Surgeon general’s advisories are strongly stated warnings meant to deliver clear messages about health risks. Advisories are uncommon and reserved for issues that need immediate awareness and action. They often become turning points in the nation’s health habits. A 1964 surgeon general’s report on smoking, for example, started to change the perception that cigarettes were benign.
The new advisory may help do the same for drinking, which was once thought to be associated with some health benefits. The new report aims to dispel any notion that alcohol is harmless.
“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 US – yet the majority of Americans are unaware of this risk,” Murthy said in a statement.
Roughly 70% of Americans consume alcohol, according to Dr. Brian P. Lee, a liver specialist at Keck Medicine of the University of Southern California who researches the health effects of alcohol, and many are confused about whether an occasional drink is good or bad for them.
Only 45% of Americans surveyed by the American Institute for Cancer Research in 2019 said they believed that drinking alcohol causes cancer, the new advisory notes.
“A lot of confusion comes from prior studies that really weren’t as robust and based on methodology that probably isn’t as accurate,” Lee said.
The new surgeon general’s report is more in tune with modern evidence, Lee said.
“Even light drinking … really, there’s no benefit, and in fact, there may be harm,” he said.
Alcohol is the third-leading preventable cause of cancer in the US, the new advisory says, after tobacco and obesity. It notes that the link between alcohol consumption and cancer risk is well-established for at least seven types of cancer: breast, colorectal, esophagus, liver, mouth, throat and voice box. And the risk remains regardless of what type of alcohol is consumed, and it increases with greater consumption.
Increasingly, evidence has mounted against alcohol consumption because of its health risks, negating a decades-long perception that some alcohol – especially red wine – could benefit health.
Still, nuances persist: A report in December from the National Academies of Sciences, Engineering, and Medicine concluded that moderate drinking – two drinks a day or fewer for men and one for women – may be associated with lower risks of cardiovascular disease. It also found that moderate drinking was associated with a higher risk of certain types of cancer.
“There was actually a time when we thought red wine increases risk of some cancers, but the positive effects for cardiovascular disease overwhelm the negative effects for cancer,” said Dr. Otis Brawley, an oncologist at Johns Hopkins University and former chief medical and scientific officer for the American Cancer Society.
Over the past three years, however, a steady stream of scientific evidence and comprehensive research reviews have disproved that idea.
“People need to be warned,” Brawley said. “There is no safe amount of alcohol.”
Alcohol causes cancer in at least four ways, the advisory notes. It is metabolized into a chemical called acetaldehyde, which damages DNA. Damaged DNA can then cause cells to divide out of control, leading to cancer.
“For those sites where there is direct contact … this is clearly the mechanism,” said Dr. Béatrice Lauby-Secretan, head of the Handbooks Programme at the International Agency of Cancer Research, or IARC. Those sites include the mouth, esophagus, stomach and colon, she added.
A recent IARC report found that about 20% of the nearly 75,000 lip and mouth cancers diagnosed worldwide each year are caused by drinking alcohol, for example.
Alcohol also creates unstable molecules called free radicals that can damage DNA and lead to cancer.
It alters levels of hormones, like estrogen and testosterone, which increases cancers at hormone-sensitive sites like the breast and prostate.
