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Human Nutrition and Metabolism

Bakery Products Enriched with Phytosterol Esters, -Tocopherol and ß-Carotene Decrease Plasma LDL-Cholesterol and Maintain Plasma ß-Carotene Concentrations in Normocholesterolemic Men and Women¹

Joan Quílez, Magda Rafecas^*, Gemma Brufau^*, Pilar García-Lorda, Isabel Megías, Mònica Bulló, Joan A. Ruiz and Jordi Salas-Salvadó^,2

Departament de Tecnologia, Europastry S.A., Barcelona, Spain; ^* Departament de Nutrició i Bromatologia, Facultat de Farmacia, Universitat de Barcelona, Barcelona, Spain; and Unitat de Nutrició Humana, Facultat de Medicina i Ciències de la Salut de Reus, Universitat Rovira i Virgili, 43201-REUS, Spain

²To whom correspondence should be addressed. E-mail: jss{at}fmcs.urv.es.

	ABSTRACT

TOP ABSTRACT MATERIALS AND METHODS Analyses RESULTS DISCUSSION LITERATURE CITED

 
The hypocholesterolemic effects of phytosterols have not been evaluated in bakery products, and the addition of liposoluble antioxidants to the carrier has never been tested. We investigated the effects of consuming croissants and magdalenas (Spanish muffins) enriched with sterol esters, -tocopherol and ß-carotene on plasma lipid and fat-soluble antioxidant concentrations in normocholesterolemic, habitual consumers of bakery products following their usual diet and lifestyle. Using a randomized, double-blind, placebo-controlled design, the control (C) group (n = 29) received two pieces daily (standard croissant and muffin) and the sterol ester (SE) group (n = 28), the same products with sterol esters added (3.2 g/d) for 8 wk. Total and LDL cholesterol (LDL-C) decreased in the SE group by 0.24 mmol/L (P < 0.01) and 0.26 mmol/L (P < 0.005), respectively, whereas these variables did not change in the control group. The total difference in total and LDL-C changes between groups was 0.38 mmol/L (8.9%) and 0.36 mmol/L (14.7%), respectively (P < 0.001). Within-group changes in HDL cholesterol, triacylglycerol or lipoprotein(a) concentrations did not differ. Similarly, within-group changes over time in plasma tocopherol and carotenoid concentrations did not differ between groups. Our findings suggest that bakery products are excellent carriers for phytosterols, and their consumption is associated with a decrease in total and LDL-C concentrations, with no changes in -tocopherol and ß-carotene. The ability of bakery products to include sufficient quantities of ß-carotene to compensate for a potential deficiency, and the fact that their efficacy was not associated with the time of day at which they were consumed, are interesting findings.

KEY WORDS: • phytosterols • cholesterol • LDL cholesterol • bakery products • ß-carotene

Hypercholesterolemia is an important risk factor for cardiovascular diseases, which are the main causes of mortality in developed countries. The high intakes of saturated fatty acids and cholesterol in these countries are associated with an increase in plasma LDL cholesterol (LDL-C),² which can promote atherogenesis and atherosclerosis (1). Dietary changes are the preferred way of improving plasma lipid variables in primary prevention. Nevertheless, these dietary changes may be insufficient to meet the LDL-C target in people with moderate hypercholesterolemia and those who adhere poorly to dietary recommendations.

Certain diet components such as phytosterols can help to improve the blood lipid status because they interfere with both dietary and biliary cholesterol absorption (2). These compounds are related and structurally similar to cholesterol and include both plant sterols and stanols, their saturated form. They occur naturally in vegetable foods and oils; a Western diet provides between 170 and 360 mg/d, depending on dietary habits and geographical location (3). In recent years, great interest has been shown in their cholesterol-lowering properties, because phytosterol consumption > 1.5 g/d reduces plasma LDL-C by 8–15%. As a result, cardiovascular risk is also reduced (4). It has been shown that this effect occurs in both normocholesterolemic and hypercholesterolemic subjects (5) and can be caused by sterols as well as stanols (6,7). Apart from a few cases of subjects suffering from sitosterolemia, a rare inborn error of metabolism, no side effects have been found in people consuming sterols or stanols other than a decreased concentration of some fat-soluble antioxidants, such as carotenoids. Some studies have observed no significant differences in carotenoid concentrations after adjusting for plasma cholesterol concentrations (8,9). Other studies, however, have found that standardized ß-carotene decreases (10,11), a diet rich in carotenoids has been recommended when phytosterols are consumed (12). Fat spreads are the main food products used for this purpose, but yogurt (13,14), salad dressings (11), chocolate (15) and ground beef (16) have also been used as carriers. Sterols in their esterified form are widely used because they present an increased lipid solubility that facilitates their incorporation into the fat phase of foods.

