop cancer by consuming two alcoholic drinks per day on average, compared to those who drink less than one drink per week, Murthy shared on X.

There are four mechanisms, or ways, by which alcohol can cause cancer, according to the advisory. The first is by alcohol breaking down into acetaldehyde, a chemical compound that damages DNA and can increase the risk of cancer.

The second mechanism is alcohol leading to oxidative stress, which occurs when there is an imbalance of free radicals and antioxidants in the body, according to the Centers for Disease Control and Prevention (CDC). This can increase inflammation as well as damage DNA and proteins, all of which increases the risk of cancer, the surgeon general's report states.

Alcohol can also alter the levels of multiple hormones, such as estrogen, which increases the risk of breast cancer, according to the report. The fourth mechanism by which alcohol consumption can increase cancer risk is by leading to a greater absorption of carcinogens, which are substances that cause cancer. Carcinogens dissolve in alcohol and subsequently are more easily absorbed by the body.

The surgeon general's advisory warns Americans to be aware of the relationship between alcohol consumption and increased cancer risk as people consider whether they should drink or how much to drink. It also "calls for a reassessment & revision of the guideline limits for alcohol consumption to account for increased cancer risk," Murthy posted on X.

Murthy further suggested updating the current warning label on alcoholic beverages to include a warning about cancer risk, similar to the warning included on packages of cigarettes.

The current government warning label on alcoholic beverages has not changed since 1988. It warns of the dangers of consuming alcohol during pregnancy because of the risk of birth defects. It also warns that alcohol impairs an individual's ability to drive a car or operate machinery, and that it "may cause health problems."

Congress would need to pass legislation in order to update the label on alcoholic beverages to add Murthy's suggested warning about a link to cancer.

Additionally, the surgeon general's advisory recommends that public health professionals, health care providers, and community groups and organizations highlight alcohol consumption as a cancer risk factor and increase general awareness of that risk among patients, including performing alcohol screenings and treatment referrals, if needed.

"I think the recognition that there is a risk of alcohol intake is an important piece of knowledge for people to have, and that people's behavior will be based on their weighing the risk versus the benefit," Ross said. "I think more knowledge is always good, and transparency is very important so that people can make educated choices."

The National Institute on Alcohol Abuse and Alcoholism provides a list of places to find help if you or someone you know has an alcohol abuse or other addiction challenge.

ABC7 Chicago's Lissette Nuñez contributed to this report.