Bioidentical hormones for menopausal hormone therapy: variation on a theme

BACKGROUND

Progesterone creams and natural or bioidentical compounded estrogen preparations are being promoted to consumers as safe alternatives to conventional menopausal hormone therapy and as health-promoting tonics. No reliable data support these claims.

SAFETY

Natural hormones, including estradiol, estriol, estrone, and progesterone, can be expected to have the same adverse event profile as conventional menopausal hormone regimens.

SALIVARY HORMONE TESTS

Salivary tests may be used to persuade asymptomatic consumers to use hormones (or symptomatic patients to use higher doses than those needed to mitigate symptoms), a practice that can be expected to result in adverse events.

Other relevant components of nuts: phytosterols, folate and minerals

Nuts contain significant amounts of essential micronutrients that are associated with an improved health status when consumed at doses beyond those necessary to prevent deficiency states. Nuts do not contain cholesterol, but they are rich in chemically related phytosterols, a class of compounds that interfere with intestinal cholesterol absorption and thus help lower blood cholesterol. Nuts also contain folate, a B-vitamin necessary for normal cellular function that plays an important role in detoxifying homocysteine, a sulphur-containing amino acid with atherothrombotic properties that accumulates in plasma when folate status is subnormal. Compared to other common foodstuffs, nuts have an optimal nutritional density with respect to healthy minerals, such as calcium, magnesium and potassium. Like that of most vegetables, the sodium content of nuts is very low. A high intake of calcium, magnesium and potassium, together with a low sodium intake, is associated with protection against bone demineralisation, arterial hypertension, insulin resistance, and overall cardiovascular risk. Phytosterols might justify part of the cholesterol-lowering effect of nut intake beyond that attributable to fatty acid exchange, while the mineral richness of nuts probably contributes to the prevention of diabetes and coronary heart disease observed in epidemiological studies in association with frequent nut consumption.

Intestinal absorption of dietary carotenoids

The assessment of carotenoid bioavailability has long been hampered by the limited knowledge of their absorption mechanisms. However, recent reports have elucidated important aspects of carotenoid digestion and absorption. Disruption of food matrix and increasing amounts of fat seem to enhance the absorption of carotenes to a larger extent than that of xanthophylls. Comparing different carotenoid species, xanthophylls seem to be more easily released from the food matrix and more efficiently micellized than the carotenes. On the other hand, carotenes are more efficiently taken up by the enterocytes. However, carotenoid emulsification and micellization steps are largely affected by the food matrix and dietary components, being the main determinant of carotenoid bioavailability from foodstuffs. Although the intestinal uptake of carotenoids has been thought to occur by simple diffusion, recent studies reported the existence of receptor-mediated transport of carotenoids in enterocytes. Comparisons between the intestinal absorption of a wide array of carotenoids would be useful to elucidate the absorption mechanism of each carotenoid species, in view of the recent indications that intestinal carotenoid uptake may involve the scavenger receptor class B type I and possibly other epithelial transporters. The unraveling of the whole mechanism underlying the absorption of carotenoids will be the challenge for future studies.

A combination of psyllium and plant sterols alters lipoprotein metabolism in hypercholesterolemic subjects by modifying the intravascular processing of lipoproteins and increasing LDL uptake

We previously demonstrated that a diet therapy involving consumption of 7.28 g psyllium (PSY) and 2 g of plant sterols (PS) per day reduced LDL cholesterol from 3.6 +/- 0.7 to 3.1 +/- 0.8 mmol/L (P < 0.01) and decreased the number of intermediate density lipoprotein particles and the smaller LDL and HDL subfractions in hypercholesterolemic individuals (n = 33). The study design was a randomized double blind crossover. Subjects consumed either 2 test cookies containing PSY+PS or 2 placebo cookies for 1 mo with a 3-wk wash out between treatments. To explore mechanisms of the lipid-lowering effects of combined PSY+PS, we present data related to intravascular and molecular regulation. Intake of PSY+PS decreased the cholesterol concentration in LDL-1 from 2.46 +/- 0.66 to 2.26 +/- 0.46 mmol/L and in LDL-2 from 0.63 +/- 0.24 to 0.54 +/- 0.27 mmol/L (P < 0.05) in the test compared with the placebo period. An increase in LDL peak size from 27.3 +/- 0.8 to 27.5 +/- 0.6 nm (P < 0.05) and a decrease in the prevalence of LDL pattern B from 27 to 18% (P < 0.05) also occurred during the PSY+PS period. Cholesteryl ester transfer protein activity was 11% lower (P < 0.05) during the test period. Notably, the abundance of the LDL receptor in circulating mononuclear cells as measured by real time PCR was 26% higher during the test compared with the placebo period (P < 0.03). These results indicate that the hypocholesterolemic action of PSY and PS can be explained in part by modifications in the intravascular processing of lipoproteins and by increases in LDL receptor-mediated uptake.

