Some people won’t smoke cigarettes because they know tobacco use causes cancer. But they may not think twice about going out for drinks — oblivious to the cancer risk alcohol also poses.
Despite stories of centenarians crediting their longevity to daily shots of whiskey or studies attributing health benefits to red wine, leading cancer organizations and now U.S. Surgeon General Vivek Hallegere Murthy say there’s no amount of alcohol that’s safe to drink without increasing cancer risk. On Jan. 3, the Surgeon General released a report that outlines the cancer risks caused by alcohol consumption.
"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,” the surgeon general says. “This advisory lays out steps we can all take to increase awareness of alcohol’s cancer risk and minimize harm.”
Among the conclusions in the report:
- More than 72 percent of American adults have one or more drinks a week, but fewer than are aware of alcohol’s cancer risk.
- Alcohol is the third leading preventable cause of cancer in the U.S. after tobacco and obesity.
- Nearly 17 percent of breast cancers in woman may be attributable to alcohol consumption.
- Just two drinks a day increases the cancer risk in women significantly more than men.
- Nearly 750 million cases of cases worldwide may be attributable to alcohol use.
- Evidence indicates that alcohol use contributes to higher risk of at least seven cancers, including:
The surgeon general’s report is based on and/or mirrors recent research from other organizations including an American Cancer Society study using data from 2014 measuring the incidence rates for the following three leading cancer risk factors.
Cigarette smoking: 19 percent of cases and 29 percent of deaths
Excess body weight: 7.8 percent of cases and 6.5 percent of deaths
Drinking alcohol: 5.6 percent of cases and 4 percent of deaths
Alcohol even ranked ahead of UV radiation, which the study linked to 5 percent of cancer cases and 1.5 percent of cancer deaths.
A 2021 study by the University of Virginia indicates that most Americans are unaware that drinking alcohol may increase cancer risk. Of those surveyed:
- 20 percent were aware that wine increases cancer risk.
- 25 percent knew that beer increased risk.
- 31 percent knew that liquor increased cancer risk.
One reason alcohol may not have the same stigma as smoking is that, while drinking may increase cancer risk, tobacco use has a much clearer correlation, 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.
“As for the scientific basis of smoking as a cause of cancer, the data is very, very strong compared to that for alcohol,” Dr. Vashi says. “There’s obviously a relationship between drinking and certain cancers, but you’re usually talking about people who drink a lot.”
This article will explore these topics:
- Why does alcohol cause cancer?
- Is moderation the answer?
- The debate over red wine
- What are the risks for cancer patients?
If you’ve been diagnosed with cancer and are interested in a second opinion about your diagnosis or treatment plan, call us or chat online with a member of our team.
Why does alcohol cause cancer?
The chemical connection
It doesn’t make a difference if you’re drinking beer, wine or whiskey—all alcoholic beverages have one thing in common: They contain ethanol.
When you drink alcohol, your body breaks down the ethanol by converting it into a chemical called acetaldehyde, a toxin and carcinogen. Acetaldehyde damages DNA and may interfere with the body’s ability to repair it. It’s that damage that may be responsible for cancer. Your cells rely on instructions from your DNA to grow and function properly. Damaged DNA may cause cells to grow out of control, potentially creating cancer tumors.
Most ethanol converts to acetaldehyde in the liver and stomach. While this change occurs with any amount of alcohol, it’s a bigger problem for heavy drinkers or binge drinkers because the body can’t process the alcohol being consumed fast enough, allowing a buildup of acetaldehyde.
“Binge drinking, say a six-pack on Saturday vs. one beer every day for six days, produces those toxins at a very high level in the circulation,” Dr. Vashi says. “The damage to healthy tissue is much more significant in binge drinkers than in people who drink the same amount over the period of one week.”
Also, alcohol triggers a process called oxidation, which may increase inflammation, also a cancer risk factor, and may damage DNA, the surgeon general report says.
Hormones are affected
Another effect of drinking alcohol is that it raises estrogen levels in the blood, increasing the risk for breast cancer in women. One way hormones work is by informing cells to grow and divide. The more they divide, the greater the possibility that something will go wrong in the process. Increased estrogen levels may lead to abnormal development of breast tissue, increasing breast cancer risk.
Absorption problems with alcohol
Researchers say alcohol makes it easier for the body to absorb cancer-causing toxins, while impeding the body from absorbing nutrients that help prevent cancer.
