7-ketocholesterol as a critical oxysterol: Impact on human health and safety in food systems

7-Ketocholesterol (7-KC) is a biologically active oxysterol formed through the oxidation of cholesterol, predominantly under conditions of oxidative stress. It is generated both enzymatically in specific tissues such as the brain and liver, and non-enzymatically via reactive oxygen species (ROS), especially in aging tissues and heat-processed animal-derived foods. 7-KC exerts multifaceted effects on human health, extending beyond lipid metabolism to disrupt glucose and amino acid utilization, impair mitochondrial function, and provoke endoplasmic reticulum (ER) stress. These disturbances contribute to chronic inflammation and oxidative damage, playing pivotal roles in the development of various diseases, including atherosclerosis, neurodegenerative disorders, diabetes, cancer, hepatic steatosis, and ocular and gastrointestinal pathologies. Additionally, 7-KC is a marker of cholesterol oxidation in the food industry, where it signals product degradation and potential toxicity in long-stored or thermally processed animal-based foods. This review explores the biosynthesis, metabolic fate, and pathophysiological role of 7-KC, highlighting its critical role in intermediary metabolism, disease progression, and food safety. Furthermore, it outlines mitigation strategies to reduce 7-KC exposure through dietary modifications, antioxidant interventions, and advanced food processing technologies aimed at enhancing public health.