By Eva Briggs, MD
On Jan. 3, the United States Surgeon General Vivek Murthy issued an advisory regarding the link between alcohol consumption and cancer risk.
An important reason for this advisory is the general lack of awareness among the general population that alcohol increases the risk of cancer.
Less than half of people know that alcohol is a cancer risk factor.
It’s the third most common preventable risk factor after tobacco and obesity.
The data is not new. It is the culmination of many studies over the past several decades.
First the definition of what constitutes a serving of alcohol. A standard drink contains 14 grams (0.6 fluid ounce) of pure alcohol. This is the amount found in 5 ounces of wine, 12 ounces of beer, or 1.5 ounces of liquor.
Previous recommendations advised that up to one drink per day for women or two drinks per day for men, was a safe limit. But the evidence now shows that drinking even at low levels imparts an increased risk for cancer.
How can alcohol cause cancer? There are at least four known ways.
• First, alcohol breaks down in the body to a chemical called acetaldehyde. This substance harms DNA. Damaged DNA can allow a cell to grow uncontrollably leading to cancer.
• Second, alcohol also produces reactive forms of oxygen leading to oxidative stress which damages DNA, proteins and cells.
• Third, alcohol alters many hormones. It increases estrogen levels which increases the risk of breast cancer.
• Fourth, alcohol dissolves other cancer-causing chemicals such as those found in cigarette smoke. It also alters the cells of the mouth and throat. This makes those toxic substances more easily absorbed, raising the chance of mouth and throat cancers.
Drinking alcohol increases the risk of seven types of cancer:
1. Mouth and oral cavity 2. throat (pharynx), 3. esophagus, 4. voice box (larynx), 5. breast, 6. liver, 7. colon and rectum
Over my career I have cared for patients with every one of these cancers.
Quitting or reducing alcohol won’t prevent all of these cancers. But all of them are so unpleasant that reducing the chance of acquiring any of these diseases is worth considering.
How significant is the risk of cancer from drinking alcohol?
The risk that a woman who drinks less than one drink per week will develop cancer in her lifetime is about 17 per 100 individuals. One drink per day increases that risk to 19 per 100 individuals and two drinks per day further increases the risk to 22 per 100 people. That means that five more women out of 100 (or one out of 20) who drink higher levels of alcohol will develop cancer during their lifetime.
For men, the risks are about 10% for those who drink less than one drink per week, to 11% for those who drink one drink per day and 13% for those who drink two drinks daily.
The surgeon general report made the following suggestions for steps to reduce alcohol-related cancers.
Update the health warning label on alcoholic beverages to warn about cancer risks. Reassess the recommended limits for alcohol consumption. Increase efforts to expand general awareness and educate the public. Inform patients during clinical encounters about the link between alcohol consumption and cancer risk.
We already know from past experience — prohibition — that making alcohol illegal is not the answer. But it’s up to us health care providers to make the public aware of these facts so that people can make informed decisions.
Eva Briggs is a retired medical doctor who practiced in Central New York for several decades. She lives in Marcellus.