Good news if you made a New Year’s resolution to drink less: A new report indicates quitting drinking could cut your risk of developing certain cancers.
The International Agency for Research on Cancer (IARC) reported in its recently published special report in the New England Journal of Medicine that ethanol, the main form of alcohol comprising alcoholic beverages, is the most popular psychoactive substance in the world. Additionally, the IARC said there is sufficient evidence to classify alcohol as carcinogenic for its ability to cause oral, pharyngeal, laryngeal, esophageal, liver, colorectal, and breast cancer. Alcohol contributed to 741,300 new cancer cases in 2020—one reason the World Health Organization (WHO) stated that “no safe amount of alcohol consumption for cancers and health can be established.”
“We cannot talk about a so-called safe level of alcohol use. It doesn’t matter how much you drink—the risk to the drinker’s health starts from the first drop of any alcoholic beverage. The only thing that we can say for sure is that the more you drink, the more harmful it is—or, in other words, the less you drink, the safer it is,” Carina Ferreira-Borges, acting unit lead for noncommunicable disease management and regional advisor for alcohol and illicit drugs in the WHO Regional Office for Europe said in a Jan. 3, 2023, news release.
Knowing the risks alcohol poses for developing cancer, the research team at IARC wanted to know if there was any less of a risk of developing certain types of cancer if people drank less or stopped drinking altogether.
To answer this question, the IARC team analyzed multiple studies from across the world to determine if cancer risk declines with reduced alcohol consumption. They looked at cohort studies, which followed a group of participants for years, and case-controlled studies examining differences between people with cancer and those without.
The results indicated that reducing alcohol use led to a reduced risk of cancer. Those who stopped drinking for five to nine years were 23 percent less likely to develop cancer, while those who stopped drinking for 10 to 19 years were 34 percent less likely. Alcohol cessation for at least 20 years suggested a reduced cancer risk of 55 percent.
For esophageal cancer in particular, there was substantial evidence that the risk was reduced by 15 percent for individuals who stopped drinking for five to 10 years; those abstinent for 15 years or longer were 65 percent less likely to develop it. Alcohol cessation provided similar risk reductions for cancers of the larynx, colon, and breast, though the evidence was quantified as “limited” rather than strong.
How Alcohol Causes Cancer
When people drink alcohol, the body metabolizes it into a compound called acetaldehyde. This process begins as soon as alcohol enters the mouth and interacts with saliva, then continues via microbes in our gastrointestinal tract. Both saliva and these microbes allow the acetaldehyde to enter our bloodstream, colon, and more. According to the IARC research team, acetaldehyde is “a potent genotoxic metabolite,” which means it can bind to and damage DNA.
In addition, acetaldehyde can lead to inflammation and create an imbalance between free radicals and antioxidants, or oxidative stress. For women, in particular, acetaldehyde can increase how much estrogen is in the blood, which can be a precursor to cancer. Alcohol also alters how the body absorbs nutrients, the IARC wrote, especially those aiding in DNA repair, such as folate. This impaired nutrient absorption makes it harder for the body to fight off carcinogens like those found in tobacco smoke.
The Importance of Dry January and Beyond
The new report comes at a vital time as many individuals across the country begin the New Year with a Dry January resolution, which could be a life-saving decision if it becomes long-term.
Alcohol is arguably the most socially acceptable mind-altering substance used throughout the world. According to the 2022 National Survey on Drug Use and Health (NSDUH), 78.5 percent of people aged 12 and older reported drinking at least one alcoholic beverage in their lives. In 2018, in the United States, 52.8 percent of adults 18 and older drank, consuming at least 12 alcoholic drinks a year. While many consume alcohol safely, over 10 percent of Americans 12 and older struggled with alcohol use disorder in the past year, according to the NSDUH.
While some studies may tout the health benefits of moderate alcohol use, more and more research is being published establishing that risks outweigh any potential benefits.
“Potential protective effects of alcohol consumption, suggested by some studies, are tightly connected with the comparison groups chosen and the statistical methods used, and may not consider other relevant factors,” said Jürgen Rehm, WHO regional director for Europe’s Advisory Council for Noncommunicable Diseases and senior scientist at the Institute for Mental Health Policy Research and the Campbell Family Mental Health Research Institute at the Centre for Addiction and Mental Health in Toronto, Canada.
