Beatrice Trum Hunter. Cambridge World History of Food. Editor: Kenneth F Kiple & Kriemhild Conee Ornelas, Volume 2, Cambridge University Press, 2000.
Substitute Foods
Substitute foods mimic their traditional counterparts: margarine as butter; nondairy products as milk, cream, and cheese; or extruded soybean mixes as bacon, beef, poultry, or fish. But although substitute food products may resemble their traditional counterparts, they are also likely to be composed of substances from totally different sources. The substitutes are partitioned and restructured, whereas the traditional foods are intact.
In the past, substitute foods were frequently developed as inexpensive replacements for more costly primary foods. An example is a cheese replacer. However, in recent years, substitute foods have been introduced and promoted for health reasons associated with reducing the intake of saturated fat, cholesterol, and calories. Examples are nonfat frozen desserts, egg replacers, and reduced-calorie baked goods.
On occasion, a substitute food, first launched as an inexpensive replacer, has become more expensive than its traditional counterpart. An example is margarine, originally offered as an inexpensive substitute for butter. But later it was promoted as more healthful than butter, and some special margarines became more expensive than butter (Sanford 1968).
Margarine as a Paradigm
Margarine was the first successful substitute food. A search for a butter substitute began in the early 1800s, and commercial production of margarine was launched in 1873.
Normally, the predominantly unsaturated oils used in margarine manufacture would soon oxidize and turn rancid when exposed to air. But the process of hydrogenation employed in its manufacture modifies the oils and makes them more saturated and durable. The raised melting point improves the fat’s consistency and color for the deep-frying of foods, and it protects both the fats and the foods made with them from developing off-flavors. These qualities made hydrogenated oils suitable for the manufacture of margarine and other solid shortenings and for use in numerous processed foods.
Although hydrogenation serves a technological purpose, there are biological and nutritional consequences. Hydrogenation converts the cis form of fatty acids, naturally present in oils, to a trans form. The original molecular pattern is rearranged, and the biological quality has become nutritionally inferior. Normally, trans isomers are not present in human tissues. If present, they are less well utilized in the human body. They do not circulate in the blood, nor do they move through the tissues as liquids. They may disrupt the permeability characteristics of the membranes of the body’s cells and prevent normal transport of nutrients into and out of cells (Emken 1984).
By the mid–1950s, warnings were sounded about the health risks of consuming hydrogenated fats and oils. A leading article in the Lancet predicted that “[t]he hydrogenation plants of our modern food industry may turn out to have contributed to the causation of a major disease” (Fats and Disease 1956: 55).
Shortly thereafter, Dr. Hugh Sinclair, at Oxford University’s Laboratory of Human Nutrition, reported that hydrogenation of fats produced a deficiency of essential fatty acids (EFAs) by destroying them, or resulted in abnormal toxic fatty acids with an antiEFA effect both in animal experiments and with clinical human studies. Sinclair demonstrated that a deficiency of EFAs is “a contributory cause in neurological diseases, heart disease, arteriosclerosis, skin disease, various degenerative conditions such as cataracts and arthritis, and cancer” (Sinclair 1957: 33).
Additional reports and critical assessments of trans fatty acids in margarine and processed foods containing hydrogenated fats and oils were made by others (Bicknell 1960; Kummerow et al. 1974; Enig, Munn, and Keeney 1978; Enig et al. 1983; Keeney 1981; Enig, Budowski, and Blondheim 1984).
By the 1980s, a Canadian government task force had noted the apparent cholesterol-raising effects of trans fatty acids (Beardsley 1991). The group recommended that margarine manufacturers should reduce the amounts by modifying the hydrogenation process.
A turning point was reached in 1990, when a study directed attention to the hypercholesterolemic effect of trans fatty acids in margarine (Mensink and Katan 1990). The researchers found that these isomers raised levels of unfavorable low-density lipoproteins (LDLs) and lowered levels of favorable high-density lipoproteins (HDLs) to an even greater extent than did saturated fat. Trans fatty acids increased the lipoprotein risk profile. The researchers recommended avoidance of trans fatty acids by those at risk of atherosclerosis.
