The influence of dietary flavonoids on human physiology and ageing is a subject of high interest, involving consumers, food producers, the medical community, and the drug industry. Anthocyanins make up a distinct class of flavonoids, conferring orange-to-blue colour to fruits and vegetables. The anthocyanins are among the few known molecules that are absorbed from the stomach and could serve as a case study for a deeper understanding of the physiology of the stomach and the pharmacology of drugs and natural compounds. “Can we identify elements and factors in the anatomy, histology, and physiology of the stomach that may rationally support the concept that some selected compounds can indeed be absorbed from this organ?” This is the main question that this chapter attempts to address by first providing a description of the multiple levels of structural organisation and functioning of the stomach. Subsequently, it focuses on evidence of gastric absorption of compounds other than anthocyanins in the belief that a given property should be seen as a general rule rather than an exception. If molecules can travel from the lumen to the blood across the gastric mucus and epithelium, then it is useful to consider if these layers act as either barriers or breaches. Finally, reports on gastric absorption of anthocyanins are critically examined with respect to the highlighted aspects of the stomach anatomy and physiology.
