Dietary Inflammatory Index and liver status in subjects with different adiposity levels within the PREDIMED trial

To assess the possible association between a validated Dietary Inflammatory Index (DII) and specific dietary components with suitable non-invasive markers of liver status in overweight and obese subjects within the PREDIMED study.

A cross-sectional study encompassing 794 randomized overweight and obese participants (mean ± SD age: 67.0 ± 5.0 y, 55% females) from the PREDIMED (PREvención con DIeta MEDiterránea) trial was conducted. DII is a validated tool evaluating the effect of diet on six inflammatory biomarkers (IL-1b, IL-4, IL-6, IL-10, TNF-α and C-reactive protein). Furthermore, a validated 137-item food-frequency-questionnaire was used to obtain the information about the food intake. In addition, anthropometric measurements and several non-invasive markers of liver status were assessed and the Fatty Liver Index (FLI) score was calculated.

A higher DII and lower adherence to Mediterranean diet (MeDiet) were associated with a higher degree of liver damage (FLI > 60) in obese as compared to overweight participants. Furthermore, the DII score was positively associated with relevant non-invasive liver markers (ALT, AST, GGT and FLI) and directly affected FLI values. Interestingly, a positive correlation was observed between liver damage (>50th percentile FLI) and nutrients and foods linked to a pro-inflammatory dietary pattern.

This study reinforced the concept that obesity is associated with liver damage and revealed that the consumption of a pro-inflammatory dietary pattern might contribute to obesity and fatty liver disease features. These data suggest that a well-designed precision diet including putative anti-inflammatory components could specifically prevent and ameliorate non-alcoholic fatty liver manifestations in addition to obesity.