By Clarinda J. Hougen, MD, and Eugene C. Lee, MD, CYT
Dr. Hougen is Resident Physician in Family Medicine, MacNeal Hospital Loyola University Health System, Chicago.
Dr. Lee is Assistant Professor of Family Medicine, MacNeal Family Medicine Residency, Berwyn IL.
Summary Points
- Dancing provides superior benefits in improvement of balance to healthy elderly adults compared to cardiovascular fitness sport, with implications for quality of life in aging.
- Physical activity induces increases in hippocampal volume; dancing, with its enhanced cognitive and sensory stimulation, leads to an increase in more hippocampal regions than aerobic physical fitness alone.
- The relationship between hippocampal growth and balance enhancement remains unclear.
SYNOPSIS: This prospective cohort study found that healthy volunteers aged 63-80 years who participated in 18 months of a dance intervention experienced an increase in more hippocampal regions and greater improvements in balance compared to their age- and sex-matched peers who underwent 18 months of an aerobic fitness intervention.
SOURCE: Rehfeld K, Müller P, Aye N, et al. Dancing or fitness sport? The effects of two training programs on hippocampal plasticity and balance abilities in healthy seniors. Front Hum Neurosci 2017;11:305.
Hippocampal aging results in deficits in memory, learning, and spatial navigation, a process that accelerates with increasing age, especially over the age of 70 years.1 Aging-related declines in balance and memory result in reduced quality of life and increased morbidity and mortality in the elderly. Notably, one in three adults older than 65 years of age is affected by fall-related injuries annually, and these injuries contribute substantially to overall healthcare expenditures in both the United States and Europe.2,3 However, the hippocampus is one of the few brain regions that demonstrates neuroplasticity throughout human life. Previous studies have shown that aerobic training at higher cardiorespiratory levels (VO2 max) are associated with higher hippocampal volumes in late adulthood, which may correlate with better memory function.4
Furthermore, dancing may be an especially beneficial activity because of the engagement of multiple cognitive processes (learning, memory, coordination) in addition to incorporating cardiovascular fitness. Cardiovascular fitness training appears to correlate with an increase in left hippocampal volume, while coordination and balance training may correlate more strongly with an increase in right hippocampal volume, suggesting differing functions in each of these areas of the brain.
Rehfeld et al launched a prospective, randomized longitudinal trial that sought to compare improvements in memory and balance between two groups of older adults — one of which was assigned to a specially designed dance program, and the other was assigned to a cardiovascular fitness program with repetitive exercises, such as cycling or Nordic walking. A total of 62 healthy volunteers aged 63-80 years were recruited for cognitive and physical screening. Exclusion criteria included any history of severe neurological conditions, metal implants, claustrophobia, tinnitus, physical activity greater than one hour weekly, cognitive impairments on Mini-Mental State Examination, or depressive symptoms (Beck’s Depression Inventory I-II > 13).
Fifty-two participants were randomly assigned to either the dance or aerobic sport group. After 18 months, there were 14 dancers and 12 sportsmen remaining in the study. The mean age of patients who finished the trial was 67.9 ± 3.3 years. There was no significant difference in age, sex, education, or body mass index (BMI) between the two groups. Study data were collected initially at month 0, after six months of starting the intervention, and at 18 months.
The intervention included training sessions in either dance or fitness sport twice a week for 90 minutes for the first six months then once a week for the subsequent 12 months. The dance classes included constantly changing choreography and required memorization of series of steps as well as arm patterns that moved away from the center of pressure. The sport fitness intervention included endurance training, strength-endurance training, and flexibility training. During the first six months, these participants took part in cycling, while the second 12 months’ intervention was Nordic walking. The sports fitness program purposefully avoided combined arm and leg movements.
T1-weighted magnetic resonance images of the hippocampus were acquired and divided into five subfields (CA1-CA3 of the cornu ammonis, dentate gyrus/CA4, and subiculum) for analysis with repeated measurement analyses of variance (ANOVAs). They then used the Sensory Organization Test implemented in the Balance Master System to assess postural control under six standard conditions in three trials for 20 seconds each.
A composite score then was calculated. Statistical analysis of hippocampal volumes and balance data were performed with SPSS. The dance and sports-intervention groups were compared to each other, as well as pre- and post-intervention, using repeated measurement ANOVAs. T-tests were used to compare longitudinal changes, unless the normal distribution was missing, in which case the Mann Whitney U-test or Wilcoxon were used.
Both the fitness sport intervention and dancing resulted in an increase in overall hippocampal volume, but only dancing demonstrated a significant increase in right hippocampal volume whereas sport resulted in an increase only in left hippocampal volume. (See Table 1.) Using paired t-tests, the investigators showed that the dance intervention demonstrated a significant increase in more areas of the hippocampus than the fitness sport intervention. (See Table 2.) Finally, repeated measurement ANOVAs showed that the dancers experienced a significant increase in all three tested postural control mechanisms — somatosensory, visual, and vestibular — compared to the fitness sportsmen, who only experienced significant increases in two — somatosensory and vestibular. (See Table 3.) Correlation analysis between all hippocampal subfields and balance did not yield any significant results. There were no apparent adverse effects of this study.
