Abstract
Introduction: The number of older adults, including those living with cognitive impairment (CI), is increasing worldwide. Although the age-specific prevalence of cognitive impairment has declined in many countries, likely due to improvements in education, nutrition, healthcare, and lifestyle, its prevalence continues to rise in low- and middle-income countries. Increasing evidence supports the role of modifiable risk factors in the development of cognitive impairment. The 2017 Lancet Commission on Dementia Prevention, Intervention, and Care identified nine potentially modifiable risk factors, including low educational attainment, hypertension, hearing impairment, smoking, obesity, depression, physical inactivity, diabetes mellitus, and social isolation. More recent evidence has added three additional modifiable risk factors—excessive alcohol consumption, traumatic brain injury (TBI), and air pollution—bringing the total to twelve. A systematic review and meta-analysis estimated that these modifiable factors account for approximately 40% of cognitive impairment and dementia cases worldwide. Preventing cognitive impairment should be considered a lifelong strategy, as it is never too early or too late to intervene. Early-life risk factors (before 45 years of age), particularly limited education, primarily affect cognitive reserve. Midlife risk factors (45–65 years), including hearing loss, traumatic brain injury, hypertension, obesity, and excessive alcohol consumption (>21 drinks per week), together with later-life risk factors (older than 65 years), such as smoking, depression, social isolation, diabetes mellitus, air pollution, and physical inactivity, contribute to the initiation and progression of neurodegenerative processes leading to cognitive decline. Strategies for prevention and management: For individuals with cognitive impairment, cholinesterase inhibitors (e.g., donepezil) remain the first-line pharmacological treatment for patients with moderate to severe dementia and should be combined with multimodal neuropsychiatric interventions. In Asia, the 2019 ASCEND 2 consensus recommends Ginkgo biloba extract EGb 761 for patients with mild cognitive impairment (MCI), with potential benefits in delaying cognitive decline. For cognitively healthy individuals, preventive strategies include promoting cognitive health through education, controlling vascular and metabolic risk factors such as hypertension (target blood pressure ≤130/80 mmHg), diabetes mellitus, and dyslipidemia, increasing physical activity, smoking cessation, limiting alcohol consumption (<21 drinks per week), reducing exposure to air pollution and excessive noise, and preventing traumatic brain injury. However, prevention, management, and treatment strategies for cognitive impairment should be individualized and implemented using a multimodal approach to achieve optimal outcomes.