Additional incriminating evidence was revealed. At an epidemiology conference in 1993 sponsored by the American Heart Association, a team of Harvard University researchers reported the results of a survey of 239 heart attack patients and 282 healthy controls. After having analyzed the eating patterns of their subjects, the investigators had calculated the trans fatty acid intake. Even after adjustments for numerous factors, the association of trans fatty acids with heart attacks remained highly significant. Individuals who consumed more than two and a half pats of margarine daily had a nearly two and a half times greater risk of heart attack than did those who never used margarine (Ascherio 1993).
Release of the Nurses Health Study in 1993 corroborated these findings (Willett et al. 1993). For eight years, 85,000 nurses had been monitored for margarine intake. Women who ate products that contained hydrogenated fats and oils had increased their risks of heart attack by 70 percent. Those who ate more than four teaspoons of margarine daily in all products, and especially in white breads and cookies, were at far greater risk of coronary heart disease (CHD) than those who consumed margarine less than once a month. The researchers noted that as a result of pressure from well-intentioned but unenlightened activists, fast-food restaurants had switched from beef tallow to partially hydrogenated vegetable oils for deep-fat frying. The quantity of trans isomers in beef tallow is 3 to 5 percent; in hydrogenated vegetable oils, it is 30 percent.
The history of margarine can serve as a paradigm for the risk inherent in the use of all substitute foods. Indeed, the European Community Commission has proposed that novel foods and ingredients be regulated. At a toxicology forum, members described the need to evaluate them as a “burning and timely issue.… We need to look at them from both toxico-logical and nutritional viewpoints. It’s a whole new era” (Somogyi 1993: 18).
Substitute Ingredients
Similar to substitute foods, ingredients, too, have been developed as inexpensive replacements for more costly or scarce ingredients. Examples are imitation vanillin, substituted for vanilla flavoring; inexpensive trash fish used in making surimi “sea legs” to simulate lobster; or the simulated maple taste in pancake blend syrup, in lieu of maple syrup.
In recent years, many substitute ingredients, like substitute foods, have been developed in response to concerns regarding certain health risks inherent in the industrialized diet, such as undesirable high levels of calories, fat, cholesterol, and sodium, or undesirable low levels of dietary fibers. One such effort has been to find a substitute for sugar.
Sugar Substitutes
The search for sugar substitutes has been driven by forces that involve health considerations. At first, the search was to meet a medical need: an acceptable sweetener that was tolerated by diabetics. Later, the driving forces were for sugar substitutes that were noncariogenic (to avoid tooth decay) and noncaloric or low caloric (to control weight).
Gradually, these specific health considerations became more generalized. A recent survey found that the main incentive for consumers to choose low-caloric products was to maintain overall health, rather than merely to reduce weight (Wilkes 1992).
In 1978, some 42 million Americans consumed low-calorie foods and beverages. By 1986, the number had more than doubled, to 93 million; and in 1991, it reached 101 million. In 1993, a national survey disclosed that the number had risen to 136 million, and low-calorie foods and beverages were being consumed by 73 percent of the total U.S. adult population (Fat Reduction in Foods 1993).The most popular low-calorie foods and beverages are soft drinks, consumed by 42 percent of all adults; sugar substitutes in other beverages and foods, consumed by 31 percent; sugar-free gums and candies, used by 28 percent; and sugar-free gelatins and puddings, eaten by 18 percent (Wilkes 1992).
Saccharin: An Early Substitute
Saccharin, an early sugar substitute, has been in continuous use as a noncaloric sweetener since the turn of the twentieth century. At present, however, it competes against more recently introduced noncaloric and low-caloric sweeteners. In fact, it was saccharin’s beleaguered history of use in the United States that gave impetus to the development of alternatives (National Academy of Sciences 1975). In 1977, saccharin was found to be carcinogenic in rats, and the Food and Drug Administration (FDA) attempted to ban its use under the Delaney Clause in the 1958 Food Additives Amendment to the 1938 Food, Drug, and Cosmetic Act (U.S. House of Representatives 1977). However, the U.S. Congress enacted a moratorium on the ban, and the moratorium was renewed several times. Then, in 1991, the FDA announced its decision to withdraw the proposed 1977 ban. Thus, saccharin continues to be used in the United States food supply, and currently, it is also employed in more than 90 other countries (Wilkes 1992; Dillon 1993; Giese 1993).
