The lowdown on faux fat

In the war on dietary fat, Procter & Gamble just fired a salvo known as olestra. It's a fat substitute that zips through the body, leaving behind no fats, no calories and, at least for some people, no offensive taste.

The U.S. Food and Drug Administration formally approved the product, which has the brand name Olean, last month. But don't start buying smaller-sized clothes just yet; foods made with Olean won't be in the grocery store for about six months.

Meanwhile, everybody's asking about it. Here are answers to some common questions about the new product.

What is olestra?

Olestra is a fat replacement. It will be used as an ingredient in other foods and will replace fats, gram for gram. It is noteworthy because it is the first heat-stable, fat-replacer and can be used for frying foods. It tastes and has the mouth-feel, or texture, of true fat.

What's it made of?

It's called a sucrose polyester; its main ingredients are ordinary sugar and vegetable oil.

But it's fat- and calorie-free?

Yes. In the making of olestra, a new molecule is formed. The body's enzymes can't break down the fatty acids in the molecule, and it passes through the alimentary canal undigested.

What are the benefits of olestra?

For those who enjoy snacks such as potato chips, the fat and calorie savings are considerable. With an ounce of regular potato chips (that's a vending-machine-sized bagful), you'd be eating 10 grams of fat and 150 calories. With olestra-fried chips, you'd be getting 0 grams of fat and 70 calories, and they'd taste virtually the same.

Aren't there already fake fats on the market, like Simplesse?

Yes. However, those fats have bases of carbohydrates or protein _ neither of which do well when heated. Protein-based fats in particular coagulate like egg whites when heated.

What foods will olestra be in?

Basically, fried snack foods: potato chips, club crackers, tortilla chips, cheese curls. Frito-Lay has said it will use olestra in some of its snack foods. A new round of research and FDA approval is required before it can be used in other foods.

What about shortening or oil made from olestra?

They are likely in the works, but the FDA must approve them first. The FDA approved the fried snacks as a comparatively narrow category of foods to keep control of studies on it. This is similar to the introduction of aspartame (brand name: Nutrasweet), that was originally approved for diet sodas, then later was broadened to ice creams and frozen desserts, and eventually, to all foods.

Has olestra been tested in humans?

Yes; human testing is required before the FDA will approve any food. Wendy Jaues, a Procter & Gamble spokeswoman, said it has been under intense scrutiny since 1987, when it was first put before the FDA. Procter & Gamble had worked with the formula, doing its own testing, since the mid-'60s. As a condition of olestra's FDA approval, P&G also must continue to study consumption of products containing olestra, and its effects.

But the FDA said it is safe, right?

The FDA evaluated the more than 150 studies done by P&G since 1987, Jaues said, and decided there was "reasonable certainty of no harm" from use of olestra.

What are the critics' concerns?

Critics, including scientists, doctors and consumer watchdog groups, have said P&G skimped on research, rushing certain studies and glossing over those involving nutrients that olestra removes from the body as it passes through. Fat-soluble vitamins A, D, E and K, and a group of nutrients called carotenoids are removed when olestra passes through the intestines.

Carotenoids are thought to prevent cancers of some types, and essential vitamins A, D, E and K prevent other diseases, particularly, eye disease which leads to blindness.

Critics say P&G research relied on short-term consumption studies, and the effects of carotenoid depletion require longer study. Others have indicated concern over whether fat-soluble medications, including birth-control pills, hormone replacements and steroid treatments, may also be affected.

"There's just not enough information yet about carotenoids and their role in nutrition," said Christina Stark, nutrition specialist at Cornell University in New York. "There are still many questions about whether they are harmful or helpful; that's still being studied."

It's premature to say that olestra is harmless, she said, if carotenoids prove essential to the diet.

P&G argues that evidence that carotenoids prevent cancer does not exist, and only a small amount of the population eats enough snacks to actually deplete those nutrients.

What about FDA testing?

