# Exercise as it relates to Disease/Exercise, your supplement to a bigger brain in old age

The following Wikibooks site is a detailed evaluation of the journal article " Aerobic Exercise Training Increases Brain Volume in Aging Humans' published by Colcombe SJ, Erickson KI, Scalf PE, Kim JS, Prakash R, McAuley E, Elavsky S, Marquez DX, Hu L, Kramer AF. (2006)

## What is the background to this research?

Changes to brain structures present as inevitable process of ageing. The volume of the brain experiences declines and in particular the temporal, frontal and parietal lobes, associated with many cognitive activities including memory and information processing, are subject to the greatest reductions. In turn increasing the risk of developing further implications on cognition in later life. However lifestyle factors can influence the rate of cognitive decline, therefore maintaining a healthier lifestyle with adequate physical activity and nutrition is likely to help preserve cognition. Yet research on the positive effects of exercise in terms of the physical brain structures is quite limited and has been predominately conducted with animals. Thus with 131.5 million people worldwide predicted to suffer from dementia specifically by 2050 and increasing care expenses, research into potential methods to alleviate this problem is essential. Implementing aerobic exercises could potentially function as a protective mechanism as proposed by Colcombe and Colleagues (2006).

## Where is the research from?

The research was conducted at Beckman Institute at the University of Illinois, United States of America, with the assistance of the National Institute on Aging and Institute for the Study of Aging. The Beckman Institute’s Lifelong Brain and Cognition Lab have published an array of research particularly in neurophysiology for numerous years. Additionally many of the authors within this study have had long histories of research within exercise and brain health.

## What kind of research was this?

A randomised control trial was utilised to obtain the data. Randomised control trials aim to display if causal relationships between intervention techniques and results can be established. Utilising this method, consists of randomly assigning participants into either treatment groups, and or control groups, a placebo is given to serve as a comparison. Review of the literature, meta-analyses, of the use of randomised control trials within exercise and brain health have also been displayed to correlate with enhancements in cognitive functioning.

## What did the research involve?

59 inactive adults aged between 60–79 years, with no health complications were recruited. Participants were randomly assigned to either a 6 month aerobic training intervention or a control training intervention of stretching and toning. Both of which were performed 3 times a week for 1 hour. Measurements in the study were taken pre and post the 6 months and assessed peak oxygen uptake with treadmill graded exercise tests and magnetic resonance imaging (MRI) scans evaluated the structural modifications in the brain. In particular the sizes of gray and white matter areas, which function predominantly in neuronal transmissions and reception, were observed. 20 adults aged 18–30 years were recruited to participate as controls for MRI scanning and were not instructed to exercise.

## What were the basic results?

Participants within the aerobic exercise intervention experienced a substantial increase in the size of both the gray and white matter areas predominately within the temporal and prefrontal lobes in comparison to the non-aerobic exercise intervention and the 20 younger MRI control participants. These results are of importance as frequently these lobes are likely to experience the most significant changes due to the ageing process and have the potential to lead to diseased states. In particular schizophrenia is associated with declines in the prefrontal lobe and Alzheimer’s disease is related to decreases in the temporal lobe.

## What was the analysis of the results?

Aerobic training is likely to be beneficial to brain health due to the increases in brain volume. The researchers proposed these results are due to alterations in nerve cell growth and survival, the growth of capillary beds and greater amounts of dendritic spines, which play a role in obtaining transmissions from other synapses, the connections between two nerve cells. Similar to the findings of many previous animal studies and the limited amounts of human studies that have been conducted.
The researchers however stated the interpretation of these results requires careful evaluation. A sample of only 59 healthy adults presents issues in terms of its applicability to wider population groups and if people diagnosed with cognitive impairments can benefit as well. The association between the structural changes and cognitive performances cannot be determined as cognitive assessments were not conducted pre and post the interventions. In addition there is limited knowledge about the physiological cellular modifications, which may have presented to cause the changes in brain structure.

## What conclusions can be drawn from this research?

This research provided the initial insight into the positive implications exercise can have on brain structure in later life. However as a result of the limitations mentioned, the researchers specified more thorough study with greater samples and implementing cognitive assessments throughout the intervention is required. Recent research utilising larger sample sizes has provided more extensive knowledge into the mechanisms to which developing good cardiorespiratory fitness has in positively impacting the volume of the brain across a vast number of areas. Additionally recent studies have also offered deeper insight into the diverse age groups in which beginning aerobic exercise can be effective.

## What are the practical implications of this research?

Findings presented in this research demonstrate aerobic exercises increased potential to operate as a successful method to reduce the risk of cognitive impairments with increasing age. In turn possibly lessening the medical burden of treatment costs for cognitive disease such as dementia. Yet additional study to gain greater understanding of the mechanisms and specific intensity levels and duration of exercise is required to establish effective strategies to preserve and increase cognition throughout the lifespan.

