There’s been a lot of noise recently over some new research that has suddenly sprung into being about yoga. Not content to be a gym class that I actively avoid, yoga can apparently “Boost your mental health,” which sounds like a fantastic deal for the cheap price of a gym membership and one of those rubber mats.
There’s just one tiny issue.
There’s no good evidence that yoga is much use for health at all.
Mystery Exercise
Yoga is one of those things that has an amazing mystique surrounding it. Maybe it’s because it came from the depths of the Orient in days gone past. Perhaps the fact that instructors are often scantily-clothed gods and goddesses, who can twist and contort their body into sensual masterpieces that most of us can only dream about. It could be the almost hypnotic nature of the movements, slow and stately and yet powerful in their intensity.
Whatever the reason, we really love yoga. Almost every gym around offers a class, you can do it for free in the park with any number of groups; it’s become a virtually ubiquitous form of exercise.
Personally, I find it a bit boring, but there’s no accounting for taste.
But as you may have heard recently, yoga isn’t just a form of exercise. It’s also the cure for all your ills.
It’s magic.
Isn’t it?
Mind Over Matter
The recent media noise has been over findings presented at the American Psychological Association conference. In a conference symposium about yoga, a number of interesting studies about yoga were introduced to the scientific community. Researchers found, across a number of studies, that yoga was significantly associated with a very broad range of positive psychological associations, as well as a number of secondary health indicators.
It all sounds really rosy: all of the studies presented at this session were positive, with yoga doing things like helping veterans improve their mental health, improve depressive symptoms, and help with anxiety.
Conference Presentations Aren’t Publications
There’s an important point here that not a single journalist picked up on. These were conference presentations. What that means is that they weren’t peer-reviewed research, they weren’t published papers, they were just people presenting the findings of ongoing work.
Conference presentations are evidence in the same way that a buttered piece of bread is a beef sandwich. It’s half-done, preliminary, and often missing the meat. The studies might turn out to be incredibly important, but there’s always the chance that, when all the data is collected, the results will be negative anyway. It’s also important to remember that there are serious issues with pre-publication research, which is often much more biased than research that has been through peer-review. This is for a number of reasons, but primarily because you don’t get much information about these pre-published studies. Rather than a 3,000 word article, you get a 200-word abstract, which tells you very little about what the researchers did, and what they might have gotten wrong.
But that’s not all.
These studies, all eight of them, were tiny. Seriously tiny. The biggest one had about 80 participants. Many didn’t even have a control group. Regardless of how interesting your results are, if you only tested 23 people and didn’t have a control group, you’ve basically wasted your time because you literally can’t prove anything with that few people. So what happens when you look at large studies of yoga?
Yoga Is Exercise
The media has represented these studies as groundbreaking research, but it turns out that they aren’t, really. People have been looking at yoga as an intervention for conditions from lower back pain to depression for years. It turns out that, when you do a massive study with hundreds or even thousands of participants, yoga does…not so well. In fact, it is basically indistinguishable from any other form of light exercise. To put it another way, there’s no health difference between yoga and going for a walk in the park.
This is not at all surprising. Yoga is basically just another form of light exercise. There’s no physiological reason to expect that yoga has any actual benefit.
Press Releases And Naughty Academics
Now, journalists should’ve known that this wasn’t a big story. A few tiny unpublished studies presented at a conference? There are thousands of those every week, and many of them don’t even get finished for any number of reasons.
But that’s not the only problem here.
The press release that sparked this whole disaster has all the makings of dubious news. There’s very little mention of how tiny these studies are. Rather than looking at these studies through the lens of already published research — which has demonstrated that yoga is no better than any other form of exercise — the press release painted yoga as a new and innovative health intervention.
So yes, the journalists did the wrong thing. This isn’t news. When the studies get published, maybe — given their size, probably not — but right now there’s not much cause to care about them at all.
But the journalists were working on a flawed premise. Press releases are the main way that the media accesses scientific research, and when they are as misleading as this one was you end up with headlines that are, basically, crap.
Sadly, the headlines got it wrong. Yoga isn’t magical. It’s no more effective a health intervention than a nice walk. But that doesn’t make for very interesting headlines.
Gideon is a health nerd and epidemiologist (public health person) working in chronic disease. He writes about how simple health science really is, how we get it so wrong and why being terrified of that New Scary Study is usually a bad idea. If you want to get in contact, he is shamefully addicted to Twitter and would love to hear from you!