The FDA no longer tests products, but reviews information gathered from company research. According to Stanley Segall, professor of nutrition and food science at Drexell University in Pennsylvania, the burden of proof for a new product is on the producer. "The FDA removed itself from proving any product was unsafe; it's instead up to the manufacturer to prove the product is safe."

The FDA can request additional research if it finds holes in the studies; most companies therefore over-study to ward off that possibility, he said.

In the case of olestra, the small amount that the normal snacker would eat probably would cause minimal loss of carotenoids, he said.

"In June, before P&G was about to go to the FDA for approval for this, we science communicators called in the heads of research on olestra at P&G and grilled them quite well. We knew we would have to answer questions about the stuff, and wanted to see their research and hear their answers.

"We had to agree that P&G did more than an adequate job of compiling effects, and making the problems that they saw public."

Are there any known downsides to eating olestra?

Some people have shown a reaction to it much like that with mineral oil. Olestra becomes liquid at body temperature. As it goes through the digestive system, it separates from the solids, and what is called "fecal incontinence"occurs. It also can cause bloating, abdominal cramping and more serious diarrhea in some.

The FDA has required a warning label be put on all products containing olestra about the side effects, and P&G also is fortifying olestra with fat-soluble vitamins.

Is olestra on the shelf in other countries yet?

No. Britain and Canada have been approached for approval for olestra, but both countries have asked for more research on nutritional aspects of the product.

It's no cure-all

Olestra may cut calories and fat for snackers, but dietitians say it won't save people from their own bad habits.

"The problem with our eating and exercise habits in the U.S. is not going to be solved by fat-free potato chips," said Christina Stark, a dietitian with Cornell University's division of nutrition sciences.

Instead, we need to modify cooking habits, eat smaller portions, and eat more fruit, vegetables and grains, she said.

"The FDA based its approval of olestra, as it does all its products, on reasonable certainty of no harm _ not whether it's a good idea, or effective for weight loss."

Since 1990, about 1,000 reduced-fat and fat-free products have been introduced in the market every year, she said. Nearly two-thirds of Americans are eating some type of reduced-fat or reduced-calorie food, research from the Calorie Control Council shows.

Despite the foods catering to those trying to lose weight, Americans continue to chart weight gains.

"Fat-free does not mean calorie free, but there is the mentality that if something is fat-free, we can eat more of it," Stark said.

Stanley Segall, head of Nutrition and Food Science at Drexell University in Philadelphia, said there are benefits to a fat substitute.

"It can help us reduce the problems associated with chemistry of metabolizing fats. It will help with heart disease, and possibly problems associated with diabetes, and so on.

"But the question is, if we don't reduce weight, we still suffer from all the other problems that come along associated with being overweight. The benefits are offset." .

Olestra

The Food & Drug Administration has approved Procter & Gamble's fat substitute, olestra (sucrose polyester), for use in cooking salty snacks and chips.

COMPARING NATURAL FATS AND FAT SUBSTITUTES

Natural fats (triglyceride) are made from three fatty acids attached to one molecule of glycerol.

Olestra (sucrose polyester) is a fat substitute made from eight fatty acids attached to one molecule of sucrose (table sugar).

DIGESTION

Enzymes attack the molecules of fat, breaking them down to smaller molecules which can be absorbed by the intestine. The enzymes cannot penetrate the mass of fatty acids to break down olestra. Because of its size, olestra cannot be absorbed.

ABSORBTION

Oil-soluble vitamins A, D, E & K, as well as some beta carotene will attach to the fatty acids. Those attached to triglyceride molecules are absorbed through the intestines into the bloodstream. Those attached to olestra fat molecules are undigested.

PRO

To some, tastes the same as natural fat.

Not digested, reducing dietary fat intake, and lowering risk of coronary disease.

CON

Undigested olestra may cause gastrointestinal disturbances including diarrhea and looser bowel movements.

Depletion of oil-soulble vitamins (A, D, E & K).

Source: Procter & Gamble