Why alcohol causes cancer
When you have a pint, a cocktail or a glass of wine, “the ethanol in the drink is broken down into acetaldehyde, a toxin that’s known to cause direct damage to the DNA in your body’s cells and cause carcinogenic mutations that can develop into cancer,” says Dr Helen Croker, the assistant director of research and policy at the WCRF. This is why “no amount of alcohol is considered safe to drink” by the WCRF and a number of other charities and health organisations.
Some cancers are much more closely linked to alcohol consumption than others, however. Colorectal, mouth, throat and liver cancers are all more likely to occur in people who drink alcohol, as “the alcohol is coming into contact with those tissues”, Croker explains. In 2020, 4% of all new cancer cases in Britain were associated with alcohol consumption. Colorectal cancer is the second most common cancer in British men, after prostate cancer.
Earlier this year, the WCRF advised that women should avoid drinking completely to prevent breast cancer, in the same way as they should avoid smoking. Men were advised merely to restrict their alcohol intake to prevent colorectal cancer, but “I do believe that the NHS and other health authorities should recommend that men follow the same advice as women and avoid alcohol completely”, says Dr Harriet Rumgay, an epidemiologist at the World Health Organisation (WHO).
Rates of this cancer are rising around the world, and while scientists are still working to determine what is driving the rise, it seems to be in part linked to dietary factors such as ultra-processed food or red meat consumption. Given that we all seem to be at a greater risk of bowel cancer these days, “now is a better time than ever to consider cutting down on how much alcohol you drink, as we know for certain that drinking alcohol increases your risk,” Rumgay says.
Two pints or more a day
Two pints of high-strength beer or cider; three pints of low-strength beer or cider; two large glasses of wine.
Men who drink two pints a day on average are at a 38% greater risk of developing colorectal cancer than men who don’t drink, says Dr Rumgay. Of 100 men who drink two pints a day, an extra two would develop colorectal cancer over the course of their lives, not taking into account factors such as weight, genetic risk and whether or not they smoke, compared with 100 men who don’t drink.
A pint of beer or cider can come in at two to three units, depending on its strength. Whichever kind you’re partial to, having more than four units a day on average puts men in the colorectal cancer danger zone, says Dr Croker. “Thirty grams of ethanol per day, or around four units, is where the significant risk threshold for colorectal cancer starts,” she says. In Britain there are more than 5000 new cancer cases a year attributable to alcohol consumption, in men alone, and half of those are cases of colorectal cancer.
If you are overweight or obese, or eat a diet high in processed food or red meat, however, your risk of colorectal cancer will be higher. “We are still trying to understand the causes of colorectal cancer, but we know that alcohol can raise your risk of other cancer types too, so for this reason we should advise that men avoid it altogether if they can,” says Rumgay.
It’s important to note that this is an average of four units a day. If you have a pint most days in the week, and have three or four on Fridays and Saturdays, then statistically speaking, you could well be at just as much risk as someone who drinks a smaller amount more regularly.
Once you start consuming more than two pints a day on average, your colorectal cancer risk really begins to spike. Men who drink 35 units of alcohol per week, equivalent to about 15 pints of low-strength lager, or 12 pints of high-strength beer or cider, have a 9% chance of developing colorectal cancer in their lifetimes. Of all colorectal cancer cases in the UK linked to drinking alcohol, two thirds are attributable to “the heaviest level of drinking” as mapped out by the WHO, Rumgay adds, at more than 53 units or around 18 pints a week.
Having two pints a day also raises your risk of developing mouth or throat cancer by 94%. This pattern of drinking also increases your risk of developing liver cancer by 84%. Of 100 men who drink two pints a day, an extra one would develop mouth or throat cancer over the course of his life, and one extra man would also develop liver cancer over the course of his life, compared with 100 men who don’t drink.
One pint every day
One pint of high-strength beer or cider; a pint and a half of low-strength beer or cider; one large glass of wine.
