Among both men and women, drinking just one alcoholic beverage a day increases the risk of liver cirrhosis, esophageal cancer, oral cancer and injuries of various kinds, according to a federal analysis issued on Tuesday.
Women face a higher risk of developing liver cancer even at this modest level of drinking. Drinking two drinks a day — double the U.S. Dietary Guidelines’ recommendation for women but the current amount condoned for men — increases the odds of a death caused by alcohol for both men and women.
The report, prepared by a scientific review panel under the auspices of the Department of Health and Human Services, is one of two dueling assessments that will be used to shape the influential U.S. Dietary Guidelines this year.
For years now, there have been fears among some scientists that the harms of moderate drinking have been underestimated, particularly the risk of cancer, the leading cause of death of Americans under 85, according to the American Cancer Society.
In December, a review by the National Academies of Sciences, Engineering and Medicine, a nongovernmental body, came to conclusions that differ from this latest report, saying that moderate drinking was linked to fewer heart attack and stroke deaths, and fewer deaths overall, compared with no drinking.
The National Academies’ analysis acknowledged that moderate drinking in women was linked to a small but significant increase in breast cancer but said there was insufficient evidence to tie alcohol to other cancers.
This month, however, the U.S. surgeon general, citing mounting scientific evidence, called for labeling alcohol with cancer warnings similar to those that appear on cigarettes. And the governmental report issued on Tuesday found that the increased cancer risk comes with any amount of alcohol consumption and rises as consumption rises.
“What a lot of folks may have previously considered ‘moderate’ drinking is actually moderately risky,” said Timothy Naimi, one of the authors of the new report and director of the Canadian Institute for Substance Use Research.
Some protective effects of moderate drinking were acknowledged. Women who have one drink a day may have a lower risk of diabetes.
But a reduction in strokes caused by blood clots seen with consumption of a single drink in both men and women disappeared when consumption increased to two drinks a day.
No protection against hemorrhagic strokes and ischemic heart disease was seen at any level of alcohol consumption, even though one of the prime arguments made for years in favor of moderate drinking was that it might prevent cardiovascular disease.
The new analysis did not make specific suggestions about how much people should be drinking; that will be left to the authors of the final dietary guidelines. But the report indicates that the health harms of alcohol start at very low levels of consumption and increase in proportion to the amount consumed.
“For me, if I were advising my loved ones, the potential harms outweigh the potential benefits at low levels of drinking,” said Katherine M. Keyes, a professor of epidemiology at the Columbia University Mailman School of Public Health and a member of the scientific review panel.
“Any suggestion that low or moderate levels of consumption are generally harmless or beneficial — the data just don’t bear that out,” she added.
Since the pandemic, harmful drinking habits have become more common, other research has shown.
The analysis should be read to mean that no level of alcohol consumption is risk-free, said Dr. Jurgen Rehm, another author of the report and a senior scientist at the Institute for Mental Health Policy Research at Canada’s Centre for Addiction and Mental Health.
“Humans accept risk for their activities, and they do things like mountain biking and other dangerous activities,” Dr. Rehm said. “If you take the usual threshold for higher risk, that would be equivalent to a little less than one drink a day.”
But, he said, even though the link between alcohol and cancer was first noted by scientists over a century ago, many Americans are still unaware of it.
Alcohol manufacturers attacked the new report, accusing the authors of bias and conflicts of interest.
“We are committed to science over bias,” said a statement by a coalition representing 23 beer, wine and spirits manufacturers; wheat, barley and hops growers; and restaurant and bartenders’ organizations.
“This report heightens our concerns that the dietary guidelines for Americans’ recommendations with respect to alcohol will not be based on a preponderance of sound scientific evidence.”
“Many lifestyle choices carry potential risks, and the consumption of alcohol is no exception,” the statement continued. “We encourage all adults who choose to drink to adhere to the Dietary Guidelines and consult with their health care providers.”
In 2020, the last time the dietary guidelines came up for review, scientific advisers suggested lowering the recommendation to one drink daily for both men and women. But the final guidelines made no change in the recommendation of two drinks for men and one for women.
Drinking is linked to a higher risk of death for seven types of cancer, including breast cancer, colorectal cancer and liver cancer as well as cancers of the oral cavity, the pharynx and larynx and the esophagus, the new report said.
Men and women are both vulnerable to these health harms, it said, but women are much more likely to develop a cancer linked to drinking.
The report, prepared under the auspices of the Health and Human Services Department’s Interagency Coordinating Committee on the Prevention of Underage Drinking, also emphasized the risk of dying from car accidents and injuries that faces those who start drinking as teenagers.
For girls and boys who start drinking at 15, the odds of a death attributed to alcohol increases more than tenfold as the number of drinks they consume increases from one per week to three per day, with higher risks for young men, the report said.
The new report evaluated evidence from previous reviews and observational studies, which cannot prove that alcohol caused an illness. It did not include data from randomized controlled trials, which could prove cause and effect, because they are very limited.
Unlike the National Academies’ report, which compared moderate drinking to not drinking, the new analysis assessed relationships between different levels of low alcohol consumption and the risk of dying overall from health conditions and accidents that are causally related to alcohol consumption in the United States.
The conclusions apply to all types of alcohol, including wine, beer and spirits.
The public will have an opportunity to comment on the two reports issued by the National Academies and the intergovernmental committee starting Wednesday and continuing until Feb. 14.
