Background: Today, Japan is becoming a super-aged society, with senior citizens already constituting over 21% of the population. In this situation, the question of how elderly people can extend their lives and enjoy independent lifestyles is becoming more important. The present study aims to clarify the relationship between the Quality of Life (QOL) of elderly females and their current oral functions and experiences of music and art education in early life.
Methods: We carried out a survey study focusing on elderly females (Takarazuka Revue Company OG group and general female group) by carrying out a questionnaire survey and comparing cognitive function, oral examinations, cerebral atrophy in magnetic resonance imaging, and other characteristics.
Results: It was shown that the Takarazuka Revue Company OG group had greater hippocampal volumes and significantly higher cognitive functions than the general female group. In addition, in the general female group, there was a significant correlation between a decrease in the number of remaining teeth and a decrease in activities in daily living, but in the Takarazuka Revue Company OG group, no such correlation was observed.
Conclusions: The results showed that those who have received art education as part of their careers over an extensive period since early life have higher levels of cognitive function, QOL, physical activity, social activity and life satisfaction compared with the general female group; showing that they sense a purpose in life and live with a positive attitude. In contrast, in the general female group, those who have continued to enjoy hobbies have higher levels of cognitive function, QOL, physical activity, social activity and life satisfaction than those who have not, thus showing that they live with a positive attitude.
As of 2009, in the demographic composition of Japan, the young population (ages 0–14 years) constituted 13.5%, the producing population (ages 15–64 years) constituted 64.1%, the elderly population (ages 65 years and older) constituted 22.4%, and the population of persons aged 75 years and older constituted 10.5%.1 This trend is expected to reach a peak in 2040, when the elderly population is expected to exceed 36%.2 Furthermore, the current percentage of elderly men and women relative to the overall population is 19.6% for men and 25.1% for women, and within the population of those aged 75 and older, 8.2% are men and 12.8% are women, which shows that women overwhelmingly enjoy longer lives.1 Furthermore, the average life expectancy for Japanese women has exceeded the age of 86 years, which has been the highest life expectancy in the world for 24 consecutive years.3 In Japanese society, one critical issue is how elderly women can enjoy a purpose in life and enjoy their lives with ‘health’ as defined by the WHO; that is, free from not only physical and mental handicaps but also social inconveniences. It is said that differences in an individual's positive attitude toward their own lifestyle, life history, social activities and other factors greatly affect their ‘health’. In addition, among elderly people, the recovery of oral functions, such as occlusion and dentition, is an important factor for not only ensuring energy for activities but also inhibiting deterioration in general bodily functions, such as brain functions, and ensuring quality of life (QOL), which includes factors such as longevity, independence and purpose in life.4–7 Additionally, higher masticatory satisfaction is correlated with higher levels of subjective happiness, better health practices and higher levels of physical activity.8,9 Furthermore, it has been reported that a lack of teeth and reduction in occlusal force are correlated with decreases in QOL,10–12 whereas music and art are related with improvements in QOL and brain activity.13,14 However, there are many aspects that are not yet fully understood.
The purpose of the present study was to survey the effects of oral functions, which are closely associated with food intake for health and the acquisition of energy for activities, on cognitive function, levels of depression, life satisfaction, masticatory satisfaction and changes in brain morphology caused by aging, including relationships with music and art education in early life, in order to extract environmental factors from these results for elderly women to live with physical and mental health, and with a purpose in life.
The present study has been approved by the Medical Ethics Committee of the Kobe University Graduate School of Medicine.
Participants provided informed consent in accordance with the provisions of the Declaration of Helsinki.
Because of continuing medical progress, improvements in nutritional status and other factors, the average life expectancy among Japanese people has increased rapidly and Japan has become the world's highest ranking country in terms of life expectancy; and with an average life expectancy of 86.05 years3 for women, healthy life expectancy is now becoming a big issue. In order to create a rich society of longevity, it is vital to extend healthy life expectancy so that people can live healthily and independently.
In order to actualize healthy longevity, even more than the mental and social environments of elderly people, it is important to maintain and restore past lifestyle habits as well as dietary habits necessary for maintaining health and the oral function that supports such habits for all elderly people. In the present study, in addition to these aspects, we analyzed the effects of experiences in receiving professional art education, the duration of such education and the subsequent continuance thereof, as well as the presence or absence of artistic experience as a hobby on the level of independence, QOL, cognitive function, degree of depression and level of daily activity of individual elderly people, and on the functional state of the oral cavity, morphological changes in the brain and other characteristics.