[Analysis of phytosterol contents in Chinese plant food and primary estimation of its intake of people]

OBJECTIVE

To analyze the phytosterol content in plant food commonly consumed in China, and to estimate the intake of phytosterols in Chinese people.

METHODS

More than 160 types of plant food in 7 kinds were chosen as samples. The contents of beta-sitosterol, campesterol, stigmasterol, beta-sitostanol, campestanol were analyzed by GC methods and the total phytosterols were calculated. The intake of phytosteols in Chinese people was estimated using the data of "Survey on the Status of Nutrition and Health of the Chinese People" in 2002.

RESULTS

The contents of phytosterols in edible oils, nuts, and soybeans were higher than those in other plant food. In cereals, phytosterol contents of wheat flour were much higher than those of rice, the refinements of cereals may decrease the phytosterol contents. The phytosterol contents in vegetables and fruits were lower. The total intake of phytosterols in Chinese people was estimated to be 322.41mg/day, in which 40% may be of edible oil origin and 40% may be of cereal origin.

CONCLUSION

The results indicated that in the current dietary pattern, increase the intake of wheat, soybean, vegetable and fruit would enhance the phytosterol intake in Chinese.

Customary use of plant sterol and plant stanol enriched margarine is associated with changes in serum plant sterol and stanol concentrations in humans

The consumption of products enriched with plant sterol or stanol esters lowers serum total and LDL-cholesterol concentrations, thereby most likely reducing the risk of coronary heart disease. However, using plant sterol (not plant stanol) enriched products elevates serum plant sterol concentrations in humans. This may be unwanted because health effects of elevated serum plant sterol concentrations are still controversial. Within postlaunch monitoring of functional foods, we compared serum plant sterol and plant stanol concentrations among users of plant sterol (n = 67) or plant stanol (n = 13) enriched margarines with those of matched nonusers (n = 81) in the ongoing Dutch Doetinchem cohort study. Subjects (aged 29-67 y) were examined in 1994-1998 (before the introduction of enriched margarines) and re-examined in 1999-2003. Serum concentrations of plant sterols and stanols were measured in samples from nonfasting subjects by GLC-MS. Intake of plant sterols was 1.1 +/- 0.6 g/d and was associated with a decrease of serum total cholesterol concentration of 0.25 +/- 0.91 mmol/L (4%, P < 0.05), a change that differed (P < 0.05) from the nonsignificant increase in nonusers (+2%, 0.12 +/- 0.78 mmol/L, P = 0.16). Cholesterol-standardized serum sitosterol and campesterol increased in plant sterol users by 22% (P < 0.0001) and 103% (P < 0.0001), respectively. Cholesterol-standardized serum sitostanol and campestanol increased in plant stanol users by 197% (P = 0.02) and 196% (P = 0.01). To our knowledge, these data are the first to show changes in serum cholesterol, plant sterol, and plant stanol concentrations after (long-term) consumption of plant sterol and stanol enriched margarines in a free-living population in a nonexperimental setting. Whether the increased serum sterol concentrations result in adverse side effects needs to be investigated in future postlaunch monitoring studies.

Long-term effects of a plant-based dietary portfolio of cholesterol-lowering foods on blood pressure

OBJECTIVE

To determine the effect on blood pressure of dietary advice to consume a combination of plant-based cholesterol-lowering foods (dietary portfolio).

METHODS

For 1 year, 66 hyperlipidemic subjects were prescribed diets high in plant sterols (1.0 g/1000 kcal), soy protein (22.5 g/1000 kcal), viscous fibers (10 g/1000 kcal) and almonds (22.5 g/1000 kcal). There was no control group. Seven-day diet record, blood pressure and body weight were monitored initially monthly and later at 2-monthly intervals throughout the study.

