Evaluating the influence of ultra-processed food intake on associations between dietary indices with systemic inflammation in adulthood and old ages.

BACKGROUND & AIMS: Low-grade systemic inflammation (LGSI) is critical to developing many chronic diseases. In turn, it has been shown that the diet can modulate favorably or unfavorably the inflammatory status. Thus, evaluating the diet from appropriate approaches is fundamental; to do so, there are different proposals for dietary indexes. We aimed to: (i) investigate the association between three well-known dietary indexes and LGSI biomarkers; (ii) test these associations individually or in combination with an indicator of ultra-processed foods (UFPs) intake. (iii) as an additional aim, hypothesizing that all the indexes should be capable of identifying the inflammatory potential of diet, we tested the hypothesis that these indexes agree and correlate with each other. METHODS: Cross-sectional population-based data of adults and older persons (n = 583). Dietary data were obtained through two non-consecutive 24-h dietary recalls (24HDR) and calculated for Dietary Inflammatory Index (DII), Mediterranean-Style Dietary Pattern Score (MSDPS); Brazilian Healthy Eating Index - Revised (BHEI-R) and energy ingested from UPFs (UPFs ratio). An LGSI score was created from some plasma inflammatory biomarkers [C-Reactive Protein (CRP), tumor necrosis factor-alpha (TNF-α), and adiponectin]. Logistic and linear regression models tested the associations between dietary indexes and LGSI score. RESULTS: The MSDPS and DII were significantly associated with our inflammatory score, but the BHEI-R did not. Including UPFs in regression models did not increase the strength of these associations. CONCLUSIONS: From the three scores, the dietary inflammatory index and the Mediterranean-style dietary pattern score (MSDPS) were the ones that showed significant association with the inflammatory biomarker. The combination of the indexes with a ratio of UPF intake did not increase the significance of our analyses. The best agreement between the indexes was found between MSDPS and UPFs ratio; the only pair of indexes considered concordant and correlated was the BHEI-R and DII.