Replacing Saturated Fat with PUFA-Rich (Sunflower Oil) or MUFA-Rich (Rapeseed, Olive and High-Oleic Sunflower Oil) Fats Resulted in Comparable Hypocholesterolemic Effects in Cholesterol-Fed Hamsters.
Replacing Saturated Fat with PUFA-Rich (Sunflower Oil) or MUFA-Rich (Rapeseed, Olive and High-Oleic Sunflower Oil) Fats Resulted in Comparable Hypocholesterolemic Effects in Cholesterol-Fed Hamsters.
Year: 1999
Authors: E A Trautwein, D Rieckhoff, A Kunath-Rau, H F Erbersdobler.
Publication Name: Ann. Nutr. Metab.
Publication Details: Volume 43; Number 3; Page 159.
Abstract:
Numerous research studies have shown that PUFAs and MUFAs significantly lower plasma TC and LDL-C concentrations compared to SFAs. Studies have shown MUFA-rich oils such as CO and OO are equally hypocholestermic as PUFA-rich oils including soybean and sunflower oils. However there is controversy over which of the PUFAs and MUFAs is more effective in lowering plasma lipids and lipoproteins. Within the MUFA-rich oils, CO has been shown to be more effective in reducing plasma TC and LDL-C than OO, perhaps due to the its overall low content of SFAs or to its high content of plant sterols. This study was done to compare the cholesterolemic effects of different MUFA-rich oils in comparison to a PUFA-rich oil (sunflower oil) and a saturated fat (palm stearin). Seventy male golden Syrian hamsters were randomly assigned to seven diet groups containing one of the following fat blends: palm stearin, sunflower 18:2 or OA-rich, cold-pressed CO, refined CO or OO either virgin or refined. In order to test whether oil refining would have an impact on the cholesterol-lowering potential, unrefined and refined oils were included in the experiment. After five weeks, results showed plasma TC levels were highest following the palm stearin diet while the MUFA- or PUFA-rich diets significantly lowered TC. The lowest TC concentrations were found with refined CO, cold pressed CO and LA-rich sunflower oil whereas TC as 10-15% higher (not significant) with OA-rich sunflower, virgin and refined OO. Liver cholesterol concentrations were lowest in hamsters fed palm stearin or LA-rich sunflower oil while MUFA-rich fats increased hepatic cholesteryl ester accumulation, especially of cholesteryl oleate. These results indicate that MUFA-rich dietary fats are comparable in their hypocholesterolemic potential and cause similar effects on plasma TC as OA-rich sunflower oil in hamsters when the dietary cholesterol intake is moderate. When dietary cholesterol is excessive, OA fails to exert a distinct cholesterol-lowering effect whereas CO exerts an independent lowering effect. The hypocholesterolemic potential of CO appears to be somewhat greater than OA although the effect was not significant under the parameters of this study. Refining appeared to have little effect on cholesterol lowering. The findings of this study emphasize the favorable effect of CO on cholesterol metabolism, as has been supported in many other studies.
