Cancer warnings on alcohol

In January, US Surgeon General Dr Vivek Murthy put the spotlight on the link between alcohol and cancer – a link that many Americans remain unaware of. His advisory report – Alcohol and Cancer Risk – suggests alcohol labels should carry cancer warnings.

This month, the WHO has made the same recommendation.

What would cancer warnings look like, how effective would they be, and should we expect to see them become mandatory around the globe?

Cancer warnings vs health warnings

While many countries now mandate some type of health warning on alcohol, few focus on cancer risk.

Labels have largely focused on issues such as underage or excessive drinking, the dangers of drinking when pregnant, or issue a warning about general health concerns.

But, in his report, Dr Vivek Murthy highlights just how big a problem alcohol is when it comes to cancer risk.

There are around 20,000 alcohol-related cancer deaths per year: which is, in fact, greater than the number of alcohol-associated traffic crash fatalities (estimated at around 13,500).

That’s one of the factors that have spurred on calls for cancer warnings on alcohol.

Real world evidence from South Korea and Canada

It’s hard to assess how effective cancer warnings on alcohol in the US would be because South Korea is currently the only country that mandates their use.

And even there, the use of cancer warnings is hard to determine: brands are required to choose one of three warning labels, one of which does not cite cancer risk – meaning that including a cancer warning is effectively optional.

With limited uptake worldwide, the effectiveness of cancer warning labels on alcohol remains largely unstudied.

But in 2020, researchers in Canada published results from the first real-world study in Yukon to test if cancer warnings on alcohol are effective.

A liquor store in Whitehorse applied cancer warning labels to alcohol containers for one month. Two liquor stores in Yellowknife, Northwest Territories, were used as a control for comparison as they did not have alcohol cancer warning labels.

Labels colored red and yellow carried the following message: ‘Chief Medical Officer of Health advises: Alcohol can cause cancer including breast and colon cancers’ (the message was displayed in both English and French).

The study – which had due to be run for 8 months in 2017 – was halted after 1 month due to alcohol industry opposition.

Yet the researchers still noticed results.

“Despite the interrupted and briefer-than-intended application of the cancer warning labels in this study, consumers noticed the labels,” notes the study.

“Two months after the cancer warning labels, almost 25% of participants exposed to the intervention recalled the cancer warning message unprompted, and recall rose to 43% when prompted.”

But, with the study pulled, this effect was not long-lasting: as expected, recall decreased six months after the cancer warning labels were removed.

Before the study started, around 25% of the population across the two sites were aware of a link between alcohol and cancer – consistent with estimates for the time across Canada.

Knowledge grew to 41.6% in the Whitehorse site, increasing 12.1% two months after, and a further 3.9% six months after the warning label was no longer being applied to containers. (Why consumers remembered the warning labels six months after is hard to pin down: although it could have been because leftover cancer labels were still stocked at home or in restaurants).

The study was marred by the alcohol industry’s opposition: not only because it was cut short, but because results could have been influenced by the high media attention surrounding the industry’s battle to stop the study.

But the researchers had the last word when publishing their study in 2020: “The alcohol industry’s opposition to cancer warnings on containers, coupled with the broad public support for health warnings on alcohol, highlights the importance of mandatory alcohol labeling to ensure that consumers are adequately informed,” concluded the publication.

Industry interference

Ireland is set to introduce a world-leading policy on alcohol warning labels in 2026: with new regulations signed into law in 2023.

Products will have to include a warning of the link between alcohol and cancer (alongside further warnings on the danger of alcohol consumption, the danger of drinking alcohol while pregnant, and information such as calorie counts.)

Research from Health Ireland showed that 79% of Irish consumers were unaware of the risk of breast cancer associated with drinking more than recommended amounts, and 60% were unaware of the bowel cancer risk.

But – as in the Canadian study – industry opposition proved to be the main challenge. That was taken as far as the World Trade Organization, where several WTO member states raised concerns, as did industry associations.

However, unlike Canada, the Irish government was ultimately successful in introducing the new laws. That’s been put down to the sheer determination from the government – as well as a multisectoral approach with the involvement of civil society, including cancer organizations – according to the McCabe Centre for Law & Cancer.

What could cancer warnings look like?

Last year, researchers from the World Health Organization conducted an online survey experiment across 14 European countries. Participants were shown different labels, some without cancer warnings, and others with different cancer warning formats.

The results showed that a third of participants exposed to a cancer message increased their knowledge of the cancer risk.

And cancer messages were perceived to have the biggest impact and relevance, compared to general health harm and responsibility messages.

Another factor was that participants responded positively to the idea of cancer warnings: finding them equally ‘acceptable’ as general health warnings on alcohol.

What’s more, the study experimented with five different warning message designs to find the more effective format. Text-only and pictogram cancer messages were seen as clear, comprehensive, and acceptable. However, participants were less open to the idea of tobacco-style warnings with graphic images of patients with cancer.

