High dietary inflammatory index scores are associated with an elevated risk of hepatocellular carcinoma in a case-control study

Chronic inflammation and diet play crucial roles in the development of hepatocellular carcinoma (HCC); yet the association between dietary inflammatory potential and risk of HCC has rarely been investigated. This study aimed to examine whether a higher dietary inflammatory index (DII®) score (indicating a pro-inflammatory diet) is associated with an increased risk of HCC in a matched case-control study conducted between September 2013 and October 2017 in South China. A total of 659 cases with newly diagnosed, previously untreated HCC and 659 controls individually matched on age (±3 years) and sex were included in this study. DII scores were computed based on dietary intake information collected via a validated 79-item food frequency questionnaire (FFQ) during the one year prior to diagnosis (for the cases) or interview (for the controls). Logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI) between the DII score and the risk of HCC, adjusted for age, energy intake, body mass index, physical activity, marital status, education, household income, smoking status, and hepatitis B virus (HBV) infection status. Compared with subjects in the lowest DII tertile, subjects in the highest tertile had an elevated risk of HCC (fully adjusted OR: 3.22, 95% CI: 1.30-7.98, P-trend = 0.009). In stratified analyses, a significantly positive association was observed only in men, individuals with lower education level, smokers and non-alcohol drinkers. In conclusion, a higher DII score, representing a more inflammatory diet, was associated with an increased risk of HCC, in men, individuals with lower education level, smokers and non-alcohol drinkers.