Mild Cognitive Impairement (MCI) - Not inevitable !

Benefits of Exercise on MCI

Mild cognitive impairment (MCI) is easily noticeable by people, but it is not serious enough to restrict people’s daily life. However, having MCI raises the chances of developing dementia, Alzheimer, or other memory related conditions (Rosenberg et al., 2013).                                     In general; assuming “overall loss of cognitive abilities with aging” is a very common misconception with most people. Actually, cognitive decline with aging may mostly be prevented or improved with healthy lifestyle such as regular vigorous exercise routines and a well-constructed diet. Sound difficult?  It is not really!

MCI can be developed from several factors which include long term use of specific medications, sensory changes (hearing, visual loss with aging or pain from physical condition such as arthritis), and changes in mood due to altered hormonal status (Larson et al., 1992). Research strongly suggests that exercise is the key to maintain and/or improve cognitive abilities as it can positively influence our body on the factors that were just mentioned. So we are going to review a bit further information about the significant benefits of exercise and physical activities and how they are related with MCI.

Our brain has high capacity for adjusting neural system according to different demands from either functional or structural changes in our body and this ability of the brain is called neuroplasticity (Hötting and Röder, 2013). On average, our brain shrinks by 5 percent per decade starting at the age of 40 which negatively affects neuroplasticity (Erickson et al., 2011). Much like sarcopenia, this can be fast-forwarded or slowed down depending on each individual’s lifestyle.

Research has consistently shown that aerobic exercise and neuro-resistance training is good way to slow down the deterioration in brain size and function, whereas sedentary lifestyle would do completely the opposite.  Cellular medicine has changed the

understanding of what muscle health is…We now know that muscles secrete special signalling molecules, that travel to other organ systems such as the brain, the heart, the bones and other organs.   These signalling molecules called ‘Myokines’ carry vital information and instructions to these other organ systems, stimulating a response and modifying their activity!  So far over 200 kinds of them!  For example, your brain improves memory because of specific neurotransmitters increased by training muscles.

This process is encouraged by stimulation of hippocampal brain-derived neurotrophic factor (BDNF), which is a type of protein found in hippocampus of our brain that is associated with long term memory and cognitive process (Erickson et al., 2011). Although multiple studies were reviewed, exercise intervention and participants in each study are different from one another which makes it difficult to clearly state which type, volume, intensity, and frequency of exercise would be best form of exercise program specifically for cognitive improvement. This is another factor that makes professional aid helpful as the trainee will be provided with the training regimen optimized for specifically him/herself. Also, exercise intervention used in most studies is 30-60 min of Low Intensity, Steady State (LISS) aerobic exercise which implies significant improvement in BDNF . To make the aerobic exercise more effective and gain progressive results, it would be wise to aid cardiovascular system with different type of cardiovascular training as well such as utilizing High Intensity Interval Training (HIIT). HIIT requires significantly shorter duration to yield equally satisfying cardiovascular gain compared to LISS (Weston et al., 2013) which makes it more efficient in improving cardiovascular ability in different aspects compared to LISS however anything related to brain health has not been established with HIIT yet. Thus, we can mix different type of cardiovascular training such as HIIT to supplement overall improvement in cardiovascular system and ultimately achieving facilitation of hippocampal neurogenesis and overall brain neuroplasticity with improved BDNF profile.

Liu -Ambrose and Donalson (2008) reviewed three randomized trials to see benefits of resistance training on seniors’ cognitive ability. The result was very positive and suggested resistance training as another equally effective training method to prevent cognitive deterioration compared to the cardiovascular training. Resistance training brings additional positive effects such as slowing down sarcopenia which is an important risk factor for increased chance of falls and fracture as well as physical disability. Postural issues that put major impact on physical performance of our body can be also positively altered through resistance training. Balanced musculoskeletal structure of the body would be the essence of anything related to human body movement which leads us to why resistance training is crucial in the exercise program. Importantly, resistance training reduces homocysteine level and increase Insulin-like Growth Factor 1 (IGF-1) (Tsai et al., 2015). High levels of homocysteine have been related to an increased risk of Alzheimer’s Disease and dementia. Normally, homocysteine would convert into two substances; SAMe and Gluthione; SAMe helps with depression, arthritis, and liver damage and gluthione is a strong antioxidant that slows aging process (Redfern, 2019). However, when there is insufficiency in specific nutrients due to imbalanced diet or lack of activity level, homocysteine level can increase above the ideal range and become neurotoxic (Tsai et al., 2015). IGF-1 is a hormone that has similar structure with insulin which produces anabolic effect (building) in adults and promotes improved cognitive performance (Kraemer and Ratamess, 2005). Considering all the potential benefits of resistance training including the mechanisms involving IGF-1 and homocysteine that are closely related to cognitive functions, it would be optimal to be included in the training regimen together with cardiovascular training to effectively prevent or improve MCI.

