Regular physical activity and high educational attainment positively affect cognitive function among older adults

Article information

J Exerc Rehabil Vol. 20, No. 6, 235-239, December, 2024

Publication date (electronic) : 2024 December 26

doi : https://doi.org/10.12965/jer.2448644.322

Sports and Healthcare Major, College of Culture and Arts, Sangmyung University, Seoul, Korea

^*Corresponding author: Suh-Jung Kang, Sports and Healthcare Major, College of Culture and Arts, Sangmyung University, 20 Hongjimun 2-gil, Jongno-gu, Seoul 03016, Korea, Email: suhjkang@smu.ac.kr

Received 2024 November 4; Revised 2024 November 12; Accepted 2024 November 22.

Abstract

Although educational attainment and physical activity tend to determine cognitive function among older adults, studies have shown inconsistent results. This study aimed to examine how physical activity and educational attainment relate to the cognitive function of older adults. Educational attainment was determined based on the total number of years of education received from formal educational institutions. All participants were classified as active or sedentary according to the Stanford Brief Activity Survey. Thereon, the participants were divided into four groups based on educational attainment and physical activity levels: the low education-sedentary (LESG; n=29, 74.06±5.39 years), low education-active (LEAG; n=34, 73.97±4.74 years), high education-sedentary (HESG; n=26, 74.34±5.17 years), and high education-active groups (HEAG; n=26, 74.11±4.53 years). Four domains of cognitive function were assessed using the Seoul Neuropsychological Screening Battery: attention, visuospatial function, memory, and frontal/executive function. Linear regression analyses were performed to investigate differences in cognitive function between the four groups, setting the low education-sedentary group as the reference. Among the domain of cognitive function, attention differed significantly in the LESG from that in the HESG and HEAG. Educational attainment and physical activity levels influence cognitive function. A greater number of early-life educational experiences and regular physical activity in old age enhanced the cognitive function of older adults.

Keywords: Physical activity; Education; Attention; Older adults; Korea

INTRODUCTION

Cognitive function determines health and longevity among older adults and is related to the risk of mortality (Tamosiunas et al., 2020). Advanced age is the strongest risk factor for cognitive decline and dementia (Morris et al., 2018; Walsh et al., 2022). As one’s ability to perform everyday tasks declines, cognitive function also declines, impeding independent living and deteriorating quality of life (Peng et al., 2023; Tucker-Drob, 2011). Therefore, identifying ways to prevent cognitive decline is crucial. Physical activity is one of the most promising interventions for delaying or preventing cognitive decline and dementia (Dominguez et al., 2021), known to enhance cognitive function among older adults (Kramer et al., 2006). Considering the demonstratable positive effects of physical activity even at low levels (Galle et al., 2023), the sustained engagement of older adults with physical activity is important to prevent cognitive decline and dementia.

In addition to physical activity, educational attainment is also known to affect older adults’ cognitive function. Educational attainment refers to the number of years of education one has received through formal educational institutions. Educational attainment has consistently been linked with cognitive function and dementia in studies and is a widely-used indicator of cognitive reserve; educational attainment is negatively associated with the risk of dementia (Caamaño-Isorna et al., 2006). A meta-analysis found that high educational attainment has a positive effect on the cognitive performance of older adults (Opdebeeck et al., 2016). In other words, the number of years of education one receives in early life has a lifelong effect on one’s cognitive function. Contrastingly, some longitudinal studies report no such relationship between the two (Cadar et al., 2016; Wilson et al., 2019).

There can be several reasons for the conflicting results on the relationship between educational attainment and cognitive function. One reason could be that the rate of change in cognitive function varies across individuals (van Dijk et al., 2008; Wilson et al., 2009), another reason is clinical-pathological influences, such as the onset of accelerated cognitive decline (Liang et al., 1996); furthermore, the diversity of methods used to evaluate cognitive function could also be a contributive factor. In studies concerning cognitive function, the most commonly used measure is the Mini-Mental State Examination (MMSE), and researchers tend to use a large dataset to increase the degree of statistical significance. However, cognitive measures used in epidemiological studies tend to have severe ceiling effects. Thus, there may have been ceiling effects in using the MMSE, and consequently, the relationship between cognitive function and measurement variables may have become insignificant (Jia et al., 2021; Scollard et al., 2023). Therefore, using a cognitive function assessment method that is reliable and valid and can be performed by experts will provide a clearer picture of the relationship between cognitive function and other variables. This study aimed to examine how cognitive function is related to educational attainment and physical activity among older adults with normal cognitive function.

MATERIALS AND METHODS

Participants and data collection

The participants of the survey, recruited on the basis of volunteering in a study ascertaining the influence of cognitive decline with education and physical activity status, signed a consent form to allow the analysis and dissemination of their personal information. Additionally, this study was approved by the Institutional Review Board of Sangmyung University, Seoul, Korea (#BE2017-26).

Measurement and classification of educational attainment

To determine educational attainment, the participants were asked how many years of education they had received in formal educational institutions. Subsequently, educational attainment was classified as either low or high. The participants were classified as having low educational attainment if their total years of education corresponded to elementary or middle school. Those whose education equaled high school education or beyond were classified as having high educational attainment.

Measurement and classification of physical activity

Physical activity was assessed using the Stanford Brief Activity Survey (Taylor-Piliae et al., 2010) and classified as either sedentary or active.

