Olestra (also known by its brand name Olean) is a fat substitute food additive that adds no metabolizable calories to products. It has been used in the preparation of otherwise high-fat foods, thereby lowering or eliminating their fat content.
The Food and Drug Administration (FDA) approved olestra for use in the US as a replacement for fats and oils in prepackaged ready-to-eat snacks in 1996, concluding that such use "meets the safety standard for food additives, reasonable certainty of no harm". In the early 2000s, olestra lost popularity due to supposed side effects and is largely phased out, but products containing the ingredient are available in some countries. As of 2024, no products using olestra are sold in the United States.
Commercialization
Olestra was discovered accidentally by Procter & Gamble (P&G) researchers F. Mattson and R. Volpenhein in 1968 while researching fats that could be more easily digested by premature infants. In 1971, P&G met with the Food and Drug Administration (FDA) to examine what sort of testing would be required to introduce olestra as a food additive.
During the following tests, P&G noticed a decline in blood cholesterol levels as a side effect of olestra replacing natural dietary fats. Following this potentially lucrative possibility, in 1975, P&G filed a new request with the FDA to use olestra as a "drug", specifically to lower cholesterol levels. The lengthy series of studies that followed failed, however, to demonstrate the 15% reduction required by the FDA to be approved as a treatment. Further work on Olestra languished.