Study on the global and national burden of Alzheimer's disease attributable to dietary fatty acids from 1990 to 2018: A combined analysis based on the global burden of disease and global dietary database

Background Despite the importance of fatty acids (FAs) for brain function, their association with the global burden of Alzheimer's disease (AD) remains unclear. Objective Using the Global Dietary Database and the Global Burden of Disease study (1990–2018), we examined global trends and projections of AD burden attributable to dietary saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs). Methods We analyzed global SFA/MUFA intake and age-standardized incidence rate (ASIR), age-standardized mortality rate (ASMR), and age-standardized disability-adjusted life year rate (ASDR) of FA-attributable AD. Spearman correlation analysis assessed associations with the Socio-demographic Index (SDI). Projections were extended to 2040. Results In 2018, SFA intake was highest in Australia and France, while MUFA intake was highest in Russia and Sweden. For attributable burden, from 1990 to 2018, SFA-attributable ASDR ranked highest annually, peaking in 2010 then declining; MUFA-attributable burden showed no significant variation. In 2018, ASIR, ASMR, and ASDR attributable to both FAs were highest in adults ≥80 years. Females had higher burdens than males, with approximately 2-fold higher SFA-attributable rates. High SFA burden concentrated in high-SDI countries, while high MUFA burden shifted from low-middle to middle-high SDI regions. ASIR of SFA-attributable AD correlated positively with SDI in 1990 (cor = 0.41, p < 0.001) and 2018 (cor = 0.5, p < 0.001); a similar correlation was observed for MUFAs. Under the assumption of 3% annual growth, SFA- and MUFA-attributable ASIR would reach 57.8 and 19.7 per 100,000 by 2040. Conclusions This study links global SFA/MUFA intake to AD burden and projects future trends, supporting targeted prevention strategies.