This may explain why combining alcohol and tobacco use greatly increases cancer risk, particularly for esophageal and throat cancers. Researchers believe alcohol makes the throat more susceptible to the poisons in tobacco smoke.
Alcohol intake also makes it harder for the body to break down and absorb some essential nutrients, such as folate and vitamins A, C, D and E.
The connection to excess weight
Alcohol may also contribute to another significant risk factor for cancer, excess body weight, because it frequently leads to weight gain.
“When people drink on a regular basis—hard liquor or beers—they’re getting empty calories. Drinking alcohol on a regular basis may also stimulate your appetite, so you end up eating more,” Dr. Vashi says.
“You’re not only piling up those calories from the beer, but then you’re eating more than you would’ve otherwise because now you’re feeling hungrier,” he says. “Obesity and alcohol have had a significant relationship in the United States. 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.”
Is moderation the answer?
Medical professionals preach moderation when it comes to many manageable risk factors for cancer and other health conditions. It’s the same with alcohol: Experts recommend no more than two drinks a day for men and one drink a day for women.
Still, those recommendations don’t mean moderate drinking is safe, given the link between alcohol and cancer risk. Moderate drinking puts you at lower risk than if you were drinking more, but at greater risk than if you didn’t drink at all.
Also, many people may think they’re drinking moderately when they’re not. A cocktail with three shots is considered three drinks, not one. And two craft beers a day at 9 percent alcohol by volume (ABV) puts a man over the two-drink-a-day guideline for moderation.
When doctors talk about a “drink,” they mean a standard drink that has about 14 grams of alcohol. Each of these is equivalent to one drink:
- 12 ounces of beer at 5 percent ABV
- 8-9 ounces of malt liquor at 7 percent ABV
- 5 ounces of wine at 12 percent ABV
- 1.5 ounces, or a "shot," of 80-proof liquor
“How much you drink is very important. There’s a level beyond which, if you do it on a regular basis, it’s definitely going to make you a high-risk patient for certain cancer types,” Dr. Vashi says.
The surgeon general hopes the new report will increase awareness of the alcohol-cancer connection and result in:
- An updated health warning label for alcohol to include cancer risk
- New alcohol consumption limits to account for cancer risk
- More doctors informing their patients about this link between alcohol and cancer
The debate over red wine
Of all the types of alcohol you may drink, Dr. Vashi says, red wine may be the most acceptable from a health perspective. He doesn’t recommend red wine as a healthy lifestyle choice—and he’s not suggesting a non-drinker start drinking red wine—but he sees it as a lesser evil compared to other alcoholic beverages.
Many Western Europeans are known to drink red wine for lunch and dinner, starting as young teens, yet those countries show a lower prevalence of cancer than in the United States. This trend may have something to do with resveratrol, a polyphenol found in the skin of red grapes that acts as an antioxidant and impedes the metabolic activation of carcinogens.
“Nobody is going to say alcohol is OK. What I’m trying to say is that if you have to drink, you might be better off drinking a glass of red wine because there’s some benefit to that,” Dr. Vashi says. “You’re better off just not drinking at all, but if you’re going to drink, red wine is better than anything else.”
What are the risks for cancer patients?
Drinking alcohol may cause other problems for people who already have cancer or are cancer survivors.
It may worsen side effects like nausea, dehydration and mouth sores caused by chemotherapy and other cancer drugs. It also increases the risk for a recurrence of diseases like breast cancer.
Dr. Vashi says he counsels cancer patients to stop drinking, but he’s also sensitive to their quality-of-life issues and understands social drinking may offer some enjoyment amid the challenges they’re facing.
“I, personally—and I think most clinicians feel this way too—would not push them to completely abstain from drinking if they’re drinking socially,” he says.
“When a primary care physician conducts annual physicals of healthy people, for younger people coming out of college and who have partied a lot, that’s a time to start talking to them about the long-term effects of alcohol,” Dr. Vashi adds. “Alcohol is not going to give you cancer in a year or two of drinking. It’s the impact of drinking for 15, 20, 30 years. That’s why you see cancer diagnoses in people in their 50s and 60s, because they started drinking starting in their college days.”
If you’ve been diagnosed with cancer and are interested in a second opinion about your diagnosis or treatment plan, call us or chat online with a member of our team.
