Dancing can counteract age-related decline in physical and mental abilities, new research shows.
Investigators at the German Center for Neurodegenerative Diseases in Magdeburg, Germany, found that older people who routinely partake in physical exercise can reverse the signs of aging in the brain, but it's dancing that has the most profound effect.
"The results of our study suggest that participating in a long-term dance program that requires constant cognitive and motor learning is superior to engaging in repetitive physical exercises in inducing neuroplasticity in the brains of seniors," study author Patrick Müller, a PhD candidate at the German Center for Neurodegenerative Diseases, told Medscape Medical News.
"Therefore, dance is highly promising in its potential to counteract age-related gray matter decline," he said.
The study was published online June 15 in Frontiers in Human Neuroscience.
For the study, the investigators compared an 18-month dance training program to 18 months of endurance and flexibility training in improving hippocampal volume and balance in healthy senior volunteers (aged 63 to 80 years).
The researchers studied the hippocampus (HC) because it is associated with learning, memory, and balance and also is the site of adult neuroplasticity in the brain.
Both groups showed increases in hippocampal volume. However, the dancers also showed increases in regions most strongly associated with neuroplasticity. In addition, only the dancers displayed significant improvement in balance.
The HC "is affected not only by pathological aging such as in Alzheimer's disease but also by the normal aging process resulting in deficits in memory, learning, and spatial navigation at old age," the authors write.
Although MRI studies demonstrate that the HC atrophies with each decade and that the process "accelerates in very old age," other research suggests that the HC "counts among the few brain regions with the ability to generate new neurons throughout the lifespan."
Aerobic fitness and training have been shown to improve hippocampal volume, which may contribute to better memory function. However, the mechanism of this association and the role of cardiorespiratory fitness in modulating hippocampal gray matter volume are "still under debate."
The HC is also involved in spatial navigation and motor sequence consolidation, "suggesting that motor skill learning and motor fitness can have an impact on hippocampal volume without any cardiorespiratory change," the authors note.
Previous research suggests that motor skill training and balance training can lead to "morphological alterations" in the brain and increases in hippocampal gray matter.
"These findings highlight the behavioral relevance of structural brain plasticity in the HC for the learning process," they note.
Dancing involves the "integration of sensory information from multiple channels (auditory, vestibular, visual, somatosensory)" and "fine-grained motor control of the whole body."
Mambo, Grapevine, Cha-Cha-Cha
Previous studies have provided evidence of improved performance on balance and memory tasks in elderly dancers, but the underlying neural mechanisms "have not been addressed comprehensively so far."
"We know from animal research that combining physical activity with sensory enrichment has stronger and longer-lasting effects on the brain than either treatment alone," said Müller.
The current study was designed to investigate that theory, he said, noting that it built on previous research conducted by his group suggesting that the effect is mediated by brain-derived neurotrophic factor.
The authors conducted a prospective, randomized, longitudinal trial in healthy seniors that compared a specially designed dance program that required participants to continually learn new choreography and a traditional fitness program consisting of repetitive exercises, such as cycling on an ergometer or Nordic walking.
The researchers used voxel-based morphometry to conduct whole-brain analyses in the precentral and parahippocampal gyrus. They noted that the hippocampus is not homoegeneous but consists of specialized subfields, including the subiculum, cornu ammonis (CA) 1 - 4, and the dentate gyrus (DG).
They investigated these regions because the subiculum is involved in working memory and spatial relations, CA3 and DG are involved in memory and early retrieval, and CA1 is involved in late retrieval, consolidation, and recognition. Although all of these regions are interconnected, the DG is one of the few regions of the adult brain in which neurogenesis occurs.
They also assessed the effects of the interventions on balancing capabilities and their relationship to hippocampal subfield volumes, because the hippocampus is also known to be involved with balance.
The first 6 months of training consisted of twice-weekly 90-min dancing or fitness classes. From months 6 through 12, the number of sessions was reduced to one per week.
Dance classes involved constantly changing choreographies, which participants were required to memorize accurately. Single-leg stances, skips and hops, steps used in chasseé, mambo, cha-cha, grapevine, and jazz square were designed to "challenge the balance system." Also included were patterns in which participants moved their arms away from the center of pressure.
The dance group's routines in the different genres were changed every second week to keep particpants engaged in a constant learning process. They were required to recall the routines under pressure of time and without cues from the instructor.
The traditional fitness-training program included mostly repetitive sequences of endurance training, strength-endurance training, and flexibility training (stretching and mobility exercises). During the first 6 months, participants engaged in a bicycle activity. During the second period of the study (12 months), the participants completed a Nordic walking program.
