Can Raising grandchildren prevent or slow cognitive decline in Chinese elderly?

With increasing life expectancy, cognitive aging is a major medical and public health challenge. Several studies have examined lifestyle factors that delay cognitive function decline in the elderly. This study aimed to explore the role of skip-generation raising on the global cognitive function and various cognitive domains by analyzing data from the China Health and Retirement Longitudinal Study (CHARLS). We analyzed longitudinal data from the CHARLS collected between 2015 and 2018, using the Mini-Mental State Examination (MMSE) for cognitive function. We verified the relationships among skip-generation raising, global cognitive function, and various cognitive domains using propensity score matching with the differences-in-differences method (PSM-DID) and various robustness tests. Further subgroup analyses examined the heterogeneity in the association between skip-generation raising and cognitive function across different geographic regions and caregiving intensity. Additionally, we developed an accurate risk screening model using XGBoost to predict cognitive decline in the elderly. The PSM-DID analyses revealed a significant positive association between the coefficients of the interaction terms in the different regression models, suggesting a significant positive effect of skip-generation raising on cognitive function in the elderly. These findings were robust regardless of the samples tested. Meanwhile, skip-generation raising had a beneficial effect only on the registration domain but not on the other cognitive domains. Subgroup analyses revealed notable heterogeneity in this association. The beneficial effect was primarily concentrated in central China, and not in the eastern or western areas. Furthermore, while skip-generation raising overall had positive outcomes, caring for more than two grandchildren had a negative impact on cognition. Additionally, the XGBoost prediction model analysis identified skip-generation raising, dyslipidemia, hypertension, drinking, and smoking as predictors of cognitive decline. Engaging in skip-generation raising (not more than two grandchildren) may enhance the social participation of the elderly, prevent or slow their cognitive decline, enabling them to cope with aging. The benefits were mostly observed in Central China. However, the global cognitive function of older adults who do not engage in skip-generation raising and have worse lifestyle habits or health status should also be examined to improve the effectiveness of measures that prevent cognitive decline.