The prevalence of dementia is increasing worldwide, particularly in low-income and middle-income countries, including south Asia, where a quarter of the world’s population lives. Several risk factors for dementia—eg, hypertension, high body-mass index, diabetes, and smoking—are modifiable. Studies done in high-income countries have shown that the prevalence of these risk factors varies among ethnic groups. For example, when compared with White people, people of south Asian origin report more frequently hypertension, obesity, diabetes, low concentrations of high-density lipoprotein, smoking, and sleep disorders.