Aspartame: A Low-Caloric Substitute
Aspartame, approved by the FDA in 1981 for table use, represented the first sugar substitute approved in America in more than 25 years. Aspartame consists of two amino acids, L-phenylalanine and L-aspartic acid, and is 180 to 200 times sweeter than sucrose. Hence, it can be used at such a low level that it contributes only 4 calories per gram, and is regarded as a low-caloric sweetener (also known as a high-intensity sweetener).
Soft drinks account for 80 percent of aspartame’s use in the United States. However, since aspartame’s original approval, its use has been extended to thousands of food and beverage products, including carbonated soft drinks, refrigerated fruit juices, milk beverages, ready-to-drink teas, and frozen desserts, puddings, fillings, and yoghurt products, in addition to its use as a table sweetener (Wilkes 1992; Dillon 1993; Giese 1993).
The United States now accounts for approximately 80 percent of the global market for aspartame, although it is predicted that worldwide consumption will more than double by the end of the twentieth century. Aspartame is approved for use in more than 90 countries and is available, worldwide, in more than 5,000 products (Wilkes 1992).
Like saccharin, aspartame has been indicted for producing various adverse health effects, especially among heavy users (U.S. Senate 1987). These include numerous central nervous system and digestive system disturbances (Centers for Disease Control 1984; Monte 1984; Yokogoshi et al. 1984; Wurtman 1985; Drake 1986; Walton 1986; Koehler and Glaros 1988; Lipton et al. 1989; Potenza and El-Mallakh 1989; McCauliffe and Poitras 1991).
In 1984, the Centers for Disease Control conducted a four-month review of 517 consumer complaints relating to aspartame usage. The conclusions were that the complaints “do not provide evidence of the existence of serious widespread adverse health consequences attendant to the use of aspartame.” However, further monitoring was advised (Centers for Disease Control 1984: 607).
Acesulfame K: A Low-Caloric Substitute
The most recently introduced low-caloric sugar substitute is acesulfame K. Presently, it is used in about 600 food products in more than 50 countries. In 1988, the FDA approved its use for tabletop sweeteners, chewing gums, dry beverage bases, and dry dessert bases. Future approvals may be extended for confectionery products, baked goods, soft drinks, and other liquid beverages (Giese 1993).
Glycyrrhizin: Flavorant and Sweetener
Glycyrrhizin, in the root of the licorice plant, is an intensely sweet triterpenoid saponin. It is from 50 to 100 times sweeter than sucrose. Extracts are used to flavor and sweeten confectionery products (Cook 1970). Glycyrrhizin is on the FDA list of GRAS (Generally Recognized as Safe) substances as a flavorant but not as a sweetening agent. However, food manufacturers have increasingly been using glycyrrhizin for its sweetening quality.
Metabolic studies have shown that glycyrrhizin can be hydrolyzed by human intestinal microflora to release glucuronic acid, a sugar that is almost completely metabolized. Moreover, glycyrrhizin has corticoid activity, influencing steroid metabolism to maintain blood pressure and volume and regulate glucose–glycogen balance. At high levels, glycyrrhizin is capable of producing a variety of health problems, including hypokalemia, high blood pressure, and muscular weakness (Chamberlain 1970; Robinson, Harrison, and Nicholson 1971; Blachley and Knochel 1980; Edwards 1991; Farese et al. 1991).
Other Available Sugar Substitutes
Numerous low- or noncaloric sugar substitutes are in use elsewhere in the world but await approval in the United States. Sucralose, for example, was approved in 1991 for use in Canada, and shortly thereafter in Australia, Mexico, and Russia. Sucralose is 600 times sweeter than sucrose, and it does not break down in the body. It is manufactured by a multistep process that involves the selective chlorination of sucrose. Although a food-additive petition for sucralose use in 15 food and beverage categories was submitted to the FDA as early as 1987, the data are still under review. Applications are pending also in the United Kingdom and the European Community (Lite Sweeteners Maneuver 1989; Canada First Country 1991; Canada Clears Sucralose 1991; U.S. Department of Agriculture 1991).
Alitame, a low-caloric sugar substitute awaiting FDA approval, is 2,000 times sweeter than sucrose. It is formed by two amino acids, L-aspartic acid and Dalanine, and 2,2,4,4-tetramethylthietanyl, a novel amine. The aspartic acid component is metabolized normally; the alanine amide goes through the body with minimal metabolic changes. In the United States, a petition was filed for use of alitame in a broad spectrum of food products as early as 1986. But although alitame has been approved for use in Australia, New Zealand, and Mexico, the FDA is still reviewing the data (Alitame 1990; U.S. Department of Agriculture 1991).
