The gold standard in scientific research is the randomized control trial, whereby subjects are randomly allocated to receive either an intervention, such as a medical treatment or a fitness programme, or a placebo. If the subjects in the intervention group change to a greater extent that those in the placebo group, then the intervention can be said to work. If the two groups are similar, then the intervention can be said to be “no more effective than placebo”. This is often taken to mean that the intervention doesn’t work, but of course, it doesn’t mean that.
Why? Because placebos can be effective. It’s well established in the medical research, particularly around pain, that placebos can exert some biological influence; indeed, around one-third of patients receiving a placebo report improvements in pain, which is essentially the same number of subjects who report that morphine does not reduce their pain. The mechanisms underpinning this relationship are both complex and, often, quite poorly understood, but as a lay summary placebos can work through a number of ways, including expectancy (you think something will help, so it does), and regression to the mean (the person would get better anyway, but providing a placebo makes them feel like they are doing something positive about it). Given the complex biopsychosocial nature of pain, in which stress and anxiety can exacerbate feelings of pain and disability, reducing this stress and anxiety in and of itself can reduce the pain; and this can be achieved readily through placebo. I can think of two anecdotes (which I’m aware are the lowest form of evidence) from my life that illustrate this. The first is that my back pain was always greatest on days when I had a competition. It seems unlikely that my underlying back issues were, for some reason, much worse of days when I was competing; instead, it seems more likely that I was more stressed and anxious on my competition days, and as a result interpreted the signals from my back as more threatening, which in turn increased my feelings of pain.
The second example is something that a researcher would struggle to get past an ethics board, such is the measure of deception and subterfuge used by the principle investigator – in this case, my mum. Early in my teenage years, I developed an entirely irrational fear of flying, and, in particular, turbulence. This made the flight from the UK to Florida for a family holiday somewhat unpleasant, both for me, and, I imagine, for my parents. Fortunately, whilst we were in Florida, my mum managed to track down some anti-anxiety medicine (don’t ask me how) that I could use on the plane; whenever I felt a bit scared, I could put a lozenge in my mouth an allow it to slowly dissolve, easing my anxiety. The lozenges themselves were very nice, which an aniseed flavor that, whilst not to everyone’s liking, is certainly to mine. As such, the long return flight how was an altogether calmer affair, which my anxiety been much lower, and I was very grateful that my mum had managed to locate these tablets which eased my anxiety. It turns out that these were just aniseed sweets she had bought at a sweet shop.
My point is two-fold – firstly, that many of our physical feelings have a psychological components, and, secondly, that by targeting this psychological component we can influence our physical sensations. And there is where placebos, and their close cousin expectancy, come in.
Let’s look at caffeine in sport. Caffeine is definitely performance enhancing for most people, in most sports, most of the time, to the point where around 75% of athletes consume it specifically as an ergogenic aid. Get a group of cyclists, tell them that they are being given caffeine, and their performance improves – even if you actually gave them a placebo. Conversely, if you consume caffeine but think that you haven’t, then your performance improves to a lesser extent than if you correctly determined you had consumed caffeine.
It’s clear, therefore, that both placebo and expectancy can have real-world impacts on a number of measures. Part of this is the theatre surrounding the treatment; in many of the studies utilizing placebos in medicine, the very act of seeing a well-qualified human being who (hopefully) takes our problems seriously is likely to have a positive impact in and of itself. Similarly, taking a substance you know will improve your performance will cause you to work harder, even if you haven’t actually taken the substance.
All of this brings me to my key point; when you see “no better than placebo” written in a study, don’t be tempted to assume that this means that the substance doesn’t work. Instead, understand that it might well work, but that its effect is likely related to other aspects outside of the particular interventions physiological impact. Secondly, whilst it’s unethical to deliberately deceive athletes, understand that their beliefs will impact their performance. They may well be utilizing something for which there is no evidence of effectiveness, but, if they believe in it, it may well be more effective that doing nothing. Obviously, you should prevent them from doing something harmful, but they key is not to try and move them away from behaviors for which is no/limited evidence, if they think it works. Because, if they think it works, it just might.