Olestra: a new food additive

Reduced-fat foods: the complex science of developing diet-based strategies for tackling overweight and obesity

Fat plays multiple roles in determining the desirable physicochemical properties, sensory attributes, nutritional profile, and biologic response of food products. Overconsumption of fats is linked to chronic diseases, such as obesity, coronary heart disease, diabetes, and cancer. There is therefore a need to develop reduced-fat products with physicochemical properties and sensory profiles that match those of their full-fat counterparts. In addition, foods may be redesigned to increase the feelings of satiety and satiation, and thereby reduce overall food intake. The successful design of these types of functional foods requires a good understanding of the numerous roles that fat plays in determining food attributes and the development of effective strategies to replace these attributes. This article provides an overview of the current understanding of the influence of fat on the physicochemical and physiologic attributes of emulsion-based food products and highlights approaches to create high-quality foods with reduced-fat contents.

Olestra is associated with slight reductions in serum carotenoids but does not markedly influence serum fat-soluble vitamin concentrations

BACKGROUND

The 1996 Food and Drug Administration approval of the fat substitute olestra (sucrose polyester) called for active postmarketing surveillance because preapproval studies showed that olestra may lower circulating concentrations of fat-soluble nutrients such as vitamins and carotenoids.

OBJECTIVE

The objective of the Olestra Post-Marketing Surveillance Study was to examine whether customary consumption of olestra-containing savory snacks was associated with changes in serum fat-soluble vitamin and carotenoid concentrations among free-living persons in geographically and ethnically distinct US cities.

DESIGN

Adults (n = 2535) and their children aged 12-17 y (n = 272) in Baltimore, Minneapolis, and San Diego attended clinic visits during which data were collected on diet, savory snack consumption, lifestyle, and anthropometric indexes. Blood samples were drawn to assay carotenoids and vitamins A, D, E, and K. Data and blood samples were collected both before and after the nationwide introduction of olestra. General estimating equations were used in multivariate-adjusted models that examined olestra's association with the specified serum nutrients.

RESULTS

Compared with no intake, the top 2 tertiles of olestra use in adults were associated with circulating carotenoid concentrations that were modestly but significantly lower (4.3% to 22.4%). There were no significant associations of olestra with any serum nutrients among adolescents.

CONCLUSIONS

This active postmarketing surveillance study of a food additive suggests that small decreases in serum fat-soluble nutrients are attributable to olestra use. Although health outcomes were not measured here, it is unlikely that these small changes in nutrient measures would adversely affect health.

Authors' financial relationships with the food and beverage industry and their published positions on the fat substitute olestra

OBJECTIVES

This study examined the association between authors' published positions on the safety and efficacy in assisting with weight loss of the Procter & Gamble (P&G) fat substitute olestra and their financial relationships with the food and beverage industry.

METHODS

Journal articles about olestra, and their authors, were classified as supportive, critical, or neutral with respect to its use. Authors not known to have industry affiliations were surveyed about their financial relationships.

RESULTS

Supportive authors were significantly more likely than critical or neutral authors to have financial relationships with P&G (80% vs 11% and 21%, respectively; P <.0001). All authors disclosing an affiliation with P&G were supportive.

CONCLUSIONS

Because authors' published opinions were associated with their financial relationships, obtaining noncommercial funding may be more essential to maintaining objectivity than disclosing personal financial interests.

Extraction of lipid membrane incorporated vitamin E by sucrose polyesters

2H and 31P solid state NMR have been used to probe, at the molecular level, the interaction between structurally different sucrose polyesters and a phospholipid membrane into which alpha-tocopherol and specifically deuterated alpha-[5,7-(2)H(6)] tocopherol has been incorporated. Our results show that at high concentration (>or=10 mol%) sucrose octapalmitate (SOP) and sucrose hexapalmitate (SHxP) deplete bilayer-associated alpha-tocopherol in dipalmitoyl phosphatidalcholine (DPPC) multilamellar dispersions and preferentially sequester the alpha-tocopherol into a fluid sucrose polyesters (SPE) phase located proximal to the membrane surface. It is demonstrated that the ability of SPEs to function as a 'lipophilic sink' depends strongly on sucrose polyester concentration and degree of esterification.

