Saturday, 18 August 2012

Using or researching tai chi?

People who love tai chi continue to practice it because they derive some benefit for themselves personally. I too fundamentally believe that tai chi is good for you. What I'm not necessarily convinced of is that tai chi is the most-ultimate-form-of exercise-ever-which-improves-every-aspect-of-your-health-and-life (everyone needs a balance exercise diet after all). Unfortunately most reporting of "scientific tai chi research" implicitly (usually through ignorance and good intentions) tries to claim/hint at the latter, rather than the former.

What it boils down to, is that you need to compare apples with apples. Unfortunately, trying to conduct tai chi research using this methodology (i.e. double-blind trials) is extremely hard if not impossible. So we generally find people comparing apples with oranges. Although the actual researchers no doubt understand this (and are in fact asking some quite specific question), as the reporting makes its way out into the wider world, these caveats are slowly lost. Eventually down the reporting chain this science (as it is branded) is reported as if it had compared apples to apples. The result is that tai chi (and in the same way alternative health) people at the end of the chain, feel as if they have scientific proof to backup their beliefs. These people then become aggrieved as they feel that the "stupid western doctors" are ignoring the science. The reality is that very little, if any, apples with apples studies have been conducted, so there's no point holding up an orange to claim that it has.

So let me explain by way of example, using two bits of tai chi research that I have seen publicised in the last week or two by respectable sources.

First of all that tai chi helps to treat chronic obstructive pulmonary disease (COPD). In summary, it seems that it does and I am happy about that, but look closely at the setup of the study and you find:
"The research team worked with 42 people with COPD with incurable lung diseases including emphysema and chronic bronchitis. Half the group attended Tai Chi lessons twice a week and practised at home, and the other half followed their usual medical management, which did not include exercise."
Did you notice that? The control group did not do any exercise at all! Surely then the headline result should be that exercise helps treat people with COPD and in this case, tai chi just happens to be a suitable form of exercise for them to undertake? I think pretty much the whole world is in agreement that doing exercise helps to improve your health, which is what this article should be saying. Exercise is good. Tai chi is exercise so that ticks the box. It may not be the best form exercise though. Perhaps yoga would be better? Maybe swimming would be better? Maybe an individually tailored programme including all sorts of different forms of exercise would be better? This study can say nothing about the marginal benefit of tai chi over other forms of exercise, only that this one particular class of exercise showed some benefits. A specific point result, not a general one. A study using tai chi, not a study about tai chi.

Secondly, Tai chi increases brain size and potentially delays the onset of Alzheimers. Clearly it does, that's great and I'm glad, but again lets look at the study setup:
"A representative sample of 120 non-demented, aged 60 – 79, selected from the same district in Shanghai was randomized [in] to four groups (Tai Chi, Walking, Social Interaction and No Intervention) for 40 weeks. One of the exclusion criteria is that participants could not have prior Tai Chi experience."
Do you spot the flaw with this? The exclusion criteria was not that people should also have had "no experience of walking" or "no experience of social interaction".... So what we get is four groups, one of the groups is learning a new skill, and being challenged in new ways. The other three groups are basically doing things with which they are no doubt highly experienced. Hence the result is that learning a new skill, or keeping mentally challenged helps to improve brain function. Well of course, pretty much everyone knew and agreed with that already. I bet if you had done the trial with "tai chi" replaced by "Scottish dancing", the results would have been similar.  The marginal benefit of tai chi over other similar activities is not being researched here. Violet Li doesn't claim that it does, but that's the tone and impression of her article. The next person in the chain will likely dilute it more (naturally), missing out some details, so that is begins to look more and more like an apples vs apples study.

For those who are interested Meditation in Motion has a third example which is deconstructed exactly as I have done here. This "tai chi study" producing the gound breaking result that getting up and moving is better than sitting around. Hardly revolutionary tai chi research I think you'll agree.

My point is that none of these examples are really tai chi research, rather they are examples of research that use tai chi. Tai chi research must compare tai chi to other equivalent forms of activity in a fair and controlled manner. If you don't do that, then you're not really saying anything about tai chi. Just because a study shows that tai chi delivers a benefit (which is good), it does not mean that that same or greater benefit cannot be delivered by other activities - a critical point that is almost always "forgotten" in the tai chi community.

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