A few months ago, on a long-haul flight at the start of a long-awaited trip to Europe, disaster struck: I caught the flu. My unwelcome new travel companion and I arrived at my friend’s doorstep in Germany – sneezing, bone-tired and ready to throw in the towel. But my friend had a plan: a megadose of vitamin C, as recommended by two-time Nobel Prize laureat Linus Pauling. I took it, and within days I was back on my feet. What could have ruined the trip became a brief hiccup. Did the vitamin C work? Maybe. But having spent years researching the placebo effect, I suspected there was something else at play.

If you have the flu, is there any reason to consider chicken soup or other seemingly non-medicinal treatments?Credit: iStock

Now that cold and flu season is here again, many of us are reaching for familiar remedies: lemon and honey tea, eucalyptus rubs, chicken soup, vitamin C. Maybe we don’t expect them to cure us, but we do expect to feel better. And often, we do. That expectation is shaped by powerful subconscious forces – experiences, beliefs, memory and culture – that science shows can produce real effects. Placebo science is evolving rapidly, revealing how these forces work and how they’re being amplified in our digital age.

The modern study of placebo effects began in the 1950s, when American anaesthetist Henry Beecher observed that wounded soldiers often reported pain relief after being given saline – believing it was morphine. His landmark paper, The Powerful Placebo, suggested that belief alone could trigger genuine physiological responses.

Since then, research has shown that expectations, context, and meaning can shape how we perceive symptoms and how our bodies respond. In the context of colds and flu, placebo effects can reduce symptoms like

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