Can One Beer a Day Increase Your Risk of Cancer? Science Says Yes

Humans and the bottle go a long way back. Archaeologists have found our love of alcohol began some 9,000 years ago (and maybe even 10 million years ago, according to some reports).

Evidence of people boozin’ it up has been found in nearly every society throughout history. And today, alcohol is still ingrained in cultures around the world, especially in places like the Midwest — dubbed the Binge Drinking Belt of the United States. Summer barbecue? Beer me. Stressed? Unwind with some wine. Bored? Hang out with Jack Daniels and Sailor Jerry. 

And for decades, there seemed to be no need to feel too guilty about imbibing, as long as you did so moderately and responsibly. After all, previous studies have tied alcohol consumption to heart health and longevity. And we’ve heard that a glass of wine a day can keep the doctor away.  

But is the party over? The growing body of work that highlights alcohol’s connection to cancer is difficult to ignore. And according to some studies, the evidence outweighs any potential heart health benefits you might get from a drink or two.

According to the World Health Organization and the International Agency for Research on Cancer, alcohol is a Group 1 carcinogen, which is the same ranking given to tobacco and solar radiation. This doesn’t mean that drinking is as bad for you as smoking. Rather, it describes the level of evidence out there showing that exposure can cause cancer. So, two carcinogens in the same category don’t necessarily carry the same cancer risk. 

But it is important to note that among avoidable risk factors of cancer, alcohol is the third-leading cause of death behind cigarette smoking and excess body weight in the United States, according to a 2018 study. Around 3.5 percent of all cancer deaths (or 19,500 deaths) in a given year are alcohol-related, according to the U.S. Centers for Disease Control and Prevention.

But this probably seems small when compared to the toll of cigarette smoking, which is responsible for approximately 30 percent of cancer deaths in the United States. That said, it can sometimes be confusing when trying to understand health risks.

One study in 2019 attempted to clear this up by equating wine consumption to cigarette smoking. The researchers estimated that drinking just one bottle of wine each week has the same carcinogenic impact as smoking five cigarettes for men and 10 for women on a weekly basis. 

And, in case you’re wondering, this gender difference has nothing to do with tolerance or body size. It’s, quite simply, because women have breasts and men don’t, said lead study author Theresa Hydes, a researcher at the University Hospital Southampton in the United Kingdom.

“While alcohol causes seven types of cancer, the risk of most of these cancers does not increase significantly until an individual starts drinking heavily. Breast cancer is the exception,” Hydes said in an email to Discover. “At moderate levels of alcohol intake (for example 10 [drinks] a week) the risk of breast cancer goes up more than it does for other alcohol-related cancers.”

But, even if you don’t have breasts, you may still want to be mindful of how much you drink. Consuming a bottle of vino per week, roughly a glass per day, is associated with an increased absolute lifetime cancer risk of 1.0 percent in men and 1.4 percent in women. In other words, if 1,000 men and 1,000 women each drank one bottle of wine per week, around 10 more men and 14 more women would develop cancer as a result, according to the study.

Other recent studies have tied an increased risk of developing cancer to what many would consider moderate drinking. For instance, in 2015, Harvard researchers published the results of a study that followed 88,084 women and 47,881 men for 30 years. They found that light-to-moderate drinking was associated with a small increased risk of overall cancer. This study defined light-to-moderate drinking as one standard drink for women and up to two standard drinks a day for men. A standard drink was equivalent to a four ounce glass of wine or a 12-ounce bottle of beer.

The study uncovered particularly strong cancer risks for women. Among females, a drink a day raised the risk of developing an alcohol-related cancer by 13 percent, primarily driven by breast cancer. Two drinks a day also increased the risk of cancer among men who had smoked. However, the study didn’t find a higher risk among never-smoking men.

And yet another buzzkill study: A 2018 review of 700 studies from around the world declared that no amount of alcohol consumption is healthful.

But if you’re not quite ready to be a teetotaler, here’s a different study for you. Sarah Hartz, a researcher at the Washington University School of Medicine in St. Louis, and her team analyzed the health records of more than 400,000 people, zeroing in on light-and-moderate drinking’s impact on mortality. Their work suggested that there is a “safe” amount of alcohol to drink per week.

