The interaction of dietary cholesterol and specific fatty acids in the regulation of LDL receptor activity and plasma LDL-cholesterol concentrations.

From these brief considerations, it is clear that the steady-state LDL-cholesterol concentration is determined in a powerful way by the interaction of dietary cholesterol and specific fatty acids. There appear to be only a few saturated fatty acids and an even lesser number of unsaturated fatty acids that significantly interact with cholesterol in the liver cell to alter hepatic LDL receptor activity. These effects are uniformly seen in most experimental animals and in humans under circumstances where the experiments are properly designed. Future work is urgently needed to define the metabolic effects of the more unusual fatty acids (e.g., the trans fatty acid) and the more intimate details of how these substances regulate LDL receptor activity in the cell. It is also of considerable importance to extend these studies to the members of the same species that exhibit variable responses to these same dietary lipids. It is now clear that the magnitude of these specific responses to dietary cholesterol and specific fatty acids varies in different individuals with different genetic backgrounds from the same species. Elucidating the reasons for this variability is another area of research of considerable importance to human biology.