In countries with reduced consumption of margarine spread, such as Spain, this product is not the best carrier for phytosterols. Bakery products are important food components at breakfast and for mid-morning and afternoon snacks. Similarly, the complex flour-water-fat of which they are composed is suitable for incorporating phytosterols, fat-soluble vitamins and also carotenes, because the yellow-orange color of these products is well accepted. The aim of the present study was to examine the effect of croissants and muffins enriched with sterol esters equivalent to 3.2 g/d of free sterols, 5.3 mg/d -tocopherol and 0.9 mg/d ß-carotene, on plasma lipid, fat-soluble antioxidant (tocopherols and carotenoids), phytosterol and cholesterol precursor (lathosterol and desmosterol) concentrations in normocholesterolemic men and women with no changes in diet and lifestyle. We also investigated these effects when bakery products were ingested as a part of a meal or between meals.

	MATERIALS AND METHODS

TOP ABSTRACT MATERIALS AND METHODS Analyses RESULTS DISCUSSION LITERATURE CITED

 
Subjects.

Normocholesterolemic individuals (n = 70) were recruited for the study; 3 wk before the start, they were invited for a screening visit. The inclusion criteria were as follows: global cardiovascular risk according to the European Society for Atherosclerosis < 20% (17), fasting plasma total cholesterol concentration 6.28 mmol/L (240 mg/dL), fasting plasma triglyceride concentration 2.26 mmol/L (200 mg/dL), BMI (weight/height²) < 40 kg/m², no alcohol abuse (<60 g ethanol/d), no medication or diet known to affect plasma lipids, no psychiatric disorders or alterations that make follow-up difficult, no metabolic, infectious, inflammatory or tumoral diseases and no antecedents of sitosterolemia. Neither pregnant nor breast-feeding women were accepted; finally, subjects were included only if they were habitual consumers of bakery products.

Of the 70 recruits, 61 met the criteria and were included in the study. Four subjects dropped out during the study, three in the first period for personal reasons and one at the end for poor compliance with the general protocol. Altogether, 57 subjects completed the assay, 29 in the control (C) group and 28 in the sterol ester (SE) group. Baseline population characteristics are presented in Table 1. The aim of the study was explained to all the subjects and they gave their informed consent before the start. The protocol was approved by the Ethics Committee of the Hospital Universitari de Sant Joan de Reus.

The study used a randomized, double-blind, placebo-controlled, repeated-measures design. Each person was assigned to the C or SE group to balance the groups in gender and smoker distribution. The study was conducted for 8 consecutive weeks.

During the intervention period, each subject received one croissant and one muffin every day. Frozen products were defrosted and cooked daily from Monday to Friday, placed in numbered plastic bags and delivered to each person. The products to be consumed on the weekend were cooked and delivered on Friday. The C group was given standard croissants and muffins, and the SE group was given the same products with sterol esters added. Subjects were allowed to eat the two pieces separately at any time of the day in place of their usual consumption of bakery products. They were also encouraged to maintain the same lifestyle and dietary habits.

Dietary intake was assessed at the beginning (wk –1), at the half-way stage (wk 4) and at the end of the study (wk 8) by means of a 7-d food record and by measuring body weight. Subjects were asked to record detailed descriptions of all food and beverages consumed (ingredients, methods of preparation, cooking) and to give quantities using weights or household measurements from a standardized list. A dietician checked the food and beverage records in each phase in the presence of the subjects. Intake was evaluated by means of food photographs (18) and the composition of diet and energy by French (19) and, in some cases, Spanish food composition tables (20). Dieticians also checked compliance by interviewing the participants and counting the number of muffin packs returned. A return < 70% was considered to be poor and participants were excluded from the study. The plasma concentration of phytosterols was also used to evaluate the compliance of the SE group subjects.

