Alcohol and Cancer Risk

Just last January, the US Surgeon General released a new advisory on alcohol consumption and cancer risk. Dr. Vivek Murthy concluded that alcohol use is a leading preventable cause of cancer. This is not a new concept. More than three decades ago, reputable studies concluded that alcohol causes certain cancers, including the oral cavity, oropharynx, hypopharynx, esophagus, colon, rectum, liver, bile duct, larynx, and female breast.

Alcohol works in four ways to cause cancer:

• It breaks down into acetaldehyde, which damages DNA.

• It induces oxidative stress, increasing the risk of cancer by damaging DNA, proteins, and cells, and increasing inflammation.

• It alters levels of multiple hormones, including estrogen, which can increase breast cancer risk.

• It leads to greater absorption of carcinogens. Carcinogens dissolve in alcohol, alcohol alters cells in the mouth, and then carcinogens become more easily absorbed.

The cancer risk appears to be dose-related. About five additional women in 100 and about three additional men in 100 may develop cancer due to consuming two drinks per day. Note that there is no minimum amount to increase risk, and that the risk rises as consumption increases. In addition, the risk of alcohol-related cancer is influenced by our genes; specifically, the genes that encode enzymes involved in breaking down alcohol.

The Surgeon General has now recommended that health warning labels be updated on alcoholic beverages. (Ireland and South Korea had already imposed similar mandates.) As might be expected, alcohol producers have strongly opposed the introduction of mandatory cancer warning labels, and it is likely that they will oppose these new warning labels as well.

So now you know: Alcohol has been shown to be a leading cause of cancer, with no lower threshold of consumption. The general population, and frankly, even health care professionals, appear to be only slowly learning this. Warning labels may be an appropriate way to educate consumers, and allow all of us to make our own informed decisions.