There is growing evidence for a global transition to a more highly processed diet. While the dietary share of ultra-processed foods depends on a country’s economic status, food choice and consumption are also influenced by the socioeconomic situation of individuals. This study investigated whether ultra-processed food consumption differed across socioeconomic subgroups and over time (2010–2018) in Korea. Cross-sectional data from the Korea National Health and Nutrition Examination Survey 2010–2018 were analyzed. Food and beverages reported in a one-day 24 h recall were classified according to the NOVA food classification criteria. The dietary energy contribution of ultra-processed foods was high among men and urban residents, and increased with education and income level; additionally, it reached its peak in adolescents and thereafter decreased with increasing age. After adjusting the socioeconomic variables, such associations remained significant, except for income level. The overall contribution of ultra-processed foods increased from 23.1% (2010–2012) to 26.1% (2016–2018), and the same trend over time was observed in all age groups and socioeconomic strata. In the Korean population, ultra-processed food consumption differed by individual socioeconomic characteristics, but gradually increased over time, and this trend was consistently found in all socioeconomic subgroups. Future strategies to promote healthy food choices are needed for the Korean population.

The RNA-dependent RNA polymerase (RdRp) of hepatitis C virus (HCV) is the essential catalytic enzyme for viral genome replication. It initiates minus-strand RNA synthesis from a highly conserved 98-nt sequence, called the X-RNA, at the 3'-end of the plus-strand viral genome. In this study, we evaluated the antiviral effects of peptide nucleic acids (PNAs) targeting the X-RNA. Our in vitro RdRp assay results showed that PNAs targeting the three major stem-loop (SL) domains of X-RNA can inhibit RNA synthesis initiation. Delivery of X-RNA-targeted PNAs by fusing the PNAs to cell-penetrating peptides (CPPs) into HCV-replicating cells effectively suppressed HCV replication. Electrophoretic mobility shift assays revealed that the PNA targeting the SL3 region at the 5'-end of X-RNA dissociated the viral RdRp from the X-RNA. Furthermore, delivery of the SL3-targeted PNA into HCV-infected cells resulted in the suppression of HCV RNA replication without activation of interferon β expression. Collectively, our results indicate that the HCV X-RNA can be effectively targeted by CPP-fused PNAs to block RNA-protein and/or RNA-RNA interactions essential for viral RNA replication and identify X-RNA SL3 as an RdRp binding site crucial for HCV replication. In addition, the ability to inhibit RNA synthesis initiation by targeting HCV X-RNA using antisense PNAs suggests their promising therapeutic potential against HCV infection.

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