Whole Grain-Derived Functional Components in the Modulation of Hepatic Endoplasmic Reticulum Stress: Mechanisms, Evidence, and Research Gaps

Hepatic endoplasmic reticulum (ER) stress plays a pivotal role in metabolic diseases, making it a key target for dietary intervention. Whole grain (WG), known for their high content of bioactive compounds such as phenolic acids, dietary fiber, and flavonoids, has been shown to have the ability to modulate hepatic ER stress. This review explores the association between hepatic ER stress and metabolic diseases and the mechanisms by which WG components, including phenolic acids, dietary fiber, and flavonoids, modulate hepatic ER stress. Bioactive components in WG have shown the potential to alleviate hepatic ER stress by reducing oxidative stress, alleviating inflammation, regulating lipid metabolism, and affecting the unfolded protein response pathway. This suggests a dietary strategy for managing ER stress and related metabolic diseases. The review also emphasizes the role of WG as a functional food for health promotion, and future studies should explore functional composition changes during WG processing, gut microbiota modulation, and therapeutic effects in combination with drugs.