Olestra

Olestra is a synthetic fat substitutes comprising fatty acid esters of sucrose (sucrose polyesters). It can not be broken down by the body's own lipases. One of the disadvantages of Olestra heard that the absorption of important vitamins like A, D, E, K, or some drugs is limited.

Olestra was synthesized in 1968 by researchers from Procter & Gamble. On January 24, 1996, after years of effort, the company, the product, the U.S. Food and Drug Administration first allowed to for use in foods, restricted to certain snacks like potato chips or tortilla chips. In Europe, Olestra is not allowed, since ( E 473 ) may contain not more than ten percent tetra-and higher esters of sucrose in Europe Sucrose esters of fatty acids.

Chemically, Olestra is a mixture, which is typically about 76 % of Oktaestern of sucrose; the remainder consisting mainly of heptaesters, and each about 0.2% hexa -and penta- esters. Olestra is not degraded by the human intestinal flora substantially. The preparation is carried by fats ( fatty acid esters of glycerol) reacted with methanol ( transesterification ) are. This results in methyl esters of fatty acids, which are then reacted with sucrose to Olestra.

Olestra is - because it is not absorbed by the body and not digested - excreted entirely again.

In a study on the environmental impact of the manufacturer indicates that Olestra is degraded in the environment by microorganisms with a half -life of 10-88 days.

Side Effects and Risks

Olestra reduces absorption of fat-soluble substances, such as vitamins A, D, E and K and the carotenoids. Therefore Olestra must be fortified with the fat-soluble vitamins, while reduction of the carotenoid in the blood is considered to be safe.

At replacement of more than about 30 percent of dietary fats by Olestra it comes to abdominal cramps and diarrhea to fecal incontinence, because the water-insoluble substance separated from the rest of the chair. This separation, and the resulting symptoms are also dependent on the fatty acid composition; long-chain fatty acids such as docosanoic reduce the symptoms.

In the United States initially had all the products containing Olestra be provided because of side effects with a warning, since 2003, this regulation is repealed despite objections.

In experiments with rats it was found that the consumption of Olestra has led to a continuous weight gain. Rats fed with normal and those with Olestra chips, weighed more than rats given only normal chips were served. Even after both groups then were given fatty foods, the animals fed with Olestra retained their higher weight.