Effects of different dietary cholesterol concentrations on lipoprotein plasma concentrations and on cholesterol efflux from Fu5AH cells

Abstract

Background:The fatty acid composition of the diet can modulate the effect of dietary cholesterol on plasma lipoproteins. However, HDL composition and its capacity to promote cholesterol efflux can be influenced by the diet. Objective: Modifications in plasma lipids and in the capacity of serum to stimulate the cholesterol efflux induced by a low-fat diet [National Cholesterol Education Program (NCEP) Step I diet], by a monounsaturated fatty acid (MUFA)-rich diet, and by addition of cholesterol to both diets was studied. Design: Fifteen young, healthy men followed 2 NCEP Step I diets (< 30% of fat as energy, with < 10% saturated fat and 14% MUFAs) for 24 d, providing 0.027 or 0.068 mg cholesterol · kJ Ϫ1 · d Ϫ1 , and 2 oleic acid-enriched diets (38% of energy as fat, with 24% MUFAs) providing the same amount of dietary cholesterol as the NCEP Step I diets. Results: Total cholesterol, LDL cholesterol, apolipoprotein (apo) B, and apo A-I concentrations decreased after the NCEP Step I and MUFA diets compared with the usual diet. HDL cholesterol also decreased after the NCEP Step I diet. Total:HDL cholesterol, apo B, and apo B:apo A-I were lower after the MUFA diets than after the NCEP Step I diets. There were no significant differences between the lipid profiles obtained after the NCEP Step I and MUFA diets were enriched with cholesterol. The capacity of serum to promote cholesterol efflux was significantly higher after the cholesterol-enriched NCEP Step I diet than after the NCEP Step I diet. Conclusions:The MUFA diet induced a better lipid profile than the NCEP Step I diet; however, the increase in the cholesterol content of both diets produced similar plasma lipid changes. The cholesterol in the NCEP Step I diet increased the cholesterol efflux induced by total serum.Am J Clin Nutr 1998;68:1028-33. KEY WORDS Cholesterol efflux, National Cholesterol Education ProgramStep I diet, monounsaturated fatty acids, dietary cholesterol, Fu5AH cells, lipoproteins, men INTRODUCTIONCoronary artery disease is still the most important cause of death and morbidity in the Western world. One of the major factors associated with its development relates to diet-induced elevations in plasma LDL concentrations. For this reason, the National Cholesterol Education Program (NCEP) has recommended a reduction in dietary fat intake to < 30% of daily energy consumption (1). The Mediterranean region has been characterized by a low prevalence of coronary artery disease (2) and it has been postulated that this apparent protection may be due in part to the relatively high proportion of monounsaturated fatty acids (MUFAs) in the traditional diet of this region (3). Therefore, some researchers consider a MUFA-rich diet to be as beneficial as a low-fat diet in the prevention of atherosclerosis (4).Reduction of dietary saturated fats is usually accompanied by a reduction in cholesterol consumption, although some foods, such as liver and eggs, are rich in cholesterol and relatively poor in saturated fats. It has also been suggested that die...

The Cholesterol Content of Western Diets Plays a Major Role in the Paradoxical Increase in High-Density Lipoprotein Cholesterol and Upregulates the Macrophage Reverse Cholesterol Transport Pathway

“…However, dietary saturated fat and cholesterol amount do not appear to affect cholesterol efflux to plasma in most of the studies conducted in humans [22][23][24] and animals. 37,38 Our in vitro cellular cholesterol efflux results were more comparable to those reported by Blanco-Molina et al 20 where the ability of serum to promote cholesterol efflux was slightly greater in 14 human subjects after a low-fat, high-cholesterol diet compared with the low-fat diet alone. Our results are also consistent with the reported HFHC diet-mediated effects on HDL-C and cholesterol efflux from macrophages and liver ABCG1 expression in mice.…”

Mechanism for the Cholesterol-Lowering Action of Egg White Protein in Rats

“…However, the results of many clinical trials have shown no correlation between egg consumption and the serum cholesterol concentration. [3][4][5][6] An epidemiological survey has fact in shown a negative correlation between the intake of eggs and cardiovascular diseases. 7) Thus, it is thought that a component in egg may help in controlling the serum cholesterol concentration.…”

Fatty acid saturation of the diet and plasma lipid concentrations, lipoprotein particle concentrations, and cholesterol efflux capacity

“…Furthermore, several studies have confirmed that the concentration of Lp A-I and Lp A-I:AII particles changes when the fatty acid composition of the diet is modified (28,29). On the other hand, the results of several studies of the effect of dietary fatty acid composition on serum capacity to promote cellular cholesterol efflux are still controversial (30)(31)(32)(33).In the present study, a long-term diet rich in vegetables, fruit, fish, and oils was administered to a healthy population. Different diets were created by varying the fatty acid saturation grade to study the effect on the plasma lipid and lipoprotein particle profile.…”

“…Furthermore, in the women, the sera obtained after the consumption of diets with a high nϪ6 PUFA content also showed significantly more cholesterol efflux than did sera drawn during the SFA and MUFA phases. Although several studies (30)(31)(32)(33)48) recently investigated the effect of dietary fat type on cholesterol efflux, the results do not agree, and this important issue remains to be clarified.Gillotte et al (32) performed a detailed study in primates of the possible effects of diets differing in degree of saturation. They concluded that all diets produce HDL of the same fluidity and size with an identical capacity to promote cellular cholesterol efflux.…”