Abstract
BACKGROUND: Obesity is becoming a global problem, rather than one found only in developed countries. Although recent studies have suggested a detrimental effect of obesity on cognition, studies of the relationship between obesity and cognition among older adults have been limited to developed countries. We aimed to examine the associations between central obesity, as measured by waist circumference, and cognition level in adults aged 50 years and older in England and Indonesia. METHODS: We used linear regression models to analyse these associations and multiple imputation to manage missing data. The 2006 English Longitudinal Study of Ageing Wave 3 is the source of data from England, while data from Indonesia is sourced from the 2007 Indonesian Family Life Survey Wave 4. FINDINGS: Centrally obese respondents had lower cognition levels than non-centrally obese respondents in England. In contrast, central adiposity had a statistically significant positive association with cognition in Indonesia. Higher levels of education and higher economic status were associated with higher cognitive ability, while age was associated with lower cognition in both countries. Elevated C-reactive protein (CRP) concentrations and smoking behaviour, both linked to higher risk of obesity, were negatively associated with cognitive ability among older adults in England, but they had no statistically significant association with cognition among Indonesians. INTERPRETATION: The contradictory findings on obesity and cognition in England and Indonesia not only create a puzzle, but they may also have different policy implications in these countries. Reducing the prevalence of obesity may be the main focus in England and other developed countries to maintain older adults' cognition. However, Indonesia and other developing countries should place more emphasis on education, in addition to continued efforts to tackle the double burden of malnutrition, in order to prevent cognitive impairment among older adults.