"[Purified diets] offer several advantages compared with the commonly used chow-based diets, including reproducibility and uniformity of content, and the ability to precisely alter composition."

 

This study demonstrates that nutritionally defined semi purified diets are appropriate for the study of diet-genetic interactions in murine atherosclerosis. They offer several advantages compared with the commonly used chow-based diets, including reproducibility and uniformity of content, and the ability to precisely alter composition. Dietary lipid saturation and concentration are frequently the focus of hypotheses in experimental atherogenesis as a consequence of the enormous body of clinical and epidemiological data suggesting their importance in vascular disease. A semi purified diet allows the investigator to alter lipid concentration by substitution for an equivalent amount of energy from carbohydrate, to maintain a constant ratio of all other nutrients to energy in the control and high-fat diets. This is impossible to achieve when adding fat by dilution to a chow diet. The dilution technique confuses the interpretation of results. Indeed many investigators using diets prepared by dilution of chow with fat are seemingly unaware of the fact that mice consuming an identical amount of energy from the high-fat diet are also exposed to a significantly lower amount of all components of the chow, such as protein, all vitamins and minerals, and biologically active but non nutrient factors such as fiber and phytochemicals, including those with antioxidant properties. The role of specific vitamin and mineral deficiencies or excess can be precisely examined by using semi purified diets because their contents can be manipulated in the AIN vitamin and mineral formulations. The use of standardized formulations will allow investigators to compare data derived from different laboratories without the concern that unquantifiable differences in the chow diets used contributed to the reported results (at 1942-1943).

 

- Lichtman, A.H., Clinton, S.K., Iiyama, K., Connelly, P.W., Libby, P., Cybulsky, M.I. Hyperlipidemia and Atherosclerotic Lesion Development in LDL Receptor Deficient Mice Fed Defined Semipurified Diets With and Without Cholate. Arterioscler Thromb Vasc Biol. 1999;19:1938-1944