## Further information and resources

For addition information on the effect of exercise on ageing and brain health see the proceeding links:
* Basic Neuroscience: http://www.qbi.uq.edu.au/brain-facts/neuroscience-basics-action-potentials-and-synapses
* What is Mild Cognitive Impairment and Treatment Options:https://www.fightdementia.org.au/about-dementia-and-memory-loss/about-dementia/memory-loss/mild-cognitive-impairment
* Exercise and Dementia: https://www.fightdementia.org.au/files/helpsheets/Helpsheet-DementiaQandA08-PhysicalExercise_english.pdf
* Exercise Releases Brain-Healthy Protein: https://directorsblog.nih.gov/2016/06/28/exercise-releases-brain-healthy-

## References

* 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Colcombe SJ, Erickson KI, Scalf PE, Kim JS, Prakash R, McAuley E, Elavsky S, Marquez DX, Hu L, Kramer AF. Aerobic exercise training increases brain volume in aging humans. Journals of Gerontology: Series A: Biological Sciences and Medical Sciences [Internet]. 2006 [cited 18th of September]; 61(11):1166-1170.
* 1 2 Kramer AF, Erickson KI. Capitalizing on cortical plasticity: influence of physical activity on cognition and brain function. Trends in cognitive sciences [Internet]. 2007 Aug 31[cited 18th of September]; 11(8): 342-348.
* 1 2 Black JE, Isaacs KR, Anderson BJ, Alcantara AA, Greenough WT. Learning causes synaptogenesis, whereas motor activity causes angiogenesis, in cerebellar cortex of adult rats. Proceedings of the National Academy of Sciences [Internet]. 1990 Jul 1 [cited 18th of September]; 87(14):5568-72.
* 1 2 Rhyu IJ, Bytheway JA, Kohler SJ, Lange H, Lee KJ, Boklewski J, McCormick K, Williams NI, Stanton GB, Greenough WT, Cameron JL. Effects of aerobic exercise training on cognitive function and cortical vascularity in monkeys. Neuroscience [Internet]. 2010 Jun 2 [cited 18th of September]; 167(4): 1239-48
* ↑ Fightdementiaorgau. Key facts and statistics 2016 [Internet]. Canberra: Alzheimer’s Australia; February 2016; [cited 18th of September]. Available at: https://www.fightdementia.org.au/about-dementia/statistics.
* ↑ Beckman Institute for Advanced Science and Technology at the University of Illinois at Urbana-Champaign. Publications [Internet]. Illinois: Beckman Institute; September 8, 2016; [cited 18th of September]. Available at: http://lbc.beckman.illinois.edu/publications.
* 1 2 Oberlin LE, Verstynen TD, Burzynska AZ, Voss MW, Prakash RS, Chaddock-Heyman L, Wong C, Fanning J, Awick E, Gothe N, Phillips SM, Mailey E, Ehlers D, Olson E, Wojcicki T, McAuley E, Kramer AF, Erickson KI. White matter microstructure mediates the relationship between cardiorespiratory fitness and spatial working memory in older adults. NeuroImage [Internet]. 2016 May 1 [cited 18th of September]; 131:91-101.
* 1 2 Voss MW, Erickson KI, Prakash RS, Chaddock L, Kim JS, Alves H, Szabo A, Phillips SM, Wójcicki TR, Mailey EL, Olson EA. Neurobiological markers of exercise-related brain plasticity in older adults. Brain, behavior, and immunity [Internet]. 2013 Feb 28 [cited 18th of September]; 28:90-99.
* 1 2 Colcombe S, Kramer AF. Fitness effects on the cognitive function of older adults a meta-analytic study. Psychological science [Internet]. 2003 Mar [cited 18th of September]; 114(2): 125-130.
* ↑ Sibbald B, Roland M. Understanding controlled trials. Why are randomised controlled trials important?. BMJ: British Medical Journal [Internet]. 1998 Jan 17 [cited 18th of September]; 316(7126): 201.
* ↑ Smith PJ, Blumenthal JA, Hoffman BM, Cooper H, Strauman TA, Welsh-Bohmer K, Browndyke JN, Sherwood A. Aerobic exercise and neurocognitive performance: a meta-analytic review of randomized controlled trials. Psychosomatic medicine [Internet]. 2010 Apr [cited 18th of September]; 72(3): 239-252.
* ↑ Woodruff A. Neuroscience Basics – Neurons, Action Potentials and Synapses [Internet]. Queensland: The University of Queensland, Australia; 2016 [cited 18th of September]. Available at: http://www.qbi.uq.edu.au/brain-facts/neuroscience-basics-action-potentials-and-synapses.
* ↑ Trejo JL, Carro E, Torres-Alemán I. Circulating insulin-like growth factor I mediates exercise-induced increases in the number of new neurons in the adult hippocampus. The Journal of Neuroscience [Internet]. 2001 Mar 1 [cited 18th of September]; 21(5): 1628-1634.
* ↑ Churchill JD, Galvez R, Colcombe S, Swain RA, Kramer AF, Greenough WT. Exercise, experience and the aging brain. Neurobiology of aging [Internet]. 2002 Oct 31 [cited 18th of September]; 23(5): 941-955.
* ↑ Tan ZS, Spartano NL, Beiser AS, DeCarli C, Auerbach SH, Vasan RS, Seshadri S. Physical Activity, Brain Volume, and Dementia Risk: The Framingham Study. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences [Internet]. 2016 Jul 15 [cited 18th of September]; glw130.
* ↑ Tian Q, Studenski SA, Resnick SM, Davatzikos C, Ferrucci L. Midlife and Late-Life Cardiorespiratory Fitness and Brain Volume Changes in Late Adulthood: Results From the Baltimore Longitudinal Study of Aging. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences [Internet]. 2016 Jan 1 [cited 18th of September]; 71(1): 124-130