The Decibel - Will alcohol have cancer warnings like cigarettes?

Episode Date: January 13, 2025

Dry January – when people decide to consume no alcohol – is a common new year resolution for many. But this month, the U.S. Surgeon General gave the public another reason to take stock of their drinking habits. They recommended that warning labels of cancer risks should be placed on alcohol containers, akin to the labelling on cigarette packaging. Dr. Adam Sherk, senior scientist and Special Policy Advisor at the Canadian Centre in Substance Use and Addiction joins the podcast to explain the push for warnings on alcohol and what the latest science tells us about the definitive links between alcohol and a number of cancers.Questions? Comments? Ideas? Email us at [e-mail]

For some of us, the start of the new year means Dry January, going alcohol free for the month after the holidays. Attention all my party people, night lifers, ravers, musicians, anyone that's thinking about Dry January, here's three tips that are going to help you be successful. How are you getting on? How are you finding it? Are you fed up? Are you loving it?

Are you feeling amazing? What are the physical things that you're noticing? Happy Dry January. Two years ago I did Dry January for the first time and today I'm two years alcohol free. Dry January, I'm so proud of you. If you're doing it, let's stretch it into February. But even if you're not doing Dry January, a lot of people are reassessing their drinking habits. That's because earlier this month, the U.S. Surgeon General released an advisory about the cancer risks of alcohol. He recommended putting warning labels on bottles.

So today, we're talking to Dr. Adam Scherk, senior scientist and special policy advisor at the Canadian Centre on Substance Use and Addiction. It's a non-governmental organization funded by Health Canada, and it designed Canada's drinking guidelines. Dr. Schirk will explain the connection between alcohol and cancer, what we know about the effectiveness of labels on bottles, and how many drinks a week could put our health at risk. I'm Maynika Raman-Wilms and this is The Decibel from the Globe and Mail.

Dr. Shirk, thank you so much for being here. Thanks for having me today. So the U.S. Surgeon General recently made a recommendation that alcoholic drinks should have labels highlighting their cancer risk. I guess what went through your mind when you heard that news? Right, I have to say it was a welcome surprise. Something that we struggle with in the alcohol and public health field is this knowledge, this education idea, particularly around alcohol and cancer. And so both in the US and in Canada, only about 50% or around half of drinkers know

that alcohol causes cancer. And so a high profile report like this from the US Surgeon General that, you know, kind of states unequivocally that alcohol causes cancer, which we've known for many years, and then further calls for cancer warning labels on alcoholic beverages was really welcome news for us. That's an astounding number. 50% of people don't realize that there is a link between alcohol and cancer.

I mean, it's not something that we talk about that frequently. Why do you think there's such a gap in knowledge there? Yeah, in fact, the alcohol cancer risk has been known in the scientific community for some time. In the late 80s, 1988, the World Health Organization classified alcoholic beverages as a carcinogen. And so it's actually something that we've known for over three decades now. But that knowledge among consumers and the everyday public, it kind of lags behind. And so it is kind of interesting to reflect on why that would be. Some parallels here with tobacco which took a little while for everyone to understand the cancer risk. Cancer

risk isn't quite as high with alcohol so I don't want to overstate it but it is alcohol is one of the three leading behavioral risk factors for cancer. The other being tobacco I I believe, and obesity. Is that correct? Yeah, that's correct. And I guess we should be clear. So this is an advisory from the Surgeon General, a recommendation, essentially.

This is not law. But how important is a recommendation like this in actually shaping law? Right, it can have a lot of importance. And so a good example to think about is in 1964, the US Surgeon General, this same office, released the first report on tobacco and human health.

Really let people know about the lung cancer risk of smoking. And this had a huge impact, both in the US and then eventually around the world. A lot of conversations among the public, in the media, the US Congress actually ended up passing just the very next year in 1965, a law requiring a health warning label on cigarettes. And so something, an advisory like this that comes out of a high level office,

it can have quite a big impact on law. So let me just quickly ask you then, when we're talking about current alcohol labels, what are the rules for the US and Canada? Yeah, great question. I'll start with Canada. As many of us know who drink alcohol, buy alcohol, see alcohol containers, there pretty much are no rules.

