"Results. Dementia incidence was 0.89 per 1000 person-years. GI (mean±SD: 48.71 ± 7.68) showed an inverse J-shaped association with dementia risk, while GL (121.49 ± 39.00) showed a J-shaped pattern, with inflection points at 49.30 and 111.01, respectively. After adjusting for potential confounders, GI values of <49.30 were inversely associated with dementia risk [HR, 0.838; 95% confidence interval (CI), 0.758–0.926], while GL values of >111.01 were associated with higher dementia risk (HR, 1.145; 95% CI, 1.048–1.251). Similar findings were observed for AD and VD.

Conclusion. Low-GI diets may offer protective effects against all-cause dementia, AD, and VD, whereas high-GL diets may increase the risk. These findings underscore the importance of considering both carbohydrate quality and quantity in dementia prevention and management strategies."