Plant sterols and soluble nonstarch polysaccharides
These compounds may be grouped together as they share a similar mode of action on LDL cholesterol, which is to reduce the availability of dietary and biliary cholesterol for absorption in the gut. This action interrupts the enterohepatic circulation and upregulates the production and activity of LDL receptors. Plant sterols and their esters such as those incorporated into margarines (stanols and stanol esters), despite being nearly identical in structure to cholesterol, are poorly absorbed and interfere with the reabsorption of cholesterol origi-nating from bile (~1 g/day) and dietary sources (300 mg/day) by either coprecipitation or competi-tion. Margarines or spreads (30–40 g/day) containing plant sterols or their derivatives have been shown to reduce LDL cholesterol by up to 14% in controlled trials. Soluble NSPs such as those found in gums and gelling agents from fruit (gum arabic and pectins) act in a similar way and have been shown to be equally efficacious in reducing LDL cholesterol.