Positive results of three new randomized controlled trials of aerobic exercise in Alzheimer’s disease, vascular cognitive impairment (VCI) and mild cognitive impairment (MCI) were reported recently at the Alzheimer’s Association International Conference. They provide hope there may soon be a tool that people with dementia can use to prolong their independence and improve their quality of life.
There is a convincing body of evidence that regular physical activity can reduce the risk of cognitive decline, and possibly reduce the risk of Alzheimer’s disease and other dementias. In healthy older people, studies suggest physical exercise can improve cognition. However, until now, whether physical exercise could improve symptoms in people with Alzheimer’s, or beneficially impact the physical changes in the brain caused by the disease, was unknown.
Exercise or regular physical activity may play a role in both protecting your brain from Alzheimer’s disease and other dementias, and also living better with the disease if you have it. These findings also highlight the potential value of non-drug therapies for Alzheimer’s disease and other dementias, and remind us that research ought to adamantly pursue combination and multi-modal approaches to Alzheimer’s therapy and prevention. There is a growing body of evidence that certain lifestyle choices, such as staying mentally active, eating a heart-healthy diet and staying socially engaged, can slow cognitive decline as people age.
Physical Exercise Reduces Psychiatric Symptoms
Steen Hasselbalch, MD, and colleagues from the Danish Dementia Research Centre (DDRC), Copenhagen, Denmark reported results from the Danish ADEX Study. In the study, 200 people with Alzheimer’s age 50-90 (average age 70.9 years) were randomly assigned to either a supervised aerobic exercise program (60-minute exercise sessions three times a week for 16 weeks supervised by experienced physiotherapists) or a control group (standard care, no extra exercise). In the exercise group, after 4 weeks of adaptation exercise, participants performed aerobic exercise at a target intensity of 70-80% of maximum heart rate for the remaining 12 weeks.
The researchers studied the effects of exercise on a range of factors related to Alzheimer’s disease. The primary outcome measure was change from baseline to 16 weeks in cognitive performance estimated by Symbol-Digit Modalities test (SDMT). Secondary outcomes were neuropsychiatric and depressive symptoms, activities of daily living, quality of life and other cognitive measures. No significant difference was found between the intervention and control group on the primary outcome, but there was a significant difference in neuropsychiatric symptoms in favor of the intervention group.
What Researchers say about Alzheimer’s
People who participated in the exercise program had far fewer neuropsychiatric symptoms (such as anxiety, irritability, and depression). Those in the control group had deteriorated on measures of psychiatric symptoms, while the intervention group improved slightly. This lead to a statistically significant difference between the two groups.
People in a subgroup of the exercise group who attended more than 80% of the classes and exercised vigorously (raising their heart rate to more than 70% of their maximal rate) had statistically significant (p=0.03) improvements on mental speed and attention, as measured by the SDMT.
In addition, people who participated in the exercise program improved in physical fitness, physical function, dual-task performance and exercise self-efficacy.
Symptoms such as anxiety, irritability, and depression that often occur in Alzheimer’s disease are the cause of great distress in both caregivers and people with the disease. While the results need to be verified in larger and more diverse groups, the positive effects of exercise on these symptoms may prove to be an effective complement or combination with antidementia drugs.