Ultimately, the format of the cancer warning was not overly important: the simple existence of the warnings was what counted, found the researchers.

“Our study suggests that brief exposure to a message about the link between alcohol and cancer significantly increased knowledge across all 14 participating countries, regardless of the cancer message variant,” wrote the researchers in the study.

“Cancer messages were also perceived to be most impactful and relevant, while being equally as acceptable as the other labels (with the exception of the graphic-image variant).”

Simple slogans over solid science?

But not everyone is on board with cancer warning labels. Mitch Frank, senior editor of Wine Spectator, says the problem is that ‘simplistic slogans sell; nuanced science doesn’t’.

There are now vast bodies of research on alcohol and health and the picture is not simple. Alcohol consumption has been linked to higher rates of certain cancers; but moderate (now more than two glasses a day) has been linked to lower rates of cardiovascular disease.

“If there is one trademark of the growing neoprohibitionist campaign, it is that simplistic slogans sell; nuanced science doesn’t,” he said. “The most effective tactic for convincing the public that all alcohol is unsafe is to issue broad statements with no gray area, no doubts and no complexity.”

And even more complicated is computing in the positive social aspects of alcohol, such as bringing together people over food and drink – ‘enjoyment matters as well as risk’, notes The Economist.

But if warning labels aren’t the answer, then what are?

“There’s a difference between a clear message for consumers on alcohol’s benefits and risks versus a simplistic, one-sided message,” said Frank. “The neo-prohibitionists calling for warning labels want to convince consumers that alcohol is as bad as tobacco. The science simply doesn’t back that up.

“Explaining that alcohol has both health benefits and risks, stressing that heavy drinking and binge drinking are dangerous and that people need to have a responsible relationship with alcohol, as well as providing help for people with alcohol use disorder — these are all going to be far more productive in the long run.”

Will the US introduce cancer warning labels?

The WHO has long proposed stricter regulations on alcohol, pointing out the global health burden. Its call for cancer warning labels is no surprise.

The US Surgeon General’s warning, however, has driven a new level of immediacy to the idea.

And yet, there’s a long way to go before that could become reality. More pressing is the US Dietary Guidelines, which are up for review this year and are already stirring up much debate over alcohol consumption guidelines.

“Congress would have to mandate cancer warning labels. It is not up to the Surgeon General,” explained Frank. “And Congress has not shown any interest so far. I think the call for warning labels will have more influence in the current fight over the US Dietary Guidelines, which are up for review this year. For decades, those guidelines have recommended that men drink no more than two alcoholic drinks per day and women drink no more than one. The scientific panel that reviews the current medical evidence offered no reason to change that, but several others in the government have suggested the recommendations should be reduced or that the guidelines should say no level of drinking is safe.”

The right to know

The number one rule for public health policy makers is to ensure that rules and regulations are evidence-based and effective.

The ultimate goal of cancer warnings would be to reduce alcohol consumption and therefore reduce alcohol-related cancers.

With a shortage of real world evidence – industry bodies also question just how effective cancer warnings would be.

But on this occasion, focusing solely on the effectiveness of cancer warnings is not the whole story, points out Tim Stockwell at the Canadian Institute for Substance Use Research and Professor Emeritus and Adjunct Professor in the Department of Psychology at the University of Victoria.

The point, he says, is to go back to the sheer lack of awareness about alcohol’s link to cancer.

“The main issue, I believe, is the consumer’s right to know,” he said. “The absence of a warning label implies there is no serious risk. Regardless of evidence for an impact on behavior, as alcohol is linked to about three quarters of a million cases of cancer worldwide each year, consumers have a right to this knowledge and producers should have an obligation to inform them.”

And raising awareness of cancer risk could have an impact on wider public health policies.

“In the Yukon, the labelling intervention including a cancer warning was associated with a significant reduction in population consumption which, had it been maintained, would have led to reduced rates of alcohol-related cancers which are very high in the Yukon, particularly for cancers of the breast and colon,” said Stockwell.

“The main impact, however, will be informing consumers about a health risk many are unaware of. A climate in which citizens are aware of the cancer risk (at present less than half of the population in most developed countries have this awareness) might lead to implementation of other policies, eg, minimum pricing, higher taxes that would have more substantial impact on consumption and harm.”

And that’s a sentiment that’s catching on around the globe. There’s been a huge drive towards transparency which has covered the alcohol industry as well as the wider food and beverage industry. Even the alcohol industry has accepted – and responded – to initiatives such as including nutritional information and calorie counts on alcohol to provide more information to consumers.

The idea of cancer warnings on alcohol is not new, but the US Surgeon General’s advisory propels this into a much more realistic proposition.

Whether cancer warnings are mandated or not, the real takeaway is the drive towards transparency.

“I think the US Surgeon General’s advisory is a huge turning point,” said Stockwell. “I have never encountered an alcohol policy issue around which there is so much public support and positive sentiment, especially towards fulfilling the consumer’s right to knowledge that affects their health.”