Olestra: Fat-Free But Not Worry-Free
Back in late January of 1996, potato chips were hot news, along with the weather, the government shutdown, and the Republican political race—at least for a day or two. On January 24th, the Food and Drug Administration (FDA) granted Procter & Gamble permission to market its fat substitute, olestra, for use in savory snacks (potato chips, tortilla chips, cheese puffs, and snack crackers).
This sounds like good news to a country that annually consumes 5.5 billion pounds of salty snacks per year, especially in light of the recent emphasis on cutting fat from our diets. A one-ounce serving of regular potato chips has 150 calories and 10 grams of fat, but the same serving of chips made with olestra has only 70 calories and no fat.
If It's Not Fat, What Is It?
Olestra, known as a sucrose polyester, is a substance that looks like fat, cooks like fat, and tastes like fat, but has a molecular structure larger than natural fats. The molecule is so large that the body cannot break it down, and it passes through the gastrointestinal tract undigested. Since it is not absorbed in the digestive tract, it adds no calories or fat to the foods prepared with it.
From Laboratory to Market
Olestra, as used in snack products, was actually discovered by accident. In the 1960s, scientists at Procter & Gamble were trying to develop a nutrition supplement for premature infants. They discovered that, instead of adding calories and fat to the infants' diets, olestra passed through the body undigested.
In 1975, the company petitioned FDA for approval of olestra as a cholesterol-lowering drug. This petition was dropped in 1988 when studies showed that olestra was not effective for this purpose. At the same time, Procter & Gamble sought FDA approval for the use of olestra as a food additive and replacement for shortening and cooking oil and for use in snacks. In 1990, the company amended its application to limit the use of olestra to snack foods only.
Although safety was FDA's principal priority in reviewing Procter & Gamble's petition for approval, their evaluation also focused on the gastrointestinal effects of olestra and on the absorption of vital nutrients. FDA evaluated more than 150,000 pages of data concerning olestra, drawn from more than 150 studies. FDA also sought advice from its Food Advisory Committee, which was comprised of a panel of outside experts.
Clinical studies indicated that olestra may cause intestinal cramps and loose stools in some people. Studies also demonstrated that olestra soaked up fat-soluble vitamins (vitamins A, D, E, and K) from foods eaten at the same time. Because olestra is not absorbed or digested, the amount of these fat-soluble vitamins available to the body is decreased. As a result, products containing olestra are fortified with these fat-soluble vitamins to offset this effect. Recent research demonstrates, however, that taking supplemental vitamins may be needed to prevent fat-soluble vitamin deficiency in patients who consume large amounts of foods containing olestra for extended periods of time.
In addition, clinical studies indicated that olestra reduced intestinal absorption of carotenoids—the nutrients found most commonly in fruits as well as yellow, orange, and dark green, leafy vegetables. A study showed that daily multivitamin pill did prevent a fall in vitamin A and E levels but not carotenoid levels. While the role of carotenoids in health is not fully understood, several clinical studies have demonstrated a protective effect of carotenoids on certain chronic diseases, including some types of cancer and heart disease.
After thorough evaluation of the data, a majority of the Food Advisory Committee concluded that there was reasonable certainty that the proposed use of olestra would be safe and recommended that FDA grant its approval. In doing so, FDA ordered Procter & Gamble to conduct postmarketing monitoring of olestra consumption levels and additional research about the effects of olestra on carotenoid absorption.
Olestra is marketed under the brand name Olean™, and products containing it are clearly marked. In addition, FDA has ordered that products made with olestra carry this warning label: “This product contains olestra. Olestra may cause abdominal cramping and loose stools. Olestra inhibits the absorption of some vitamins and other nutrients. Vitamins A, D, E, and K have been added.”
Because olestra has been approved for use only in savory snacks, Procter & Gamble will have to start the FDA application process all over again if they wish to extend the use of olestra to other products.
Despite FDA's stamp of approval and call for postmarketing testing, several scientists and consumer groups have expressed their opposition to olestra. Leading the public crusade against olestra is the Center for Science in the Public Interest (CSPI), a nonprofit consumer advocacy group based in Washington, D.C. Michael Jacobson, executive director of CSPI, has called Olestra a "public-health time bomb," and wrote in a USA Today opinion column that olestra's potential side effects are "downright dangerous."
CSPI wrote to then FDA Commissioner David Kessler urging FDA to rescind its approval of olestra, or at the very least, to require a more prominent, explicit warning label.
A Dieter's Dream?
Americans are gobbling up lowfat food products in record numbers, many in the hopes of aiding weight loss. According to the Food Marketing Institute, 65% of Americans in 1995 were concerned about fat intake, up from just 16% in 1987. So far, the effect of olestra on body weight is mixed. In one study involving overweight men who consumed olestra over 9 months, weight loss continued during this period whereas those men on a low-fat diet regained most the weight. However, in another study, olestra consumption failed to reduce blood lipids and body weight remained unchanged.
A recent national survey conducted for Parade magazine revealed that the most popular method of reducing fat in the diet is to buy the lowfat versions of popular products. Despite these statistics, Americans are more overweight now than ever before. According to the National Center for Health Statistics, in 1962 about 44.8% of American adults were overweight and in 2006 about 66.9% of American adults were overweight.
The Bottom Line
There is no doubt that Olestra increases the choices that consumers have available to them. But nutrition experts still recommend the same healthful diet they've advocated for years—one that stresses vegetables, fruits, beans, and grains, and de-emphasizes fat, salt, sugar, and food of little nutrition value, including snack foods. Procter & Gamble spokeswoman Wendy Jacques was quoted in the Washington Post saying, "Olestra is going to be a replacement for some fat in our diet, but it won't replace common sense." Let's hope she's right.
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Last reviewed January 2009 by ]]>David Juan, MD ]]>
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