The researchers used MRI and voxel-based morphometry with hippocampal mask and analyzed volume changes in five subfields of the HP: the CM (CA1-CA3), DG (including CA4), and subiculum.
Thwarting a Major Health Risk
Postural control was assessed using the Sensory Organization Test, which provides information about the contribution of the visual, somatosensory, and vestibular systems in the maintenance of balance.
Of the participants, 14 members of the dance group (aged 67.21 ± 3.78 years, seven women), and 12 members of the fitness group (aged 68.67 ± 2.57 years, five women) participated for the entire 18-month study period.
There were no group differences at baseline.
To explore changes in hippocampal gray matter volume during the intervention, the researchers used repeated comparisons of baseline and posttest values. They found a significant interaction effect in the right hippocampus (MNI-coordinates: x = 28, y = −16, z D = −23; P [FDR] = 0.049, F + 17.03]). But post hoc paired t-tests showed significant increases in right hippocampal volume only in the dance group (MNI-coordinates: x = 29, y = −16, z D = −27; P [FDR] = 0.001, t = 6.10]).
There were no group differences at baseline. However, repeated measurement of hippocampal subfield volumes showed a main effect of time in the left CA1, the left CA2, the left and right subiculum, and the left CA4/DG.
Although there were no significant interactions by group, paired t -tests showed significant volume increases for the dancers in the left CA1, the left CA2, the left CA4, the DG, and the left and right subiculum. For the exercise group,volume increases were observed in the left CA1, the left CA2, and the left subiculum.
On the composite equilibrium score, repeated measurement of balance data showed an interaction effect with group. In particular, there was a "main effect of time" in the somatosensory and vestibular contribution, but no significant time × group interaction effects after 18 months of fitness training.
Post hoc tests revealed that the dancers improved in the use of the sensory, visual, and vestibular systems (P = .004, P = .027, and P = .007, respectively). The exercise group improved in the use of the somatosensory and vestibular systems (P = .006 and P = .004, respectively) but not in the visual system.
"We know from animal research that combining physical activity with sensory enrichment has stronger and longer-lasting effects on the brain than either treatment alone," Müller noted.
"For humans, dancing has been suggested to be analogous to such training, and we presume that the advantage is related to the multimodal nature of dancing, which combines physical, cognitive, and coordinative challenges," he explained.
The authors add that balancing is "an important everyday function crucial, for example, for social mobility" and that impaired balance leads to falls, which constitute a "major health risk factor and consequences both on morbidity (and even mortality) and health care costs."
The authors note that the lack of an inactive control group, the small sample size, and the relatively small change in the overall score limit their findings.
Commenting on the study for Medscape Medical News, Madeleine E. Hackney, PhD, assistant professor of medicine, Division of General Medicine and Geriatrics, Emory School of Medicine, Atlanta, Georgia, said the study "provides promising initial evidence that multimodal physical activity, which is both mentally and physically challenging, may directly alter the central nervous system specifically in areas involved in memory operations."
The findings "will justify future larger trials that may or may not confirm these findings," said Dr Hackney, who was not involved with the study.
She noted study limitations beyond those cited by the authors. The control group switched from ergometer cycling during the first 6 months to the Nordic walking program during the remaining 12 months, and the cycling "would not be expected to benefit balance," although walking might have done so.
Additionally, the authors state that they "avoided combined arm and leg movement" in the control group so as to minimize coordinative demands, "but that is hard to imagine in a Nordic walking program."
Nevertheless, "the results are compelling and the methods the researchers employed seem to be vigorous," she said.
The study has important take-home messages for practicing clinicians, she emphasized.
"Exercise is good for you, and certainly traditional cardiovascular/resistance training has its place. However, dance typically will engage more cognitive resources and may be ultimately more functional because movements are trained, not just specific muscles."
Müller stressed that the study can fill an important gap in approaches to dementia prevention in that there is a "demographically induced increase in the prevalence of dementia on the one hand and a lack of causal pharmacologic therapies on the other hand." Preventing dementia by modifying lifestyle factors is therefore of increasing importance.
"Our study results suggest that 'social enrichment' and a combination of physical and cognitive activities influences neuroprotection best," he said.
He added that beyond dancing, "a healthy lifestyle and physical exercise in general can help the brain stay young."
The authors and Dr Hackney have disclosed no relevant financial relationships.
Front Hum Neurosci. Published online June 15, 2017. Full text
Medscape Medical News © 2017
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