Scientists asked 28 female cyclists to ride a pair of one-kilometre time trials, and before one of the trials gave them a pair of red-and-white capsules which they knew to contain nothing but flour They raced on average 0.7 per cent faster after taking the inert capsules, a slight but statistically significant edge.
I’ll confess that it’s tempting to go with a simple news headline – one that promises that all you have to do is take a pill, literally any pill, and you’ll improve your athletic performance.
On the surface, that’s the message you get from a new study in the journal PLOS One, but the story is much more complicated than that. Researchers at the University of Sao Paulo in Brazil examined the use of “open-label placebos,” in which subjects know they’re getting a dummy treatment. They asked 28 female cyclists to ride a pair of one-kilometre time trials, and before one of the trials gave them a pair of red-and-white capsules, which they knew to contain nothing but flour. They raced on average 0.7-per-cent faster after taking the inert capsules, a slight but statistically significant edge.
But this superficial message – equating dummy pills with placebos – misses a far more interesting discussion about what’s really happening when we respond to a seemingly “fake" stimulus. "More and more evidence suggests that if you believe something will work, it will,” says Bryan Saunders, the study’s lead researcher, “and I don’t think that has to be limited to a pill.”
In the new study, the cyclists also received a PowerPoint presentation from two white-coated doctors explaining that prior research had suggested that placebo pills can make you faster or healthier even when you know it’s just a placebo. That act of persuasion, in itself, was another layer of placebo – as Israeli researchers showed a few years ago when they enlisted actors to play doctors with varying personal styles and found that the effectiveness of a pain-relieving cream depended on how engaging the doctor was.
In fact, University of Kent placebo researcher Prof. Chris Beedie argues, these sorts of effects are simply a consequence of how we’ve evolved to respond to predictable cues in our environments. Even worms and fruit flies show placebo-like metabolic changes in response to the smell of food, because in nature (unlike in the lab) smelling food is reliably followed by eating it. In a sports context, social cues such as home-field crowds, inspirational coaches and hated rivals all trigger some of the same changes in brain chemistry and performance that placebos do.
Placebos produce other biochemical effects. When you think you’re getting an opioid drug, your brain activates the body’s internal opioid pathways. The same thing happens with other brain pathways such as dopamine and endocannabinoids, the body’s internal version of cannabis, making the distinction between a placebo response and a “true” physiological response impossible to delineate.
All of this makes the superficially attractive idea of prescribing a placebo pill a lot more complicated – because the power doesn’t really reside in the pill, it resides in the social and environmental context surrounding the pill, and that’s different for every individual.
In Saunders’s study, 11 of the 28 subjects rode more than a second faster after taking the flour capsules. “I put it in my head that the supplement would help me,” one of them told the experimenters afterward. But four of them rode more than a second slower. Saunders hopes to explore in a follow-up study what genetic or behavioural factors might explain the individual variations, but it won’t be a simple task.
In the end, perhaps the most important take away from Saunders’s study isn’t that you should start taking sugar pills before your workouts; it’s that the pill itself is a red herring. The word “placebo” has long had negative associations, evoking the idea of deception and trickery – but it’s just as much about faith in others and belief in yourself.
“Trust me,” Beedie says, “most practitioners in sport and medicine are using placebos every day without realizing it.”
Alex Hutchinson is the author of Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance. Follow him on Twitter @sweatscience.
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