FAHFAs: structures, distribution, analytical methods, and health implications

Branched fatty acid esters of hydroxy fatty acids (FAHFAs) comprise a recently identified class of endogenous lipid molecules that are closely linked to diseases such as type 2 diabetes, obesity, and cancer. They exhibit a range of biological activities, including metabolic regulation, anti-inflammatory, antioxidant, and immunomodulatory effects. FAHFAs have attracted considerable scientific interest since their initial discovery. Advances in analytical technologies have enabled the identification of numerous FAHFA family members and isomers in various food sources. In parallel, their biological activities and physiological roles have been elucidated. This review comprehensively summarizes the current research progress on FAHFAs, covering their structural characteristics, endogenous synthesis and metabolism, detection and identification techniques, dietary occurrence, and physiological functions. It aims to establish a theoretical foundation and systematic research framework to promote further investigation into FAHFAs, clarify their mechanisms of action in health and disease, and offer insights into the development of targeted functional foods.