It is recommended for seniors to have exercise program individualized or tailored by specialists according to each person’s capabilities in order to match the person’s goals and maximize the benefits of exercise. Improvements including neurotrophin levels can only be optimally maintained when the exercise program provides appropriate intensity to the individual (Bherer et al., 2013).  Exercising below the optimal intensity range would not be sufficient stimulant to make changes to our brain and prolonged overly high intensity exercise can elevate the stress hormones cortisol, which may negatively influence BDNF level and cognitive function. How do we know?  Therefore, training with the supervision of professional can make it safe and effective as the program can be fine-tuned with adjustments along with progression in different variables. Given that other daily life factors, such as balanced diet and healthy postural habits, are well maintained, people would be able to see the outcome more evidently from different physical trainings and consequently reversing the cognitive decline with progression of BDNF profile or overall brain health.

written by Caleb Park, Kinesiologist BODiWORKS Institute

edited by the team at the BODiWORKS Institute

www.healthisfreedom.net

References

Bherer, L., Erickson, K. I., & Liu-Ambrose, T. (2013). A Review of the Effects of Physical Activity and Exercise on Cognitive and Brain Functions in Older Adults. Journal of Aging Research, 2013, 1-8. doi:10.1155/2013/657508

Erickson, K. I., Voss, M. W., Prakash, R. S., Basak, C., Szabo, A., Chaddock, L., . . . Kramer, A. F. (2011). Exercise training increases size of hippocampus and improves memory. Proceedings of the National Academy of Sciences, 108(7), 3017-3022. doi:10.1073/pnas.1015950108

Hötting, K., & Röder, B. (2013). Beneficial effects of physical exercise on neuroplasticity and cognition. Neuroscience & Biobehavioral Reviews, 37(9), 2243-2257. doi:10.1016/j.neubiorev.2013.04.005

Kraemer, W. J., & Ratamess, N. A. (2005). Hormonal Responses and Adaptations to Resistance Exercise and Training. Sports Medicine, 35(4), 339-361. doi:10.2165/00007256-200535040-00004

Larson, E. B., KuKull, W. A., & Katzman, R. L. (1992). Cognitive Impairment: Dementia And Alzheimers Disease. Annual Review of Public Health, 13(1), 431-449. doi:10.1146/annurev.publhealth.13.1.431

Liu-Ambrose, T., & Donaldson, M. G. (2008). Exercise and cognition in older adults: Is there a role for resistance training programmes? British Journal of Sports Medicine, 43(1), 25-27. doi:10.1136/bjsm.2008.055616

Redfern, R. (2019, January 09). Homocysteine: The Toxic Amino Acid. Retrieved from https://naturallyhealthynews.com/articles/healtharticles/homocysteine-the-toxic-amino-acid/

Rosenberg, P. B., Mielke, M. M., Appleby, B. S., Oh, E. S., Geda, Y. E., & Lyketsos, C. G. (2013). The Association of Neuropsychiatric Symptoms in MCI with Incident Dementia and Alzheimer Disease. The American Journal of Geriatric Psychiatry, 21(7), 685-695. doi:10.1016/j.jagp.2013.01.006

Tsai, C., Wang, C., Pan, C., & Chen, F. (2015). The effects of long-term resistance exercise on the relationship between neurocognitive performance and GH, IGF-1, and homocysteine levels in the elderly. Frontiers in Behavioral Neuroscience, 9. doi:10.3389/fnbeh.2015.00023

Weston, K. S., Wisløff, U., & Coombes, J. S. (2013). High-intensity interval training in patients with lifestyle-induced cardiometabolic disease: A systematic review and meta-analysis. British Journal of Sports Medicine, 48(16), 1227-1234. doi:10.1136/bjsports-2013-092576