New research uncovers effective strategies to combat cognitive decline and enhance brain function as you grow older.
In 2021, more than 50 million individuals across the globe were affected by dementia, resulting in costs surpassing $800 billion US dollars. While a cure for dementia remains elusive, a significant transformation has occurred in the approach to addressing the condition.
The focus has shifted towards targeting individuals at risk through nonpharmacological and lifestyle interventions aimed at enhancing cognitive abilities and potentially postponing the onset of dementia.
Mild cognitive impairment (MCI) serves as a transitional phase between typical cognitive aging and early dementia, presenting an opportune time to implement preventive strategies and early treatments.
Research has shown that both aerobic exercise and resistance training independently contribute to improved cognition in older adults. However, it remains unclear whether combining these two modalities provides additional benefits.
Computer-based cognitive training has also demonstrated positive effects on cognition in older adults by engaging cognitive processes through challenging and adaptive tasks.
Additionally, vitamin D supplementation, alongside exercise and cognitive training, has been suggested to enhance cognition due to its neuroprotective properties.
Thus, delivering these interventions together as a multidomain treatment has the potential to delay the progression from MCI to dementia.
Previous multidomain intervention trials conducted on healthy older adults, such as the FINGER (Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability) trial, have shown primary efficacy in improving cognition.
Similarly, post hoc analyses of specific higher-risk subgroups in trials like MAPT (Multidomain Alzheimer Preventive Trial) and PREDIVA (Prevention of Dementia by Intensive Vascular Care) have exhibited positive results.
However, the effectiveness of multidomain interventions in cognitively impaired populations remains unclear. For instance, the recent MEDEX (Mindfulness-Based Stress Reduction, Health Education and Exercise) factorial trial failed to demonstrate an improvement in cognition when combining mindfulness training and exercise in older adults with subjective cognitive concerns.
In MCI populations, multidomain trials combining exercise with other interventions have yielded mixed results. Notably, two previous randomized factorial trials indicated that combining exercise with cognitive training was less effective than exercise alone in enhancing cognition. Additionally, the sustainability of cognitive improvements following interventions has yet to be established.
To address these uncertainties, the SYNERGIC Trial (Synchronizing Exercises, Remedies in Gait and Cognition) was conducted to evaluate the cognitive benefits of a multidomain intervention consisting of aerobic-resistance exercises, computer-based cognitive training, and vitamin D supplementation in older adults with MCI.
This randomized clinical trial, known as the SYNERGIC Study, was a double-masked, fractional factorial trial conducted across multiple sites. It assessed the effects of aerobic resistance exercise, computerized cognitive training, and vitamin D on cognition.
Eligible participants aged 65 to 84 years with MCI were enrolled between September 19, 2016, and April 7, 2020. Data analysis was performed from February 2021 to December 2022.
The participants were randomized into five study arms and received treatment for 20 weeks. Arm 1 received the multidomain intervention, including 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.
Lastly, arm 5 served as the control group, receiving balance-toning exercise, sham cognitive training, and placebo vitamin D. The vitamin D regimen consisted of a 10,000 IU dose administered three times weekly.
Out of 175 randomized participants (with a mean age of 73.1 [6.6] years, and 86 [49.1%] women), 144 (82%) completed the intervention, and 133 (76%) completed the follow-up at 12 months. At the 6-month mark, all active arms (arms 1 through 4) that included aerobic-resistance exercise demonstrated improved ADAS-Cog-13 scores compared to the control group (mean difference, -1.79 points; 95% CI, -3.27 to -0.31 points; P = .02; d = 0.64).
When comparing exercise alone (arms 3 and 4) to exercise combined with cognitive training (arms 1 and 2), the latter resulted in a superior improvement in ADAS-Cog-13 scores (mean difference, -1.45 points; 95% CI, -2.70 to -0.21 points; P = .02; d = 0.39). Notably, vitamin D supplementation did not yield significant improvements.
Ultimately, the multidomain intervention (arm 1) led to a significant improvement in ADAS-Cog-13 scores compared to the control group (mean difference, -2.64 points; 95% CI, -4.42 to -0.80 points; P = .005; d = 0.71). However, changes in ADAS-Cog-Plus scores did not reach significance.
In conclusion, this clinical trial demonstrated that older adults with MCI who underwent aerobic-resistance exercises, coupled with sequential computer-based cognitive training, experienced a significant improvement in cognition, although some results were inconsistent.
Vitamin D supplementation did not show an effect.
These findings suggest that a multidomain intervention of aerobic-resistance exercises with cognitive training may enhance cognition and potentially delay the onset of dementia in individuals with MCI.
Source: 10.1001/jamanetworkopen.2023.24465
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