Looking back on my 25 years in medicine, one of my earliest realisations was Australia’s penchant for alcohol.
A routine part of taking a patient’s “social” (not medical) history was, “How much do you drink?”
The standard answer: not much. Except the story didn’t match when the patient was found unconscious, and the tell-tale signs of alcoholic liver disease were evident.
I once had to ask a patient how much wine was in a cask (an Australian invention; between two and five litres) and then incredulously ask if he drank all of it in a day.
“It isn’t hard, love,” he replied.
About 77% of Australians drink alcohol, with more than a quarter of adults exceeding safe drinking guidelines, which advise no more than 10 standard drinks a week and no more than four standard drinks a day. (A standard drink contains 10g of alcohol; many common drinks contain more than one standard serve.) The Australian per capita consumption of alcohol of 10.6 L surpasses the global average of 6.4L.
Oncologists have long regarded alcohol and cancer as partners in crime but have not often said so, perhaps loath to question an entrenched part of the culture and be labelled a killjoy.
But in recently publicising alcohol as a carcinogen, I couldn’t help noticing that the US surgeon general leaned on a familiar Australian tale of harm.
The 45 and Up study enrolled over 267,000 Australian participants (226,000 of whom were included for analysis). It found that increasing levels of alcohol intake were associated with increased risk of cancers of the upper aerodigestive tract, liver, colon and rectum and breast. Compared to people who drank less than one drink per week, those consuming more than 14 drinks per week had a higher absolute risk of a cancer diagnosis over their lifetime. The risk was 4.4% for men and 5.4% for women.
There was also a suggestion (notably for breast cancer) that not only the amount but also the pattern of drinking increased the risk of cancer, possibly because acute and heavy alcohol exposure affects susceptible tissues differently than chronic exposure.
Given that 16% of Australians are estimated to consume more than two standard drinks a day on average, these figures are of public health significance.
I have not met a patient who doesn’t know that smoking causes cancer, but it took decades after the publication of that incontrovertible link for the knowledge to saturate public awareness.
How does alcohol cause cancer? It can damage the oral cavity via direct contact and makes it easier for other carcinogens to be absorbed. Its byproduct of acetaldehyde can cause irreversible DNA damage, potentially setting in train a variety of cancers. And it can increase circulating levels of estrogen implicated in breast cancer.
The surgeon general is right to lament the low public awareness of alcohol being a carcinogen. Reversing this would be arduous enough on its own without also having to combat the common belief that “a bit” of alcohol is good for the heart.
Contrary to popular opinion, alcohol is not good for the heart and is a major risk factor for common forms of cardiovascular disease including hypertension, atrial fibrillation and heart failure.
More recent research has overturned the past opinion based on observational studies and studies funded by the alcohol industry. The World Heart Federation alleges that “this interference by the alcohol industry closely reflects the universally vilified activities of tobacco companies”.
The WHO and many countries including Britain and Canada now warn that there is no safe level of drinking. South Korea labels alcohol as causing liver cancer and, from next year, all alcohol sold in Ireland will carry a health warning about the direct link between alcohol and cancers.
But in Australia, where a former prime minister is still remembered for his drinking habit, who will tell the four out of five Australians who don’t know that alcohol is a carcinogen?
It is unlikely to be oncologists, who are so pressed keeping pace with modern treatments and their complications that they can’t address significant public health concerns, including alcohol and obesity, which is now thought to contribute to as much as 40% of the cancer burden.
But this “other stuff” matters, which is why we need schools, parents, public health agencies and governments to step up.
The days are gone when people were advised to start drinking for their health. (Yes, I remember them.)
However, I won’t be telling anyone that they should never touch alcohol because when it comes to health, exaggeration is the enemy of credibility.
I will advise the heaviest drinkers at the greatest risk of cancer to cut down and point them to services that can help them change long-term behaviour.
I would ask people in the regular habit of downing a glass or two of wine while cooking, or after the kids have gone to bed, to reconsider. Replace mindless drinking with mindful drinking.
And to those who enjoy a drink every now and then with friends and find bonhomie and connection in it, I would say: carry on with the same care, because the dangers of loneliness could be just as malignant.
Ranjana Srivastava is an Australian oncologist, award-winning author and Fulbright scholar. Her latest book is called A Better Death
