A review article on alcohol and cancer in the Journal of the American Medical Association shows that alcohol at any dose can increase risk for cancer (Jan 7, 2020;323(1):23-24). Compared to non-drinkers, people who take one or two drinks per day for one year are at increased risk for cancer (Cancer, December 9, 2019), and drinking even one glass of wine a day raises the risk of cancer of the throat, esophagus, liver, colon, rectum or breast (Addiction, Jul 21, 2016). The more you drink, the greater your risk for developing these cancers. Alcohol has also been associated with cancers of the skin (Am J Clin Nutr, Nov 2015;102(5):1158-66), prostate and pancreas. A review of 27 studies showed that taking up to two drinks a day is associated with a 23 percent increased risk for prostate cancer (BMC Cancer, Nov 5, 2016). A review of 222 scientific papers that followed 92,000 light drinkers and 60,000 non-drinkers showed that taking just one alcoholic drink a day is associated with increased risk for cancer of the mouth and throat, esophagus and breast (Annals of Oncology, Feb 2013; 24(2):301-308). Thirty-seven percent of North American adults take one or two drinks a day. Several studies show that mouth, throat and liver cancer patients who stop drinking have a reduced chance of recurrence of their cancers compared to those who continue to drink.
The World Health Organization and the American Institute for Cancer Research recommend not drinking any alcohol. A review of more than 700 studies involving millions of people in 195 countries found that “No level of alcohol consumption improves health” (Lancet, Sept 22, 2018;392(10152):987-988). A review of 83 prospective studies showed that alcohol is also associated with increased risk for stroke, heart failure, fatal hypertensive disease, and fatal aortic aneurysms; and the more alcohol you drink, the more likely you are to die prematurely (Lancet, 2018;391(10129):1513-1523). The United States Public Health Service says that alcohol kills more than 88,000 people in the United States each year, and shortened the lives of those who died by an average of 30 years. Alcohol also causes one in 10 deaths among working-age adults aged 20-64 years, and the health damage it causes costs $223.5 billion, or about $1.90 per drink.
Alcohol Industry Tactics
The alcohol industry downplays the cancer risks of their products in the same way that the tobacco industry did 70 years ago. A study from the London School of Hygiene and Tropical Medicine and Sweden’s Karolinska Institutet analyzed the websites of almost 30 alcohol industry organizations between September and December 2016 and found that most showed incredible “distortion, denying, distraction and misrepresentation” of evidence associating alcohol with cancer, specifically the abundant data of alcohol’s association with breast and colon cancers (Drug and Alcohol Review, September 7, 2017).
The alcohol industry claims that moderate drinking is safe, yet 30 percent of all alcohol–related deaths are caused by cancer, with 60 percent of these deaths from breast cancer. One third of these deaths were associated with an average of fewer than two drinks a day (Drug Alcohol Rev, June 16, 2016).
Moderate Drinking Has Not Been Shown to Help Prevent Heart Attacks
For many years the wine, beer and alcoholic beverage industries have promoted studies showing that a drink or two of alcohol can help to prevent heart attacks, yet drinking alcohol regularly is associated with high blood pressure, heart failure, strokes and sudden death. In the studies cited by the alcohol industry, more than half of the people in the “non-drinker” groups were recovering alcoholics or people who had been told to stop drinking because they had already suffered from diseases related to drinking, such as liver, heart or kidney disease, high blood pressure, heart attacks, certain cancers, alcoholism, or stomach ulcers (J Stud on Alc and Drugs, March 2016;77(2):185–198). When people with alcohol-related diseases were removed from the abstainer control groups, the data showed that moderate drinkers did not have a lower incidence of heart attacks than the non-drinkers.
Researchers at the University of Victoria in British Columbia reviewed 54 studies and found that only seven of those studies had corrected their non-drinking population for people who had been told to stop drinking for health reasons (Addiction Research and Theory, April 2006). The Canadian researchers re-analyzed 47 studies that associated wine or other alcohol with a longer life and decreased risk for heart attacks. When the studies were corrected to remove the people who had been ordered to stop drinking for health reasons, they found no advantage in death rate between moderate drinkers and those who did not drink at all. Another study from England followed 53,000 men and women over 50 for 6-10 years and found that alcohol consumption had no demonstrable health benefit and did not reduce risk of death during the study period (British Medical Journal, February 10, 2015).
People who take in just one drink a day are at significantly increased risk for an enlarged upper heart and irregular heartbeats called atrial fibrillation that can cause clots and strokes, compared to non-drinkers (J Am Heart Assoc, Sep 14, 2016;5:e004060), and abstaining from alcohol use reduces the incidence of irregular heartbeats in people who have atrial fibrillation (N Engl J Med, Jan 2, 2020; 382:20-28).
How Alcohol Can Lead to Cancer
Alcohol can damage every cell in your body. Your liver is the only organ that can break down significant amounts of alcohol, and it can typically break down less than an ounce in an hour. The alcohol is first converted to acetaldehyde, which is even more damaging to your cells than alcohol. Acetaldehyde can cause cancer by damaging DNA and stopping your cells from healing from this damage. The highest risk for alcohol-induced cancer is in your mouth and throat because some bacteria there are able to convert ethanol directly into acetaldehyde. Alcohol damages cells to produce Reactive Oxygen Species (ROS) that can alter DNA to cause cancer. Alcohol reaches the colon, rectum and liver later, so the link between these cancers and alcohol is not as strong.
Other Unhealthful Habits Increase Cancer Risk from Alcohol
Smoking, being overweight, eating an unhealthful diet or not exercising all markedly increase risk for alcohol-related cancers. The risk for cancers of the mouth, throat and esophagus is much higher if you both drink and smoke than if you use either alcohol or tobacco alone, and the more you drink and smoke, the greater your risk (Int J Cancer, 2011;128:533-540).
Alcohol Increases Risk of Permanent Liver Damage
Drinking alcohol regularly increases risk for permanent liver damage called cirrhosis (Journal of Hepatology, January 26, 2015). Wine is associated with a lower risk for liver damage than beer or liquor. The authors of this study warn that older drinkers are more likely to have health conditions affected by alcohol or to take medicines that impair their ability to metabolize alcohol.
Definition of a Drink
In all of the studies and reports mentioned here, a “drink” is defined as the amount that takes an average person’s liver one hour to clear half the alcohol from the bloodstream. However, this can vary with body weight, sex, age, metabolic rate, recent food intake, the type and strength of the alcohol, and any medication you take. Typically, one drink contains 0.6 ounces (14.0 grams or 1.2 tablespoons) of pure alcohol, the amount found in:
• 12 ounces of beer (5% alcohol content)
• 8 ounces of malt liquor (7% alcohol content)
• 5 ounces of wine (12% alcohol content)
• 1.5 ounces of 80-proof liquor (40% alcohol content, e.g., gin, rum, vodka, whiskey)
Many people have the mistaken belief that it is safe for women to take up to one drink per day and for men to take up to two drinks per day. Almost 30 percent of North Americans drink more than that. The studies I have listed in this article and many more have never shown that any amount of alcohol is “safe” or beneficial. Whatever you decide about your own consumption of alcohol, do not base your decision on bad information from the alcoholic beverage industry.