According to a 2022 report, men in Britain consume an average of 17.6 units a week, equivalent to between one and two pints a day. Men who drink one three-unit pint a day, on average, are at a 17% greater risk of developing colorectal cancer than men who don’t drink, says Dr Rumgay. Of 100 men who drink one pint a day, an extra one would develop colorectal cancer over the course of their lives, not taking into account factors such as weight, genetic risk and whether or not they smoke, compared with 100 men who don’t drink. Having one pint every day also raises your risk of developing mouth or throat cancer by 39%.
Unfortunately, your drink of choice does little to mitigate your risk of cancer, though 16% of men in Britain now choose red wine over other drinks because of the perceived health benefits, according to the WCRF’s new research. It is true that the plant chemicals in red wine can have positive effects on your health, “but they’re also present in other foods like grapes and tea and coffee, and when it comes to red wine, the negative impact on your health far outweighs any positives,” says Croker.
If you are going to have a pint every day, sticking to lower-strength or non-alcoholic beers is a wiser bet, “as this reduces the amount of alcohol you’re consuming overall,” Rumgay advises.
Drinking only at the weekend
Eight pints of high-strength beer or cider; 12 pints of low-strength beer or cider; eight large glasses of wine.
Men who drink eight three-unit pints over the course of a weekend, on average, are at a 20% greater risk of developing colorectal cancer than men who don’t drink, says Rumgay. Of 100 men who drink eight pints over a weekend, an extra one would develop colorectal cancer over the course of his life, not taking into account factors such as weight, genetic risk and smoking, compared with 100 men who don’t drink. This drinking pattern also leads to a 46% increased risk of mouth or throat cancer.
Men who drink four three-unit pints over the course of a weekend, meanwhile, are not at a significantly greater risk of developing colorectal cancer than men who don’t drink, says Dr Rumgay. This drinking pattern does lead to a 21% increased risk of mouth or throat cancer, however.
Alcohol can also cause an inflammatory response in your body, another reason that it has been linked to cancer incidence. Keeping your alcohol consumption to the weekend, but at lower levels, or simply having sober days in between drinking days, can help to mitigate the danger caused by consuming alcohol.
14 units (five-seven pints) in a week
Five pints of high-strength beer or cider; seven pints of low-strength beer or cider; five large glasses of wine.
Fourteen units of alcohol is the most that you can drink in a week, as a man, without significantly raising your risk of developing colorectal cancer. Men who stick to this limit have a 6.5% lifetime risk of developing colorectal cancer, the same as non-drinking men, compared with the lifetime risk for men who have two pints a day on average, which is around 9%. This level of drinking still significantly increases your risk of mouth or throat cancer, however. Men who drink 14 units a week are at a 24% greater risk of developing mouth or throat cancer.
According to the NHS, having fewer than 14 units per week as a man means that your drinking is “low-risk”. The reality, however, is that you begin to up your risk of cancer when you drink more than a unit every day on average, says Croker. “And one unit doesn’t mean one pint,” she adds. Half a pint of a weak beer or cider is all that’s needed to meet this threshold. Some research shows that drinking two units a day, or 14 a week, can increase your risk of any alcohol-related cancer by as much as 15%.
A third of men in Britain drink more than 14 units a week, according to the NHS. Rumgay suggests that you track how much alcohol you are actually consuming each week, as “it can be surprisingly easy to go over 14 units without realising”, she says.
One pint a few times a week
Two pints of high-strength beer or cider; three pints of low-strength beer or cider; two large glasses of wine.
Six units of alcohol – under one unit per day – is the most that you can drink in a week, as a man, without significantly increasing your risk of liver cancer. Doing so will still increase your risk of mouth or throat cancer, however, by 13%, according to Rumgay’s estimates. If you smoke and drink at the same time, “there is lots of evidence to say that you are making both activities more dangerous in terms of your cancer risk,” Rumgay says.