The four different products, croissants or muffins in C or SE recipes, were all produced in a single batch, immediately deep-frozen and stored at –18°C (Europastry S.A., Barcelona, Spain) until they were defrosted and cooked as described above. The final weight was 68 g for croissants and 54 g for muffins. The compositions of these products are shown in Table 2; the main difference between C and SE products was the partial substitution of fat by sterol esters from soy sterols esterified with canola oil fatty acids (Raisio Group, Raisio, Finland). Furthermore, experimental croissants and muffins were enriched with -tocopherol and ß-carotene (Roche, Basel, Switzerland). The yellow-orange color of SE bakery products was mimicked in C products by the addition of tartrazine and ponceau-4R colorants (Iproa, Barcelona, Spain). In addition to color, SE and C products were similar in appearance and taste to preserve the double-blind design.

	Analyses

TOP ABSTRACT MATERIALS AND METHODS Analyses RESULTS DISCUSSION LITERATURE CITED

Blood samples were taken twice at the beginning of the experimental period (d -2 and 0) and twice at the end (d +54 and +56) after a 12-h fast to decrease the intraindividual variability. Plasma was obtained by centrifugation at 2000 x g for 10 min at 4°C directly after sampling, and snap-frozen and stored in small portions at –80°C. All analyses were carried out at the same time after the plasma samples had been defrosted.

Lipids, lipoproteins and apolipoproteins.

Total cholesterol was analyzed by the CHOD/PAP method, as was HDL cholesterol (HDL-C) after apolipoprotein (apo) B-containing lipoproteins had been precipitated by adding phosphotungstic acid and magnesium ions. Triacylglycerols were determined by the GPO-Trinder method. All kits were supplied by Roche Diagnostics Systems. The intra-assay CV were <1.6% for total cholesterol, <5.0% for HDL-C and <3.2% for triacylglycerols. LDL-C was calculated with the Friedewald equation (21). The analyses were performed in a Cobas Mira autoanalyzer (Basel, Switzerland) and the cholesterol results validated with a standard certified by the Centers for Disease Control (Atlanta, GA) and the National Cholesterol Education Program (Bethesda, MD).

Apo A-1 and apo B were measured using an immunoturbidimetric reaction (UNI-KIT Apo A-1 and UNI-KIT Apo B; Roche Diagnostics Systems). The intra-assay CV were <2.7% for apo A-1 and <4.0% for apo B. Plasma lipoprotein(a) concentrations were analyzed by ELISA, using a commercial kit [Lp(a) SPQ II System, DiaSorin, Stillwater, MN]. The intra-assay CV was <5.4%. All samples from one subject were analyzed in one assay at the end of the study. Plasma lipid, lipoprotein and apolipoprotein results from d –2 and 0 and from d +54 and +56 were averaged for data analysis.

Plasma sterols.

Plasma sterols were measured as described by Philips et al. (22). Briefly, 0.7 mL of plasma was added to a centrifuge tube, and spiked with 1 mL of 5-cholestane internal standard solution (10 µg/L). Total lipid was extracted using chloroform/methanol 2:1 followed by a 9 g/L sodium chloride solution. The chloroform phase was filtered and evaporated completely. Then, 8 mL of ethanol with 30 g/L pyrogallol and 1 mL of saturated potassium hydroxide solution were added to the extract. Samples were saponified at 87°C for 30 min, and the nonsaponifiable fraction was extracted twice with cyclohexane. After solid-phase extraction to achieve a cleaner extract, samples were derivatized with 50 µL bis-(trimethyl-silyl) trifluoroacetamide containing 10 g/L trimethyl-chlorosilane and 50 µL pyridine.

Samples were injected into a Shimadzu GC-17A GLC coupled to a QP-5050A MS detector, with a 30-m capillary column SAC-5 (Supelco, Bellefonte, PA). Sterols were identified by comparison with standard compounds supplied by Sigma Chemical (St. Louis, MO) and HPLC grade reagents by Panreac (Barcelona, Spain). The intra-assay CV were <8.0% for desmosterol, <7.0% for lathosterol, <6.6% for campesterol and <7.8% for ß-sitosterol. For purposes of standardization, all of the results were adjusted for plasma total cholesterol concentrations (µmol/mmol total cholesterol).

Tocopherols and carotenoids.