Oligofructosaccharides (FOS) are natural sugar polymers that are potential sugar replacers. They contribute only 1.5 calories per gram and can be manufactured from sucrose by means of a fungal enzyme. They are reported to stimulate the growth of healthy bifidobacteria in the human intestine. At present, they are used in Japan (Mitsuoka 1990; Modler, McKellar, and Yaguchi 1990; Fat Reduction in Foods 1993). In the United States, interest in FOS is focused more on their value as dietary sweeteners than on their therapeutic benefits.
Potential Botanical Substitutes
Numerous substitute sweeteners can be derived from botanicals. Many have had a long history of use elsewhere but lack regulatory approval in the United States.
Dihydrochalcones are derived from two flavones, naringin and neohesperidin, found in citrus peels, and are several hundred times sweeter than sucrose. Many studies have confirmed their safety. The Scientific Committee for Food of the Commission of the European Community has allocated for dihydrochal-cones an Acceptable Daily Intake (ADI) of 5 milligrams per kilogram of body weight. Currently, this sugar substitute is approved for use in Belgium and Argentina. The FDA has requested additional toxico-logical tests (New ‘Super Sweeteners’ 1970; McElheny 1977).
Stevia rebaudiana is a South American plant that yields several sweet compounds. Purified glycoside components of this plant have been employed for many years in South America. Currently, the main consumers of steviosides are the Japanese. Dental research suggests that S. rebaudiana may suppress the growth of oral microorganisms (Shock 1982).
The red serendipity berry (Dioscoroephyllum cuminsii Diels) from Africa contains a sweet component, monellin. A sweet herb from Mexico (Lippia dulcis) has hernandulcin, an intensely sweet sesquiterpene. Some plants commonly grown in the United States also have sweet constituents. Leaves of the herb, sweet cicely (Myrrhis odorata), known as the candy plant, have been used as a sweetener and flavor enhancer in conserves and to sweeten tart foods. The dried leaves of the big-leafed hydrangea (Hydrangea macrophylla var. Thunbergii) and the rhizomes of the common fern (Polypodium vulgare L.) also contain sweet constituents.
A final sweetener from botanicals is Lo Han Kao (Momordica grosvenori Swingle), a fruit from southern China. The purified sweetener from the dried fruit is about 400 times sweeter than sucrose (Inglett 1981).
Alternative Approaches for Substitutes
One innovation in the search for sugar substitutes is the utilization of molecules that are mirror images. Natural sugars usually occur in the so-called D-form, which is metabolized. The mirror image, which rarely occurs in nature, is in the L-form and is not metabolized. This feature makes L-sugars attractive candidates as noncaloric sugar substitutes. Currently, 3 of the 10 known L-sugars have been selected for safety testing and scale-up production studies (Process Yields NoCal 1981; The Use of Sucrose 1982; L Sugars 1989; Giese 1993).
Another approach is to attach small molecules of sweeteners that are normally absorbed to much larger polymer molecules that are not absorbed. The sweetening agent leached to the polymer passes intact through the intestinal tract and is excreted unabsorbed (In the 1980s 1979).
The introduction of noncaloric and low-caloric sugar substitutes has not lessened the consumption of caloric sweeteners. On the contrary, there has been a steady increase in the use of all types of sweeteners – caloric, noncaloric, and low caloric (U.S. Department of Agriculture 1988). By 1993, the annual consumption of caloric sweeteners had reached 144.8 pounds per person in the United States (U.S. Department of Agriculture 1993).
Concomitantly, obesity continues as one of the most common and important medical conditions in the United States. More than one-third of all adults in the population are significantly overweight (Najjar and Rowland 1987; Sichieri, Everhart, and Hubbard 1992). The prevalence of obesity in some minority groups, especially Native Americans, African-Americans, and Hispanic women, reaches as high as 50 percent of these populations (Williamson et al. 1990). Although the problem of obesity is multifactorial, caloric intake is an important aspect. Clearly, the sweetening substitutes have not alleviated this problem; rather, they offer increased possibilities for food technologists to create a range of highly processed foods and beverages that further encourage poor food choices.