Sticking to fewer than one unit per day on average is much safer when it comes to cancer risk than exceeding this limit, however, “as your risk of developing any cancer increases with each unit you drink per day,” says Croker. That means having no more than two pints of high-strength beer or cider or three pints of low-strength beer or cider in a week. Again, Rumgay recommends keeping a close eye on your units wherever possible, and choosing lower-strength drinks.
One pint a week
The effects of drinking regularly but having fewer than one unit a day on average “are less well understood”, says Croker. We do know, however, that while drinking this much will not significantly increase your risk of colorectal or liver cancer, having one three-unit pint every week, on average, will increase your risk of mouth cancer by 5%, says Rumgay.
Some 57% of British men drink alcohol at least once a week, according to an NHS survey. “Reducing your alcohol consumption by swapping out your pint for a non-alcoholic drink would be a very good move for your health, if it means that it allows you to keep socialising and enjoying yourself without consuming more alcohol,” Rumgay says.
One pint a few times a year
Having one three-unit pint every few weeks, on average, would increase your risk of mouth or throat cancer by 4%, according to Rumgay. Having a pint every few months, meanwhile, would increase your risk of mouth or throat cancer by just 0.4%. Neither drinking pattern would cause a significant increase in your risk of colorectal or liver cancer.
So while no amount of drinking is completely safe, you may be pleased to know that celebrating with a pint or few a couple of weekends a year will up your cancer risk only marginally.
What these statistics mean
The following risk estimates have been provided by Rumgay. They are based on the lifetime risk of different cancers among men who don’t drink at all. For colorectal cancer in men, this is 6.5%, while the lifetime risk of mouth or throat cancer is 0.8%, and the lifetime risk of liver cancer is also 0.8%.
This combines with the additional risk posed by how many grams of alcohol you drink per day on average to give your “absolute risk”, not taking into account your health in general. Where we talk about a number of men out of 100 who will develop one of these cancers in their lifetime, we have rounded it to the nearest whole number.
There are many other factors that increase a man’s risk of cancer, such as smoking, being overweight, or having a family history of the disease. All these factors mean that you may be at an increased or decreased risk from drinking compared with other men who consume a similar amount of alcohol to you.
These figures compare the “relative risk” of different groups of men and don’t reflect your personal risk as a whole. For this reason, “if you’re young, maintain a healthy weight and exercise regularly, then the risk posed to you by drinking alcohol is lower, but any amount is still dangerous,” Dr Rumgay says.
How to say no to another drink
By Professor Richard Cooke
Men find it much harder than women to say no to “another one”. The WCRF’s recent survey found that a quarter of men worry about being judged or being seen as boring when they say no to alcohol, and one in five of us has called in sick the day after a weekday night out as we can’t make it into work (compared with just one in 10 women).
We also know that men rely on excuses more than women – half of men have made an excuse not to drink, compared with 40% of women. My work as a health psychologist shows that coming up with a reason that’s personal to you when you’re turning down a drink is the best way to stick to your guns.
Work out why you’re doing it
Decide why it is that you want to drink a bit less – whether it’s to reduce your cancer risk or feel clearer-headed on Sunday morning. (Tip: avoid saying something such as you want to save money or that you’re trying to lose weight, because research suggests that these reasons are quite easy to counteract, by other people buying you a drink, or saying something such as, “The diet can wait!”) Instead, choose something that’s specific to you, something that you care about, as your reason to reduce your drinking.
Explain it to people confidently
Evidence suggests that when you explain clearly and confidently why you don’t want another pint, people are more likely to accept your explanation and less likely to push you to drink. Just over 10% of men choose to say that they are trying to get fitter or need to avoid a hangover to make it to the gym the next day, and for them, this seems to work well.
Try different moderation techniques
There are different ways to drink less without suffering the feeling of missing out. One is to try low-and-no drinks that look very similar to alcoholic drinks, which can be especially helpful if you struggle with peer pressure (though the jury is out on whether these may increase drinking in the long term). Another is bookending: starting and ending the night with soft drinks and having alcoholic drinks in the middle. Giving a few a go and seeing what works for you can be a big help.