The Prediction of Age-Related Cognitive Decline and Executive Functions Based on Social Isolation, Physical Activity and Nutritional Habits in Older Adults

Social factors and health-related behaviors, including physical activities and nutrition, serve an important role in status of cognitive abilities in older adults. Therefore, this study was conducted with the aim of investigating the role of social isolation, physical activity and nutritional habits in predicting age-related cognitive decline and executive function failure in older adults. This was a descriptive study, of correlational type. The statistical population of this research included all older men and women residents in nursing homes in Tehran in 2023, among whom 258 participants were selected based on Tabachnick and Fidell’s formula by convenience sampling, and were asked to respond the Folstein et al.’s mini-mental state examination, Barkley deficits in executive functioning scale, Lubben social network scale, Washburn et al.’s physical activity scale for the elderly, and Guigoz et al.’s mini nutritional assessment. Data were analyzed using Pearson’s correlation and multiple regression analysis in SPSS-26 software. The results figured out that physical activity and nutritional habits have a negative and significant relationship with age-related cognitive decline and executive function deficiency (P<.001). Social isolation had no significant relationship with age-related cognitive decline and executive function failure (P>0.05). In addition, the physical activity predicted 20% of the age-related cognitive decline, and the nutritional habits predicted 14% of executive function failure in older adults (P<.001). It is concluded that proper physical activity and good nutrition pattern can be associated with the reduction of age-related cognitive deficits in older adults. This result contains implications in developing preventive and intervention programs to improve the cognitive ability in older adults.
EXTENDED ABSTRACT
 Introduction
Aging, as a sensitive stage in human psychological evolution, causes fundamental changes in body systems and decreases motor and cognitive functions. Social factors and health-related behaviors, including physical activities and nutrition, play important roles in cognitive abilities in older adults. Age-related cognitive decline and deficits in executive functions are multifactorial phenomena that require early recognition and intervention. Additionally, cognitive decline and deficits in executive functions, which are associated with negative consequences and a decrease in the quality of life in older adults, are influenced by psychosocial processes such as social isolation or feelings of loneliness and health-related behaviors such as physical activities and nutritional patterns or habits. Considering the lack of research in the field of the role of social factors and health-related behaviors together in examining the determinants of age-related cognitive decline and executive functions, this research is necessary and important from a scientific and socio-cultural perspective. Therefore, this study was conducted with the aim of investigating the role of social isolation, physical activity, and nutritional habits in predicting age-related cognitive decline and executive function failure in older adults.
Method
This was a descriptive study, of correlational type. The statistical population included all older men and women residents of nursing homes in Tehran, Iran in 2023, among whom 258 participants (160 women and 98 men) were selected based on Tabachnick and Fidell’s sampling formula using convenience sampling. The inclusion criteria included (1) the age range of 65 to 80 years, (2) living in nursing homes in Tehran, and (3) the ability to read and write. The exclusion criteria were (1) suffering from chronic physical and psychological diseases based on the report of psychologists working in centers, and (2) the inability to answer questions due to various reasons such as Alzheimer’s disease. Finally, after the removal of the dropout cases (18 participants) due to several reasons, such as not meeting the inclusion criteria or not being able to cooperate with the researcher, the final sample of this study included 240 people. out of all participants, 150 (62%) were women and 90 (38%) were men. The age range of the older adults was between 65 and 80 with an average of 72 (SD=.891). 95% of participants had children, and only 5% of them were childless. The participants were filled out Folstein et al.’s mini-mental state examination, Barkley deficits in executive functioning scale, Lubben social network scale, Washburn et al.’s physical activity scale for the elderly, and Guigoz et al.’s mini nutritional assessment. Data were analyzed using Pearson’s correlation and multiple regression analysis in SPSS-26 software.
Results
Before analyzing the data, we considered the assumptions of the statistical tests used in the current study, the results of which showed that the distribution of scores of all variables is normal and there is no collinearity between the variables. The results indicated that cognitive decline has a negative and significant relationship (P<.001) with physical activity (r=-0.453) and nutritional habits (r=-0.228). Executive functions failure also had a negative and significant relationship (P<.001) with physical activity (r=-0.279) and nutritional habits (r=-0.376). Additionally, a positive and significant relationship between executive function failure and cognitive decline (r=.527) was obtained (P<.001). Social isolation had no significant relationship with cognitive decline and executive functions failure (P>.05). Table 1 shows the results of regression analysis (enter mode) predicting cognitive decline and executive functions failure based on social isolation, physical activity, and nutritional habits. According to Table 1, social isolation explains only 1% of the variance of cognitive decline in older adults(R=.115). Physical activity could explain 20% of the variance of cognitive decline in older adults (R=.453). Nutritional habits explain 5% of the variance of cognitive decline in older adults (R=.328). Additionally, social isolation did not have the power to predict the failure of executive functions in older adults (R=.128). Physical activity explains only 7% of the variance of executive function failure in older adults (R=.279). Nutritional habits explain 14% of the variance of executive function failure in older adults (R=.376).