RESULTS

Fifty subjects completed the 1-year study. When the last observation was carried forward for non-completers (n=9) or those who changed their blood pressure medications (n=7), a small mean reduction was seen in body weight 0.7+/-0.3 kg (P=0.036). The corresponding reductions from baseline in systolic and diastolic blood pressure at 1 year (n=66 subjects) were -4.2+/-1.3 mm Hg (P=0.002) and -2.3+/-0.7 mm Hg (P=0.001), respectively. Blood pressure reductions occurred within the first 2 weeks, with stable blood pressures 6 weeks before and 4 weeks after starting the diet. Diastolic blood pressure reduction was significantly related to weight change (r=0.30, n=50, P=0.036). Only compliance with almond intake advice related to blood pressure reduction (systolic: r=-0.34, n=50, P=0.017; diastolic: r=-0.29, n=50, P=0.041).

CONCLUSIONS

A dietary portfolio of plant-based cholesterol-lowering foods reduced blood pressure significantly, related to almond intake. The dietary portfolio approach of combining a range of cholesterol-lowering plant foods may benefit cardiovascular disease risk both by reducing serum lipids and also blood pressure.

Food sources of plant sterols in the EPIC Norfolk population

OBJECTIVE

To investigate the intake of plant sterols and identify major dietary sources of plant sterols in the British diet.

SUBJECTS

A total of 24 798 men and women recruited during 1993-1997, participating in the European Prospective Investigation into Cancer (EPIC-Norfolk).

INTERVENTIONS

A database of the plant sterol (campesterol, beta-sitosterol, stigmasterol, campestanol and beta-sitostanol) content in foods, based on gas-liquid chromatography (GLC) analyses, was linked to nutritional intake data from food frequency questionnaires in the EPIC-Norfolk population.

RESULTS

The mean (s.d.) intake of total plant sterols was 300 (108) mg/d for men and 293 (100) mg/d for women. Bread and other cereals, vegetables and added fats were the three major food sources of plant sterols representing 18.6 (8.9), 18.4 (8.5) and 17.3 (10.4)% of the total plant sterol intake respectively. Women had a higher plant sterol density than men (36.4 vs 32.8 mg/1000 kJ, P<0.001) and in relation to energy intake higher intakes of plant sterols from vegetables, bread and other cereals, added fats, fruits and mixed dishes (all P<0.001), whilst men had higher intakes of plant sterols from cakes, scones and chocolate, potatoes (all P<0.001) and other foods (P<0.01).

CONCLUSIONS

The intake of plant sterols in UK, mainly from bread, cereals, fats and vegetables, is much higher than previously reported but comparable to recent European studies.

Basal plasma concentrations of plant sterols can predict LDL-C response to sitosterol in patients with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) is associated with a high risk of coronary heart disease. Pharmacological treatment and diet are both essential for the management of FH. Foods rich in plant sterols (PS) may play an important role in the treatment of patients with these disorders.

OBJECTIVE

To test the effect of the intake of PS on low-density lipoprotein (LDL) concentration, endothelial function (EF) and LDL particle size in 30 patients with FH.

DESIGN

Randomized and crossover dietary intervention study.

SETTING

Tertiary outpatient care.

SUBJECTS

Thirty-eight were recruited, but only 30 were subjected to four low-fat dietary intervention periods, each of 4 weeks.

METHODS

Each intervention had a different content of cholesterol (<150 or 300 mg/day) and sitosterol (<1 or 2 g/day). Lipid response, EF and LDL particle size were analysed after the intervention.

RESULTS

Plasma sitosterol/cholesterol ratio was higher during both plant sterol-rich periods than during the low plant sterols periods. Basal sitosterol concentrations predicted the LDL-cholesterol response during the intake of plant sterol-enriched diets. The change in LDL-cholesterol was significantly greater in subjects in the upper and intermediate tertiles of basal plasma sitosterol concentrations (-21+/-8 mg/dl, P=0.03; -19+/-7 mg/dl, P=0.04, respectively) than in subjects in the lower tertile (8+/-5 mg/dl) when they changed from a low cholesterol diet to a low cholesterol plus plant sterol diet.