So there are very few labeling requirements for alcoholic beverages. Alcohol is specifically exempt from having a nutrition facts label or virtually any other information about health, about calories. None of that is present. And so if we think about an alcohol container, we're only going to see two things that are required. The size of the container in milliliters or liters and we're going to see that ABV, the alcohol by volume percentage, 5.0 percent or 12.0 percent for a wine. So it's not a lot of information, Monica, I have to say. You know, it's difficult for people to know how much alcohol they're drinking, certainly to know how many calories they're getting

from what they're drinking. And then there's definitely no information about cancer risk, for example. And just very briefly, how does the US label alcoholic beverages? There is a small warning from the US Surgeon General on alcoholic beverage containers. Quite hard to see small print. But what that warning does,

it talks about two things specifically. The first is operating heavy machinery and driving, you know, so we shouldn't do that sort of thing when we're drunk. And then the second one is an alcohol and pregnancy risk. So it's very specific. It's about these two lanes and it doesn't really talk about the kind of broader health effects that alcohol has. And in, and it doesn't really talk about the kind of broader health

effects that alcohol has, and in particular, it doesn't mention cancer. Okay. Well, let's talk about this new recommendation then about highlighting the cancer risk specifically of alcohol. What does the current science say, Adam, about the connection really between alcohol and cancer? It's been known in the scientific community that alcohol causes cancer. The way that it does this in the alcoholic beverages that we drink, the alcohol in there

is ethanol. But ethanol, the chemical compound ethanol, is a carcinogen. It's a group one carcinogen, as labeled by the World Health Organization. The group one kind of sounds scary. What it means is it's definitively carcinogenic. So it's proven beyond a reasonable doubt that ethanol is a carcinogen. And then further, as it goes through our digestive systems, our body's breaking it down into other compounds. And the first metabolite of ethanol is called acid aldehyde. Acid aldehyde is also a group one carcinogen.

To be a carcinogen, both ethanol and acid aldehyde, what they're doing is they're coming into contact with our cells and they're degrading them, specifically with a cancer risk. They are making it more likely that the cell will mutate in such a way that its replication will become out of control, which is what cancer is. And you mentioned there's a few different cancers that are directly connected then to alcohol. Adam, which cancers are those?

Yeah, there's at least six types of cancer that are caused by alcohol. So the first one kind of starts where we drink it from its mouth and oral cavity cancer and then laryngeal cancer, which is our larynx, our voice box. And then we go down through, we're kind of tracing it as it follows through our body, esophageal cancer on its way to the stomach. Stomach is currently kind of classified as being likely caused by alcohol so it's not one of the ones that I'm talking about today because it hasn't reached that definitive level. The fourth one is

colorectal cancer, liver cancer, and then also breast cancer. So it's interesting so yeah you kind of follow through the digestive track, but then I'm wondering about breast cancer because this seems a little bit different. Do we know how alcohol affects that? We do. So with the breast cancer risk, yeah, it's not part of the digestive system. So alcohol can also modify our hormone levels, and in particular around the breast cancer risk, what alcohol consumption can do, it increases estrogen levels in females. And that increased estrogen level increases the risk of breast cancer.

The Surgeon General's report says that alcohol is the third leading preventable cause of cancer in the U.S. behind smoking and obesity. You mentioned this a little bit earlier. Contributing to about 100,000 cancer cases and 20,000 deaths per year. Do we know how those numbers compare to Canada? We do, yeah. Alcohol causes almost 4,000 cancer deaths per year and so you know so there's 4,000 deaths in Canada, 20,000 deaths in the US which is what you mentioned. So the US is about nine times bigger in terms of population than Canada is. And so our rates are, our alcohol and cancer death rates are a little bit higher, right, than the US's would be.

These days we do associate smoking as being a cancer risk. We kind of, we know this now, right? I guess I wonder about the health risk of alcohol compared with smoking. Are we are we able to kind of look at those two, Adam? We are. A few years ago did a scientific article with some authors that CAMH, the Center for Addiction and Mental Health in Toronto, and we specifically looked at equivalencies between alcoholic drinks and cigarettes. As compared to one drink a day, how much would one cigarette per day kind of harm us in terms of mortality risk?

