Exercise and training can improve global cognition in elderly patients with mild dementia

According to the results of a study published in JAMA network open.

Both aerobic exercise and resistance training have been shown to improve cognition in older adults, although the benefits of combining these 2 modalities are unclear, the study authors wrote. Computer-based cognitive training also improves cognition in older adults through the repeated engagement of cognitive processes using challenging and preferably adaptive tasks. Additionally, vitamin D, in addition to exercise and cognitive training, has been argued to improve cognition due to its neuroprotective attributes. Therefore, providing these interventions together, as a multidomain treatment, has the potential to delay the progression from MCI to dementia.

The study found that vitamin D supplementation or exercise alone may not significantly improve overall cognition.

Our study is to our knowledge the first to show a greater effect of a multidomain intervention than exercise alone, the study authors wrote in the article.

Researchers conducted the SYNERGIC (multisite, double-mask, fractional factorial) study to evaluate a multidomain intervention of progressive exercise, cognitive training, and vitamin D supplementation for older adults with MCI, also called mild dementia.

The primary outcomes were change in Alzheimer’s disease rating scale Cognitive 13 (ADAS-Cog-13) and ADAS-Cog-Plus variant score at 6 months. ADAS-Cog-13 measures global cognition, including memory, attention, word recognition, and orientation, which is worse in patients with MCI.

The cohort included 175 Canadian adults with MCI, aged 65 to 84 years, divided into 1 of 5 arms:

• Arm 1: Multidomain intervention (aerobic endurance exercise, cognitive training, and vitamin D).
• Arm 2: aerobic endurance exercise, cognitive training, and vitamin D placebo.
• Arm 3: Aerobic endurance exercise, mock cognitive training, and vitamin D.
• Arm 4: Aerobic resistance exercise, sham cognitive training, and vitamin D placebo.
• Arm 5: Control (balance and toning exercise, sham cognitive training, and vitamin D placebo).

At 6 months, all active arms (1 to 4) significantly improved ADAS-Cog-13 scores compared with the control (mean difference, 1.79 points; 95% CI, 3.27 to 0.31 points; P=0.02; d=0.64). Arm 1 improved the ADAS-Cog-13 score by 44%. The ADAS-Cog-13 score increased by 37% in arm 2, 14% in arm 3, 24% in arm 4 and 15% in arm 5.

Previous studies have identified resistance and aerobic training as independent factors that may improve cognitive function in older adults. Computerized cognitive training has also shown benefits on cognition. The 12-month (post-intervention) analysis revealed that aerobic resistance training and cognitive training may provide not only safe, but long-lasting benefits for older adults with MCI.

[Patients in the multidomain intervention] did not return to baseline scores, suggesting a lasting effect even without participants engaging in exercise regimens during the follow-up period, the study authors wrote.

They added that this may suggest that continued exercise and cognitive training maintain positive cognitive improvements. The ADAS-Cog-Plus scale did not improve clinically after any intervention. Additionally, exercise alone or vitamin D supplementation also did not improve ADAS-Cog-13 scores, despite the latter being said to have neuroprotective properties that can improve cognition.

Dementia is an incurable disease affecting more than 50 million people worldwide. However, non-pharmacological and lifestyle interventions can delay the onset of dementia, and interventions such as these may be more effective when given during the MCI phase, the study authors concluded.

Reference

Montero-Odasso M, Zou G, Speechley M, et al. Effects of exercise alone or in combination with cognitive training and vitamin D supplementation to improve cognition in adults with mild cognitive impairment. JAMA network open.2023;6(7):e2324465. doi:10.1001/jamannetworkopen.2023.24465