CONCLUSION

Our study demonstrates that basal sitosterol values can predict hypolipidemic response in patients with FH.

The lipid lowering effect of plant sterol ester capsules in hypercholesterolemic subjects

BACKGROUND

Foods enriched with phytosterols have been proven to be an effective therapy to improve blood lipid profiles. However, none of the studies have investigated the efficacy in lipid lowering of plant sterol esters (PSE) in capsule form. The objective of this study is to determine if the plant sterol esters (PSE) in capsule form (1.3 grams of PSE/day) lowered plasma cholesterol levels and lipid ratios in free-living hypercholesterolemic subjects during a 4-week intervention period.

METHODS

Sixteen subjects participated in a double-blind, placebo-controlled, sequential study with a 4-week placebo phase followed by a 2-week wash-out period and a 4-week treatment phase. Subjects were instructed to maintain stable diet pattern and physical activities. Blood samples were collected at 7, 21 and 28 days of each phase. The primary measurements were change in plasma total cholesterol (TC), HDL-cholesterol (HDL) and LDL-cholesterol (LDL) between phases and within each phase. The secondary measurements were change in triglycerides, lipoprotein ratios (TC/HDL, LDL/HDL) and C-reactive protein (CRP).

RESULTS

In comparison to placebo, LDL-cholesterol was significantly reduced by 7% and 4% (P < 0.05) at both week 3 and week 4; HDL at week 3 of the treatment was significantly increased by 9% (P < 0.01), but not at week 4 (4%); total cholesterol was not significantly different from placebo throughout the period, TC/HDL and LDL/HDL were significantly reduced by (8%, 8%, 6%, 10%, respectively) (P < 0.01) at both week 3 and week 4. CRP and triglycerides did not differ either between the two phases or during the treatment phase.

CONCLUSION

In conclusion, plant sterol ester capsule is effective in improving lipid profiles among hypercholesterolemic subjects in a free-living setting at the minimum dosage recommended by FDA. The significant improved lipid profiles were reached after three weeks of administration. To achieve better lipid lowering results, higher dosages and combination with diets low in saturated fat and cholesterol are recommended.

Estimation of plant sterol and cholesterol intake in Finland: quality of new values and their effect on intake

The Finnish national food composition database Fineli®was updated with recent analytical values for plant sterols (PS) (sitosterol, campesterol, stigmasterol, avenasterol, brassicasterols and stanols) and cholesterol. The quality of the new analytical data was assessed. The aims of the present study were: (1) to compare the effect of old and new database values on PS and cholesterol intakes based on average per capita food consumption data; (2) to estimate the current intake and major sources of these compounds in various population groups according to the national FINDIET 1997 survey data. The intake of total PS was 305 mg/d for men and 237 mg/d for women. The respective intakes for cholesterol were 284 mg/d and 201 mg/d. Women had a higher density of PS in their diets than men, whereas the cholesterol density in the diets did not differ between genders. Cereals, margarine, vegetables and vegetable oils were the main food sources of PS. Meat, meat products and eggs were the main sources of cholesterol. A 9 % greater PS intake estimate was obtained with the new PS database compared with the old PS database, probably due to minor methodological differences between the new and old analyses. Notable changes in analytical methods suggest a lower value (−19 %) for cholesterol intake calculated from the new database compared with the old one. We conclude that researchers can have confidence in the new values for PS and cholesterol, because systematic evaluation of the new analytical values showed them to be of high quality.

Simulation of prospective phytosterol intake in Germany by novel functional foods

A blood cholesterol-lowering margarine containing plant sterolesters was the first functional food placed on the European food market pursuant to the regulation (EC) 258/97. In the following years nine further applicants submitted the request to add plant sterol compounds to dairy products, cheeses, bakery products, sausages, plant oils and other products. The European Scientific Committee on Food (SCF) declared a precautionary intake limit of 3 g plant sterols per d by multiple dietary sources. Using the consumption data of the German National Food Consumption Study, carried out from 1985 to 1988 with 23 209 participants, we hypothetically added 0·3–2 g plant sterols to usual daily servings of ten different food products, selected from the novel food applications. We calculated the prospective plant sterol intake regarding each kind of enriched food and by stepwise accumulation of different functional foods in three enrichment scenarios. Within our enrichment context we find a phytosterol intake satiation, if multiple plant sterol-enriched foods are eaten. An enrichment amount of 2 g plant sterols per proposed food serving size results in an intake maximum of 13 g/d.

