The dietary inflammatory index and hepatic health in the US adult population

Abstract

Background: There is limited evidence on the role of an anti‐/pro‐inflammatory diet in the prevention of non‐alcoholic fatty liver disease (NAFLD). We aimed (i) to assess the anti‐inflammatory diet profile and its association with transient elastography parameters, including liver stiffness measurement (LSM) and controlled attenuation parameter (CAP), and (ii) to analyse the relationship between the anti‐inflammatory diet and surrogate markers of liver disease in a multiethnic US population. Methods: A cross‐sectional study was conducted on a nationally representative population of 4189 US adults aged 20–80 years. A FibroScan® 502 V2 device (Echosens) was used to estimate the CAP and LSM. Liver markers, including the aspartate transaminase (AST) to alanine transaminase (ALT) ratio, fatty liver index (FLI) and fibrosis‐4 score, were also calculated. The Dietary Inflammatory Index (DII) was calculated using a 24‐h diet recall. Results: Lower DII scores (anti‐inflammatory diet) were associated with a lower AST:ALT ratio (p < 0.001) and FLI (p < 0.036) after adjusting for covariates. Linear regression analysis revealed that gamma‐glutamyl transferase levels (β = 1.702, 95% confidence interval [CI] = 0.325–3.080, p = 0.015), ALT levels (β = −0.616, 95% CI = −1.097 to −0.135, p = 0.012), AST:ALT ratio (β = 0.025, 95% CI = 0.014–0.036, p < 0.001) and FLI (β = 1.168, 95% CI = 0.224–2.112, p = 0.015) were significantly associated with the DII in the multivariable‐adjusted model. Participants in the highest anti‐inflammatory tertile had the lowest odds ratio (OR) for NAFLD assessed by FLI in both unadjusted (OR = 0.652, 95% CI = 0.539–0.788, p ≤ 0.001) and adjusted models (OR = 0.722, 95% CI = 0.537–0.972, p = 0.032). For the transient elastography parameters (LSM and CAP), no significant associations were identified. Conclusions: There was no relationship between the transient elastography parameters and the anti‐inflammatory diet profile, although our study showed an association between higher pro‐inflammatory properties of diet and poorer hepatic health assessed by surrogate markers of liver disease. Therefore, strategies to promote an anti‐inflammatory diet should be considered to prevent NAFLD in adults.