Canada’s health authorities have this week reduced guidelines on how much alcohol is safe to drink, suggesting that any more than two standard drinks a week could increase risk of cancer.
This has fallen from “10 standard drinks a week for women, with no more than two drinks a day most days, or 15 standard drinks a week for men” in its 2011 guidelines.
Australian guidelines, which were updated in 2020, suggest “healthy men and women should drink no more than 10 standard drinks a week and no more than 4 standard drinks on any one day”.
“The Australian guidelines were based around a risk threshold of someone having a 1 in 100 chance of dying of an alcohol-related condition,” Curtin University Associate Professor Michael Livingston told Cosmos. “It was based on the best epidemiology and modelling that we could access, and that came out at around 10 standard drinks per week for both men and women.”
“The underlying evidence base hasn’t dramatically changed since the Australian guidelines were prepared, but the Australian committee just chose a slightly different way of picking a threshold level than the Canadian committee.
“In all cases, committees are basically picking a somewhat arbitrary point on a risk curve for the simple guidelines they put out – whether you set your threshold at 0, or 1 in 100, or 1 in 20, it will influence what your final guidelines look like.”
Canada’s standard drink and an Australia’s standard drink are slightly different. Canadians have 13.45 grams of pure alcohol in one standard drink, whereas Australians have 10 grams. However, even with the figures adjusted, Australia’s guidelines allow for over four times as much alcohol as Canada’s.
Livingston points out that some risks like cancers begin at very low levels of drinking, while others such as liver disease are almost negligible at a few drinks a week.
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“Alcohol contributes to over 5000 deaths per year. Around 1500 are based on solely alcohol attributable deaths – for things like alcoholic liver cirrhosis and alcohol poisoning and a further 4000 or so where alcohol is a contributing cause – i.e. some proportion of cancer deaths and heart disease deaths,” he says
The Canadian guidelines explain that three to six standard drinks per week increases risk of developing several types of cancer, including breast and colon cancer. Seven standard drinks or more per week (which is equivalent to almost 10 Australian standard drinks) the risk of heart disease or stroke increases significantly.
“There’s lots of evidence that lowering the level of per-capita alcohol consumption means lowering the number of people drinking heavily and lowering the harms from alcohol,” he adds.
Professor Simone Pettigrew, the George Institute Program Director, Health Promotion and Behaviour Change agrees.
“Even the 2009 Australian alcohol guidelines stated, ‘Every drinking occasion contributes to the lifetime risk of harm from alcohol’. Alcohol is a known toxin and carcinogen – we have just done a poor job of making the community aware of this to date,” she told Cosmos.
“We’ve got these massive meta-analyses … and the evidence is just getting clearer and clearer that it’s a linear relationship. It’s a carcinogen. Every drinking occasion is a risky occasion and people just need to minimise or entirely eradicate the alcohol consumption.”
“But in a culture where alcohol comes along pretty much every event, that’s a really, really hard message.”
However, Pettigrew explains the news isn’t all doom and gloom. Australia’s consumption of alcohol is less than other countries such as the UK, France and Spain and our alcoholic drinks per capita has also been decreasing over the past few decades.
“Our guidelines are actually pretty good on the international scene. There are definitely a lot of countries with much worse guidelines, still allowing a lot more intake. And then there are others like Canada that are more stringent,” says Pettigrew.
“One of the things they take into consideration when developing and disseminating guidelines is you don’t want people to think it’s so unrealistic that they ignore it altogether.” “Our guidelines do a pretty good job of that, but I think we will see in the future that the guidelines become more and more stringent, along the lines of what we’ve seen in Canada.”