Phytosterol-mediated inhibition of intestinal cholesterol absorption is independent of ATP-binding cassette transporter A1

An increased activity of ATP-binding cassette transporter (ABC) A1 has been proposed as a mechanism underlying the hypocholesterolaemic effect of phytosterols. In the present study, ABCA1-deficient mice (ABCA1−/− mice) were used to examine the involvement of the ABCA1 in the reduction of intestinal cholesterol absorption in response to a phytosterol-enriched diet. A decrease in intestinal cholesterol absorption of 39 and 35% was observed after phytosterol treatment in ABCA1+/+ mice and in ABCA1−/− mice, respectively. No statistically significant changes in plasma lipoprotein profile or in intestinal ABCG5, ABCG8 and Niemann-Pick C1-Like 1 gene expression levels were found when phytosterol-treated ABCA1−/− mice and untreated ABCA1−/− mice were compared. We conclude that phytosterol inhibition of cholesterol absorption in mice is independent of ABCA1

Consumption of a novel dietary formula of plant sterol esters of canola oil fatty acids, in a canola oil matrix containing 1,3-diacylglycerol, reduces oxidative stress in atherosclerotic apolipoprotein E-deficient mice

The antiatherogenic properties of a novel dietary formula (PS-CO) of plant sterol esters of fatty acids, produced by enzymatic interesterification of plant sterols with canola oil (CO), in a CO matrix containing 1,3-diacylglycerol, were evaluated in apolipoprotein E-deficient mice. PS-CO consumption strongly tended to lower total plasma cholesterol levels by 21%, compared to the placebo group. Blood triglycerides were reduced by 38% and 36% compared to CO and placebo-fed mice, respectively. Serum lipid peroxide levels were lowered following PS-CO administration by 62% and 63%, compared to CO and placebo administration, respectively. Unlike CO supplementation, PS-CO consumption preserved serum paraoxonase (PON1) activity. Mouse peritoneal macrophages from PS-CO-fed mice exhibited reduced cellular uptake of oxidized-LDL compared to those from placebo-fed mice and demonstrated a tendency toward a decreased capability to release superoxide anions. These findings indicate that PS-CO supplementation is beneficial in reducing serum lipid levels, and serum and macrophage oxidative stress, thus contributing to the reduction in atherogenic risk factors.

Simultaneous intake of beta-glucan and plant stanol esters affects lipid metabolism in slightly hypercholesterolemic subjects

Intake of food products rich in water-soluble fiber beta-glucan and products enriched with plant stanol esters lower serum cholesterol. Combining 2 functional food ingredients into one food product may achieve additional reductions of serum cholesterol. Our objective was to investigate the effects of a simultaneous intake of beta-glucan plus plant stanol esters on lipid metabolism in mildly hypercholesterolemic volunteers. In a randomized, controlled, 3-period crossover study, 40 mildly hypercholesterolemic men and women received muesli in random order twice a day for 4 wk, which provided, in total, 5 g control fiber from wheat (control muesli), 5 g oat beta-glucan (beta-glucan muesli), or 5 g oat beta-glucan plus 1.5 g plant stanols (combination muesli). beta-Glucan muesli decreased serum LDL cholesterol by 5.0% compared with control muesli (P = 0.013). Combination muesli reduced LDL cholesterol by 9.6% compared with control muesli (P < 0.001), and by 4.4% compared with beta-glucan muesli (P = 0.036). Serum HDL cholesterol and triacylglycerol concentrations did not differ after the 3 treatments. Compared with control muesli, beta-glucan muesli increased bile acid synthesis (P = 0.043) and decreased cholesterol absorption (P = 0.011). Addition of plant stanols did not influence bile acid synthesis but decreased cholesterol absorption (P < 0.001) and raised cholesterol synthesis (P = 0.016) compared with control muesli, and the plant stanols decreased cholesterol absorption compared with beta-glucan muesli (P = 0.004). The combination muesli decreased serum concentrations of sitostanol compared with control muesli (P = 0.010). Plasma concentrations of lipid-soluble antioxidants did not differ after the 3 treatments. beta-Glucan muesli effectively lowered serum LDL cholesterol concentrations. The addition of plant stanol esters to beta-glucan-enriched muesli further lowered serum LDL cholesterol, although effects were slightly less than predicted.

