Manuel Montero-Odasso, MD, PhD

Credit: St. Joseph's Health Care London

Older adults who have mild cognitive decline (MCI) and are given aerobic-resistance exercises along with sequential computerized cognitive training substantially improve their cognitive abilities, according to recent findings, and Vitamin D supplementation does not affect cognitive improvement.¹

These findings were the results of a study which was conducted to assess whether an intervention classified as multidomain and including aerobic-resistance exercise along with vitamin D supplementation and cognitive training could improve cognition for older adults with such impairment.

Prior research has shown that vitamin D combined with both cognitive training and physical exercise could possibly enhance older adults’ cognitive abilities due to the vitamin’s neuroprotective qualities.²

As a result, this research was conducted and it was authored by Manuel Montero-Odasso, MD, PhD, from the Gait and Brain Lab at the Parkwood Institute in Ontario, Canada.

“The SYNERGIC Trial (Synchronizing Exercises, Remedies in Gait and Cognition) was conducted to evaluate the cognitive benefits of an aerobic-resistance exercise regime, alone or in addition to computer-based cognitive training, and vitamin D supplementation in older adults with MCI,” Montero-Odasso and colleagues wrote.

Background and Findings

The investigators titled the study the ‘SYNERGIC Trial,’ and it would assess the effects of 20-week multidomain interventions on the cognitive function in older adults with reported MCI. The trial was conducted at 5 Canadian academic institutions: Western University (sponsor site), Wilfrid Laurier University, University of British Columbia, University of Waterloo, and University of Montreal.

The study’s participants, aged 60 to 85 years, were recruited by the investigators from the community and had to have met specific MCI criteria, including objective cognitive impairment in memory, subjective cognitive concerns, attention, and/or language, executive function, preserved daily living activities, and having no dementia. Exclusion criteria involved certain medical conditions, participation in other exercise programs, and the use of certain types of medications.

The research team randomly assigned the study’s participants to 5 different arms, with each given a different combination of interventions. Arm 1 received aerobic-resistance exercise, cognitive training, and vitamin D; arm 2 received exercise, cognitive training, and placebo vitamin D; arm 3 received exercise, sham cognitive training, and vitamin D; arm 4 received exercise, sham cognitive training, and placebo vitamin D; and arm 5 received balance and toning exercise, sham cognitive training, and placebo vitamin D.

The team concealed the allocation of arms from the participants and outcome assessors were blinded to the study’s allocations. Additionally, all of the participants attended group-training sessions 3 times per week for 20 weeks.

The way the study was set up, each session lasted 90 minutes in total and was set to include either active cognitive training or sham cognitive training later followed by aerobic-resistance exercise or control exercises (e.g., balance and toning). Additionally, the study participants were given vitamin D or a placebo capsule 3 times a week for 20 weeks.

The cognitive training the investigators used involved visuomotor tasks targeting working memory and attention, with the difficulty of the tasks being designed to increase over time. Participants were given continuous feedback by the team on their performance, and sham cognitive training involved the use of different tasks with the same time exposure as the actual intervention training.

The research team’s exercise program they used in the research consisted of supervised progressive aerobic and resistance training based on exercise prescriptions for older adults. Control exercises included balance, stretching,and toning exercises. The exercise groups had a trainer-to-participants ratio of approximately 1:4, and all of the trainers were required to have followed the same manual of procedures to guarantee consistency.

To ensure intervention fidelity, the study participants had to attend a minimum of 85% of the study’s sessions, and absent participants were also followed up by telephone. The outcomes measured by the team from baseline to post intervention were changes in cognitive function using both the Alzheimer Disease Assessment Scale Cognitive 13 (ADAS-Cog-13) and the Plus variant.

Overall, 175 participants ended up being randomly selected by the investigators and they had an average age of 73.1 years. The intervention was completed by a total of about 82% of them, and 76% were found to have done the follow-up at the 12-month mark.

Following 6 months, the research team found that all active exercise groups (arms 1 to 4) were shown to have made improvements in ADAS-Cog-13 compared to the control group. Specifically, exercise combined with cognitive training (arms 1 and 2) showed greater improvement in ADAS-Cog-13 scores versus exercise alone (arms 3 and 4).

However, the team’s addition of vitamin D for the participants did not demonstrate substantial improvement. Notably, the multidomain intervention in arm 1 strongly improved the ADAS-Cog-13 score compared to the results of the control group. However, there were no major changes in ADAS-Cog-Plus.

“Our findings suggest that this multidomain intervention could induce a clinically meaningful cognitive improvement in individuals with MCI, which may have important implications for their quality of life,” they wrote, though the investigators also noted that some of their results were found to be inconsistent.

References

1. ^{Montero-Odasso M, Zou G, Speechley M, et al. Effects of Exercise Alone or Combined With Cognitive Training and Vitamin D Supplementation to Improve Cognition in Adults With Mild Cognitive Impairment: A Randomized Clinical Trial. JAMA Netw Open. 2023;6(7):e2324465. doi:10.1001/jamanetworkopen.2023.24465.}
2. ^{Morley JE. Dementia: does vitamin D modulate cognition? Nat Rev Neurol. 2014;10(11):613-614. doi:10.1038/nrneurol.2014.193.}