Bioactive Polyphenols and Carotenoids

Abstract

Several groups of lipids have been shown to provide health bene fi ts either through modi fi cation of tissue fatty acid composition or induction of cell signaling pathways. While some health bene fi ts are derived from consumption of shortto medium-chain fatty acids, evidence suggests that the polyunsaturated fatty acids (PUFAs) are the most important bioactive lipids. PUFAs are found mostly in plant seed oils and are important substrates for the biosynthesis of cellular hormones (eicosanoids) and other signaling compounds that modulate human health. The bene fi cial health effects of PUFAs seem to be dependent on their isomer con fi guration as the cis -isomer is the predominant bioactive form. Moreover, fatty acids in the cis -con fi guration have a rigid nonlinear structure, which enhances membrane fl uidity when incorporated into cells. Increased membrane fl uidity enhances cell to cell communication and helps maintain normal homeostasis or prevent the development of metabolic disorders. Therefore, this chapter will focus mostly on PUFAs but with brief discussions on a short-chain fatty acid (butyric acid) and mediumchain fatty acids. Detailed descriptions of the metabolic effects of short-chain fatty acids have been discussed in other parts of this book.