Exercise, mindfulness training do not seem to impact cognition in older adults

Neither mindfulness training nor exercise appeared to have a significant effect on cognitive function, according to results of a randomized clinical trial published in JAMA.

Eric J. Lenze, MD, director of the Healthy Mind Lab and head of the department of psychiatry at Washington University School of Medicine, and colleagues conducted the study to assess the impacts that exercise, mindfulness-based stress reduction (MBSR) or a combination of the two might have on cognitive function in older people.

“We know beyond any doubt that exercise is good for older adults, that it can lower risk for cardiac problems, strengthen bones, improve mood and have other beneficial effects — and there has been some thought that it also might improve cognitive function,” Lenze said in a press release. “Likewise, mindfulness training is beneficial because it reduces stress, and stress can be bad for your brain. Therefore, we hypothesized that if older adults exercised regularly, practiced mindfulness or did both there might be cognitive benefits — but that’s not what we found.”

Lenze and colleagues enrolled 585 adults — 72.5% of whom were women — aged 65 and 84 years “with subjective cognitive concerns, but not dementia” in the trial. The participants were randomly assigned to a health education control group or one of three, 18 month-long interventions:

• MBSR with a meditation goal of 60 minutes per day;
• exercise with strength, functional and aerobic components with a goal of 300 minutes per week; or
• a combination of MBSR and exercise.

A total of 568 participants completed 6 months in the trial and 472 completed 18 months. The researchers found that, after 6 months, “there was no significant effect” of mindfulness training or exercise on executive function or episodic memory.

When it came to executive function, MBSR vs. no MBSR was 0.39 vs. 0.31, with a mean difference of 0.08 points (95% CI, –0.02 to 0.19). For exercise vs. no exercise, the comparison was 0.39 vs. 0.32 with a difference of 0.07 (95% CI, –0.03 to 0.18).

For episodic memory, the MBSR vs. no MBSR comparison was 0.44 vs. 0.48, with a mean difference of –0.04 points (95% CI, –0.15 to 0.07). For exercise vs. no exercise, the comparison was 0.49 vs 0.42, with a difference of .07 (95% CI, –0.04 to 0.17).

Lenze and colleagues also noted that “there was no significant interaction between mindfulness training and exercise” at 6 months and no effects after 18 months.

They noted several potential causes for the findings. Because every group saw increases in cognitive performance over time, “it could be posited that all interventions (including health education) benefited participants equally and these increases reflect those benefits, and thus the study failed due to lack of a proper negative control,” they wrote. However, the researchers added that the health education intervention was specifically designed for the study so that it would not affect cognition.

Though the results were not what they anticipated, the researchers said that their findings do not necessarily mean that mindfulness or exercise is useless.

“We aren’t saying, ‘Don’t exercise’ or, ‘Don’t practice mindfulness’,” Lenze said in the release. “But we had thought we might find a cognitive benefit in these older adults. We didn’t. On the other hand, we didn’t study whether exercise or mindfulness might benefit older adults who are impaired due to dementia or to disorders such as depression. I don’t think we can extrapolate from the data that these practices don’t help improve cognitive function in anyone.”

Study coauthor Julie Wetherell, PhD, a professor of psychiatry at the University of California, San Diego, added that “it’s important for studies like ours to develop and test behavioral interventions to try to provide [older adults] with neuroprotection and stress reduction as well as general health benefits.”

Lenze said in the release that the researchers have received funding from the NIH to continue their work.

“We didn’t see improvements, but cognitive performance didn’t decline either,” Lenze said. “In the study’s next phase, we’ll continue following the same people for 5 more years to learn whether exercise and mindfulness training might help slow or prevent future cognitive declines.”

References:

• Exercise, mindfulness don’t appear to boost cognitive function in older adults. https://medicine.wustl.edu/news/exercise-mindfulness-dont-appear-to-boost-cognitive-function-in-older-adults/. Published Dec. 13, 2022. Accessed Dec. 15, 2022.
• Lenze EJ, et al. JAMA. 2022;doi:10.1001/jama.2022.21680.