Dietary and Circulating Advanced Glycation End Products in Relation to Inflammation and Cognitive Function in Healthy Young Adults

Background: Advanced glycation end products (AGEs) may link diet, systemic inflammation, and cognitive function; however, evidence in healthy young adults is limited. Objective: To examine the associations of dietary AGEs (dAGEs) intake, circulating AGE–RAGE biomarkers, inflammation, and oxidant–antioxidant markers with cognitive performance. Methods: This cross-sectional study included healthy young adults aged 19–26 years. dAGEs intake was estimated independently using a food-frequency questionnaire (FFQ) and a three-day food record (3D-FR). Serum AGEs (sAGEs), soluble RAGE (sRAGE), interleukin-6, tumour necrosis factor-alpha (TNF-α), malondialdehyde, catalase, superoxide dismutase, and glutathione were measured. Cognitive performance was assessed using Digit Span Forward, Backward, and Total scores and Stroop Interference. Separate multivariable linear regression models were adjusted for age, sex, body mass index, and depressive symptoms, with Benjamini–Hochberg false-discovery-rate correction. Covariate-adjusted partial least squares structural equation modelling (PLS-SEM) examined the prespecified AGE–RAGE–inflammation pathways. Results: Neither FFQ-derived nor 3D-FR-derived dAGEs intake was associated with serum AGEs. In the separate regression models, higher sAGEs (β = −0.36, 95% CI −0.54 to −0.16) and TNF-α (β = −0.33, 95% CI −0.53 to −0.13) were associated with poorer Digit Span Backward performance after false-discovery-rate correction. No other cognitive associations remained significant. In PLS-SEM, sAGEs were positively associated with sRAGE (β = 0.505, p < 0.001), and sRAGE was positively associated with inflammation (β = 0.601, p < 0.001). Greater inflammation was associated with poorer Digit Span Backward performance (β = −0.398, 95% CI −0.697 to −0.110, p = 0.009), whereas the direct sRAGE–Digit Span Backward path was not significant. An indirect inverse association between sRAGE and Digit Span Backward through inflammation was supported (β = −0.239, 95% bootstrap CI −0.457 to −0.057). Conclusions: Circulating AGE–RAGE-related and inflammatory activity, rather than estimated dAGEs intake, was associated with selected aspects of cognitive performance in healthy young adults. Longitudinal studies with larger samples are needed to establish temporality and confirm the significance of these associations.