A 91-day feeding study in rats with heated olestra/vegetable oil blends

A 91-day feeding study in rats was conducted to assess the potential toxicity of heated olestra/vegetable oil blends. Olestra is a mixture of the hexa-, hepta- and octa- long-chain fatty acid esters of sucrose. The blends tested were 35/65 olestra/vegetable oil (w/w), pan-fried at 380 degrees F for 30 min to simulate home-use conditions and 75/25 olestra/vegetable oil, deep-fried at 365 degrees F for 84 hr to simulate extended food-service use. Vegetable oil, prepared using both heating conditions, unheated vegetable oil and unheated olestra/vegetable oil blends served as controls. The olestra/vegetable oil blends and vegetable-oil control were generally fed at 10% (w/w) of the diet. Two further groups received the heated olestra/vegetable oil blends at 5% of the diet. Survival, clinical signs, body weight, feed consumption, feed conversion efficiency, organ weights, organ-to-body-weight ratios, haematological parameters and histomorphology were evaluated. No adverse effects from the ingestion of heated olestra/vegetable oil blends were detected. These findings indicate that heated olestra was non-toxic and, in this respect, no different from unheated olestra or heated or unheated vegetable oil.