The medical community has issued mixed messages over the years about the potential health risks and benefits of alcohol consumption, even when it comes to the impact of small amounts of alcohol on reduce stress or prevent heart disease.
But in January, the U.S. surgeon general issued a leave-no-doubt advisory warning that outlines the direct link between alcohol use and cancer risk, even for those who drink in moderation.
“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,” says U.S. Surgeon General Vivek Murthy, M.D. “This advisory lays out steps we can all take to increase awareness of alcohol’s cancer risk and minimize harm.”
Murthy is calling on Congress to update health warning labels on all alcoholic beverages¬¬ — beer, wine and spirits — to inform consumers about the link between drinking alcohol and increased cancer risk.
According to the advisory, alcohol consumption is the third leading preventable cause of cancer in the United States, after tobacco and obesity, increasing the risk for developing at least seven types of cancer. For certain cancers, including breast, mouth and throat, cancer risk may increase by drinking as little as one alcoholic beverage per day.
While scientific evidence has been growing for more than four decades, many Americans don’t recognize alcohol consumption as a risk factor for cancer.
“Education is the key,” agrees Pashtoon Kasi, M.D., medical director of GI Medical Oncology, City of Hope® Cancer Center Orange County tells KTLA. “There was a recent survey that even though two-thirds of Americans are consuming one or more alcoholic beverages per week, less than half of them are aware of any association between alcohol and cancer.”
This article will explore these topics:
- How Much Does Alcohol Increase Cancer Risk?
- Which Cancers Does Alcohol Cause?
- Why Does Alcohol Cause Cancer?
- Does Alcohol Make Cancer Spread Faster?
- How Much Alcohol Is Safe to Drink?
- What Can You Do to Help Reduce Cancer Risk?
If you or a loved one has been diagnosed with lung cancer and are looking for a second opinion, call us 24/7 at 877-524-4673.
How Much Does Alcohol Increase Cancer Risk?
Each person’s risk for developing cancer depends on multiple factors. In addition to alcohol consumption, genetic makeup, lifestyle and environmental factors come into play. However, over the last 20 years, hundreds of studies have confirmed a significant relationship between drinking alcohol and increased cancer risk.
The surgeon general’s new warning is based on more than 600 research studies examining data from millions of cancer patients. Evidence cited in the report found:
- The risk for developing mouth cancer increased by 40% for people who consumed about one drink daily compared to nondrinkers, based on results from 26 studies
- The risk for developing breast cancer increased by 10% for women who consumed about one drink daily compared to nondrinkers, based on results from 20 studies involving one million women
The advisory also cites evidence that the more alcohol a person drinks — particularly over time — the higher his or her risk of developing cancer.
In women, consuming two drinks per day, compared to less than one drink per week, increases the chances of developing cancer from 16.5% to nearly 22%. That means 5 more women out of 100 who would develop cancer.
In men, consuming two drinks per day, compared to less than one drink per week increases the risk for developing cancer from 10% to 13%, meaning 3 more men out of 100 would develop cancer.
Which Cancers Does Alcohol Cause?
The advisory points to strong evidence accumulated by the National Cancer Institute that alcohol use causes at least seven different types of cancer, as detailed below.
Breast cancer (in women): Alcohol increases estrogen levels, which may cause breast tissue to grow abnormally. This leads to the development of a cancerous tumor. The advisory warns that as little as one drink a day increases a woman’s risk for developing breast cancer.
Colorectal cancer: Alcohol damages DNA and may lead to polyps, which are benign growths that may turn into colorectal cancer. Moderate drinking (two drinks a day or less) may increase colorectal cancer risk by 20%
Esophageal cancer: Any alcohol consumption is linked to an increased risk of esophageal squamous cell carcinoma. Smoking and alcohol together heighten this risk.
Liver cancer: Heavy alcohol consumption (more than three drinks a day for women and four drinks a day for men) doubles the risk for developing liver cancer.
Oral cancer: The risk for developing oral cancer increases by 40% for those who consume about one drink daily compared to nondrinkers.
