By Nicha Talamona
We all know that exercising is good for our physical health, but what about the brain? As we age, we experience a natural decline in cognitive abilities like sustaining attention, memory and multitasking. With age we also become more susceptible to neurodegenerative diseases – like Alzheimer’s disease – which damage neurons, resulting in further cognitive decline.
So how can exercise help? Surprisingly, many studies have found that exercise interventions can slow cognitive decline and even improve cognitive ability in those suffering from Alzheimer’s disease and mild cognitive impairment, highlighting that exercise can have a significant role in maintaining and regaining brain health.
The Brain and Alzheimer’s Disease
Alzheimer’s disease is the most common type of dementia, affecting roughly 5.8 million Americans. The disease is characterized by memory loss and often results in impairment of language understanding and production, known as aphasia (Centers for Disease Control and Prevention [CDC], 2020) due to shrinkage in related brain regions. It has a profound effect on many other aspects of cognition, and can progress rapidly.
Alzheimer’s disease can impact:
- Memory
- Attention
- Communication
- Decision making
- Learning ability
- Personality
- Executive function (planning, setting goals, etc.)
- Coordination
(NIH National Institute on Aging [NIA], 2022)
Alzheimer’s disease progresses with time, causing impairments to worsen as brain volume is lost (NIA, 2024). Mild cognitive impairment (MCI) can be an early indicator of neurodegenerative disease, so it is also featured in much of the research on the efficacy of exercise interventions.
Exercise as Prevention
There is no such thing as a cure-all when it comes to diseases as complex as Alzheimer’s disease. Research shows that Alzheimer’s disease can be caused by a number of factors like genetics, environment, and lifestyle (Alzheimer’s Association, 2024).
While we can’t control our genetics, we can control our lifestyle through exercise and diet choices. Many studies have found that a lack of exercise is a significant risk factor for Alzheimer’s disease, with one study finding that physical activity can reduce risk by 45% (Hamer and Chida, 2008, cited in Meng et al., 2020).
A further meta-analysis (Sofi et al., 2011, cited in Huuha et al., 2022) found that low to moderate levels of physical exercise can reduce the risk of cognitive decline in the next 1-2 years by 35%! These studies indicate that consistent exercise is beneficial for your cognitive health, showing that a healthy lifestyle can significantly decrease risk of Alzheimer’s disease and dementia.
Exercise also stimulates the formation of new neurons (Neuroscience News, 2023) – this could be especially important to combat Alzheimer’s disease, which degrades neurons over time.
Limiting this risk factor by regularly exercising can clearly have a positive impact on cognitive health and aid in the prevention of Alzheimer’s disease. Due to this, some research has shifted its focus to intervention in order to explore exercise as a potential treatment for cognitive decline.
Exercise Interventions
Exercise may improve cognition through a number of mechanisms, including increased blood flow to the brain which improves nutrient supply and an increase in important growth factors which can improve brain structure and function (Mandolesi et al., 2018). Cognitive improvements can be measured using a variety of tests which can include many different activities such as memory tests, performing an action, and abstract thinking tests (Cleveland Clinic, 2022). Neuroimaging techniques like MRI could also be used to assess structural changes to the brain.
There are many different types of exercise, ranging from yoga to long distance running! So can any type of exercise improve our cognition? Or are specific exercises more helpful? Intense exercises cause our heart to beat faster, which makes blood flow around our body. This increase in circulation might contribute to improved blood flow to our brains.
Netz (2019) divides exercise into two distinct categories: physical, which are aerobic or strength related exercises and motor activities, which are exercises involving balance and coordination. For example, running would be physical exercise, and yoga would be a motor activity. Physical exercise studies have found that aerobic exercise can significantly reduce brain tissue loss in older adults and reduce the risk of cognitive impairment significantly (Erickson et al., 2010, cited in Netz, 2019).
Yoga and other ‘motor activities’ are well known for reducing stress. Chronic stress is thought to be a contributing factor to dementia (Alzheimer’s Society, 2022) so perhaps relaxing exercises like this could help. While more research is needed on the relationship between stress reduction and cognition, a review by Hoy et al. (2021) examined the research on the cognitive benefits of yoga. The review found that yoga interventions can improve memory, attention and information processing (amongst many other benefits) in healthy adults.
In Summary…
Much more research is needed to understand the relationship between exercise and cognition. There’s no way to say exactly which exercise is the best, as this depends on what is accessible, enjoyable and realistic for you. Ultimately, many studies find that regular exercise – usually 40-60 minutes multiple times a week – results in cognitive improvement and can prevent cognitive decline.