Tocopherols (-tocopherol and -tocopherol) and carotenoids (-carotene, ß-carotene and lycopene) were determined as described (23). Briefly, 500 µL of ethanol containing an internal standard (25 mg/L of -tocopheryl acetate) was added to 500 µL of plasma in a 10-mL centrifuge tube and mixed for 30 s. Then, 2 mL of n-hexane was added and the tube was shaken again for 1 min. After centrifugation at 2000 x g for 10 min, the mixture was extracted twice with 2 mL of n-hexane. The solvent in the upper phase was removed under nitrogen steam and the dry residue was immediately dissolved again in 500 µL of n-hexane.

Samples were injected into a Shimadzu HPLC system with a variable wavelength UV-visible SPD-10A detector and a Tracer Extrasil ODS-2 column (250 x 4.0 m i.d., 5-µm particle size) protected by an ODS guard cartridge system (Teknokroma, Barcelona, Spain). Samples were isocratically eluted with a methanol/n-hexane mixture (85:15, v/v), with the detector at 292 nm for detecting tocopherols and at 450 nm for carotenes. The intra-assay CV were <4.5% for tocopherols, <3.0% for ß-carotene, <7.0% for -carotene and <8.2% for lycopene. Standards were supplied by Sigma Chemical and HPLC grade reagents by SDS (Peypin, France) and Scharlau Chemie SA (Barcelona, Spain). Results are presented as absolute values (µmol/L) or standardized by adjusting for plasma total cholesterol concentrations (µmol/mmol total cholesterol).

Statistical analyses.

Results are presented as means ± SD. Statistical analyses were performed with the statistical software SYSTAT 10 for Windows (SPSS, Chicago, IL). Normal distribution of variables was verified before further statistical analyses with the Kolmogorov-Smirnov one-sample test. Many variables did not follow normal distribution criteria, and nonparametric tests were used for comparison. The paired mean changes within each group (final vs. baseline) were analyzed with the Wilcoxon signed-rank test. Differences in changes over time between groups were analyzed with the nonparametric Mann-Whitney U-test. The relationships between variables were tested using Spearman’s correlation. Differences were considered significant when P 0.05.

Sample size was calculated assuming an 8% change in LDL-C concentrations, with a power of 90% and an risk of 5%. The calculation also assumed a potential drop-out rate of 15%.

	RESULTS

TOP ABSTRACT MATERIALS AND METHODS Analyses RESULTS DISCUSSION LITERATURE CITED

 
The groups did not differ in gender, age, weight, BMI, blood pressure, smoking habits or plasma lipid concentrations at the beginning of the study (data not shown).

Dietary intake and side effects.

The changes in the percentage of energy derived from carbohydrate, protein, fat and saturated fat during the study were similar in the two groups. The two groups differed in their changes in total energy and cholesterol intakes (Table 3). No side effects were mentioned by the subjects or observed in medical checks, except for one case of diarrhea in a subject from the C group, which was not considered attributable to the intervention. Body weight and blood pressure did not change within either group during the study. The bakery products were very well accepted in all cases and after the study, when asked about what kind of product they had consumed during study, most subjects were not able to identify their group. Therefore, the double-blind design was preserved.

During the 8-wk trial, plasma total cholesterol did not change in the C group, whereas it decreased in the SE group (-0.24 mmol/L; 95% CI: -0.06, -0.42; P = 0.001) (Table 4). The changes in total cholesterol induced by the two interventions differed by 8.9% (P < 0.001). A similar trend was observed for the LDL-C, i.e., no change in the C group and a decrease in the SE group (-0.26 mmol/L; 95% CI: -0.09, -0.43; P = 0.002). The changes in LDL-C differed by 14.7% between interventions (P = 0.001).

The degree of reduction in LDL-C was positively related to the baseline concentration in the SE group (r = 0.42, P < 0.05), but did not correlate with BMI or the fat or cholesterol consumption.

When individuals who ate bakery-modified products as part of a meal (n = 14) were compared with those who ate them separately from meals (n = 14), the decrease in LDL-C did not differ between the two types of consumption (-0.26 ± 0.53 vs. -0.26 ± 0.34 mmol/L, respectively).

Plasma sterols and cholesterol precursors.

