Some Interventions Improve Cognition in Older Adults More Than Others

Multidomain interventions — ones that combined cognitive and physical training, for example — improved cognitive outcomes in older adults with mild cognitive impairment compared with a single intervention, a meta-analysis showed.

Short-term programs composed of two or more interventions led to better global cognition and cognitive domain scores in people with mild cognitive impairment, reported Sarah Fraser, PhD, of University of Ottawa in Canada, and co-authors in JAMA Network Open.

“In this study, nonpharmacological, multidomain interventions mainly focused on physical exercise, cognitive training, mind-body, music, dietary supplements, social engagement, and education were associated with small to medium effect sizes indicating improvements in global cognition, executive function, memory, and verbal fluency,” Fraser and colleagues wrote.

“A synergistic association was found, suggesting combined interventions may be superior to single interventions to improve cognitive functioning in older adults with mild cognitive impairment,” they added.

In mild cognitive impairment — an intermediate stage between normal aging and dementia — people typically demonstrate objective cognitive deficits that don’t interfere with daily functioning. People with mild cognitive impairment are at high risk to progress to dementia. However, up to a third of older adults with mild cognitive impairment may revert to normal cognition.

Nonpharmacological interventions like cognitive training can help improve mood and preserve memory. Multidomain interventions have been examined in healthy older adults, but there’s been inconclusive evidence to support outcomes in people with mild cognitive impairment, Fraser and co-authors noted.

“Additionally, reviews on this topic have primarily focused on memory or are limited to investigations of cognitive and physical training, while interventions such as mindfulness and nutrition are overlooked,” they observed.

In their analysis, the researchers evaluated 28 clinical trials from 2011 through 2021 that included 2,711 people 65 and older with mild cognitive impairment. All trials compared nonpharmacological multidomain interventions with a single active control.

Exposure to the interventions lasted an average of 71.3 minutes for 19.8 weeks, with sessions taking place 2.5 times per week. All interventions lasted less than 1 year.

Multidomain interventions included cognitive components, physical components, nutritional supplements, mind-body components, education, social components, cognitive training with transcranial direct current stimulation, and exercise with music.

Eighteen trials conducted the intervention components sequentially; ten conducted them simultaneously. Interventions were completed in a group setting in 19 studies. In 21 studies, the active control contained one component of the multidomain intervention.

In four cognitive domains, multidomain interventions showed greater effect sizes than single interventions:

• Global cognition: standardized mean difference (SMD) 0.41, 95% CI 0.23-0.59, P<0.001
• Executive function: SMD 0.20, 95% CI 0.04-0.36, P=0.01
• Memory: SMD 0.29, 95% CI 0.14-0.45, P<0.001
• Verbal fluency: SMD 0.30, 95% CI 0.12-0.49, P=0.001

Attention and processing speed did not differ between intervention groups. There were too few studies to pool data about reaction time and visuospatial abilities, Fraser and co-authors noted.

Thirteen studies using the Mini-Mental State Examination (MMSE) demonstrated that the overall pooled effect size favored the multidomain intervention (SMD 0.40, 95% CI 0.17-0.64, P<0.001), showing a greater increase in MMSE scores after the intervention in the multidomain group than the control group.

Scores on other tests — the category verbal fluency test, Trail Making Test-B, and Wechsler Memory Scale-Logical Memory I and II tests — also favored the multidomain group.

The review predominantly featured multidomain cognitive-physical interventions, the researchers pointed out. “However, nutrition, mind-body, music, and social interventions also contributed to small-medium effect sizes in global cognition, executive function, memory, and verbal fluency immediately after the intervention,” they wrote.

The analysis also had several limitations, Fraser and colleagues acknowledged. Bias may have been introduced if participants were co-recruited for several studies from the same research groups. In addition, the studies lacked sufficient data to account for different cognitive subtypes, like amnestic mild cognitive impairment.