Measurement of cognitive function

Certified clinical psychologists assessed participants’ cognitive function using the Seoul Neuropsychological Screening Battery (Ryu and Yang, 2023). Four domains of cognitive function were evaluated: attention, visuospatial function, memory, and frontal/executive function. The t-score of each domain was used in data analysis.

Data analysis

The participants were divided into four groups based on their educational attainment and physical activity levels: the low education-sedentary group (LESG; n=29), low education-active group (LEAG; n=34), high education-sedentary group (HESG; n=26), and high education-active group (HEAG; n=26). Linear regression analysis was conducted to investigate differences in cognitive function according to educational attainment and physical activity levels, with the LESG serving as the reference group. Age and sex were included as covariates, and cognitive function differences were examined both with and without adjusting for these covariates. All statistical analyses were performed using IBM SPSS Statistics ver. 27.0 (IBM Co., Armonk, NY, USA), with statistical significance set at α=0.05.

RESULTS

The average ages in the LESG (n=29), LEAG (n=34), HESG (n=26), and HEAG (n=26) were 74.06±5.39 years, 73.97± 4.74 years, 74.34±5.17 years, and 72.11±4.53 years, respectively. Table 1 and Table 2 present the results of the analysis of cognitive function differences across the four groups, both with and without adjustments for covariates. Among the four domains of cognitive function, attention showed significant differences. Attention in the HESG (Sig=0.006, P<0.05) and HEAG (Sig= 0.002, P<0.05) differed significantly from that in the LESG. These findings remained consistent even after adjusting for the age and sex covariates. The differences in attention between the LESG and the HESG suggest that educational attainment affects cognitive function, while the differences between the LESG and HEAG indicate that both physical activity and educational attainment levels affect cognitive function.

Table 1

Differences in cognitive function based on physical activity and educational attainment levels after adjusting for age and sex

Table 2

Differences in cognitive function based on physical activity and educational attainment levels without adjusting for age and sex

DISCUSSION

Our results demonstrated significant differences in attention between the LESG and the HEAG. This result indicates that regular physical activity positively impacts cognition and highlights the importance of promoting physical activity for healthy aging, particularly for cognitive health. Our results align with those of previous studies indicating that brain degeneration and cognitive decline can be mitigated through physical activity (Di Liegro et al., 2019; Dominguez et al., 2021). In fact, research has shown that even a minimal amount of physical activity can reduce mortality (Wen et al., 2011), and light-intensity physical activity is associated with a lower risk of dementia (Yoon et al., 2021). Additionally, high levels of sedentary behavior have been linked to decreased cognitive function (Falck et al., 2017). In other words, addressing the health issues of older adults can be achieved by incorporating physical activities in daily life. Therefore, it is essential to reduce sedentary time through physical activity (Bull et al., 2020) to enhance health management for older adults.

Our results also showed that attention differs significantly between the LESG, HESG, and HEAG. This result indicates that educational attainment affects some domains of cognitive function, aligning with the findings of several studies, especially those of Sharp and Gatz (2011) and Xu et al. (2016), respectively, who determined that low educational attainment increased risk for dementia. Furthermore, Lövdén et al. (2020) found that educational attainment in the early stages of life can affect the cognitive function of older adults. Song et al. (2022) reported that the higher the educational attainment, the better cognitive function in old age. This means that even if the brain changes due to aging and disease, it can cope with these changes through the education it has received and maintain cognitive function. Educational experiences can increase one’s cognitive reserve (Stern, 2002), and studies have determined that long-term experiences, such as education, physical activity, and cognitive activity (Kim et al., 2024), along with health-related lifestyle habits (Clare et al., 2017), can increase cognitive reserve, and a high cognitive reserve can lower the risk of dementia. This can explain the claim that personal experiences can play an important role in cognitive function. This study confirmed that education contributes to good cognitive function, with higher educational attainment in early life stages being related to better attention in old age. However, some studies have reported that the relationship between education and cognitive function is not significant (van Zwieten et al., 2019). The conflicting results could be because this study did not include other variables that may impact cognitive function, such as diseases, environmental factors, lifestyle behavior, and socioeconomic factors. Additionally, studies have reported that education received from social activities in old age, such as community-based activities, can also enhance the cognitive function of older adults (Peeters et al., 2020). Therefore, our future studies should include more diverse predictors of cognitive function. Therefore, for future research, investigating the relationship between education received from social activities in old age and cognitive function would be noteworthy.

This study has some limitations. First, previous literature ascertained that non-degree educational experiences after middle age can improve cognitive function and impart a considerable influence, even on people with low levels of education (Mcdougall et al., 2010). However, this study considered only formal education received in early-life stages. Second, this study did not include other factors that may affect cognitive function, such as socioeconomic status, lifestyle habits, and diseases. Third, as a cross-sectional study, an interpretation of the causal pathway was not possible. Nonetheless, this study is salient as it used a highly reliable and valid tool to evaluate cognitive function.

In conclusion, formal educational experiences in early life stages and physical activity in old age have great potential to enhance the cognitive function of older adults. Therefore, programs aimed at enhancing cognitive function should promote physical activity among older adults.

Notes

CONFLICT OF INTEREST

No potential conflict of interest relevant to this article was reported.

ACKNOWLEDGMENTS

This work was supported by Sangmyung University.

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