Pflanzen-Sterole und Stanole – Wissenschaftliche Befunde zur Wirkung und Sicherheit

Phytosterole und -stanole haben analoge Funktion zum Cholesterin in tierischen Zellen als wichtige strukturelle und funktionelle Bestandteile von pflanzlichen Zellmembranen. Sie finden sich vor allem in Obst und Gemüse, Getreideprodukten, Samen, Nüssen sowie in Pflanzenölen. Phytosterole führen zu einer Senkung des Gesamt- und des LDL-Cholesterins bei Erwachsenen und bei Kindern. Phytosterolester lassen sich beispielsweise in Margarinen integrieren, was breiter angelegte Studien zur Wirksamkeit ermöglichte. Limitierend vor allem beim Einsatz von Phytosterolen in der Sekundärprophylaxe kardiovaskulärer Krankheiten, ist der Mangel an evidenzbasierten Studien, welche zeigen würden, dass harte Endpunkte, wie kardiovaskuläre und totale Mortalität, günstig beeinflusst würden.

Exposure and effectiveness of phytosterol/-stanol-enriched margarines

BACKGROUND

Studies on effectiveness of phytosterol/-stanol-enriched margarines in the community have received low priority. For postlaunch monitoring purposes including risk-benefit analyses, it is needed to investigate both exposure and effectiveness of these margarines.

OBJECTIVE

To study the use and effectiveness of phytosterol/-stanol-enriched margarine.

DESIGN, SETTING AND SUBJECTS

The study population consisted of 2379 subjects that participated in a community intervention study ('Hartslag Limburg') aged 28-76 years. In 1998 and 2003, blood samples for total and high-density lipoprotein (HDL) cholesterol were obtained. A general questionnaire and food frequency questionnaire (FFQ) were administered. From 1999 onwards, phytosterol/-stanol-enriched margarines were introduced on the Dutch market. On the basis of 2003 data, subjects were classified in users of (a) phytosterol/-stanol-enriched margarine, (b) cholesterol-lowering drugs, (c) the combination (both enriched margarine and drugs) and (d) neither enriched margarines nor cholesterol-lowering drugs.

RESULTS

Mean (+/-s.d.) daily intake of phytosterol-enriched margarine (n=99) and phytostanol-enriched margarine (n=16) was 14+/-9 g. From 1998 to 2003, total serum cholesterol concentration changed significantly different among the four groups: in the combination users -2.04+/-1.50 mmol/l (-29%), in cholesterol-lowering drug users -1.09+/-1.17 mmol/l (-17%), in the enriched margarine users -0.24+/-0.75 mmol/l (-4%) and in non-users +0.10+/-0.72 mmol/l (+2%)(P<0.05).

CONCLUSION

Recommended doses are not consumed, but phytosterol/-stanol-enriched margarines can modestly reduce serum total cholesterol in the community. These margarines cannot equal the effect of cholesterol-lowering drugs, but may act additively. Further investigation of the health effects that may occur during simultaneous cholesterol lowering drugs and phytosterol-or -stanol-enriched margarines usage is important, as well as community education about the cholesterol lowering foods and drugs.

SPONSORSHIP

Netherlands Organization for Health Research and Development (ZonMW) (data collection of Hartslag Limburg and further data- analyses).

