BBC Horizon 2015 The Power of the Placebo BBC Documentary

Summary

The documentary explores how placebos can produce measurable effects—not because of an active drug, but through expectations, context, and the brain and body’s own chemical systems. It also examines whether these effects can be used ethically, without deceiving patients.

Experiments and findings

• Cycling performance: Sports researcher Chris Beedie gave elite cyclists capsules containing cornflour, while leading them to expect a performance supplement. More than half cycled faster in their second time trial, and one set a personal best. Beedie said placebo effects in sports studies often improve performance by around 2–3%—a potentially significant margin in competition.
• Sham vertebroplasty: In a trial led by David Kallmes, patients with spinal fractures received either vertebroplasty or a carefully staged sham procedure. Among 130 patients, researchers found no statistically significant difference between the groups in pain relief or improved function. The programme also mentions a similar Australian study. Both groups improved, raising questions about how much of the benefit came from the procedure itself and how much from the treatment context.
• Placebo oxygen at altitude: Fabrizio Benedetti studied volunteers exercising at high altitude. Participants told they were receiving oxygen—but given no additional oxygen—showed a decrease in the neurotransmitter-related marker PGE2, despite no change in blood oxygen saturation. The programme links lower PGE2 with reduced pain and easier exertion, suggesting that expectation can trigger measurable physiological changes.
• Placebo pain relief and brain activity: In Tor Wager’s heat-pain experiment, a participant rated pain after receiving a real local anaesthetic and a cream presented as an anaesthetic, though it was only moisturizer. The placebo reduced reported pain. Brain scans showed the release of endogenous opioids, the brain’s own pain-relieving chemicals, including activity in the periaqueductal gray, part of the brain’s pain-control system.
• Placebo and Parkinson’s disease: Neurologist John Stoessl described research in which patients with Parkinson’s improved after receiving a placebo they believed was medication. Brain scans indicated increased dopamine release. The programme stresses that this effect can be substantial but is short-term; it does not establish that placebos can replace Parkinson’s medication.
• Open-label placebos for IBS: In a Harvard trial led by Ted Kaptchuk, people with irritable bowel syndrome were told that their pills were placebos with no active ingredient, but that they might help through the body’s self-healing processes. Around 62% reported adequate relief, compared with about 30% of those who received no treatment. The pills were used for only a few weeks, and symptoms returned for one participant after she stopped. The study was small and short-term, and does not show that placebos can replace effective medication.
• Hypnosis during dental treatment: Dentist and hypnotist Mike Dowd used hypnosis to prepare David for wisdom-tooth extraction without pharmacological anaesthetic. David rated the pain at about 4 out of 10 at the most difficult point. The programme presents hypnosis as a way to use expectation and attention to engage the body’s own pain-control systems without a dummy pill or sham procedure.
• The clinician–patient relationship: In another IBS study, patients received sham acupuncture using needles that did not puncture the skin. About 42% of patients in the minimal-interaction group reported adequate relief, compared with 62% in the group whose practitioner offered a warm, supportive interaction. The results suggest that empathy, attention, and confidence may strengthen placebo responses.

Broader concepts

• Placebo effects can involve real, measurable changes in the body, including changes in pain-related chemicals and dopamine—not merely imagined improvement.
• Expectations and the circumstances surrounding treatment may influence how the brain’s natural chemical systems respond.
• Treatment details may also affect expectations. The programme cites research suggesting that capsules, larger pills, higher prices, and pill colour can alter perceived effectiveness. Colour effects may depend on cultural associations.
• Placebos have limits. The programme notes that they will not repair a broken bone or shrink a tumour, and cautions against treating these findings as a reason to replace effective medical care.
• A central challenge is finding ways to support placebo effects without deception. The open-label placebo and supportive-practitioner studies offer possible approaches, but the documentary describes the research as still developing.

Researchers and sources featured

Researchers and clinicians

• Dr Chris Beedie — sports-performance placebo research
• Dr David Kallmes — vertebroplasty and sham-procedure trial
• Fabrizio Benedetti — high-altitude placebo research
• Tor Wager — placebo, pain, and brain-imaging research
• Professor John Stoessl — Parkinson’s disease and placebo research
• Ted Kaptchuk — Harvard placebo studies, including IBS research
• Mike Dowd — dentist and hypnotist

Named participants and patients

• Bonnie Anderson — vertebroplasty trial participant
• Marco — high-altitude study participant
• Jake — pain and brain-imaging experiment participant
• Paul Patterson — Parkinson’s disease patient
• Linda Bonanno — open-label placebo trial participant
• David — dental hypnosis patient