“It looks like drinking one to two drinks a few times weekly is probably not harmful,” she said in an email to Discover. “[But] people who don’t drink shouldn’t start drinking.”

Read More: What Are Short and Long Term Effects of Alcohol On the Brain?

Hartz said a few cancers, in particular, have been linked to alcohol: Breast, colon, rectum and liver, as well as oral and esophageal cancers.  

And a recent study in mice sheds light on the mechanisms behind how alcohol causes cancer. As the body processes alcohol, it is converted into acetaldehyde, a highly toxic substance and known carcinogen.

Acetaldehyde permanently damages the DNA within blood stem cells, leading to rearranged chromosomes and permanently altered genetic sequences. And damaged DNA can lead to cancer.

But DNA damage isn’t the only way that alcohol may cause cancer. Alcohol can also cause oxidative stress, which damages our bodies, and it can impair a person’s ability to absorb nutrients from food. Additionally, it can elevate estrogen, a female sex hormone linked to breast cancer.  

But it seems that the risks of drinking alcohol aren’t one-size-fits-all. Some heavy drinkers never develop cancer, while light-to-moderate drinkers do sometimes eventually develop an alcohol-related cancer. Researchers think this may be influenced by genetic differences that determine how our bodies break down alcohol.

For instance, people of East Asian ancestry may carry a highly active form of an enzyme called alcohol dehydrogenase (ADH), which speeds up the conversion of alcohol into cancer-linked acetaldehyde. Japanese people who carry this version of the enzyme have been found to have higher rates of pancreatic cancer.

Another enzyme, known as aldehyde dehydrogenase 2, helps to convert toxic acetaldehyde into nontoxic substances. But some people, particularly people of East Asian ancestry, carry a defective version. So, acetaldehyde tends to build up in their bodies when they drink. Heavy drinkers who carry this enzyme defect are more prone to esophageal cancer as well as head and neck cancers. 

Read More: Quitting Alcohol: What Happens To Your Brain When You Stop Drinking?

If this research is news to you, you’re not alone. Data from the American Institute for Cancer Research shows that roughly 60 percent of Americans are in the dark when it comes to alcohol’s cancer risk.

That’s why health groups in the United States are now pushing for an update to warning labels on alcoholic beverages. “Government Warning: According to the Surgeon General, consumption of alcoholic beverages can cause cancer, including breast and colon cancers,” is the proposed new language. 

“Despite all of the evidence, and the scientific consensus around it, most consumers are not aware that alcohol causes cancer,” said Thomas Gremillion, the Director of Food Policy at the Consumer Federation of America, in an email to Discover. The non-profit consumer advocacy organization is one of several groups that signed a letter to government regulators requesting updated labels. 

But for others, the science on alcohol’s cancer risk is less settled. The American Beverage Institute, a lobbying group supporting the restaurant industry that strongly opposes the labeling request, says they wouldn’t do much good.

“Americans are already aware of the real dangers that arise from alcohol abuse and do not need the government to repeat the guidance. Adding a new label on alcohol products is not going to reduce binge drinking and other dangerous behaviors, but it may unnecessarily frighten Americans who want to enjoy a drink with dinner,” said Jackson Shedelbower, a spokesperson for American Beverage Institute, in an email to Discover.

Would a greater awareness of alcohol’s cancer risk change behavior? It’s hard to say. But a survey of middle-aged Australian women in 2019 found that warnings about an increased risk of cancer probably wouldn’t make them drink less. Negative impacts on weight, relationships and lifestyle were more likely to make them abstain, the women indicated. 

But, as we’ve seen from previous public health campaigns, you can’t change awareness overnight. Gremillion says that similar to tobacco, a sustained effort to raise awareness of the link between alcohol and cancer is needed. But turning alcohol into “the new cigarettes” isn’t anyone’s intent. “No one wants to go back to prohibition, but the government should help consumers to make informed decisions,” Gremillion said. “Some consumers may learn of the risks, and decide to drink less or stop drinking altogether. Others may choose to continue drinking, because of perceived cardiovascular benefits or because they simply enjoy drinking alcohol. Whatever the case, consumers have a right to know.”

Read More: How Effective is Alcoholics Anonymous, According to Science?