Lipoproteins, Cell Proliferation and Cancer
In experimental animals, diets high in polyunsaturated fatty acids (USF) greatly promote tumorigenesis relative to the same animals fed saturated fat (SF)1–6. It appears that the tumor-promoting properties of a high fat diet are more a function of fatty acid composition than of fat content per se or total caloric intake5. Various mechanisms that were examined to explain the promotion of tumorigenesis by USF diet include: alterations in hormone levels, membrane fluidity, intracellular communication, prostaglandins, protein kinases, immune system and cell proliferation5. In spite of studies by cancer biologists and nutritionists, the exact mechanism(s) by which USF diets promote tumorigenesis is not well understood. It is likely that the tumor promoting properties of high USF diets may be related to their capacity to eliminate bile acids, stimulate de novo cholesterogenesis and decrease serum cholesterol ester levels7. Moreover, in various experimental tumor model systems3–5 and in epidemiological studies8, the serum cholesterol and triglyceride levels were found to be reduced. However, a cause and effect relationship between low serum low density lipoproteins (LDL) and promotion of cancer has not been explored thoroughly. Nonetheless, it is widely accepted that there is a cause and effect relationship between serum LDL and coronary heart disease (CHD) and that a reduction in serum LDL will greatly reduce the risk of CHD9.
KeywordsSerum Lipoprotein Acinar Cell Carcinoma Skin Allograft Choline Deficient Research Clinic Coronary Primary Prev
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