Conclusion
According to the results, physical activity and nutritional habits exhibit a strong relationship with cognitive decline and executive functions failure in older adults. The increase of physical activity and the improve of healthy nutrition are associated with a decrease in cognitive decline and executive functions failure among older adults. Regular physical and sports activities have been found to improve cognitive function in older adults. Physical activity can reduce reaction time, enhance blood flow in the body, and promote richer neural connections, which in turn, improve brain function. Furthermore, nutrition plays a crucial role in brain function and seems to be a significant factor in healthy aging and reducing age-related cognitive decline. Malnutrition among older adults is considered an underlying cause of cognitive decline, and those suffering from malnutrition may experience serious impairments in cognitive functions. These findings have important implications for the development of preventive and intervention programs aimed at improving and promoting the cognitive abilities of older adults. Given the predictive power of physical activity in cognitive decline and failure of executive functions among older adults, it is recommended that daily activity programs for older individuals living in nursing homes be designed to include opportunities for physical activity and encourage adherence to proper nutritional patterns. Such programs can contribute to enhancing cognitive health and overall well-being in aging populations.
Ethical Consideration
Ethical Code
This research has an ethics approval number IR.SEMUMS.REC.1402.004 from Semnan University of Medical Sciences.
Financial Support
This research has not received financial support from any institution.
Authors’ Contributions
Z.M: writing- original draft, Data curation, formal analysis, writing-review & editing; I. R: Conceptualization, Supervision, Project administration, writing-review & editing; S. T: Conceptualization, methodology, writing-review & editing
Conflict of Interest
According to the authors, there was no conflict of interest in the present study.
Acknowledgments
This article is extracted from the master’s thesis in cognitive psychology at Semnan University, and the authors hereby sincerely thank the Vice-Chancellor of Education and Graduate Studies of the University, all older people who participated in the present research, and the officials and staff of the nursing homes in Tehran for their cooperation.
References
 Aliberti, M. J. R., Cenzer, I. S., Smith, A. K., Lee, S. J., Yaffe, K., & Covinsky, K. E. (2019). Assessing Risk for Adverse Outcomes in Older Adults: The Need to Include Both Physical Frailty and Cognition. Journal of the American        Geriatrics Society, 67(3), 477–483. https://doi.org/10.1111/jgs.15683
Arevalo-Rodriguez, I., Smailagic, N., Roqué-Figuls, M., Ciapponi, A., Sanchez-Perez, E., Giannakou, A., Pedraza, O. L., Bonfill Cosp, X., & Cullum, S. (2021). Mini-Mental State Examination (MMSE) for the early detection of dementia in people with mild cognitive impairment (MCI). The Cochrane database of systematic reviews, 7(7), CD010783. https://doi.org/10.1002/14651858.CD010783.pub3
Ball, H. A., McWhirter, L., Ballard, C., Bhome, R., Blackburn, D. J., Edwards, M. J., Fleming, S. M., Fox, N. C., Howard, R., Huntley, J., Isaacs, J. D., Larner, A. J., Nicholson, T. R., Pennington, C. M., Poole, N., Price, G., Price, J. P., Reuber, M., Ritchie, C., Rossor, M. N., … Carson, A. J. (2020). Functional cognitive disorder: dementia's blind spot. Brain: a journal of neurology, 143(10), 2895–2903. https://doi.org/10.1093/brain/awaa224
Barkley, R. A. (2011). Barkley Deficits in Executive Functioning Scale (BDEFS). The Guilford Press.
