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Alcohol has long been classified as a cancer-causing substance, but a study out Thursday gives a clearer sense of just how many cancer cases and deaths may be driven by drinking.
Researchers from the American Cancer Society and International Agency for Research on Cancer estimate 40% of all cancer cases in the United States in people 30 and up were due to “potentially modifiable risk factors,” including cigarette smoking, physical inactivity, consumption of processed meat, viruses, excess body weight, alcohol drinking and more. Data was from 2019 in order to avoid the influence of the pandemic, when cancer diagnoses declined because of delayed care. The results were published in the American Cancer Society’s journal, CA: A Cancer Journal for Clinicians.
Cigarettes have long been a cause of cancer, and remained in the top spot — about 19% of cancer cases included were attributable to smoking. Excess body weight was deemed a cause for about 7.6% of cases, including malignancies of the gallbladder, esophagus, liver and kidneys.
Alcohol came in third, with 5% of cases in men and women over 30 attributable to drinking — perhaps a surprising result to the public, given low awareness of the links between drinking and cancer. In a national survey of adults in the U.S. in 2020, less than a third of respondents knew alcohol increased cancer risk. About 10% said they thought drinking wine reduced their risk of developing cancer.
In all, about 24,000 cancer deaths and 95,000 cases in a single year were attributable to alcohol consumption, according to the researchers’ calculations.
In the study, alcohol was associated with seven cancers: oral cavity, pharynx, larynx, colorectum, and female breast, as well as squamous cell carcinoma in the esophagus, and hepatocellular carcinoma in the liver. Beyond those, “there is accumulating evidence” that alcohol can cause other cancers, such as pancreatic cancer, said lead author Farhad Islami, senior scientific director of cancer disparity research at ACS (which funded the study).
“The increased risk is because of the alcohol in alcoholic beverages, not the type of beverage,” he said. A standard alcoholic beverage in the United States has about 14 grams of pure ethanol. That looks like one 12-ounce serving of 5% ABV beer, a 5-ounce serving of 12% ABV wine, 8-10 ounces of 7% ABV hard seltzer, or 1.5 ounces of 40% ABV liquor. Research suggests the higher a person’s consumption, the higher the risk of cancer.
However, even relatively low amounts of drinking might carry certain risks. A recent study by investigators at the Centers for Disease Control and Prevention found about 17% of cancer deaths were attributable to low levels of alcohol consumption — less than the national dietary guidelines’ recommended cap of two drinks per day for men and one drink per day for women.
Other research, including from Canada and from up to a decade ago in the U.S., has also pinned tens of thousands of cancer cases on alcohol. And a rising tide of disease and death associated with drinking, especially among women and younger people, has experts alarmed. Cancer is a major component of that concern, even though mortality from cancer has been on the decline for years.
Breast cancer has strong ties to drinking, according to a growing body of research. Islami’s study found female breast cancer was the cancer type with the most cases attributable to alcohol — with about 44,000, or 16% of cases, in 2019 alone linked to drinking. Another 18,000 cases, or 13%, of colorectal cancers in men and women combined were also tied to drinking. The share of cancer cases by type that could be blamed on alcohol were mostly higher in men than in women. In liver cancer, men’s share of alcohol-attributable cases was three times higher than women’s (23% versus 8%).
The notable exception to that rule was esophageal cancer, in which 24% of cases among women were attributable to alcohol, compared to 17% of cases in men.
The data suggest about half of all oral cavity and pharynx cancers in men, or about 17,000 cases, were due to alcohol. In women, a quarter of oral cavity, esophageal and pharyngeal cancers were attributable to alcohol consumption.
Oral cavity and pharynx cancer deaths were the types with the highest share due to alcohol use, at 40% and 38%, respectively. Over a quarter of larynx cancer deaths were attributable to drinking.
While some research has associated drinking with a lower risk of certain cancers, including kidney, non-Hodgkin lymphoma, and thyroid cancer, it may be outweighed by potential harms. Alcohol has been linked to diseases in nearly every organ system.
Research has found that reducing drinking levels can also bring down the risk of related cancers. If every person in the U.S. who drinks stayed within the dietary guidelines, “about 80% of all alcohol-related cancer deaths could be prevented,” Islami said, pointing to the CDC data.
STAT’s coverage of chronic health issues is supported by a grant from Bloomberg Philanthropies. Our financial supporters are not involved in any decisions about our journalism.