US top doctor wants cancer warning on alcohol: What does the science say?

Dr. Vivek Murthy, the head of the United States, has sparked a public health debate by proposing cancer warnings on alcoholic beverages.

A new advisory (PDF) outlining growing evidence linking alcohol consumption to various cancer types was submitted alongside Murthy’s proposal.

What does science have to say about the risks associated with drinking, and why is this a significant demand for warning labels?

Why is the US surgeon general now urging alcohol bottles to contain cancer warnings?

The current text-only alcohol warning labels, which were introduced in 1988, do not address cancer risks and pregnancy risks.

Given today’s knowledge of the effects of alcohol on people’s health, Murthy contends that these labels are out of date and insufficient.

On Friday, Murthy wrote on the social media platform X, “Be aware that cancer risk increases as you drink more alcohol.” Keep in mind that less is better when it comes to reducing the risk of cancer when deciding whether or not to drink.

How big a cancer risk is alcohol?

According to the surgeon general’s report (PDF), alcohol consumption is directly linked to an estimated 100 000 cancer cases and 20 000 fatalities per year. In addition to obesity and tobacco use, it is the third most curable cause of cancer.

In other parts of the world, comparable findings have also been reported. In 2018, alcohol consumption was linked to 180, 000 cancer cases and 92, 000 deaths in the World Health Organization’s European region, accounting for 4.2 percent of all cancer cases.

In China, alcohol consumption is linked to 93, 596 cancer cases (3.6 percent of total cases) and 78, 881 cancer deaths (4.4 percent of total deaths), with men being significantly more affected than women. Alcohol consumption is typically much lower for women in China than for men.

This link has also been demonstrated by other studies. One study, which was published in the British Journal of Cancer, identified alcohol as a significant carcinogen that damages DNA and prevents cell repair after analysing data from 572 studies involving 486, 538 cancer cases.

Despite these concerns, public awareness remains low — only 45 percent of Americans recognise alcohol (PDF) as a cancer risk, compared with 91 percent for tobacco.

How much alcohol does a person drink to raise their risk of developing cancer?

There is no “safe” level for alcohol consumption in terms of cancer risk. Even the smallest amounts of pollution, according to the WHO and other public health organizations, can harm health.

According to data from US surgeon general advisories, consuming two drinks per day increases the risk of developing cancer in about five out of 100 women and three out of 100 men.

Will the warning curb drinking?

The surgeon general wants to update the warnings on alcoholic beverages, drawing comparisons to cigarette warnings, which are said to lower smoking rates, according to studies. However, some people are unsure about the efficacy of text warnings.

In its push for cigarette packs to carry graphic new health warnings, including pictures, the US Food and Drug Administration (FDA) said in 2019 that existing text warnings on cigarette packs, unchanged since 1984, are deemed ineffective and “virtually invisible”.

Regardless of whether warning labels have an immediate impact on public health, Timothy Naimi, director of the University of Victoria’s Canadian Institute for Substance Use Research, contends that they are essential for promoting transparency and consumer rights.

Naimi points out that alcohol labels in North America lack even basic consumer information, whereas other packaged food and beverage products are required to list detailed details like ingredients, calorie content, and potential health risks.

There isn’t much information about what people consume when it comes to alcohol, he told Al Jazeera. People should not only have access to information but also the freedom to make their own decisions.

Dr Carina Ferreira-Borges, head of alcohol, drugs, and prison health at the WHO’s Europe regional office, says these types of labels play a broader role beyond individual behaviour.

“Alcohol health warning labels are a systemic tool for change — they raise awareness, support broader alcohol policies, and reduce the marketing appeal of alcohol packaging”, she told Al Jazeera.

How else can alcohol consumption be reduced?

According to experts, additional regulatory measures are essential for reducing consumption.

According to David Jernigan, professor of health law, policy, and management at the Boston University School of Public Health, “the single most effective step would be to increase the federal excise tax on alcohol.” Congress dropped the alcohol tax in 2017, making it permanent in 2020.

