The Australian NHRMC (National Health Research Medical Council) recently released its updated guidelines for safe alcohol consumption, surprising many of us with its highly conservative recommendations which can very briefly be summarised as:
1. No more than two standard drinks for men and women each day (half the previous recommendation for men and one less for women)
2. No more than four standard drinks on any single occasion
3. No alcohol for pregnant or breastfeeding women or for those under 18 years of age.
I’ll briefly explain their reasoning in reverse order. Basically, for point 3, they have no actual evidence for harm or safety when it comes to low-moderate alcohol consumption, so they decided to err on the side of caution. In the text of their 140-odd page report they admit that there is probably little to no risk for people in these categories drinking small amounts of alcohol occasionally. They also state, quite frankly, that because they see themselves as a health advisory body, they are deliberately being conservative; not that you’ll get that nuance when the media delivers you the mini version you’ll hear on TV or read in the newspaper. The NHRMC also justifies its stance by quoting a poll reporting most people being in favour of such a recommendation. Good science, huh?
Regarding point 2 – safe alcohol limit on any single occasion – fear not; you’re not actually damaging your health by exceeding four standard drinks. No, the reasoning stems from emergency department data, showing the risk and severity of injury in ED attendees rises proportionally to alcohol intake. The problem of sample bias was clearly not factored in to their decision – one could postulate, for instance, that ED patients are more likely to be those who have consumed alcohol in potentially riskier situations – nightclubs, certain types of parties, whilst driving etc. But again, all you’ll likely hear is a blanket “no more than four” soundbite.
To the first point now: no more than two drinks/day. What about those Mediterraneans, you ask, who put away at least twice that every day? You’re right, of course – all-cause mortality is actually slightly lower in regular moderate drinkers (maybe not significantly so, but it certainly ain’t higher). It seems that the NHRMC is basing this recommendation on a study by Corrao in 1999, which I can’t be bothered paying the thirty dollars to access. Fortunately, Junkfood Science (see here and here) has analysed some of the other research on this topic for us, and in short, low-moderate alcohol consumption does not statistically alter the rates of any cancer. There are small protective trends for some and small harmful trends for others (which you would expect to find in epidemiological studies of this nature, where the chances of bias and confounding factors affecting the results are huge). The cancers supposedly increased by alcohol are those of the upper digestive and airway tracts. I can only wonder if the Corrao study adjusted for the possible higher rates of smoking amongst drinkers; certainly other studies purporting similar results did not (see first link above).
The NHRMC isn’t the only health council out there making such recommendations. I for one will be keeping my feelers out for more details on their evidence for such claims, especially the cancer links. But at this point, I remain sceptical.