A placebo pill improved memory and physical performance — even when people knew it was fake

The placebo effect is usually framed as something that only works when people are deceived into thinking they’re getting a real treatment. A 2026 Università Cattolica del Sacro Cuore study challenges that assumption directly: healthy older adults who were openly told they were taking an inert pill still saw real improvements in memory, physical performance and stress — in some measures, larger improvements than the group that was told it was a real supplement.

How the trial was structured

90 healthy older adults were randomly assigned to one of three groups: no treatment at all; a deceptive placebo group told the (inactive) pills contained active ingredients for well-being and physical function; and an open-label placebo group told plainly that the pills were inert but that placebos can still trigger beneficial mind-body responses. All participants completed cognitive tests (short-term memory, selective attention), physical performance measures, and questionnaires on stress, well-being and other factors before and after three weeks.

The results, by group

Both placebo groups improved on cognitive and physical measures relative to the no-treatment control. Physical performance rose 7% in the deceptive placebo group and 9.2% in the open-label group; cognitive test scores improved 12.6–14.6% in the deceptive group and 6.9–21.5% in the open-label group, depending on the specific test. Stress levels improved most in the group that knowingly took a placebo — the opposite of what a purely deception-based model of placebo effects would predict.

"These are significant effects — comparable to those seen in some experimental studies on physical activity regarding physical performance and cognitive training." — Prof. Francesco Pagnini, Università Cattolica

Why this matters beyond a curiosity

If deception isn’t required for a placebo-style benefit, "open-label placebos" become a genuinely ethical tool: older adults can be told honestly that a treatment has no active ingredient and still plausibly benefit from the ritual, expectation and attention involved in taking it seriously. The researchers frame this as evidence that mindset, expectation and self-perception measurably influence physical and cognitive function in aging — not just subjective mood, but objectively tested memory and movement scores.

What this does — and doesn’t — mean for your own habits

This is not an argument that expectation alone can substitute for real interventions like resistance training, protein intake or sleep — those have their own, much larger evidence base. But it is a genuine data point that the ritual of consistent daily practice, taken seriously, carries some benefit independent of the specific "active ingredient" — a reason to take your existing habits (supplements, stretching routines, daily check-ins) seriously rather than dismissing them as "just placebo."

This pairs naturally with the Yale finding that positive age-beliefs predict who improves with age — both point toward mindset and expectation being a real, if modest, lever alongside the physical training and nutrition changes Misi tracks day to day.