In a comparison of the subjects in the OG group with entertainment careers of 10 years or more with subjects in the overall general female group, the MMSE values were significantly higher in the former group. It is believed that one of the causal factors is that from early life, the subjects of the former group had been educated to learn ballet and music by heart within short periods of time through art education and had to attract audiences by their own expressive styles. As stage plays are an instantaneous art, we believe that concentration was also cultivated. In addition, it was found that within the OG group, individuals who had received art education for over 10 years had higher MMSE values than subjects with less than 10 years of art education, and the MMSE values were also high for subjects who stopped art activities at a later age. In addition, based on the fact that no significant differences were recognized in other items including MMSE values between individuals who were still continuing art activities and subjects who were not, it was clarified that receiving 10 or more years of art education in early life was one of the major factors for preventing decreases in cognitive function.
The results of the present study show that subjects who received art education for a prolonged period from early life tended to have better results regarding their cognitive function, physical activity, social activity and life satisfaction in comparison to general females; thus suggesting that they are able to find a purpose of life in this aging society and are living with a positive attitude. In contrast, in the control group, the GDS scores were significantly lower, and the QOL and masticatory satisfaction was higher among individuals who had continued their hobbies compared with subjects who had not. Based on these results, it was assumed that the subjects of the former group were therefore living with a positive attitude.
It was further shown that the LSI values were notably higher in the overall OG group compared with the overall general female group, and furthermore, within the overall OG group, individuals who had an entertainment career of 10 or more years had significantly higher LSI values than general female subjects with no experience in cultural activities. According to these results, it is assumed that individuals who had received education for stage art from early life had felt a sense of achievement and happiness in overcoming difficulties when they demonstrated the results of their daily practice in front of audiences, and they came to know the pleasure borne from hardship. In particular, it is believed that subjects with entertainment careers of 10 or more years store a sufficient sense of achievement and happiness from appearing on stage into their memories. However, as shown from the results of the questionnaire Survey 1, most of these subjects had been living as homemakers in much the same way as the general females, and the period of art education in early life before the age when they stopped receiving art education was the only term when they spent time in a different manner from general females. From these facts, we believe that subjects who had received art education for an extensive period from early life had made a life habit of finding happiness and joy even in daily life and live their lives positively.
Regarding the QOL and purpose of life, in comparisons of the subjects in the OG group with entertainment careers of 10 or more years and subjects in the control group with no experience of cultural activities, the QOL was higher in the former group. In contrast, it was also shown that for subjects in the control group, the continuation of cultural activities late in life affected improvements in QOL.
In addition, regarding relationships between the number of remaining teeth and GDS scores, it can be said that in the control group, the lack of right anterior teeth was significantly correlated with increases in GDS scores and the lack of left anterior teeth tended to increase GDS scores. At the same time, in the overall OG group, it was also clarified that the number of remaining anterior teeth was not associated with the GDS scores. Considering the difference between these two groups, the anterior teeth are generally an important factor that affect the beauty of an individual's facial appearance and are a major aesthetic factor, especially for females. Individual might feel a sense of psychological inferiority as a result of the lack of anterior teeth, which is believed to lead to a sense of psychological ‘melancholy’. Particularly for general females, it is also possible that they had become unable to bring themselves to leave the sidelines as a result of the aforementioned issue, leading to a form of social withdrawal, which is assumed to lead to ‘melancholy’. In contrast, although it is possible for subjects in the OG group to fall into a similar mind state, as a result of the education and discipline that they received to go on stage and place themselves at the forefront, they might seem to have a mentality of emphasizing physical and facial beauty; therefore, aesthetic restoration and sufficient care are provided for defective conditions and are believed to develop a normal state with an absence of feelings of psychological inferiority. We therefore believe there was no correlation between the number of remaining anterior teeth and depression for this reason.