Fat Substitutes
The growing interest in fat and cholesterol reduction gained impetus in the 1980s and led to a multiplicity of developments for partial and total fat substitutes. In 1989 some 450 new food products introduced in the U.S. marketplace were labeled “low fat” or “nonfat.” By 1992, 519 new low-fat or low-cholesterol products had been launched. Fully one-third of these products were dairy foods. Others included baked goods, condiments, meats, and snacks (Mancini 1993).
By 1993, more than two-thirds of all American adults were consuming low- or reduced-fat foods and beverages, and they expressed the desire to have still others available. It was predicted that, eventually, a low-fat version of virtually every type of food would become available (Mancini 1993).
Hydrocolloid-Based Fat Substitutes
Many partial fat substitutes are made from cellulosics. Some are hydro-colloid stabilizers, such as cellulose gel from micro-crystalline cellulose (MCC) isolated from plants (Cellulose Gel Helps 1990); powdered cellulose, a by-product of the pulp paper industry (Powdered Cellulose Reduces 1990); and semi- or totally synthetic celluloses that are nonabsorbable (Klose and Glicksman 1968).
Carbohydrate-based hydrocolloid fat substitutes consist of water-soluble polymers from vegetable gums, such as carrageenan and guar (Starches Replace Fat 1989; Fat Substitutes 1990).The polymers are also derived from plant starches, such as those from potato and corn (Potato Starch Replaces 1989); from dextrins, such as those in tapioca (Potato Starch Replaces 1989); and from maltodextrins, such as those in hydrolyzed cornstarch (Get Rid of Unwanted Fat 1989). Some of these complex carbohydrates are absorbable, whereas others are not (Klose and Glicksman 1968).
One cereal-based fat substitute, “oatrim,” has notable characteristics as a fat substitute. It is derived from soluble oat fiber and from beta-glucans – complex carbohydrates contained in oat and other cereal grains – that have been found useful in lowering cholesterol. Thus, oatrim not only serves as a fat substitute but also as a cholesterol reducer.
Oatrim is made by treating oat bran and oat flour with alpha amylases. The starches are converted to amylodextrins, which, along with the beta-glucans, go into solution. The process yields a smooth, bland, white gel that can be used in numerous types of foods, such as extra-lean ground-beef mixtures, luncheon meats, cookies, muffins, and nonfat cheeses.
Consumption of oat bran had been promoted because of its ability to reduce cholesterol. However, it was found that the amounts needed were too great and could lead to gastrointestinal problems. In contrast, oatrim retains the cholesterol-reducing properties of oats and can be useful for this purpose at realistic levels of consumption (McBride 1993; American Chemical Society 1990).
Oatrim has been honored as being among the hundred most significant new technologies of 1993 (Hardin 1993). George E. Inglett and his associates at the U.S. Department of Agriculture’s National Center for Agricultural Research at Peoria, Illinois, patented Oatrim in 1991. Several national and multinational food companies have obtained licenses to manufacture and use oatrim in food products.
Microparticulated Protein
Several protein-based low-fat substitutes have been developed. The first to win FDA approval (1990) was Simplesse, developed by NutraSweet, a subsidiary of Monsanto. Simplesse contains only 1.3 calories per gram of food, compared to 9 calories in traditional fats. It is composed primarily of milk and egg white proteins, with added vegetable gum, lecithin, sugar, acid, and water. The molecules of the proteins are rearranged in a process called microparticulation. The resulting proteins consist of extremely small spherical particles, about one-thousandth of a millimeter in diameter. In this shape and size, the particles roll over one another, are perceived as being fluid, and mimic the mouthfeel and appearance of real fat (Fat Substitutes on the Horizon 1988).
Although the FDA concluded that Simplesse is safe because it consists of common food components, such an assumption has been challenged. The decreased particle size and homogenization of milk and egg white proteins may influence free cholesterol absorption. The technique creates stereochemical changes of amino acids and peptides, which could alter ratios of neurotransmitters and induce hyperinsulinemic responses (Roberts 1989).
In addition, concerns have been expressed about the potential sensitizing properties of Simplesse for individuals who have egg and/or milk intolerance. Dr. Ronald A. Simon, a member of FDA’s Ad Hoc Advisory Committee on Hypersensitivity, warned of the possibility of unique antigens in Simplesse that might be sensitizing and induce allergenicity. He urged that careful studies be conducted prior to sanctioning Simplesse for general use to determine what reactivity-sensitivity there might be, and encouraged allergenicity tests for both the product and any metabolic breakdown products (Allergy Specialist Expresses Concern 1988; see also Zikakis 1974 and Roberts 1989).
