Effects of Various Dietary Cholesterol Levels on Serum Tocopherol and Fatty Acid Composition in Female Rats

The effect of dietary cholesterol (0-1%) on the levels of serum cholesterol, vitamin E (tocopherol), and fatty acid composition was determined in female rats fed a 10% butter diet with 10mg% tocopherol. When the dietary cholesterol level was increased, serum cholesterol and tocopherol also increased (r=0.72 and r=0.64, respectively), and a direct relationship was found between the concentrations of serum cholesterol and tocopherol (r=0.97). An increase in dietary cholesterol decreased the ratio of serum tocopherol to cholesterol (r=-0.80). Elevated dietary cholesterol caused an increase in serum total fatty acid (r=0.64) due to increases in saturated fatty acid (SFA, r=0.63) and monounsaturated fatty acid (MUFA, r=0.67), but no significant changes were found in the level of polyunsaturated fatty acid (PUFA, r=0.22). The ratios of PUFA/SFA and PUFA/MUFA decreased with an increase in dietary cholesterol (r=-0.82 and r=-0.81, respectively). A direct relationship was found between the ratios of tocopherol/cholesterol and PUFA/SFA in serum (r=0.77). These results indicate that dietary cholesterol affects vitamin E status and fatty acid composition of serum and that it has a detrimental effect on the ratios of tocopherol/cholesterol and PUFA/SFA in serum.