AHAO Health Conversation

Make your move for a healthier brain

Physical activity: The key to a healthier life for older adults

BY DR. SEEMA MISRA THAKUr and Zahraa Hameed

As we approach Australia’s winter season in the second year post COVID-19, we need to be conscious about maintaining a healthy lifestyle, being physically active and staying fit.  Physical exercise is key to maintaining a healthy life for individuals across all ages. According to the Australian Department of Health, regular exercise maintains physical wellbeing and prevents unhealthy weight gain.  Importantly, it reduces anxiety and stress in older adults and lowers the risk of lifestyle health conditions such as stroke and heart disease. Physical inactivity and the ongoing difficulty of getting older adults to stay engaged with exercise is an increasingly common concern. Furthermore, social distancing measures put in place as a result of the current pandemic have made it even harder for older adults to remain physically active.

Below are some evidenced based research findings on the link between physical activity and maintaining brain health:

Finding 1: Physical activity positively impacts cognition and brain health.

According to the 2020 report of the Lancet Commission,  one of the 12 modifiable risk factors for late life dementia is physical inactivity. Physical inactivity is estimated to be the third largest modifiable risk factor for dementia.  The Australian Imaging, Biomarkers and Lifestyle flagship study (AIBL) found that physical inactivity is associated with cognitive decline in older adults.  As cognitive decline continues to affect older populations, with an estimated 150 million cases of dementia by 2050, focusing on modifiable lifestyle factors, such physical activity (PA), is a crucial dementia prevention strategy.

Figure 1: Physical activity has an impact on overall brain health. Image source: Unsplash (Bruno Nascimento)

Finding 2: Association between physical activity and cognitive decline

1)          White Matter Microstructure- a marker for Alzheimer’s disease

White Matter Microstructure (WMM) is considered a marker for Alzheimer’s disease.  A longitudinal study conducted on the association between physical activity, cognition and the risk of dementia reported a significant association between baseline WMM and physical activity. Baseline WMM refers to the initial WMM intensity at the beginning of the study used as a benchmark for comparison

2)      Can PA reduce the progression of White Matter Hyperintensity?

 White Matter Hyperintensities (WMHs) are brain lesions that are a considered a risk factor for cognitive decline and have been associated with vascular risk factors (VRFs) such as obesity, diabetes and lack of exercise. Physical activity intervention trials targeting VRFs can potentially reduce the risk of cognitive decline in late life. Results of studies have been mixed.  A study found no significant impact of moderate intensity physical activity intervention on WMH progression in older adults at risk of dementia and with VRFs.  Other studies have reported mixed results regarding the association between physical activity and WMHs. This opens the door for further research and intervention trials to better understand the effect of physical activity on WMHs progression.

3)      Correlation between Metabolic syndrome and cognitive impairment.

Metabolic syndrome (MetS), another increasingly common health concern, such as abdominal obesity, hypertension, elevated triglyceride and glucose levels, increase the risk of heart disease as well as diabetes. A cross sectional study, involving participants with Mild Cognitive Impairment or Subjective Memory Complaints with at least one cardiovascular risk factor, found a significant association between the risk of Metabolic syndrome and reduced global cognitive performance. Therefore, maintaining physical activity is one way to target MetS risk factors such as abdominal obesity.

Figure 2: Lack of physical activity can negatively impact cardiovascular health. Image: Unsplash (Ali Hajiluyi)

As noted above, staying physically active in late life is of paramount importance. However, the difficulty lies in getting older adults to stay engaged with physical activity. The key solution lies in establishing physical activity programs that are easily accessible and enjoyable that target older adults. A longitudinal study reported that maintaining physical activity in older adults is achievable using well-structured and engaging programs. Home-based and easily accessible programs make it easier for adults to get involved and stay physically active.

The WHO guidelines on physical activity and sedentary behaviour recommend a minimum of a 150-300 minutes of moderate-intensity aerobic physical activity or 75-150 minutes of vigorous-intensity aerobic physical activity for older adults throughout the week. In addition to the benefits of physical activity on cognitive functioning, a study reported that moderate intensity physical activity can potentially reduce the risk of muscle loss in target groups. Loss of muscle mass, known as sarcopenia, increases with age and has been linked to cognitive impairment.

References:

Australian Government, Department of Health and Aged care. (2021). Physical activity and exercise guidelines for all Australians. https://www.health.gov.au/health-topics/physical-activity-and-exercise/physical-activity-and-exercise-guidelines-for-all-australians?utm_source=health.gov.au&utm_medium=callout-auto-custom&utm_campaign=digital_transformation

Cox, K. L., Cyarto, E. V., Ellis, K. A., Ames, D., Desmond, P., Phal, P., Sharman, M. J., Szoeke, C., Rowe, C. C., Masters, C. L., You, E., Burrows, S., Lai, M., & Lautenschlager, N. T. (2019). A Randomized Controlled Trial of Adherence to a 24-Month Home-Based Physical Activity Program and the Health Benefits for Older Adults at Risk of Alzheimer's Disease: The AIBL Active-Study. Journal of Alzheimer's disease : JAD, 70(s1), S187–S205.

Lai, M.M.Y., Ames, D.J., Cox, K.L. et al. Association Between Cognitive Function and Clustered Cardiovascular Risk of Metabolic Syndrome in Older Adults at Risk of Cognitive Decline. J Nutr Health Aging 24, 300–304 (2020).

Livingston, G., Huntley, J., Sommerlad, A., Ames, D., Ballard, C., Banerjee, S., Brayne, C., Burns, A., Cohen-Mansfield, J., Cooper, C., Costafreda, S. G., Dias, A., Fox, N., Gitlin, L. N., Howard, R., Kales, H. C., Kivimäki, M., Larson, E. B., Ogunniyi, A., Orgeta, V., … Mukadam, N. (2020). Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. Lancet (London, England), 396(10248), 413–446.

Venkatraman, V. K., Steward, C. E., Cox, K. L., Ellis, K. A., Phal, P. M., Sharman, M. J., Villemagne, V. L., Lai, M., Cyarto, E. V., Ames, D., Szoeke, C., Rowe, C. C., Masters, C. L., Lautenschlager, N. T., & Desmond, P. M. (2020). Baseline White Matter Is Associated With Physical Fitness Change in Preclinical Alzheimer's Disease. Frontiers in aging neuroscience, 12, 115.

Venkatraman, V. K., Sanderson, A., Cox, K. L., Ellis, K. A., Steward, C., Phal, P. M., Gorelik, A., Sharman, M. J., Villemagne, V. L., Lai, M., Cyarto, E. V., Merkel, B., Ames, D., Szoeke, C., Rowe, C. C., Masters, C. L., Lautenschlager, N. T., & Desmond, P. M. (2020). Effect of a 24-month physical activity program on brain changes in older adults at risk of Alzheimer's disease: the AIBL active trial. Neurobiology of aging, 89, 132–141.

World Health Organisation. (2020). WHO guidelines on physical activity and sedentary behaviour. https://www.who.int/publications/i/item/9789240015128