So when we did that study to look at alcohol and tobacco equivalencies, what we found that was that at two drinks per day, as compared to two cigarettes per day, the two drinks per day carried about 70% the mortality risk of two cigarettes per day, the two drinks per day carried about 70% the mortality risk of two cigarettes per day. And so for, you know, just thinking about alcohol as compared to tobacco, it's not exactly one to one, but if you're going to have that drink, it's about 70% the mortality risk of a cigarette. Now, I will say that when someone's a smoker they tend to

have a lot more you know kind of units of cigarettes per day than they do for drinks. So that's something to keep in mind you know there wouldn't be exactly one-to-one in that sense either. But a drink you know has a bit less but pretty comparable mortality risk to a cigarette. Yeah so so 70%. That's interesting that we can actually quantify it to that level. This makes me think we should talk about the current recommendations then about how much Canadians should drink.

What are the current recommendations? Just pretty much exactly two years ago in 2023, my center, the Canadian Center for Substance Use and Addiction, released a report which is named Canada's Guidance on Alcohol and Health. It was mandated by Health Canada to update previous national advice that came out in 2011. And so that report, Canada's Guidance on Alcohol and Health, its main recommendation is kind of following along what we've been mostly discussing today,

which is that people learn more about alcohol and health. We did further state a spectrum of risk, a gradient of risk, where there were four different risk zones. And those risk zones are, there's a no-risk risk zone, which is associated with not drinking alcohol. There's a low risk risk zone, that's one to two drinks per week. A moderate risk zone, that's three to six drinks per week.

And then a higher risk zone, that's seven or more drinks per week. One drink or more per day on average. So this is important because I think a lot of people in their head might have this idea of, you know, max two drinks a day for women, three drinks a day for men, which is actually on the Health Canada guidelines. So where are those numbers from, Adam? That advice that you mentioned, Menaka, the two drinks per day for females and three drinks per day for males, that came out in

2011. So that was also released by my center, the Canadian Center on Substance Use and Addiction. So that was also released by my center, the Canadian Center on Substance Use and Addiction, but we have since updated that advice. And so when that came out, kind of kicked off a national conversation about alcohol, whether we like it or not, back in 2023. And so especially the low risk zone, it was revised downwards quite a lot, which is another thing that the US Surgeon General called for in his report, the revision of US guidelines downwards. And so that revision downward, it's maybe a little hard for people to hear. We thought it was important to show this gradient of risk, the spectrum of risk, so that people can situate themselves within that gradient, understand

how the risk evolves as we drink more and kind of make decisions, based on their own drinking patterns, on their own lives about how much risk they're willing to take on, if any. We'll be right back. We actually have tried labels on alcohol in Canada before. There was a bit of an experiment that actually your organization was involved in with alcohol labels in Yukon a few years ago. So Adam, can you tell me about that and how it went?

So this study was called the Northern Territory Alcohol Label Study. And it was done by Dr. Ern Hoben at Public Health Ontario and Dr. Tim Stockwell at the University of Victoria. What happened in the ENTEL study was in Yukon, we were actually able to place three alcohol warning labels on containers. And so some of our researchers went up there and physically placed the labels on every alcohol container in the Whitehorse Liquor Store. One of them was a cancer warning label.

One of them was a standard drink label that kind of showed people how much alcohol was in, in some standard size bottles of alcohol. And the third one was the low-risk drinking guidelines, the previous ones, which were in effect at that time. The purpose of the study was to find out if this changed consumer education and knowledge. Would people going to the store, buying alcohol, seeing these labels, be more likely to know that alcohol causes cancer,

be more likely to understand what a standard drink is so they can track their alcohol intake, be more likely to know what the lowest drinking guidelines are so that they can stay within them if they choose. Tangential to that, we were interested in if these alcohol labels reduced alcohol sales. At the end of the study, there was a suite of about 12 scientific articles that came out around this study, and the results were quite conclusive.