Supplementation of test meals with fat-free phytosterol products can reduce cholesterol micellarization during simulated digestion and cholesterol accumulation by Caco-2 cells

Phytosterols have been shown to reduce cholesterol absorption in humans. Supplementing phytosterols in fat-free formulations, however, has yielded controversial results. In the present study, we investigated the effect of supplementing test meals with different fat-free phytosterol products on cholesterol incorporation into mixed micelles during simulated digestion and accumulation of micellar cholesterol by Caco-2 cells: control orange juice (OJ), orange juice supplemented with either multivitamin/multimineral tablets (MVT), multivitamin/multimineral tablets containing phytosterols (MVT+P), and phytosterol powder (PP). These combinations were added to Ensure-based test meals and spiked with cholesterol of natural isotopic composition or 13C2-cholesterol to differentiate external from endogenous cholesterol. After simulated gastric/small intestinal digestion, micelle fractions were analyzed for cholesterol enzymatically (n = 6-20/product) and by high-performance liquid chromatography-tandem mass spectrometry (n = 12/product) and added to Caco-2 cells to determine the accumulation of 13C2-cholesterol (n = 10-24/product). As compared to OJ, PP and MVT+P significantly decreased cholesterol micellarization (determined enzymatically) by 70 +/- 39 (mean +/- SD) and 70 +/- 39%, respectively (P < 0.001, Bonferroni). The stable isotope experiments revealed that both PP and MVT+P reduced cholesterol micellarization [by 25 +/- 12 (P = 0.055) and 21 +/- 8% (P = 0.020), respectively, Fisher's protected LSD test] and Caco-2 cell accumulation (by 28 +/- 8 and 10 +/- 8%, respectively; P < 0.010, Bonferroni). OJ+P did not inhibit micellarization or accumulation of cholesterol by Caco-2 cells. This study shows that fat-free phytosterol-containing products can significantly inhibit cholesterol micellarization and Caco-2 cell bioaccessibility, albeit to different extents depending on individual formulations. This is most likely explained by inhibition of cholesterol micellarization.

Similar serum plant sterol responses of human subjects heterozygous for a mutation causing sitosterolemia and controls to diets enriched in plant sterols or stanols

OBJECTIVE

We investigated the serum phytosterol responses of heterozygous relatives of sitosterolemia patients to diets enriched in phytosterols or stanols.

DESIGN

Randomized double-blind crossover design.

SETTING

Muenster, Germany.

SUBJECTS

Eight heterozygous and 13 control subjects were recruited. One heterozygote and three controls dropped out.

INTERVENTIONS

Seven heterozygotes and 10 controls received daily portions of margarine containing 2 g of plant sterols, 2 g of stanols or a control margarine for 6 weeks each in a randomized order. These phases were intercepted by wash-out periods of 6 weeks each.

RESULTS

Compared to the control period, serum phytosterol concentrations increased overall by more than 20% when subjects consumed the plant sterol margarine (F((1,15))=8.719, P=0.01), with no significant difference between heterozygotes (mean +14.5 (s.d. 17.2) micromol/l, +23.0%) and controls (+4.9 (9.9) micromol/l, +20.5%; F((1,15))=2.168, P=0.162), but decreased when subjects consumed the stanol-enriched margarine (F((1,15))=12.124, P=0.003), again to a similar extent in heterozygotes (-34.2 (41.2) micromol/l, -54.2%) and controls (-12.2 (9.2) micromol/l, -50.6%; F((1,15))=2.729, P=0.119). The lowest total serum concentrations of cholesterol and phytosterols were seen after the diet enriched in stanols. Serum stanol concentrations increased on this diet, but on a very low level and never exceeded 0.05% of serum cholesterol levels in any subject.

CONCLUSIONS

Serum phytosterol concentrations increased only moderately in heterozygotes consuming a diet enriched in phytosterols, indicating that they retained considerable capacity to excrete phytosterols even at higher intakes.

Effects of phytosterols in diacylglycerol as part of diet therapy on hyperlipidemia in children

BACKGROUND

The incidence of hyperlipidemia in children is increasing in Japan, but drug therapy for such children is limited. The ingestion of 4% phytosterols-containing diacylglycerol (PS/DAG) decreases serum total cholesterol and low density lipoprotein cholesterol (LDL-C) concentrations in adults. In the present study, we examined the effect of PS/DAG as part of a diet therapy in pediatric patients with hyperlipidemia.

METHODS

Pediatric patients with hyperlipidemia with > or =5.18mmol (200 mg/dL) serum total cholesterol and/or >or =1.70mmol (150 mg/dL) triglycerides (N=22) ingested bread containing PS/DAG (total daily intake, 10g) for 6 months. Blood chemistry was examined prior to and 2, 4, 6 months after the initiation of ingestion, and 4 months after the ingestion period.