Bu, Z., Huang, A., Xue, M., Li, Q., Bai, Y., & Xu, G. (2021). Cognitive frailty as a predictor of adverse outcomes among older adults: A systematic review and meta-analysis. Brain and behavior, 11(1), e01926. https://doi.org/10.1002/brb3.1926
Buckinx, F., & Aubertin-Leheudre, M. (2021). Nutrition to Prevent or Treat Cognitive Impairment in Older Adults: A GRADE Recommendation. The journal of prevention of Alzheimer's disease, 8(1), 110–116. https://doi.org/10.14283/jpad.2020.40
Cardona, M., & Andrés, P. (2023). Are social isolation and loneliness associated with cognitive decline in ageing? Frontiers in aging neuroscience, 15, 1075563. https://doi.org/10.3389/fnagi.2023.1075563
Chen, F. T., Etnier, J. L., Chan, K. H., Chiu, P. K., Hung, T. M., & Chang, Y. K. (2020). Effects of Exercise Training Interventions on Executive Function in Older Adults: A Systematic Review and Meta-Analysis. Sports medicine (Auckland, N.Z.), 50(8), 1451–1467.https://doi.org/10.1007/s40279-020-01292-x
Escher, C., Asken, B. M., VandeBunte, A., Fonseca, C., You, M., Kramer, J. H., & Casaletto, K. B. (2023). Roles of physical activity and diet in cognitive aging: is better? The Clinical neuropsychologist, 37(2), 286–303. https://doi.org/10.1080/13854046.2022.2060867
Evans, I. E. M., Martyr, A., Collins, R., Brayne, C., & Clare, L. (2019). Social Isolation and Cognitive Function in Later Life: A Systematic Review and Meta-Analysis. Journal of Alzheimer's disease: JAD, 70(s1), S119–S144. https://doi.org/10.3233/JAD-180501
Fleischhacker, E., Gleich, J., Hesse, E., Bücking, B., Liener, U. C., & Neuerburg, C. (2021). Individuelle Besonderheiten bei hochbetagten Patienten mit Fragilitätsfrakturen [Individual aspects in eldery patients with fragility fractures]. Der Radiologe, 61(12), 1107–1114. https://doi.org/10.1007/s00117-021-00928-x
Folstein, M. F., Folstein, S. E., & McHugh, P. R. (1975). "Mini-mental state". A practical method for grading the cognitive state of patients for the clinician. Journal of psychiatric research, 12(3), 189–198. https://doi.org/10.1016/0022-3956(75)90026-6
Fu, P., Zhou, C., & Meng, Q. (2020). Associations of Sleep Quality and Frailty among the Older Adults with Chronic Disease in China: The Mediation Effect of Psychological Distress. International journal of environmental research and public health, 17(14), 5240. https://doi.org/10.3390/ijerph17145240
Guigoz, Y., Vellas, B., & Garry, P. J. (1996). Assessing the nutritional status of the elderly: The Mini Nutritional Assessment as part of the geriatric evaluation. Nutrition reviews, 54(1 Pt 2), S59–S65. https://doi.org/10.1111/j.1753-4887.1996.tb03793.x
Huang, Q., Zhao, J., Jiang, W., & Wang, W. (2022). The Association between Physical Activity and Cognitive Function: Data from the China Health and Nutrition Survey. Behavioural neurology, 2022, 3438078. https://doi.org/10.1155/2022/3438078
Iso-Markku, P., Aaltonen, S., Kujala, U. M., Halme, H. L., Phipps, D., Knittle, K., Vuoksimaa, E., & Waller, K. (2024). Physical Activity and Cognitive Decline Among Older Adults: A Systematic Review and Meta-Analysis. JAMA network open, 7(2), e2354285. https://doi.org/10.1001/jamanetworkopen.2023.54285
Kojima G. (2018). Frailty as a Predictor of Nursing Home Placement Among Community-Dwelling Older Adults: A Systematic Review and Meta-analysis. Journal of geriatric physical therapy (2001), 41(1), 42–48. https:// doi.org/10.1519/JPT.0000000000000097
Kumar, M., Srivastava, S., & Muhammad, T. (2022). Relationship between physical activity and cognitive functioning among older Indian adults. Scientific reports, 12(1), 2725. https://doi.org/10.1038/s41598-022-06725-3
Lin, M., Ma, C., Zhu, J., Gao, J., Huang, L., Huang, J., Liu, Z., Tao, J., & Chen, L. (2022). Effects of exercise interventions on executive function in old adults with mild cognitive impairment: A systematic review and meta-analysis of randomized controlled trials. Ageing research reviews, 82, 101776. https://doi.org/10.1016/j.arr.2022.101776
Lubben, J. E. (1988). Assessing social networks among elderly populations. Family & Community Health: The Journal of Health Promotion & Maintenance, 11(3), 42–52. https://doi.org/10.1097/00003727-198811000-00008
