December 16, 2013

expert reaction to acupuncture and weight loss

The journal Acupuncture in Medicine published a small study which suggested 5-point ear acupuncture was better than single point in trying to reduce abdominal fat. A before the headlines analysis was sent out to accompany the comments.

Professor Edzard Ernst, Emeritus Professor of Complementary Medicine, University of Exeter, said:

“It is hard to think of a treatment that is less plausible than ear acupuncture.  Testing such a treatment is arguably a waste of resources.  If it is studied nevertheless, the test should be rigorous, which unfortunately cannot be said for this study.  The trial has several serious flaws, e.g. small sample size, high drop-out rate, questionable statistics and doubtful blinding of patients or evaluators.  Collectively, these limitations render the findings far too unreliable for issuing recommendations about the use of ear acupuncture.  Consulting an acupuncturist will reduce your cash but not your body weight.”

Professor Kevin McConway, Professor of Applied Statistics, The Open University, said:

“While it’s good to see attempts to evaluate so-called ‘alternative’ treatments using the same approach as is used for more conventional treatments, this study has several features that complicate the picture. It’s a small study, with 91 participants in total. They were recruited through newspaper adverts and pamphlets, and people who respond to such ads may not even be typical of the Korean public, let alone other populations. Study participants were allocated to the three treatments (two different kinds of acupuncture, and sham treatment) at random, which is of course appropriate, but in one respect the randomisation did not turn out helpfully – there were quite large differences in age between the treatment groups, with the sham-treatment people being eight years older, on average, than those in one of the acupuncture treatment groups. (The researchers did try to allow for this in analysing the data, but that cannot always be done perfectly.)

“Many participants – over a third of those who started the study – did not complete the treatment, and the main results do not take this into account. The study lasted only 8 weeks, which is not long when it comes to a long-term issue like being overweight – it tells us nothing about what might happen after 8 weeks, and the world is full of weight-loss treatments that have no demonstrable longer-term effect. Half of the participants in the sham treatment group dropped out of the study before the 8 week treatment finished – that’s more than in the acupuncture groups, though even in those, about 30% did not finish the study.  Overall, the drop-out rate is pretty high and that again makes the results harder to interpret. (Note that the press release reports the number of dropouts incorrectly – it says there were 24 in all, but the paper itself makes it clear there were actually 33 (15 in the sham-treated group and 9 in each of the two acupuncture groups), so that 36% of those who started did not last out the full 8 weeks.

“It’s not surprising that participants in all three groups lost weight on average during the study – their diet was somewhat restricted. The average weight loss in the acupuncture groups wasn’t huge – about 4kg over 8 weeks – but that is in accord with NHS recommendations on safe rates of weight loss, 0.5 to 1 kg per week. The question of what actually caused the average differences in body mass index (BMI), weight and body fat between the acupuncture groups and the sham-treatment group is not easy to unpick, and the age difference between the groups doesn’t help.

“In randomised clinical trials like this, it’s standard good practice to ‘blind’ the participants, that is, as far as possible to disguise from them which treatment they are receiving. In this study the ‘blinding’ was done by using sham treatment – but in the other groups, the acupuncture needles remained in place for a week at a time, while they were removed immediately in the sham-treatment group. It is possible the participants could feel which treatment they had (the researchers point out that they did not check for this possibility, or, apparently, ask the participants at the end of the study which treatment they thought they had received.)”

‘Randomised clinical trial of five ear acupuncture points for the treatment of overweight people’ by Sujung Yeo et al. published in Acupuncture in Medicine on Monday 16 December 2013.