Prospect of Fat Substitute Spurs Hope, Caution
Imagine indulging in a morning doughnut, secure in the knowledge that it had fewer calories than a glass of orange juice--and might lower the cholesterol levels in your blood to boot.
Envision eating French fries, chocolate blackout cake and double-dip cones, confident you were placing neither your heart nor your waistline at risk.
If this sounds good to you, it has an even better ring to executives at Procter & Gamble. The consumer-products conglomerate hopes to be first in the race to reach the market with a bona fide noncaloric fat substitute.
Last May, P&G; filed a petition with the Food and Drug Administration for approval of its candidate, a form of sucrose polyester (SPE) that it calls olestra.
P&G; has asked the FDA for permission to substitute olestra for up to 35% of the fat in many shortenings and cooking oils, and for up to 75% of the fat used for commercial deep-fat frying and in fried snack foods.
FDA to Take Its Time
The FDA is unlikely to approve or veto the petition for at least a year. If it is approved, the company will almost certainly ask for broader clearance of its product.
P&G; has high expectations for olestra and has fostered interest and anticipation via media reports. News magazines, newspapers and network TV have all trumpeted the glories of olestra. The company may well hope consumer clamor for the new diet aid will grease FDA’s often-slow wheels and encourage the agency to grant swift approval.
But rapid approval might not, in the long run, be to anyone’s advantage. Tests performed on olestra have raised questions about its safety.
P&G; scientists stumbled upon SPE while trying to devise a source of nourishment that could be absorbed easily by premature infants. Instead, by chemically binding sucrose (table sugar) to fatty acid (the principal component of fats), the researchers create SPE--a class of compounds the body absorbs poorly, if at all.
This family of substances looks, feels and tastes like fat. Depending on the specific mixture, SPE may be liquid or solid, and various formulations can be used as fat substitutes in frying, baking and other kitchen tasks.
But because SPE is not broken down by digestive enzymes, it is not absorbed and provides no calories. So, theoretically, consumers of the additive should be able to enjoy “fatty” foods without paying the usual price for such indulgence.
No Evidence of Weight Loss
However, no one has furnished strong evidence that dining on foods made with SPE, instead of with fats and oils, actually helps people lose weight. Dieters who eat potatoes fried in olestra instead of oil may feel entitled to have an extra helping of steak.
So far, some studies have shown that SPE promotes weight loss, while others suggest that it does not, according to the International Journal on Obesity.
Nevertheless, dieters’ lives would certainly be more pleasant if fat-free baked and fried foods were available. And if weight watchers replaced fatty foods with SPE-containing products, they would have more room in their diets for truly nutritious foods.
For these reasons, Hercules Segalas of the Drexel Burnham Lambert investment firm foresees a huge market for olestra.
“It would have wide use, ranging from almost pure fats like margarines and salad oils to foods like cake and ice cream,” Segalas says. “And it will do to those products what aspartame has done to soft drinks. Aspartame has sales of about $700 million a year. Olestra could make at least a billion and a half.”
But olestra’s lures are not for dessert-lovers and would-be bikini-wearers alone. The additive might also directly benefit health. It would accomplish this by decreasing blood cholesterol, high levels of which increase the risk of heart disease.
Olestra (which contains no cholesterol) could lower blood cholesterol levels modestly by replacing a portion of the saturated fat in people’s diets. Also, studies show that SPE prevents some of the cholesterol present in the intestines from being absorbed into the bloodstream. This cholesterol washes out of the body along with SPE, reducing the amount of cholesterol in the blood.
Studies Fall Under Cloud
These conclusions appear to be reliable--at least when a lot of SPE is consumed--but some of the studies on which they are based have fallen under a cloud.
One of the principal researchers, Charles J. Glueck, of the University of Cincinnati College of Medicine, was recently censured by the National Institutes of Health for misrepresenting data, although the discredited work did not involve SPE.
Assuming the cholesterol findings are correct, SPE could be especially beneficial because it apparently lowers “bad,” or LDL, cholesterol, without affecting the “good,” or HDL, variety. In fact, Drexel Burnham’s Segalas predicts that if FDA approves olestra as a food additive, P&G; will later apply for its approval as a drug.
Unfortunately, cholesterol isn’t the only substance washed out of the body by SPE. Because it acts as a fat does, SPE mixes with fat-soluble vitamins, such as A and E, in the intestines. And since the SPE isn’t absorbed, these vitamins are not absorbed well either, the American Journal on Clinical Nutrition says.
Unfortunately, P&G;’s tests of olestra don’t furnish convincing evidence of safety. For instance, in a test during which rats were fed SPE for two years, 48% of the males that were fed the highest dose died before the end of the experiment.
Among control animals, who did not eat the additive, just 28% died. In addition, groups of animals fed some doses of SPE developed pituitary tumors, leukemia or abnormal liver changes.
P&G; scientists also observed reproduction in rats fed SPE for two generations. In one experiment, animals fed the highest dose of SPE gave birth to an unusually high percentage of stillborn young. Also, high-dose rats produced four abnormal offspring, including a fetus without eyes and a pup with a structural defect of the nervous system.
P&G; denies that any of these findings are meaningful.