Both high intensity and relaxing forms of exercise have their own benefits. The main point is that exercise is beneficial to our health in a plethora of ways, so any form of exercise is worth it. Discover the types of exercise you enjoy most, as this will make it much easier to exercise regularly.
If you would like to know more about the benefits of exercising, have a look at some of the articles cited here.
Disclaimer: Before starting any exercise program, it is important to consult with a qualified healthcare professional or physician to ensure that it is safe for you to do so, especially if you have any pre-existing medical conditions, injuries, or concerns about your health.
References
Alzheimer’s Association. (2024). Causes and Risk Factors for Alzheimer’s Disease. Retrieved 29 Feb, 2024, from https://www.alz.org/alzheimers-dementia/what-is-alzheimers/causes-and-risk-factors#:~:text=Researchers%20believe%20there%20isn’t,as%20genetics%2C%20lifestyle%20and%20environment.
Alzheimer’s Society. (2022). Can stress cause dementia? Retrieved 9 Mar, 2024, from https://www.alzheimers.org.uk/blog/can-stress-cause-dementia
Centers for Disease Control and Prevention. (2020). Alzheimer’s Disease and Related Dementias. Retrieved 29 Feb, 2024, from https://www.cdc.gov/aging/aginginfo/alzheimers.htm#:~:text=Alzheimer’s%20disease%20is%20the%20most,thought%2C%20memory%2C%20and%20language.
Cleveland Clinic (2022) Cognitive Test. Retrieved 9 Mar, 2024, from https://my.clevelandclinic.org/health/articles/22306-cognitive-test
Hoy, S., Östh, J., Pascoe, M., Kandola A., Hallgren, M. (2021). Effects of yoga-based interventions on cognitive function in healthy older adults: A systematic review of randomized controlled trials. Complementary Therapies in Medicine, 58. https://doi.org/10.1016/j.ctim.2021.102690 This work is licensed under CC BY 4.0
Huuha, A. M., Norevik, C. S., Moreira, J. B. N., Kobro-Flatmoen, A., Scrimgeour, N., Kivipelto, M., Praag, H. V., Ziaei, M., Sando, S. B., Wisløff, U. and Tari, A. R. (2022). Can exercise training teach us how to treat Alzheimer’s disease? Aging Research Reviews, 75. https://doi.org/10.1016/j.arr.2022.101559 This work is licensed under CC BY 4.0
Image by macrovector on Freepik (www.freepik.com) https://www.freepik.com/free-vector/brain-anatomy-composition-with-isolated-profile-view-human-brain-with-colored-parts-text-captions-vector-illustration_43869051.htm#fromView=search&page=1&position=43&uuid=1607c3f6-9c95-4e3e-8499-05f931aff5d9
Mandolesi, L., Polverino, A., Montuori, S., Foti, F., Ferraioli, G., Sorrentino, P. and Sorrentino, G. (2018). Effects of Physical Exercise on Cognitive Functioning and Wellbeing: Biological and Psychological Benefits. Frontiers in Psychology, 9. https://doi.org/10.3389/fpsyg.2018.00509 This work is licensed under CC BY 4.0
Meng Qing, Lin Muh-Shi, Tzeng I-Shiang. (2020). Relationship Between Exercise and Alzheimer’s Disease: A Narrative Literature Review. Frontiers in Neuroscience, 14. https://doi.org/10.3389/fnins.2020.00131 This work is licensed under CC BY 4.0
Netz, Y. (2019). Is There a Preferred Mode of Exercise for Cognition Enhancement in Older Age?—A Narrative Review. Frontiers in Medicine, 6. https://doi.org/10.3389/fmed.2019.00057 This work is licensed under CC BY 4.0
Neuroscience News (2023) Exercise and the Brain: The Neuroscience of Fitness Explored. Retrieved 9 Mar, 2024, from https://neurosciencenews.com/fitness-neuroscience-23228/
NIH National Institute on Aging. (2022). What Are the Signs of Alzheimer’s Disease? Retrieved 29 Feb, 2024, from https://www.nia.nih.gov/health/alzheimers-symptoms-and-diagnosis/what-are-signs-alzheimers-disease
NIH National Institute on Aging. (2024). What Happens to the Brain in Alzheimer’s Disease? Retrieved 29 Feb, 2024, from https://www.nia.nih.gov/health/alzheimers-causes-and-risk-factors/what-happens-brain-alzheimers-disease#:~:text=Loss%20of%20neuronal%20connections%20and%20cell%20dysfunction&text=By%20the%20final%20stages%20of,the%20loss%20of%20brain%20volume.