The consumption of bakery products enriched in plant sterols increased plasma sterol concentrations (Table 5). Standardized campesterol and sitosterol concentrations increased considerably in the SE group (P < 0.001) and the changes in campesterol and sitosterol concentrations during the study differed significantly between groups (P < 0.001). Plasma concentrations of cholesterol precursors, desmosterol and lathosterol, increased in the SE group (P < 0.005), but did not change in the C group. The changes in desmosterol and lathosterol concentrations induced by the two interventions differed significantly (P < 0.001 and P = 0.003, respectively).

Both the absolute and standardized plasma -tocopherol concentrations increased in the C group (0.98 µmol/mmol cholesterol; 95% CI: 0.62, 1.35; P < 0.001), and SE group (0.57 µmol/mmol cholesterol; 95% CI: 0.24, 0.90, P = 0.005) (Table 6), whereas -tocopherol did not change in either group.

	DISCUSSION

TOP ABSTRACT MATERIALS AND METHODS Analyses RESULTS DISCUSSION LITERATURE CITED

 
The effect of administering both the free and esterified forms of phytosterols was evaluated previously with different carriers, mainly fat spreads. This is the first study to analyze how bakery products enriched with phytosterols can affect the plasma lipid profile.

Our results show that enriching bakery products with 3.2 g/d of sterols (1.55 g/croissant and 1.68 g/muffin) reduces total cholesterol by 5.5% and LDL-C by 10.4%, and does not significantly modify triacylglycerol and HDL-C concentrations in normocholesterolemic subjects. This effect is consistent with previously published studies that showed a reduction between 8 and 15% in LDL-C when between 1.5 and 3 g/d of sterol or stanol esters was administered (5,7,13,14,24,25).

It could be argued that bakery products are not the best carrier for phytosterols because of their fat composition, but the same could be said for margarines, the carrier approved by the Scientific Committee on Food in Europe (26). As mentioned, we chose croissants and muffins as carriers because they are commonly consumed in Mediterranean countries that are not habitual consumers of fat spreads.

In our study, we tried to diminish the intraindividual variability in plasma lipid concentrations by analyzing two plasma samples collected within 48 h. In spite of this, the interindividual variability of the response was considerable, as described by others (13). Genetic factors may be one explanation for this variability. To date, only differences in apo E genotypes have been associated with the effects of sterol consumption (7). However, to establish the genetic causes of this variability, future research must study other genotypes involved in lipid absorption and metabolism such as ATP-binding cassette (ABC) transporters (27).

The main undesirable effect of administering phytosterols is that they can interfere with the absorption of carotenoids. Although some studies with phytosterols have shown no differences in plasma carotenoid concentrations (8,9,25), others have demonstrated that the reduction in the intestinal absorption of cholesterol also affects the carotenoids and significantly reduces the post-treatment ß-carotene/cholesterol ratio (5,10,14,24,28). Controlled diets (29) or diets providing high quantities of carotenoids (30) could compensate for this side effect. Therefore, the FDA suggests that the regular consumption of fruits and vegetables should be encouraged when phytosterols are consumed (31). However, it seems reasonable not to subject the safety of phytosterols to external dietary factors. For these reasons we investigated the enrichment of bakery products with ß-carotene (0.9 mg/d), taking into account that its bioavailability when added as a pure product to fat-rich foods is one order of magnitude higher than when it is consumed as a natural product, such as in whole fruits or vegetables (32). This moderate amount of ß-carotene is widely used as a natural colorant by the food industry.

In our study, the consumption of bakery-enriched products is accompanied by an 8.5% increase in ß-carotene plasma concentration. The final difference in ß-carotene changes between the groups was 12% (P = 0.11). The decrease in plasma concentrations of those carotenoids that were not added to the bakery products (i.e., -carotene and lycopene) suggests that adding ß-carotene has a positive effect on maintaining plasma concentrations. Similarly, it is to be expected that adding other carotenoids such as natural extracts of carotenoids, with - and ß-carotene or lycopene, will give good results; however, further research is required to confirm this.