Another fat substitute based on egg and milk is under FDA review. Kraft General Foods has petitioned for approval of its product Trailblazer, which is a modified protein texturizer. It consists of a mixture of dried egg white and whey protein concentrate or skim milk, changed in form, and combined with xanthan gum and food-grade acid. Vitamin A, normally present in milk fat, is absent from this mixture, and Kraft announced that it would add vitamin A to any frozen dessert products made with Trailblazer (Dziezak 1989).
Emulsifier-Based Fat Substitutes
Emulsifiers to reduce fat levels were introduced as early as the 1930s, in “superglycerated” shortenings. In recent years, the application of emulsifier technology, in conjunction with other functional ingredients, has made it possible to achieve greater fat reduction (Fat Reduction in Foods 1993).
Emulsifiers themselves may be fat derivatives, with mono- and diglycerides constituting a major category. By changing the positions on the glyceride molecule, emulsifiers can be made to function differently in the body (Richard 1990). Every emulsifier has both hydrophilic and lipophilic portions, which makes the characteristic oil-and-water interface possible. The hydrophilic-lipophilic–based emulsifiers have a fat-derived component, usually one or more fatty acids attached to the hydrophilic portion of such substances as glycerine, sorbitol, sucrose, or propylene glycol. These emulsifiers, usually combined with water, can replace fat in food products. Some, such as the polyglycerol esters (PGEs), with or without added fat, offer the mouthfeel of fat. The PGEs have been used to provide about one-third fewer calories than traditional fats in food products (Richard 1990).
Due to their chemical composition or molecular weight, some of the emulsifiers (although fat derived), are poorly metabolized and absorbed. Similarly, some PGEs, which are complex molecules of glycerine and fatty acids, may be so large that they are hydrolyzed only partially in normal fat metabolism. Thus, they are not absorbed fully by the body (Richard 1990). Medium-chain triglycerides (MCTs) are metabolized by a different pathway, and normally are not stored in the body. Rather, they are burned as energy (Richard 1990).
Future Synthetic Fat Substitutes
Sucrose polyester (SPE) functions and tastes like fat. Its molecules are too large to be broken down by the body’s enzymes, and so it is neither digested nor absorbed. SPE is a mixture of hexa-, hepta-, and octa-esters that form when sucrose is esterified with long-chain fatty acid molecules derived from a fat, such as soy oil (Inglett 1981). Under development for several decades, SPE was accidentally discovered by researchers at Procter and Gamble (P&G) who were searching for fatty acids more easily digestible by premature infants than were those found in milk. It was patented by P&G in 1971 (The Use of Sucrose 1982).
In 1987, P&G petitioned the FDA to approve its SPE product (Olestra) for use as a fat substitute to replace up to 35 percent of traditional oils and shortenings for home and commercial uses, such as grilling; seasoning of vegetables, meats, and fish; and making doughnuts, sauces, and salad oils. It also replaces up to 75 percent of traditional oils and shortenings used in deep-fat frying in food-service outlets. Another use is in the commercial manufacture of snack foods, such as potato chips (McCormick 1988).
Researchers have suggested that in addition to such SPE features as its escape from digestion and absorption, other characteristics may also prove beneficial. By interfering with cholesterol absorption, SPE might lower blood cholesterol and prevent or retard the development of atherosclerosis and bowel cancer. Moreover, it was thought that SPE might help block absorption of such toxins as DDT (dichlorodiphenyltrichloroethane) and other harmful compounds that remain in the body’s fatty tissues for long periods, and might also help to expedite the excretion of such toxins from the body (Glueck, Mattson, and Jandecek 1979; Progress with Sucrose Polyester 1980; The Use of Sucrose 1982; Mellies et al. 1983; Sucrose Polyester 1983).
In human tests, however, SPE produced some adverse effects, such as gastrointestinal distress, including bloating, flatulence, nausea, diarrhea, soft oily stools, anal leakage, and increased urgency or frequency of bowel movements (Mellies et al. 1983). To avoid these problems, researchers modified the prod-uct’s chemical structure. Another problem was that SPE blocked absorption of vital fat-soluble vitamins, especially A and E. Thus SPE could produce serious vitamin deficiencies (Mattson, Hollenbach, and Kuehlthau 1979).
