Free phytosterols effectively reduce plasma and liver cholesterol in gerbils fed cholesterol

The potential of free phytosterols (including 20% stanols) to lower plasma and liver lipids was assessed in three experiments with gerbils fed diets containing cholesterol. The first explored the ability of phytosterols (0.5%) to block absorption of 0.05, 0.10, and 0.5% cholesterol. The second assessed the importance of consuming phytosterols (0.75%) simultaneously with cholesterol (0.15%). The third compared free phytosterols (0.75%) with similar levels of esterified sterols or stanols using diets containing 0.15% cholesterol. A 5:1 ratio of phytosterols:cholesterol effectively blocked cholesterol absorption when the dietary cholesterol load was moderate. Consuming a 5:1 ratio with every meal was more effective than receiving equal phytosterols in a 10:1 ratio every other day. Finally, free phytosterols dissolved in fat were as effective as esterified sterols and stanols in lowering plasma and liver cholesterol, and all were equally effective at blocking cholesterol absorption as shown by increased fecal cholesterol output. Plant sterol accumulation in the liver was minimal for all test groups.