Americans will soon be eating potato chips made with the first zero-calorie artificial fat.
The Food and Drug Administration approved Procter & Gamble's olestra Wednesday, over the protests of some scientists who called the fake fat dangerous.
The FDA warned consumers that olestra can cause side effects such as diarrhea and can literally wash out of the body certain nutrients, particularly when eaten along with that lunchtime bowl of soup or pile of carrot sticks.
But the FDA concluded that while some people will find olestra unpleasant, it is safe for the general population to eat in potato chips and other snack foods _ as long as the foods bear a label warning of those side effects.
"There are real effects in some people," said FDA Commissioner David Kessler. "They may be annoying. . . . But we do not believe they are medically significant."
Procter & Gamble spent 25 years and $250-million developing olestra, which it will put in its own Pringles potato chips and sell to other snack makers, including Frito Lay, under the brand name Olean.
Olestra has the cooking characteristics and "mouth feel" of fat but is not absorbed by the digestive tract. Test marketing will begin in several months.
"By replacing the fat in snacks, Olean can help millions of Americans cut excess fat and move closer to achieving an important dietary health goal," said P&G Chairman John Pepper.
But consumer advocate Michael Jacobson of the Center for Science in the Public Interest urged Americans not to eat olestra because it depletes nutrients believed to fight disease.
"It will cause everything from diarrhea to cancer, heart disease and blindness," said Jacobson, who threatened to sue to block olestra's sale.
Olestra is a synthetic chemical made of sugar and vegetable oil. It looks like regular fat, but its molecules are too large and tightly packed to digest. So it passes through the body without stopping to clog arteries or fatten hips.
One ounce of regular potato chips has 10 grams of fat and 150 calories, but olestra chips have no fat and just 60 calories, about the same as a plain baked potato.
There are other fat substitutes on the market, but none can withstand the high heat of frying and none is calorie-free like olestra. The low-fat chips sold today reduce fat by baking instead of frying, giving them a different taste.
But olestra can act as a laxative, causing diarrhea, cramps and other gastrointestinal problems. It also can rob the body of the vitamins A, D, E and K and the carrot-derived nutrient beta-carotene, because they stick to the fatty substance and slide out of the body.
Top nutritionists in November told the FDA to approve olestra as long as P&G fortified it with vitamins A, D, E and K, something FDA insisted on.
Of most concern to Jacobson is olestra's depletion of nutrients called carotenoids, including beta carotene. While the government last week proclaimed that supplements of beta carotene don't ward off disease, some doctors insist that getting enough carotenoids from food is important to prevent cancer, heart disease and age-related blindness.
National Institutes of Health specialists told the FDA that carotenoid connections to disease were still hypothetical _ and thus not a reason to block olestra.
Still, the FDA is making P&G study olestra's long-term dietary effects and will check the results at a public meeting within 30 months.
The tests _ usually performed by drug companies, not food makers _ will follow more than 2,000 olestra eaters, taking blood samples to check their carotenoid levels and even checking them for eye deterioration.
Does that mean Kessler is worried about olestra? He insisted he is not.
"Whenever you add something to the food supply of the American people, you have to be thorough," he said. But, he added, "I commit to you if these studies raise new questions, the agency will take appropriate regulatory action."
Meir Stampfer, a professor of epidemiology at Harvard who opposed olestra's approval, was dubious.
"I think Dr. Kessler got some bad advice on this one," he said. "If you think the stuff is really safe, why does it need a warning label? If it needs a warning label, it should not be in our food supply."
In the meantime, a label on olestra-containing foods will read: "Olestra may cause abdominal cramping and loose stools. Olestra inhibits the absorption of some vitamins and other nutrients."
_ Information from the Washington Post was used in this report.