A practical aspect of the response to treatment with phytosterols is the frequency of consumption within the day. Because their primary mechanism of action is that they reduce the micellar solubility of cholesterol, it was assumed that to be effective, phytosterols should be ingested at the same time as meals (33). However, a study of consumption frequency (9) revealed that a single daily dose is sufficient to achieve the desired effect, which is not significantly different from the effect obtained when the same quantity is distributed into three daily doses. Other work with ground beef as the carrier, consumed in a single daily dose, corroborates this fact (16). Our study also clarifies the role of consumption time. In our trial, although the participants were instructed to eat the two daily pieces separately, the results show that there were no differences in the reduction of LDL-C between those who usually consumed them at the same time as meals and those who ate them between meals. This also confirms that the effect of phytosterols is not linked only to their simultaneous ingestion with cholesterol; the fat content of bakery products consumed between meals may promote sufficient biliary secretion to inhibit biliary cholesterol absorption. This may also be explained by the long-term effect of phytosterols hypothesized by Plat and Mensink (34), who proposed a new mechanism based on increased ABCA1 expression and decreased cholesterol absorption in enterocytes after plant sterol intake.

As expected, consumption of phytosterol enriched-bakery products increases plasma concentrations of campesterol and sitosterol. Compared with previous studies (7), we found relatively high concentrations of ß-sitosterol (campesterol/sitosterol ratio 1), but this is consistent with the consumption of olive oil in the Spanish diet, in which ß-sitosterol represents 85% of the sterol fraction. Under these conditions, although the increase in both sterols was significant at the end of the study in the SE group, campesterol tripled its baseline value (campesterol/sitosterol ratio 2). Apart from these considerations, these data indicate that the compliance of the voluntary participants was very good. In addition, we observed a significant increase in the plasma concentrations of cholesterol precursors, desmosterol and lathosterol, associated with phytosterol consumption. This increase can be explained by the increase in endogenous cholesterol synthesis because intestinal absorption was inhibited by phytosterol intake.

In conclusion, the results of the present study show that the consumption of croissants and muffins enriched with sterol esters, -tocopherol and ß-carotene significantly decreases the plasma levels of total and LDL-C and does not affect the -tocopherol and ß-carotene concentrations in normocholesterolemic subjects under normal lifestyle conditions. Moreover, our study showed no differences in LDL-C changes induced by phytosterol-enriched bakery between different daily patterns of consumption. Our findings suggest that bakery products are excellent carriers for phytosterols and are a practical option in helping to control cholesterol in a healthy population normally consuming these products.

	ACKNOWLEDGMENTS

 
We thank R. Balanzà, Margarita Moreno and Anna María López for their technical assistance and the IRCIS Foundation (Reus, Spain) for its administrative support during this study.

	FOOTNOTES

 
¹ Supported by Europastry S.A. (Barcelona, Spain).

³ ABC, ATP-binding cassette; apo, apolipoprotein; C, control; HDL-C, HDL cholesterol; LDL-C, LDL cholesterol; SE, sterol ester.

Manuscript received 9 April 2003. Initial review completed 7 May 2003. Revision accepted 25 June 2003.

	LITERATURE CITED

TOP ABSTRACT MATERIALS AND METHODS Analyses RESULTS DISCUSSION LITERATURE CITED

 

1. McNamara, D. J. (1992) Dietary fatty acids, lipoproteins, and cardiovascular disease. Adv. Food Nutr. Res. 36:253-351.[Medline]

2. Ros, E. (2000) Intestinal absorption of triglyceride and cholesterol. Dietary and pharmacological inhibition to reduce cardiovascular risk. Atherosclerosis 151:357-379.[Medline]

3. de Vries, J.H.M., Jansen, A., Kromhout, D., van de Bovenkamp, P., van Staveren, A., Mensink, R. P. & Katan, M. B. (1997) The fatty acid and sterol content of food composites of middle-aged men in seven countries. J. Food Comp. Anal. 10:115-141.

4. Law, M. (2000) Plant sterol and stanol margarines and health. Br. Med. J. 320:861-864.[Free Full Text]

5. Hendriks, H.F.J., Weststrate, J. A., van Vliet, T. & Meijer, G. W. (1999) Spreads enriched with three different levels of vegetable oil sterols and the degree of cholesterol lowering in normocholesterolemic and mildly hypercholesterolaemic subjects. Eur. J. Clin. Nutr. 53:319-327.[Medline]

6. Vanstone, C. A., Raeini-Sarjaz, M., Parsons, W. E. & Jones, P.J.H. (2002) Unesterified plant sterols and stanols lower LDL-cholesterol concentrations equivalently in hypercholesterolemic persons. Am. J. Clin. Nutr. 76:1272-1278.[Abstract/Free Full Text]

