Older adults who knowingly took placebo pills showed significant gains in memory, physical performance, and stress reduction, highlighting the mind’s role in healthy aging.

Can the mind help slow some of the effects of aging? A new study suggests it can. Researchers at Università Cattolica in Milan found that older adults who took a placebo supplement for just three weeks showed measurable improvements in memory, physical performance, and well-being—even when they knew the pills contained no active ingredients.

The findings add to growing evidence that expectations, beliefs, and other psychological factors can influence physical and cognitive health. The study, published in the International Journal of Clinical and Health Psychology, was led by Diletta Barbiani, Alessandro Antonietti, and Francesco Pagnini and supported by PNRR grants through the Age-IT project.

“The study is part of an established line of research in which we analyze the role of the mind in aging processes, which is very important,” Pagnini, Full Professor of Clinical Psychology at the Faculty of Psychology of the Università Cattolica emphasizes.

Previous research had not explored whether a traditional placebo, an inactive treatment presented as effective, could influence abilities that typically decline with age. “Our goal,” Professor Pagnini explains, “was to clarify whether an open-label placebo therapy (i.e., where the recipient is aware it is a placebo) or a fake supplement (people don’t know it’s a placebo) could influence psychological, cognitive, and physical functions in older adults living in the community.”

Testing Placebo Effects on Mind and Body

The study included 90 healthy older adults who were randomly assigned to one of three groups. One group received no intervention. A second group received placebo pills but was told they contained active ingredients that could improve functioning and well-being. A third group received open-label placebos and was informed that the pills were inactive, while also being told they could still trigger beneficial mind-body responses.

Before and after the three-week intervention, participants completed self-report questionnaires measuring factors such as perceived stress, psychological well-being, sleepiness, fatigue, optimism, self-efficacy, and beliefs about aging. They also completed objective assessments of short-term memory, selective attention, and physical performance.

After three weeks, participants in the open-label placebo group reported lower stress levels than both the deceptive placebo group and the control group. They also showed significant improvements in short-term memory compared with those who received no intervention. Overall, both placebo groups experienced cognitive and physical benefits, although the strongest effects were generally seen among participants who knowingly took the placebo.

Cognitive and Physical Performance Improvements

The results showed that physical performance increased by 7% in the deceptive placebo group and by 9.2% in the open-label placebo group. Cognitive performance improved by 12.6% to 14.6% among participants who believed they were taking an active supplement and by 6.9% to 21.5% among those who knew they were taking a placebo, depending on the specific tests used.

“These are significant effects,” the psychologist emphasizes, “comparable to those seen in some experimental studies on physical activity regarding physical performance and cognitive training, especially with regard to memory.” Researchers also observed reductions in drowsiness and, particularly among participants aware they were taking a placebo, lower stress levels.

The findings indicate that placebo interventions can improve several aspects of functioning in older adults. Open-label placebos produced benefits that matched or exceeded those seen with deceptive placebos, suggesting they could serve as an effective and ethically acceptable tool for supporting healthy aging.

According to Professor Pagnini, the results add to growing evidence that mental factors such as thoughts, emotions, and self-perception play an important role in aging. Their influence extends beyond psychological well-being and may also affect physical and cognitive functioning.