The FDA classified Olestra as a food additive, and, legally, this classification required P&G to demonstrate that the substance was safe under conditions of its intended use (Definition of the Term 1985). After this classification, safety questions were raised by a panel of a dozen scientists organized by the Medatlantic Research Foundation, a private research group. The panel requested the FDA to require additional studies on the long-term health effects of Olestra and its possible absorption by humans (Swasy 1989). In 1989, P&G initiated additional safety tests to avoid having the FDA delay any further review by several years and secured approval for Olestra in 1996.
Meanwhile, other fatty acid–based fat substitutes are being developed. Among them is phenylmethylpolysiloxane (PS), a polymeric liquid oil that is chemically inert and nonabsorbable (Braco, Baba, and Hashim 1987). Another is dialkyl dihexadecylmalo-nate (DDM), a synthetic fat substitute with potential applications for high-temperature use with fried snack foods. DDM is reported to be minimally digested and absorbed (Fat Substitute Menu 1990; Spearman 1990).
In addition, work is proceeding on an esterified propoxylated glycerol (EPG) nonabsorbable fat substitute intended for cooked and uncooked food products (Dziezak 1989). Under investigation are alkyl glycoside fatty acid polyester (AGFAP) (Schiller, Ellis, and Rhein 1988); raffinate polyesters (trisaccharide fatty esters) (Schiller et al. 1988); and trialkoxytricarbally-late (TATCA) (Fat Substitute Menu 1990), a nonhydrolyzable noncaloric oil-like compound.
Fat Substitutes and Safety Concerns
The prospect of many food products with fat substitutes raises safety concerns. Many of the fat substitutes, such as SPE, are regarded by the FDA as food additives, and, as a rule, a food additive represents only a very small percentage of a food product, at most only 1 or 2 percent. But with synthetic fat substitutes, the percentage is far higher. As replacers of fat – a macronutrient in the diet – these substances might replace up to 40 percent of calories consumed daily.
In this event, it seems clear that present safety tests are inadequate, and new ones need to be devised that go beyond the traditional guidelines, which in this instance would mean guidelines that address more than 100 percent of the test diet. For widely used fat substitutes, the traditional margins of safety – between no effect levels in animals and estimated exposure levels in many humans – may need to be reduced. The FDA needs to find ways of modifying the traditional safety factor and, at the same time, to assure that food additives are safe (Scarbrough 1989).
Fat Substitutes and Nutritional Concerns
It has been suggested that low-fat diets might compromise the intake of adequate amounts of certain nutrients, including essential fatty acids, calcium, iron, and zinc (Rizek, Raper, and Tippett 1988). Unfortunately, few feeding studies have been conducted with fat substitutes. Some trials suggest that they are ineffective for weight control, because individuals fed a meal that contained a lower than usual amount of caloric fat tended to compensate by eating more food at the next meal (Stark 1988).
Similarly, in animal studies, decreased carbohydrate intake made the subjects more hungry and resulted in an increased total food intake (Gladwell 1990). All of this, of course, raises the question of whether a decreased fat intake will result in a similar compensatory mechanism if fat substitutes gain widespread use.
Many health professionals are wary about the trend toward extensive use of fat substitutes. For years, public health programs have attempted to modify dietary habits. Americans have been encouraged, repeatedly, to increase consumption of nutrient-rich vegetables, fruits, whole-grain products, and lean foods of animal origin, while decreasing consumption of high-fat and high-sugar foods.
Thus, some health professionals are concerned that the availability of numerous low-fat and nonfat products (as well as those with low-caloric and noncaloric sweeteners) will lure consumers away from healthful nutrient-dense foods to poorer selections. A spokesperson for the American Heart Association cautioned that Simplesse, the first of the newly approved fat substitutes, “may do little but reinforce the country’s taste for high-fat foods” (Fat Substitute Rolled Out 1990: 39).
Food products made with fat substitutes may follow a consumption pattern similar to that of the sugar substitutes. The latter originally were hailed as the great hope for banishing obesity. However, this condition is more of a problem than ever. Will the fat substitutes, which offer a similar promise, also prove ineffective?