Olive oil phenolics protect LDL and spare vitamin E in the hamster.

An animal feeding trial was conducted to investigate whether olive oil phenolics can act as functional antioxidants in vivo. To this end, hamsters were exposed for a period of 5 wk to a dietary regime with either a phenol-rich extra virgin olive oil or extra virgin olive oil from which phenols were removed by ethanol/water-washing. The original oil used in the high olive phenol diet was also used for the preparation of the low phenol diet in order to keep the FA compositions exactly the same. In addition, the vitamin E content was kept identical in both diets. This careful preparation of the diets was undertaken in order to prevent these factors from influencing the antioxidative status in plasma and LDL. Removal of olive oil phenols was shown to reduce both the vitamin E level in plasma and the resistance of LDL to ex vivo oxidation. The results of this study support the idea that extra virgin olive oil phenols improve the antioxidant defense system in plasma by sparing the consumption of vitamin E under normal physiological circumstances.