He adds that framing alcohol as “a different and potentially unhealthy product” makes it more valuable, which could open the door for more effective measures, such as tax increases, to gain legislative support.

The WHO also recommends three “best buys” to reduce alcohol consumption: raising taxes, limiting marketing, and reducing physical availability, such as restricting the number of sellers and their operating hours.

By enacting stricter marketing and tax laws, the Nordic nations and Thailand have successfully reduced alcohol consumption.

What health effects does drinking alcohol have?

Alcohol consumption increases the risk of at least seven cancers, including breast, colon, liver, mouth, throat, oesophageal, and laryngeal cancers, according to the surgeon general.

This occurs through a number of mechanisms, including:

• DNA damage: Alcohol metabolises into acetaldehyde, a toxic compound that damages DNA, the molecules that guide how humans grow and function, and prevents cells from repairing themselves.
• Hormonal disruption: Alcohol disrupts hormone levels, particularly oestrogen, increasing breast cancer risk.
• Absorption of carcinogens: Alcohol heightens the body’s absorption of other carcinogens, such as those found in tobacco.

Does moderate drinking have health benefits?

It is complicated.

The “French Paradox” was a 1991 study that was well-known and suggested that moderate wine consumption might prevent heart disease in people who eat high-fat diets. This was supported by observational studies that found a link between moderate drinking (one or two drinks per day) and a lower risk of cardiovascular disease.

However, recent studies have largely disproven these claims, highlighting issues from earlier research and highlighting risks that outweigh any potential advantages.

A 2022 review in JAMA Network Open, which analysed 107 studies, found that previous claims about heart benefits of moderate drinking were based on flawed methodologies, particularly failure to account for “sick quitters” — people who stopped drinking due to health problems.

Naimi acknowledges that public perceptions are stifled by debates about whether consuming fewer alcohol can improve heart health, but he says that recent research supports the idea that drinking less is better for both heart health and cancer prevention.

Even if you think a little bit of alcohol might be good for your heart, Naimi cautions against it, only consuming a few drinks per week. Beyond very low levels, alcohol increases the risk of heart disease, including heart attacks, high blood pressure, heart failure, and irregular heartbeats.

However, industry representatives, such as Amanda Berger, senior vice president of the Distilled Spirits Council, contend that moderate drinking may have some health benefits and that label updates should reflect a thorough analysis of scientific evidence.

According to Berger, “many lifestyle choices have potential risks, and it is the federal government’s responsibility to decide any proposed changes to the warning statements based on the results of comprehensive scientific research.”

Ferreira-Borges, the WHO representative, says the alcohol industry’s responsibility lies not in promoting responsible drinking campaigns, but in reducing the harm caused by their products through regulatory measures and reformulation.

She said, “Alcohol industry claims that alcohol harms are a matter of personal responsibility serve to refute the widespread nature of, and misrepresents, who experiences, alcohol harms.”

Will Congress approve new labels?

Despite the surgeon general’s advisory and new research on alcohol’s risks, Congress is unlikely to act quickly on updating warning labels.

Nearly 40 years ago, the last alcohol warning label, which addressed impaired driving and pregnancy risks, was approved.

The bill was introduced in the House in September 1988 under the name “Alcohol Beverage Labeling Act” and became law in a few months. The alcohol industry, however, expressed strong opposition to the warnings, who claimed they would be ineffective and could harm business. Additionally, the labels used were comparatively thin and absent from extensive health warnings.

The powerful alcoholic beverage sector, which lobby Congress for $30 million annually, is likely to oppose efforts to add a cancer warning.

Analysts also anticipate pushback.

“This seems to be one of the industry’s greatest fears – that this marks the beginning of their going down the same road as tobacco”, said Jernigan.

According to the 2023 National Survey on Drug Use and Health, 49.6 percent of those aged 18 to 25 reported drinking in the past month in 2023, down from 59.6 percent in 2013.

Trends among them indicate a growing preference for non-alcoholic alternatives, with movements like “Dry January” gaining traction, while social shifts may also play a role.

Source: Aljazeera