Olestra is a fat substitute used in the cooking and preparation of foods, most commonly those foods normally containing high concentrations of fat. Potato chips were one of the first commercially available products to have it used in their preparation. The benefit is the extreme lowering or complete elimination of a traditionally fatty food's fat content. Like insoluble fiber found in corn and apples, olestra is not digested or absorbed by the body, and it passes through the human digestive system completely unchanged.
Olestra, also known by the brand name Olean®, was discovered by researchers Fred Mattson and Robert Volpenhein of Proctor & Gamble (P&G) in 1968. The original study, which surrounded fats that could be more easily digested by premature infants, led to P&G contacting the Food and Drug Administration (FDA) in 1971 to investigate the testing that would be necessary to manufacture and market Olean® as a food additive, specifically as a fat replacement.
In the testing that followed, P&G scientists noted an interesting side effect when olestra was used to replace natural dietary fats. A drop in the level of blood cholesterol resulted when olestra was used. P&G subsequently filed a request with the FDA to market olestra as a drug in the treatment of high cholesterol. However, P&G's studies failed to produce the 15% decline in cholesterol levels to quality olestra as a treatment.
It wasn't until 1996 that the FDA finally approved olestra as a food additive. The first product to use Olean® as a substitute for dietary fat was the WOW® brand of potato chips by Frito-Lay®. Following their national launch in 1998, the WOW® chips were initially successful, raking in sales in excess of $400 million US Dollars (USD). However, due largely to reports of certain unpleasant side effects that were subsequently listed on a health warning label on the product as mandated by the FDA, sales dropped sharply.
The side effects—including loose stools, abdominal cramping, and olestra's interference with the body's ability to absorb certain crucial vitamins, namely Vitamins A, D, E, and K—were enough to cut sales in half by 2000 to $200 million USD. Although the intestinal side effects, which became commonly known as "anal leakage" in the media, occurred only as a result of over-consumption, it was enough to tarnish the product's reputation and diminish consumer appeal. Citing further studies, the FDA decided that the warning label wasn't warranted and approved its removal despite complaints numbering over 20,000 regarding side effects. It has also been proven since the time of the original studies that Olean® has no impact on the body's ability to absorb fat-soluble vitamins.
Olestra, under the brand name Olean®, is still used primarily as a fat substitute in the manufacture of certain savory snack foods including Lays® Light Potato Chips, Doritos® Light Snack Chips, Pringles® Light Potato Crisps, Ruffles® Light Potato Chips, and Tostitos® Light Tortilla Chips. The FDA declared Olean® as "Generally Regarded As Safe" (GRAS) in late 2008 for use in the production of prepackaged, ready-to-eat cookies using Olean® BakeLean. BakeLean products are proprietary blends of Olean® and vegetable oils used as a substitute for butter, margarine, and shortening in the manufacture of baked goods, reducing the calories and fat content of the end product by 75%. Olean® is not approved for use or sale in Canada or the European Union.