Throat cancer: Moderate drinking increases the risk for developing this type of cancer by 1.4 times, but heavy drinking (especially with smoking) increases throat cancer risk fivefold.
Laryngeal cancer: Moderate drinking nearly doubles the risk for developing this type of cancer, while heavy drinking triples it.
Additional research suggests that heavy drinking may contribute to increased risk for developing stomach, pancreas and prostate cancers. More site-specific cancer and alcohol studies are needed.
Why Does Alcohol Cause Cancer?
All alcoholic beverages contain ethanol, which is believed to cause cancer in at least four ways:
- It breaks down into acetaldehyde, a cancer-causing chemical that damages DNA and interferes with its repair.
- It triggers oxidation, increasing inflammation, a cancer risk factor, and damages DNA, proteins and lipids (fats) in the body.
- It alters hormone levels (including estrogen), increasing breast cancer risk by promoting abnormal breast tissue development.
- It causes cells in the mouth to absorb carcinogens more readily, especially tobacco smoke. This may explain the heightened risk for developing esophageal and throat cancers in people who smoke and drink.
Alcohol may also hinder the body’s ability to absorb essential nutrients like folate and vitamins A, C, D, and E. Nutrient deficiencies are linked to increased cancer risk. Additionally, alcohol often leads to weight gain, contributing to cancer risk.
“Obesity and alcohol have had a significant relationship in the United States,” says Pankaj Vashi, M.D., A.G.A.F., F.A.S.P.E.N., vice chief of staff at City of Hope Cancer Center Chicago. It’s possible that the obesity connection to excessive alcohol use is what adds fuel to the fire, so to speak. Then it becomes two risk factors for cancer.”
Does Alcohol Make Cancer Spread Faster?
Although more research is needed, some studies suggest alcohol may cause cancer to spread by altering molecules, like cytokines and chemokines, which regulate inflammation. Alcohol may also harm blood vessel linings, allowing cancer cells to spread from one part of the body to another more easily.
Additionally, drinking alcohol may increase the risk for developing a second cancer, especially in the mouth, pharynx, larynx and esophagus. According to one study, for every four ounces of alcohol consumed daily before a first cancer diagnosis, the risk for developing another mouth or throat cancer increased by about 9%.
How Much Alcohol Is Safe to Drink?
For people who choose to drink alcohol, the 2020-2025 U.S. Dietary Guidelines for Americans recommend no more than one drink per day for women and no more than two drinks per day for men. However, the surgeon general’s advisory calls for these guidelines to be reassessed, stating: “17% of the 20,000 cancer deaths each year occur at levels within the recommended guidelines”.
The National Institute on Alcohol Abuse and Alcoholism (NIAA) defines several levels of alcohol use, including those listed below.
Moderate drinking: Two drinks or less per day for men; one drink or less per day for women.
Binge drinking: Consumption that produces a blood-alcohol level of 0.08 or higher in about two hours. For men, this usually means five drinks or more; for women, four drinks or more.
Heavy drinking: Five drinks or more a day or over 15 drinks per week for men; four drinks or more a day or over eight drinks per week for women.
“Binge drinking, say a six-pack on Saturday versus one beer every day for six days, produces toxins at a very high level in the circulation,” says Dr. Vashi. The body can’t process the alcohol being consumed fast enough, allowing a buildup of the cancer-causing chemical, acetaldehyde.
What Can You Do to Help Reduce Cancer Risk?
A Surgeon General’s Advisory is a public statement that calls attention to an urgent public health issue and provides recommendations for how it should be addressed. Consumers, particularly cancer patients, can help reduce cancer risk by taking these actions:
- If you don’t drink alcohol, don’t start.
- If you do drink, talk to your doctors about your alcohol consumption and understand your personal risk.
- Learn how alcohol affects your health and decide if you need to cut down. Resources like Rethinking Drinking, sponsored by NIAAA, can help.
If you or a loved one has been diagnosed with lung cancer and are looking for a second opinion, call us 24/7 at 877-524-4673.