Can Alcohol Cause Cancer?

Alcohol and Cancer Risk

Many people have heard that alcohol can help prevent cardiovascular disease, however, it can also have a harmful effect in increasing cancer risk. Risk of cancer depends on the type of cancer and the amount of alcohol consumed. Many studies define daily alcohol consumption as one of multiple categories: light drinking (1-2 beverages), moderate drinking (1-4 beverages), and heavy drinking (more than 4 drinks). It is important to remember that the recommended alcohol limit is 2 drinks per day for men, and 1 drink per day for women. For women, this is especially concerning because the risk of breast cancer increases with just 10 grams of ethanol (12.5 grams of ethanol is a standard drink). There is also no safe limit established for alcohol and the risk of cancer in tissues in the upper gastrointestinal tract (esophagus, etc.). Moderate alcohol consumption may also increase the risk of other cancers, such as those in the larynx, liver, and colorectum. Binge drinking is also a concern because it has no proven benefit. Binge drinking is defined as 4 or more drinks per day for women and 5 or more for men.

Why would alcohol cause cancer when it may help prevent cardiovascular disease? One reason for the increased risk of cancer in association with alcohol intake is the ability of alcohol to increase estrogen levels in the blood, which may lead to estrogen receptor-positive breast cancer. In addition, cancer is also a free radical and known carcinogen and as it is metabolized, it is broken into more carcinogens. Alcohol may also act on other carcinogens and cause them to wreak havoc on cells and DNA. Alcohol, when consumed in excess, may also cause oxidative stress, or inflammation, in the body which increases cancer risk. And, of course, genes play a role, although further research is needed to identify which genes may affect alcohol’s impact on cancer.

So how much alcohol presents a benefit and how much presents a risk? Research shows that one drink per day to one drink per week may benefit cardiovascular health, but more than one drink per day may start to decrease benefits and increase risks of other diseases. One drink is defined as 14 grams of ethanol, or 5 ounces of wine, 12 ounces of beer (5% alcohol), or 1.5 ounces of 80 proof liquor. Of course, not all beer is 5% alcohol, and not everybody chooses 80 proof liquor so serving sizes change when the alcohol concentration changes. Serving glasses also have different sizes, hence it is important to keep in mind that a 16 ounce glass of beer may appear to be one serving but is actually more, or that wine glasses may present in different sizes in different restaurants. Lastly, although wine is sometimes viewed as a health halo and is considered a component of the Mediterranean diet (which can have beneficial health effects), it still poses the same cancer risk as other types of alcohol when it is not consumed in moderation.

Alcohol is only one factor in cancer risk and prevention. It is important to remember that some types of cancer are at an increased risk with just a very small amount of alcohol, while others are at an increased risk with moderate or heavy intakes. There is no difference in the type of alcohol consumed, but the amount consumed is important. The limit for women is one drink per day and the limit for men is two drinks per day, although the Dietary Guidelines for Americans does not recommend any person to begin consuming alcohol.

Centers for Disease Control and Prevention (2018). Facts sheet – Alcohol use and your health. Retrieved from: https://www.cdc.gov/alcohol/fact-sheets/alcohol-use.htm.

Collins, K. (2018). Alcohol consumption and cancer risk – The other side of a health halo. Today’s Dietitian 20(4). Retrieved from: http://www.todaysdietitian.com /newarchives/0418p34.shtml.

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