Lubben, J., Blozik, E., Gillmann, G., Iliffe, S., von Renteln Kruse, W., Beck, J. C., & Stuck, A. E. (2006). Performance of an abbreviated version of the Lubben Social Network Scale among three European community-dwelling older adult populations. The Gerontologist, 46(4), 503–513. https://doi.org/10.1093/geront/46.4.503
Mantovani, E., Zucchella, C., Schena, F., Romanelli, M. G., Venturelli, M., & Tamburin, S. (2020). Towards a Redefinition of Cognitive Frailty. Journal of Alzheimer's disease: JAD, 76(3), 831–843. https://doi.org/10.3233/JAD-200137
Maxwell, C. A., Patel, M. B., Suarez-Rodriguez, L. C., & Miller, R. S. (2019). Frailty and Prognostication in Geriatric Surgery and Trauma. Clinics in geriatric medicine, 35(1), 13–26. https://doi.org/10.1016/j.cger.2018.08.002
Mello, B. H., Lenardt, M. H., Moraes, D. C., Setoguchi, L. S., Seima, M. D., & Betiolli, S. E. (2021). Cognitive impairment and physical frailty in older adults in secondary health care. Revista da Escola de Enfermagem da USP, 55, e03687. https://doi.org/10.1590/S1980-220X2019029803687
Melzer, T. M., Manosso, L. M., Yau, S. Y., Gil-Mohapel, J., & Brocardo, P. S. (2021). In Pursuit of Healthy Aging: Effects of Nutrition on Brain Function. International journal of molecular sciences, 22(9), 5026. https://doi.org/10.3390/ijms22095026
Pilotto, A., Custodero, C., Maggi, S., Polidori, M. C., Veronese, N., & Ferrucci, L. (2020). A multidimensional approach to frailty in older people. Ageing research reviews, 60, 101047. https://doi.org/10.1016/j.arr.2020.101047
Qi, Y., Zhang, Z., Fu, X., Han, P., Xu, W., Cao, L., & Guo, Q. (2023). Adherence to a healthy lifestyle and its association with cognitive impairment in community-dwelling older adults in Shanghai. Frontiers in public health, 11, 1291458. https://doi.org/10.3389/fpubh.2023.1291458
Rosselli, M., Tappen, R., Williams, C., & Salvatierra, J. (2006). The relation of education and gender on the attention items of the Mini-Mental State Examination in Spanish speaking Hispanic elders. Archives of Clinical Neuropsychology, 21(7), 677–686. https://doi.org/10.1016/j.acn.2006.08.001
Sugimoto, T., Arai, H., & Sakurai, T. (2022). An update on cognitive frailty: Its definition, impact, associated factors and underlying mechanisms, and interventions. Geriatrics & gerontology international, 22(2), 99–109. https://doi.org/10.1111/ggi.14322
Tabachnick, B. G., & Fidell, L. S. (2007). Using multivariate statistics (2nd. ed.). Cambridge, MA: Harper & Row.
Vellas, B., Guigoz, Y., Garry, P. J., Nourhashemi, F., Bennahum, D., Lauque, S., & Albarede, J. L. (1999). The Mini Nutritional Assessment (MNA) and its use in grading the nutritional state of elderly patients. Nutrition (Burbank, Los Angeles County, Calif.), 15(2), 116–122. https://doi.org/10.1016/s0899-9007(98)00171-3
Victor, C. R., Scambler, S. J., Bowling, A., & Bond, J. (2005). The prevalence of, and risk factors for, loneliness in later life: A survey of older people in Great Britain. Ageing & Society, 25(3), 357–375. https://doi.org/10.1017/S0144686X04003332
Washburn, R. A., Smith, K. W., Jette, A. M., & Janney, C. A. (1993). The Physical Activity Scale for the Elderly (PASE): development and evaluation. Journal of clinical epidemiology, 46(2), 153–162. https://doi.org/10.1016/0895-4356(93)90053-4
Xu, L., Gu, H., Cai, X., Zhang, Y., Hou, X., Yu, J., & Sun, T. (2023). The Effects of Exercise for Cognitive Function in Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. International journal of environmental research and public health, 20(2), 1088. https://doi.org/10.3390/ijerph20021088
Yuan, Y., Lapane, K. L., Tjia, J., Baek, J., Liu, S. H., & Ulbricht, C. M. (2021). Physical Frailty and Cognitive Impairment in Older Adults in United States Nursing Homes. Dementia and geriatric cognitive disorders, 50(1), 60–67. https://doi.org/10.1159/000515140
Zheng, J., Su, X., & Xu, C. (2022). Effects of exercise intervention on executive function of middle-aged and elderly people: A systematic review of randomized controlled trials. Frontiers in aging neuroscience, 14, 960817. https://doi.org/10.3389/fnagi.2022.960817