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Mild cognitive impairment (MCI) is a common threat to the well-being of older adults and can potentially progress into dementia. MCI is defined as the early stages of declining cognitive function, including memory loss, in individuals who are still considered to be full capable of completing daily tasks, and of living independently. While there is currently no cure or approved medication to reverse MCI, there are several interventions that can slow further decline and even improve brain health. These interventions include cognitive training, aerobic and resistance exercises, and consuming adequate levels of vitamin D.

Cognitive training, or ‘brain training’, is one type of intervention that has been shown to be effective and beneficial for the brain. One example of brain training would be a computerized game that challenges memory skills. While more research is needed to account for individual differences, current evidence suggests that the use of computerized brain training is effective in boosting cognitive abilities.

Aerobic and resistance exercises are also recognized for their abilities to enhance cognition. Previous studies have shown that both aerobic and resistance exercises, performed independently and collectively, can promote an increase in cerebral flow, neuroplasticity, and neurogenesis which in turn benefits memory and cognitive function.

Adequate consumption of Vitamin D is another intervention that has shown benefits in maintaining cognitive function. It has also been found that a deficiency in Vitamin D may lead to more rapid rates of age-related cognitive decline. These studies suggest that vitamin D and cognitive function have a causal relationship and having sufficient levels may increase the chances of healthy brain aging.

The effects on cognition from aerobic and resistance exercises, cognitive training, and vitamin D consumption have been studied individually, and these interventions are all recognized for their neuro-protective benefits for adults. With that being understood, would taking a multidomain approach potentially have a greater effect on the treatment for MCI? A recent study published in the journal JAMA Network was conducted to answer this question.

“…would taking a multidomain approach potentially have a greater effect on the treatment for MCI?”

In order to determine the possible benefits of using a combination of these interventions would have a potentiating effect on lowering mild cognitive impairment in older adults, and even decrease the likelihood of MCI developing into dementia, investigators from several universities in Canada and the UK randomly enrolled a group of 175 older adults, 89 (50.9%) male and 86 (49.1%) female, between the ages of 65-84 years old, with a mean age of 73 years into a study with five different treatment arms over the course of 20 weeks.

“In order to determine the possible benefits of using a combination of these interventions would have a potentiating effect on lowering mild cognitive impairment in older adults…”

The five study arms were as follows:

Arm 1: Aerobic and resistance exercises, cognitive training, and vitamin D

Arm 2: Aerobic and resistance exercises, cognitive training, and placebo vitamin D

Arm 3: Aerobic and resistance exercises, sham cognitive training, and vitamin D

Arm 4: Aerobic and resistance exercises, sham cognitive training, and a placebo vitamin D

Arm 5: Control group with balance-toning exercise, sham cognitive training, and a placebo vitamin D

Participants in all 5 study arms listed above completed 90-minute group training sessions three times a week over the course of 20 weeks. Within each training session, participants completed 30 minutes of cognitive training, whether active or sham. Arms 1-4 followed it with 60 minutes of aerobic and resistance exercises, whereas arm 5 followed it with 60 minutes of balance and toning exercises. The Borg Rating of Perceived Exertion scale was used to measure the outcomes of the exercise progress and intensity of the training. All participants also received a vitamin D capsule of either a 10,000 IU dose or matching placebo, three times a week over the course of the 20 weeks.

The cognitive training consisted of either active or sham training sessions or sham training sessions on a computerized tablet. The active training included visuomotor tasks that targeted both memory and attention with the tasks becoming increasingly more difficult over time. The sham training consisted of participants alternating between a search of touristic information and watching a video over the course of the training time.

The outcomes of the study were assessed by evaluating a change in cognitive function using the Alzheimer Disease Assessment Scale Cognitive 13 (ADAS-Cog-13) and the Plus variant of the scale. The ADAS-Cog-13 includes thirteen tests which work to assess different cognitive domains. The Plus variant incorporates five additional tests and is more sensitive to executive function. Significant improvements in either the ADAS-Cog-13 or Plus variant were considered as proof of efficacy in performing these tasks.

Among the 175 participants who originally enrolled in the study, 133 completed the full treatment over 20 weeks. Arm 1 (physical exercises, cognitive training, and vitamin D) improved their ADAS-Cog-13 score by 44%, arm 2 (physical exercises, cognitive training, and placebo vitamin D). by 37%, arm 3 (physical exercises, sham cognitive training, and vitamin D) by 14%, arm 4 (physical exercises, sham cognitive training, and a placebo vitamin D) by 24%, and arm 5 (balance-toning exercise, sham cognitive training, and a placebo vitamin D) by 15%. While vitamin D supplementation or exercise alone did not significantly improve scores, study results suggested that the use of cognitive training in combination with aerobic and resistance exercises had a significant impact on cognition. Previously, these interventions had only been identified independently as factors that may increase cognitive abilities.

“…researchers did find that the use of computerized cognitive training in combination with aerobic and resistance exercises had a significant impact on cognition.”

This large multicenter study was the first to identify both the effectiveness and long-lasting results that a multidomain approach can have on cognitive function. By combining the use of cognitive training with aerobic and resistance exercises, older adults can see greater improvements in MCI and delay or prevent the onset of dementia. With dementia affecting over 55 million individuals worldwide, finding a practical approach that yields greater results in treating MCI is key to reducing the number of older adults developing serious cognitive decline and Alzheimer’s disease.