In the control group, there was a marked correlation between the number of remaining left and right anterior and posterior teeth and ADL. In contrast, in the OG group, it was found that there was no correlation between the number of remaining teeth and ADL. Considering the difference between these two groups, it is believed that individuals in the OG group, who have received strict art education as a profession from early life, build up robust legs and waists through ballet or classical Japanese dance have a daily habit of walking with a proper posture, strongly care about dietary life and health, actively enjoy communication with friends, maintain interest in newspaper and magazine articles, and maintain an active state both physically and psychologically. We believe that as a result of implementing sufficient supplemental procedures for defects, which are important for daily conversations and dietary life, no correlation was observed between the number of remaining teeth and the physical and social activities constituting ADL. Although there are reports in which significant positive correlations were observed between the number of remaining teeth and the physical and social activities constituting ADL,8,9 similar outcomes were obtained for the control group from the results of the present study.
Although there are also some reports in which a positive correlation was observed between the number of remaining teeth and the MMSE/ADL of elderly people,5,15 it has been found that a lack of teeth decreases chewing ability and cognition, which thus become a cause of decreased independence.10,16,17 Accordingly, it is apparent that daily oral care and supplemental restoration of defective areas in teeth alignment play an important role that is necessary for obtaining health and a purpose of life, and leading an independent life in a society of longevity.18–20 Based on the findings in the present study, we clarified how art education affects individuals in later life.
Recently, there have been several reports on the effects of music and art therapy on increases in QOL and ADL for elderly people.13,14 However, there have been no reports other than the present study showing that professional music and art education in early life can be a factor for maintaining cognition in later life and improving the quality of life, purpose of life and the level of life activity. Conventionally, it is said that music and art education are relative to scientific states, and it is difficult to prove scientifically. However, from the present research and study on the effects on the later life of receiving music and art education for a certain period of time in early life, it was found that professional music and art education controlled decreases in cognitive function from a medical perspective and also affected levels of physical activity and social activity.
The periphery of the hippocampal area has been drawing attention as an area of the brain that expresses structural changes (i.e. atrophy) from the earliest stages from among cerebral degeneration associated with Alzheimer's disease (AD),21,22 and there are several reports that support the conclusion that a relationship between hippocampal atrophy and decline in cognitive function exist based on the findings of MRI.23 First, regarding the relationship between the hippocampal volume and decline in cognitive function in cases of mild cognitive impairment (MCI) and AD, some reports have stated that significantly higher levels of brain atrophy were observed in several areas of the brain, including the hippocampus in cases of MCI24,25 and cases of AD24,26 compared with healthy subjects. In addition, other reports have stated that higher degrees of advancement of hippocampal atrophy are expressed in AD, MCI and healthy subjects in that order, and that this advancement is correlated with the first MMSE score and subsequent temporal changes.27 Furthermore, another report states that hippocampal atrophy advances more rapidly in healthy subjects with ApoE4 compared with subjects without ApoE4 and that hippocampal atrophy advanced more rapidly in cases transitioning from MCI to AD in comparison with non-transitioning cases.27 At the same time, it has been reported that in cases of AD and MCI, and in healthy elderly people, there is no relationship between hippocampal atrophy and decreases in cognitive function (MMSE, Clinical Dementia Rating (CDR)), ApoE genotype or blood pressure,24 and that in cases of MCI, the presence of hippocampal atrophy is a prognostic factor of increases in the advancement rate of subsequent hippocampal atrophy.22
In the results of the present study, significant differences in the hippocampal volume were observed between the two groups; however, the implications of these results for subjects without dementia are unknown. More recently, there have been reports regarding prognoses for hippocampal atrophy and decreases in subsequent cognitive function in longitudinal studies of healthy subjects.28,29 However, in both of these studies, the temporal changes in brain atrophy were studied by year, and it was reported that prognoses were possible for a transitional group of healthy subjects developing MCI. Therefore, it is difficult to directly compare these two reports and the results of the present study, which examined hippocampal atrophy in a single MRI test for subjects without dementia.
Currently, there is a report by Morra JH et al.24 regarding the relationship between the presence of hippocampal atrophy and decreases in cognitive function in healthy subjects, but no conclusions have been reached. Therefore, regarding the interpretation of the present study results, further examinations will be necessary by obtaining image data of brain functions from positron emission tomography and single photon emission computed tomography imaging and temporal changes by year using MRI tests while conducting more detailed examinations of the cognitive function.30
Presently, as the ‘85-year-old generation’ is quickly approaching, maintaining a purpose of life and the closing of one's valuable life with happiness and joy have now become major issues in our society.