You may have seen some surprising headlines the other day. Alcohol is “never good for people under 40”, according to the Guardian. The Daily mail reports that “people under 40 should avoid ALL alcohol for their health”, but… “a small glass of red can reduce the risk of heart disease, stroke and diabetes in older people”.
What is happening ? Alcohol is bad for you if you’re 39 but good for you if you’re 41? How can that mean anything?
Life begins at 40, apparently
These stories are based on an article published last week in the Lancet, a “meta-analysis” that aggregates the results of several previous studies. It is carried out by the Global Burden of Disease (GBD) team at the University of Washington, Seattle. And he indeed says that the evidence supports “stronger interventions, especially those tailored to young people”, to reduce alcohol consumption. In fact, the study’s lead author, Professor Emmanuela Gakidou, goes so far as to say in the press release that “our message is simple: young people shouldn’t drink, but older people can benefit from drinking. small amounts”.
But, in short, this is really research that lumps together a lot of weird stuff that probably shouldn’t be lumped together, gives advice that doesn’t help individuals or policy makers in any way, and – most bizarrely of all – implicitly assume that the only reason people drink alcohol is for the sake of their health. Sir David Spiegelhalter, Winton Professor for the Public Understanding of Risk at the University of Cambridge, told the I that “Everything is wrong with this. Absurd logic, inappropriate interpretation of results, completely unjustified policy recommendations.
To explain what the problem is, we need to look at why all these previous studies were talking about a protective effect. People who drink a lot and heavily are more likely to die in a given year than people who don’t drink at all: their “all-cause mortality” is higher. But, interestingly, people who drink only a small amount have lower all-cause mortality. On a graph, you see the risk first going down and then going up, in (sort of) the shape of a J. This “J-shaped curve” is a constant finding, and it’s usually associated with cardiovascular disease – heart failure, stroke, high blood pressure, that sort of thing.
So here it is, right? Is moderate drinking good for you? Well – probably, but it’s still controversial. The main objection is that in societies like Britain, people who don’t drink at all are unusual. Maybe a large percentage of them don’t drink because they have a medical reason not to. There is still an ongoing dispute in alcohol research about whether the J-shaped curve is real. “If you want to fight at an alcohol research conference, cardiovascular protection is the way to go,” says Colin Angus, an alcohol policy researcher at the University of Sheffield.
In fact, the GBD team lastalso widely reported, a major meta-analysis made headlines in 2018 for stating that the J-shaped curve was not real and concluding that there was no safe alcohol level for everyone.
This new article completely contradicts that – according to this, the J-shaped curve is real, but it’s much bigger for older people.
How they get to that conclusion, however, is really weird. What they do is unite everything the bad things alcohol can do – from heart disease and stroke, to cancer, liver disease and pancreatitis, to drink-driving injuries, to violence and suicide. And then they combine them into one big picture of risk.
And when you do that, you see that indeed the apparent protective effect of alcohol is much greater in older people than in younger people. But it’s extremely obvious, because – fortunately – young people don’t tend to die of cardiovascular disease, and in fact they don’t tend to die at all. But when they do Death is often from injury – and alcohol is often the cause, whether through violence, suicide, drunk driving or simply getting drunk.
So, naturally, the protective effect of alcohol seems much weaker, in relative terms, for younger people, because the thing that alcohol is supposed to protect against doesn’t happen very often. It’s a bit like complaining that shark repellent doesn’t work very well in Wolverhampton because people who use it there are no less likely to be attacked by sharks than people who don’t. not.
The study also assumes that all forms of alcohol consumption are equally bad, but it is clear that a 22-year-old who drinks one drink a day is much less likely to die in an accident than a man who drinks nothing for six days and then drinks seven glasses. Friday.
A theory of relativity
Stick with the analogy of sharks in the Midlands. Imagine you were just told that wearing red swim shorts increases your risk of being eaten by a shark by 50% at Wolverhampton Swimming and Fitness Center.
Wait, you might think. My risk of being eaten by a shark in Wolverhampton was quite low. Let’s say it was one in three billion before. If you increase that by 50%, it’s about one in 2 billion now. The relative risk increased a lot – 50%! – but the absolute risk, one in three billion, is tiny, so you don’t care that much. But if you don’t to know absolute risk, then you just see the scary statistic “Your risk has increased by 50%”.
This is why it is very important to report absolute risks. And in fact the Lancet own guidelines make it clear that articles should always give absolute risk, not just relative. But the GBD document does not.
Which is a shame, because – obviously – older people are at a much higher absolute risk of dying from alcohol-related problems. Basically, according to the GBD’s own data on its website, about 10 out of every 100,000 people between the ages of 20 and 24 die each year from alcohol-related causes. About 140 people between the ages of 70 and 74 do it. “For a youngster, a five percent increase in all cum is still all cum,” says Angus. “Whereas a 1% increase for an elderly person could be much larger. They have to compare the absolute risks, and they could have done that, but they just didn’t.
Of course, if a 22-year-old man dies, many more years of life are likely lost than if a 72-year-old man dies. But the newspaper does not mention it. And according to Angus, when you pull the GBD’s own data, it suggests that when you look at “disability-adjusted years of life lost (DALYs)” it’s inevitably younger, but it still doesn’t suggest that we should worry the under 40s more than the over 40s.
Here is an idea of the magnitude of the risk. In 2018, the last time the GBD published a meta-analysis, the Lancet press office compensated for the surveillance of scientists and gave absolute risks. Writing at the time, Spiegelhalter pointed out that 25,000 moderate drinkers – people who drink one drink a day – would have to be stopped from drinking in order to prevent a single serious health problem. Most of us would consider this level of risk “safe”.
A Jägerbomb a day keeps the doctor away
Picture the J-shaped curve. If you’re a non-drinker, you have some level of risk for various diseases we call “alcohol-related” – things like cancer and heart disease. (People get these things even if they don’t drink, of course.)
If you are a moderate As a drinker, your risk is slightly lower – either due to a genuine protective effect or due to confusion that non-drinkers are unhealthy for some reason.
And when you look at people who drink more, the risk goes up until it reaches, and then exceeds, the risk for non-drinkers.
The point where they meet is called the “non-drinker equivalent”. And that’s what the GBD considers the “safe level” of drinking: when your risk is the same as someone who doesn’t drink.
But we would never think in those terms for anything else we like: if we like scuba diving or skiing, we don’t think the level of safety is “how much dive could I do before my risks above that of someone who has never scuba dives”. Obviously, that would be zero, because scuba diving involves small but real risks. Instead, we think how many risks am I comfortable taking, for a given pleasure?
And you can’t do that if, first, you don’t recognize the absolute risks – I might be willing to trade a 1 in 10,000 chance of dying for a scuba diving vacation, for example – and second, recognize that These things have value to people, beyond whether or not they extend our lives.
“You would think the point of research like this is to help people make decisions about how much or whether to drink,” says Kevin McConway, professor emeritus of statistics at the Open University. “Or to help public health agencies make recommendations.” But this study – which again got a lot of attention in the press – does not help. “All he does is shout at people, ‘If you’re young, drinking is worse for you than not drinking.’ But people don’t drink because it’s good for them, they drink because they like it.
To be clear, drinking lots and lots of alcohol is not good for you. But the idea that there is no “safe level” of alcohol for young people implies a definition of the word “safe” that we wouldn’t use in any other context – there is no “safe level”. safe” to drive or eat peanuts. “It’s absurd logic,” says Spiegelhalter. “According to this thought, people should not do anything that is harmful to their health. Mountain bike? I shouldn’t do this. Should we even get out of bed? Life has risks.
#Dont #worry #drinking #safe