Table 1. Difference in Hippocampal Volume in Sport vs. Dance |
||
| Sport vs. Dance | P Value | |
Hippocampal volume pre-intervention |
No significant difference |
0.658 |
Hippocampal volume post-intervention |
Overall increase in hippocampal volume with either intervention; greater increase in right hippocampal volume with dancing |
0.001 |
Table 2. Effect on Hippocampal Volumes of Five Different Anatomical Subsections Pre- vs. Post-Intervention |
|||
| Hippocampal Area | Sport | Dance | P Value |
Left CA1 |
Increase |
Increase |
< 0.05 |
Left CA2 |
Increase |
Increase |
< 0.05 |
Left subiculum |
Increase |
Increase |
< 0.05 |
Left CA4/dentate gyrus |
No significant difference |
Increase |
< 0.05 |
Right CA1 |
No significant difference |
No significant difference |
|
Right CA2 |
No significant difference |
No significant difference |
|
Right subiculum |
No significant difference |
Increase |
< 0.05 |
Right CA4/dentate gyrus |
No significant difference |
No significant difference |
|
Table 3. Effect on Postural Control Mechanisms Pre- vs. Post-Intervention |
||
| Sport | Effect | P Value |
Somatosensory |
Increase |
0.006 |
Visual |
No significant difference |
N/A |
Vestibular |
Increase |
0.004 |
| Dance | ||
Somatosensory |
Increase |
0.004 |
Visual |
Increase |
0.027 |
Vestibular |
Increase |
0.007 |
COMMENTARY
The results of this small, prospective cohort study add to the large existing body of research promoting regular physical activity to enhance well-being and quality of life in old age. Previous studies have shown that regular vigorous activity is strongly correlated with longevity, as compared to leading a sedentary lifestyle.3,5,6 This may be a result of higher levels of growth hormones, such as brain-derived neurotrophic factor, insulin-like growth factor-1, and vascular endothelial growth factor, that previous studies have shown are induced by increased cardiac output and skeletal muscle activity, and which promote new capillary formation and synaptic plasticity.7-9
Additionally, physical activity has been linked to increases in volume of several different areas of the brain, including the frontal and entorhinal cortices and the hippocampus, which correlates with improvements in memory, cognition, and executive functioning.
While the existing literature clearly demonstrates that aerobic physical fitness in any form is beneficial to an individual’s overall health, the present study suggests that dancing, as a form of physical activity, is superior to other, more repetitive forms of exercise that lack a focus on balance and coordination or that do not require constant learning and memorization of new combinations of steps.
The role of the visual system in balance is demonstrated in the outcomes of this study — in other words, the dance program, which placed particular emphasis on practicing movements that intentionally required engaging all mechanisms of balance, resulted in significant improvement in all three measured areas, unlike aerobic fitness training alone. Intuitively, the coordination of movements in three-dimensional space, as would be required of dancing but not necessarily in simple aerobic activity, exercises visual perception of that space, so this result is perhaps unsurprising. In the context of making recommendations to elderly patients when choosing between different types of training, three-dimensional visual awareness of the individual’s environment and corresponding improvement in balance and coordination likely is beneficial in reducing the risk of injury or falls, although the degree of reduction would realistically be difficult to measure.
While the data collected herein appear both intuitive and statistically significant, this study was limited by its small sample size of only 26 total participants who completed the entire 18 months of training. It is not stated clearly why such a small fraction of the initially recruited study participants ultimately was able to complete the training course. The investigators also were not able to show a significant correlation between changes in hippocampal subfield volumes and improvements in balance. Thus, it is unclear from these data what the functional implications of the observed volumetric increases are. Additionally, the authors do not comment on any effect of simultaneously listening to music while exercising on improvements in memory, nor do they appear to control for this between the two groups.
Despite these limitations, clinicians should not hesitate to prescribe dance as a fun, low-risk, potentially superior program of exercise for older adults. Dancing uniquely relies on the individual’s perception of three-dimensional space and trains participants to focus on balance, memorization, and coordination — skills that are well worth trying to preserve to maintain functional status and quality of life in the elderly. The positive social interactions that are likely to come along with dancing also are an important factor to take into consideration when recommending an exercise regimen to an often socially isolated older population, given that this also can affect cognitive and functional decline.
REFERENCES
- Jack CR Jr, Petersen RC, Xu Y, et al. Rate of medial temporal lobe atrophy in typical aging and Alzheimer’s disease. Neurology 1998;51:993-999.
- Ambrose AF, Paul G, Hausdorff JM. Risk factors for falls among older adults: A review of the literature. Maturitas 2013;75:51-61.
- Marques EA, Baptista F, Santos DA, et al. Risk for losing physical independence in older adults: The role of sedentary time, light, and moderate to vigorous physical activity. Maturitas 2014;79:91-95.
- Erickson KI, Voss MW, Prakash RS, et al. Exercise training increases size of hippocampus and improves memory. Proc Natl Acad Sci U S A 2011;108:3017-3022.
- van Leeuwen KM, van Loon MS, van Nes FA, et al. What does quality of life mean to older adults? A thematic synthesis. PLoS One 2019;14:e0213263.
- Yates LB, Djoussé L, Kurth T, et al. Exceptional longevity in men. Arch Intern Med 2008;168:284-290.
- Hardcastle C, O’Shea A, Kraft JN, et al. Contributions of hippocampal volume to cognition in healthy older adults. Front Aging Neurosci 2020;12:593833.
- Zammit AR, Ezzati A, Zimmerman ME, et al. Roles of hippocampal subfields in verbal and visual episodic memory. Behav Brain Res 2017;317:157-162.
- Foster PP. How does dancing promote brain reconditioning in the elderly? Front Aging Neurosci 2013;5:4.
This prospective cohort study found that healthy volunteers aged 63-80 years who participated in 18 months of a dance intervention experienced an increase in more hippocampal regions and greater improvements in balance compared to their age- and sex-matched peers who underwent 18 months of an aerobic fitness intervention.
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