7. Hallikainen, M. A., Sarkkinen, E. S., Gylling, H., Erkkilä, A. T. & Uusitupa, M.I.J. (2000) Comparison of the effects of plant sterol and plant stanol ester-enriched margarines in lowering serum cholesterol concentrations in hypercholesterolaemic subjects on a low-fat diet. Eur. J. Clin. Nutr. 54:715-725.[Medline]

8. Hallikainen, M. A., Sarkkinen, E. S. & Uusitupa, M.I.J. (1999) Effects of low-fat stanol ester enriched margarines on concentrations of serum carotenoids in subjects with elevated serum cholesterol concentrations. Eur. J. Clin. Nutr. 53:966-969.[Medline]

9. Plat, J., van Onselen, E.N.M., van Heugten, N.M.A. & Mensink, R. P. (2000) Effect on serum lipids, lipoproteins and fat soluble antioxidant concentrations of consumption frequency of margarines and shortenings enriched with plant stanol esters. Eur. J. Clin. Nutr. 54:671-677.[Medline]

10. Gylling, H., Puska, P., Vartiainen, E. & Miettinen, T. A. (1999) Retinol, vitamin D, carotenes and -tocopherol in serum of a moderately hypercholesterolemic population consuming sitostanol ester margarine. Atherosclerosis 145:279-285.[Medline]

11. Judd, J. T., Baer, D. J., Chen, S. C., Clevidence, B. A., Muesing, R. A., Kramer, M. & Meijer, G. W. (2002) Plant sterol esters lower plasma lipids and most carotenoids in mildly hypercholesterolemic adults. Lipids 37:33-42.[Medline]

12. Ntanios, F. Y. & Duchateau, G. (2002) A healthy diet rich in carotenoids is effective in maintaining normal blood carotenoid levels during daily use of plant sterol-enriched spreads. Int. J. Vitam. Nutr. Res. 72:32-39.[Medline]

13. Volpe, R., Niittynen, L., Korpela, R., Sirtori, C., Bucci, A., Fraone, N. & Pazzucconi, F. (2001) Effects of yoghurt enriched with plant sterols on serum lipids in patients with moderate hypercholesterolaemia. Br. J. Nutr. 86:233-239.[Medline]

14. Mensink, R. P., Ebbing, S., Lindhout, M., Plat, J. & van Heugten, M.M.A. (2002) Effects of plant stanol esters supplied in low-fat yoghurt on serum lipids and lipoproteins, non-cholesterol sterols and fat soluble antioxidant concentrations. Atherosclerosis 160:205-213.[Medline]

15. De Graaf, J., De Sauvage-Nolting, P. R., Van Dam, M., Belsey, E. M., Kastelein, J. J., Haydn-Pritchard, P. & Stalenhoef, A. F. (2002) Consumption of tall oil-derived phytosterols in a chocolate matrix significantly decreases plasma total and low-density lipoprotein-cholesterol levels. Br. J. Nutr. 88:479-488.[Medline]

16. Matvienko, O. A., Lewis, D. S., Swanson, M., Arndt, B., Rainwater, D. L., Stewart, J. & Alekel, D. L. (2002) A single daily dose of soybean phytosterols in ground beef decreases serum total cholesterol and LDL cholesterol in young, mildly hypercholesterolemic men. Am. J. Clin. Nutr. 76:57-64.[Abstract/Free Full Text]

17. Second Joint Task Force of European and other Societies (1998) Prevention of coronary heart disease in clinical practice. Recommendations of the Second Joint Task Force of European and other Societies on coronary prevention. Eur. Heart. J. 19:1434-1503.[Free Full Text]

18. Deheeger, M., Le Moullec, N., Montero, P., Potier de Courcy, G., Cheroubrier, F., Mouget, A. L., Galan, P., Chantrel, A. M., Preziosi, P., Valeix, P., LiGotte, C., Christides, J. P., Rolland-Cachera, M. F., Conti, K. & Hercberg, S. (1994) Portions Alimentaires: Manual Photos pour l’Estimation des Quantitiés 1994 Suvimax-Candia Polytechnica, Paris, France.