And so in terms of that educational and awareness piece, the labels definitely had a very strong effect on increased acknowledge among consumers about the cancer risk, about standard drink quantities, and about lower drinking guidelines. So that was really positive. Another thing that even we were surprised about when it came out was we did an analysis regarding the effect on alcohol sales of those alcohol labels. And it was actually found that the alcohol labels brought down alcohol sales by about 6%, which is a pretty substantial amount, and that would have an important health benefit for the people of Yukon if those labels continued

to be on there, if that was a robust finding where the 6% decrease continued through time. So it sounds like from this situation, these labels actually seem to be quite effective in at least increasing people's awareness of what they were consuming. What happened after that though, Adam? Because we don't actually still have

these labels on those bottles. So it was a study and then there was no particular plan for them to stay on the bottles moving forward. But what happened during the study, Menneke, actually, is that the study was paused after about two months. As researchers, we weren't exactly knowing what was going on, but then a press conference was held by the minister responsible for Yukon Liquor Corporation in Yukon. What the minister said was that they were choosing

to remove the cancer warning labels because of the threat of prolonged litigation. And so the study then restarted, but without the cancer warning label, with the other two labels intact, the standard drink label and the low risk drinking guidelines label, but the cancer warning label was no longer in the rotation.

Huh. It's really interesting when we're talking about this kind of labeling on alcohol bottles because I think about cigarettes, this is something we've had warning labels on for more than three decades in Canada now. We even have warnings on individual cigarettes these days. So I guess why such a focus on cigarette labels and the warnings there, but really kind of a lack of warnings on alcohol?

It is probably one of the most interesting things is to reflect on the differential treatment of tobacco and alcohol, maybe particularly around cancer risk. And so like you said, we label every single cigarette, the packages of course are kind of like famously dramatic, right? Like they're very effective at preventing people from beginning smoking but they're quite, you know, visually you'll be taken aback by them. Yeah, they have very visual representations, right, of liver cancer, all kinds of things that you can develop with

smoking, yeah. Right, yeah, exactly right. And then another thing is pricing. So very high taxes on tobacco. I have this picture in a presentation that I do where it has a warning label on a cigarette package, and then it shows kind of a typical alcohol container, which is like a lovely vineyard or like an artsy design

on a beer can. And so they're just so different. Given that they're both kind of in the top three of behavioral risk factors for cancer, it is odd that they are treated so differently. If we're alcohol drinkers and we don't know about the alcohol cancer risk, that's a big failure. That's a big kind of abdication of the duty to warn us about potential health impacts that could come from consuming alcohol. A lot of this sounds like there has to be government action then to make some of these changes.

So I guess what kind of action would be helpful at the government level in Canada when it comes to giving people more information about the risks of drinking? I think that it kind of goes with the US Surgeon General's report. Alcohol labeling is a good one. And so the US Surgeon General's report called specifically for cancer warning label on alcoholic beverages. There is a bill in the Canadian Senate, which is about alcohol and cancer warning labels. So I think that this would help, you know, particularly because the awareness of the alcohol cancer risk is so low in Canada, less than 50%. We need to do something to increase that awareness because of the this quite high level of risk. And so warning labels of some kind that provide us

some information on alcoholic beverages would be very impactful, very helpful. So Adam, just lastly here before I go, I think a lot of people are probably listening and thinking, well, this sounds important. But of course, at the same time, I enjoy having a couple of drinks with friends or having a glass of wine with dinner

People don't necessarily always want to give that up completely, right? So what would you say to them how people are trying to find the right balance here? How should they be thinking about this something that came out of Canada's guidance on alcohol and health? We kind of have this this overall flavor of less is more or less is better And so if we drink, we're not saying to drive that down to none. What we are saying is that the more that we drink, the higher the risk,

which is the same with lots of different behaviors that carry risk. And so we kind of have to, first of all, understand what the risks of drinking alcohol are, and then make a choice for ourselves, you know each person about where we want to fall on that gradient of risk. Of course when it comes to health there's many different aspects of our health. Alcohol is just one component, I realize that. The more information though the better that we have I think Menaka. So in terms of alcohol

warning labels this could be important to increase public awareness. And we would just, all of us would have more information at our disposal to think about our drinking, to be thoughtful about our drinking, to figure out where on the risk gradient we would want to fall. This was very interesting. Thank you so much for taking the time to be here today. Thanks so much for having me. That's it for today. I'm Maynika Ramon-Wilms. This episode was edited and mixed by Kevin Sexton.

Our producers are Madeleine White, Michal Stein, and Allie Graham. David Crosby edits the show. Adrian Chung is our senior producer, and Matt Frainer is our managing editor. Thanks so much for listening, and I'll talk to you soon.