Membrane perturbing properties of sucrose polyesters

Sucrose polyester (SPE), in the form of sucrose octaesters and sucrose hexaesters of palmitic (16:0), stearic (18:0), oleic (18:1cis), and linoleic (18:2cis) acids, have many uses. Applications include: a non-caloric fat substitute, detoxification agent, and oral contrast agent for human abdominal (MRI) magnetic resonance imaging. However, it has been shown that the ingestion of SPE was shown to generate a depletion of physiologically important lipidic vitamins and other lipophilic molecules. In order to better understand, at the molecular level, the type of interaction between SPE and lipid membrane, we have, first synthesized different type of labelled and non-labelled SPEs. Secondly, we have studied the effect of SPEs on multilamellar dispersions of dielaidoylphosphatidylethanolamine (DEPE) and dipalmitoylphosphocholine (DPPC) as a function of temperature, SPE composition and concentration. The effects of SPEs were studied by differential scanning calorimetry (DSC), X-ray diffraction, 2H and 31P NMR spectroscopy. At low concentration (< 1 mol%) all of the SPEs lowered the bilayer to the inverted hexagonal phase transition temperature of DEPE and induced the formation of a cubic phase in a composition dependent manner. At the same low concentration, SPEs in DPPC induce the formation of a non-bilayer phase as seen by 31P NMR. Order parameter measurements of DPPC-d62/SPE mixtures show that the SPE effect on the DPPC monolayer thickness is dependent on the SPE, concentration, chains length and saturation level. At higher concentration (> or = 10 mol%) SPE are very potent DEPE bilayer to HII phase transition promoters, although at that concentration the SPE have lost the ability to form cubic phases. SPEs have profound effects on the phase behaviour of model membrane systems, and may be important to consider when developing current and potential industrial and medical applications.

Effect of the moderate consumption of olestra in patients receiving long-term warfarin therapy

We conducted a prospective, randomized, double-blind, placebo-controlled, parallel-group trial to evaluate the effect of the moderate consumption of snacks containing olestra on the international normalized ratio (INR) in 40 patients receiving long-term warfarin therapy. Patients continued their warfarin regimen and were assigned to receive 1.5 servings/day (42 g) for 2 weeks of Pringles Original Flavor Fat Free Potato Crisps with Olean (12 g olestra/1.5 servings) or Pringles Original Flavor Potato Crisps (placebo group). Patients' INRs were measured weekly for 2 weeks. Thirty-six patients completed the first week of the trial. After 1 week, the mean change in the INR from baseline increased by 0.02 +/- 0.5 in the olestra group and by 0.17 +/-0.4 in the placebo group (p= 0.327). Ten patients in the olestra group and 12 in the placebo group completed the second week of the study. Mean change in the INR from baseline was similar at week 2, -0.18 +/- 0.38 and 0.09 +/- 0.53 (p=0.193), respectively. Gastrointestinal side effects (diarrhea, gas, bloating) occurred in three patients in the olestra group and five in the placebo group (p=0.3). Moderate consumption of snacks containing olestra did not significantly affect the INR (> 0.3 U) at 1 week in patients receiving long-term anticoagulation with warfarin. It does not appear that moderate consumption of these snacks would affect the INR after 2 weeks, but this must be confirmed in a larger sample with adequate power at 2 weeks.

Demographic, dietary and lifestyle factors differentially explain variability in serum carotenoids and fat-soluble vitamins: baseline results from the sentinel site of the Olestra Post-Marketing Surveillance Study

Biochemical measures of nutrients or other dietary constituents can be an important component of nutritional assessment and monitoring. However, accurate interpretation of the nutrient concentration is dependent on knowledge of the determinants of the body pool measured. The purpose of this study was to identify the determinants of serum carotenoid and fat-soluble vitamin concentrations in a large, community-based sample (n = 1042). Multiple linear regression analysis was used to examine effects of demographic characteristics (age, sex, race/ethnicity, education), health-related behavior (exercise, sun exposure, smoking, alcohol consumption), and intake (diet, supplements) on serum retinol, 25-hydroxyvitamin D, alpha-tocopherol, phylloquinone, and carotenoid concentrations. Age, sex, race/ethnicity, vitamin A intake, and alcohol consumption were found to be determinants of serum retinol concentration. Race/ethnicity, vitamin D intake, body mass index, smoking status, and sun exposure were determinants of serum 25-hydroxyvitamin D concentration. Determinants of serum alpha-tocopherol were age, sex, race/ethnicity, alpha-tocopherol intake, serum cholesterol, percentage of energy from fat (inversely related), supplement use, and body mass index. Age, sex, phylloquinone intake, serum triglycerides, and supplement use were determinants of serum phylloquinone concentration. Primary determinants of serum carotenoids were age, sex, race/ethnicity, carotenoid intake, serum cholesterol, alcohol consumption, body mass index, and smoking status. Overall, the demographic, dietary, and other lifestyle factors explained little of the variability in serum concentrations of retinol (R2 = 0.20), 25-hydroxyvitamin D (R2 = 0.24), and the carotenoids (R2 = 0.15-0.26); only modest amounts of the variability in serum phylloquinone concentration (R2 = 0.40); and more substantial amounts of the variability in serum alpha-tocopherol concentration (R2 = 0.62).