19. Favier, J. C., Creland-Ripert, J., Toque, C. & Feinberg, M. (1995) Repértoire Général des Aliments. Table de Composition. 1995 INRA. CNEVA-CIQAL, Lavoisier TEC Doc, Paris.

20. Mataix-Verdú, J. & Mañas-Almendros, M. (1998) Tabla de Composición de Alimentos Españoles 3rd ed. 1998 Instituto de Nutrición y Tecnología de Alimentos Universidad de Granada, Granada, Spain.

21. Friedewald, W. T., Levy, R. I. & Frederickson, R. S. (1972) Estimation of the concentration of low density lipoprotein cholesterol in plasma without use of the preparative ultracentrifugation. Clin. Chem. 18:499-502.[Abstract]

22. Phillips, K. M., Ruggio, D. M. & Bailey, J. A. (1999) Precise quantitative determination of phytosterol, stanols and cholesterol metabolites in human serum by capillary gas-liquid chromatography. J. Chromatogr. B. 732:17-29.

23. Gavina, G., Gallinella, B., Porra, R., Pecora, P. & Suraci, C. (1988) Carotenoids, retinoids and alpha-tocopherol in human serum: identification and determination by reversed phase HPLC. J. Pharm. Biomed. Anal. 6:259-269.[Medline]

24. Weststrate, J. A. & Meijer, G. W. (1998) Plant sterol-enriched margarines and reduction of plasma total and LDL-cholesterol concentrations in normocholesterolemic and mildly hypercholesterolaemic subjects. Eur. J. Clin. Nutr. 52:334-343.[Medline]

25. Nestel, P., Cehun, M., Pomeroy, S., Abbey, M. & Weldon, G. (2001) Cholesterol-lowering effects of plant sterol esters and non-esterified stanols in margarine, butter and low-fat foods. Eur. J. Clin. Nutr. 55:1084-1090.[Medline]

26. Scientific Committee on Food: European Commission (2000) Opinion of SCF on a Request for the Safety Assessment of the Use of Phytosterol Esters in Yellow Fat Spreads. SCF/CS/NF/DOS/1 Final. http://europa.eu.int/comm/food/fs/sc/scf/out56_en.pdf.

27. Chen, H. C. (2001) Molecular mechanisms of sterol absorption. J. Nutr. 131:2603-2605.[Abstract/Free Full Text]

28. Davidson, M. H., Maki, K. C., Umporowicz, M. S., Ingram, K. A., Dicklin, M. R., Schaefer, E., Lane, R. W., McNamara, J. R., Ribaya-Mercado, J. D., Perrone, G., Robins, S. J. & Franke, W. C. (2001) Safety and tolerability of esterified phytosterols administered in reduced-fat spread and salad dressing to healthy adult men and woman. J. Am. Coll. Nutr. 20:307-319.[Abstract/Free Full Text]

29. Raeini-Sarjaz, M., Ntanios, F. Y., Vanstone, C. A. & Jones, P.J.H. (2002) No changes in serum fat-soluble vitamin and carotenoid concentrations with the intake of plant sterol/stanol esters in the context of a controlled diet. Metabolism 51:652-656.[Medline]

30. Noakes, M., Clifton, P., Ntanios, F., Shrapnel, W., Record, I. & McInerney, J. (2002) An increase in dietary carotenoids when consuming plant sterols or stanols is effective in maintaining plasma carotenoid concentrations. Am. J. Clin. Nutr. 75:79-86.[Abstract/Free Full Text]

31. Food and Drug Administration (2002) Food Labeling: Health Claims; Plant Sterol/Stanol Esters and Coronary Heart Disease. Interim Final Rule. Fed. Regist. 65:54685-54739.

32. Van het Hof, K. H., West, C. E., Weststrate, J. A. & Hautvast, J.G.A.J. (2000) Dietary factors that affect the bioavailability of carotenoids. J. Nutr. 130:503-506.[Abstract/Free Full Text]

33. Mattson, F. H., Grundy, S. M. & Crouse, J. R. (1982) Optimizing the effect of plant sterols on cholesterol absorption in man. Am. J. Clin. Nutr. 35:697-700.[Abstract/Free Full Text]

34. Plat, J. & Mensink, R. P. (2002) Increased intestinal ABCA1 expression contributes to the decrease in cholesterol absorption after plant stanol consumption. FASEB. J. 16:1248-1253.[Abstract/Free Full Text]

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