Dietary inflammatory index and its association with serum cytokines in mexican older adults with mild cognitive impairment and dementia.
BACKGROUND Chronic low-grade inflammation has been implicated in the pathophysiology of cognitive dysfunction and neurodegenerative processes. Diet represents a key modifiable determinant of inflammatory status. We aimed to evaluate the associations between dietary inflammatory index (DII) scores and the serum levels of interleukin-6 (IL-6), leptin, and adiponectin in older adults with mild cognitive impairment (MCI), dementia, and normal cognition in Yucatan, Mexico. METHODS A case-control study was conducted between March 2022 and December 2025. Cases were defined as adults aged ≥ 55 years with a previous diagnosis of MCI or dementia, and controls were defined as adults aged ≥ 55 years with no prior history or current complaints of cognitive impairment and with normal performance on cognitive assessments. Dietary intake was assessed with a validated food frequency questionnaire, and the DII was calculated using 24 food parameters. Cytokine levels were determined using sandwich enzyme-linked immunosorbent assay kits. RESULTS Participants with MCI and dementia exhibited a diet with higher pro‑inflammatory potential, characterized by lower intake of dietary fiber, vitamins, unsaturated fats and β-carotenes, as well as significantly higher adiponectin levels than controls. DII scores were inversely associated with adiponectin levels in patients with MCI and dementia (β = - 48, 95% CI: - 75 to - 22, p < 0.01). CONCLUSIONS A pro‑inflammatory diet was associated with lower adiponectin in MCI and dementia, despite paradoxically elevated adiponectin. This association may be attenuated by excess adiposity. Adiponectin emerges as a promising biomarker, warranting longitudinal studies.