Evaluation of jojoba oil as a low-energy fat. 1. A 4-week feeding study in rats

The nutritional properties of jojoba oil (JO) were examined in a 4-wk feeding study of rats fed a diet with JO at dose levels of 2.2, 4.5 and 9%, supplemented with a conventional fat up to 18%. General health, survival and food intake were not adversely affected. Body-weight gains showed a dose-related decline, which amounted to 20% of the body weight in the high-dose group of both sexes. Clinical chemistry revealed significantly increased levels of various enzymes that were indicative of cell damage. Haematology showed a dose-related increase in white blood cells. On necropsy an apparent distension of the small intestine was found. Histopathological evaluation revealed marked intestinal changes characterized by massive vacuolization and lipid deposition in the enterocytes, accompanied by distension of the villi and an increased cell turnover of small intestinal cells. Faeces production and faeces lipid content were increased with increasing JO levels. The recovery of JO in the faeces also increased in a dose-related manner and was found to be correlated with the intestinal histopathological changes. The significant adverse clinical and histopathological effects observed in this study imply that JO cannot be considered as a promising alternative dietary fat with a low digestibility.