RESULTS

No significant differences in energy intake or cholesterol intake during the study period were found. After 4 months of ingestion of PS/DAG, LDL-C, lipoprotein(a) [ Lp(a)], free fatty acids and total ketone bodies decreased significantly. In seven patients with familial hypercholesterolemia, total cholesterol and remnant-like lipoprotein particles (RLP)-cholesterol also significantly decreased in addition to LDL-C and Lp(a).

CONCLUSIONS

PS/DAG improves serum lipid metabolism in pediatric patients with hyperlipidemia for whom drug therapy is limited, suggesting that PS/DAG may reduce the risk of developing various diseases induced by hyperlipidemia.

[The mechanisms of blood LDL-cholesterol lowering by phytosterols--a review]

Daily cholesterol consumption in western countries reaches as much as 400 mg. According to the health recommendations the daily intake should not exceed 300 mg and in the case of people with cardiovascular disease it should be less than 200 mg. For 50 years it is known that phytosterols can decrease the level of cholesterol in blood. One of the mechanisms is based on the fact that phytosterols stop absorption of cholesterol in digestive tract, which results in the decrease of the concentration of cholesterol in blood. The second mechanism is based on the fact that cholesterol is pumped back out of enterocytes into the lumen of small intestine by ABC transporter and phytosterols increase this process. The above merftioned mechanisms are different than the way statins can lower cholesterol level and they are commonly used as hipocholesterolemic medicine. Because different mechanisms are implemented both statins and fitosterols can be used in therapy of hipercholeserolemia. The people taking statins who still have increased level of total cholesterol and LDL-cholesterol in blood can include phytosterols in their diet what can lead to the decrease of its level.

Dietary plant sterols supplementation does not alter lipoprotein kinetics in men with the metabolic syndrome

Dietary plant sterols supplementation has been demonstrated in some studies to lower plasma total and LDL cholesterol in hypercholesterolemic subjects. The cholesterol lowering action of plant sterols remains to be investigated in subjects with the metabolic syndrome. In a randomized, crossover study of 2 x 4 week therapeutic periods with oral supplementation of plant sterols (2 g/day) or placebo, and two weeks placebo wash-out between therapeutic periods, we investigated the effects of dietary plant sterols on lipoprotein metabolism in nine men with the metabolic syndrome. Lipoprotein kinetics were measured using [D3]-leucine, gas chromatography-mass spectrometry and compartmental modeling. In men with the metabolic syndrome, dietary plant sterols did not have a significant effect on plasma concentrations of total cholesterol, triglycerides, LDL cholesterol, HDL cholesterol, apolipoprotein (apo) B, apoA-I or apoA-II. There were no significant changes to VLDL-, IDL-, LDL-apoB or apoA-I fractional catabolic rates and production rates between therapeutic phases. Relative to placebo, plasma campesterol, a marker of cholesterol absorption was significantly increased (2.53 +/- 0.35 vs. 4.64 +/- 0.59 mug/ml, p < 0.05), but there was no change in plasma lathosterol, a marker of endogenous cholesterol synthesis. In conclusion, supplementation with plant sterols did not appreciably influence plasma lipid or lipoprotein metabolism in men with the metabolic syndrome. Future studies with larger sample size, stratification to low and high cholesterol absorbers and cholesterol balance studies are warranted.

Phytosterols, but not pectin, added to a high-saturated-fat diet modify saturated fatty acid excretion in relation to chain length

The main objective of this article was to study how the excretion of saturated fatty acids (SFA) is modified after the consumption of a high-saturated-fat diet that was supplemented with phytosterol and pectin. We present the results of a longitudinal 4-week study on guinea pigs. Diets were supplemented with 0.33% of cholesterol and differed in the content of pectin (three levels) and of phytosterols (three levels). Seventy-two female Dunkin Hartley guinea pigs were randomly assigned to the treatment groups (8 animals/group). Addition of phytosterol resulted in a decrease of lauric (12:0) and myristic (14:0) excretions and in an increase of arachidic (20:0) and behenic (22:0) excretions. Palmitic (16:0) and stearic (18:0) acids did not show a clear change after phytosterol supplementation. Addition of pectin resulted in a decreased excretion of all SFA, although this was not significant. These results suggest that phytosterols added to a high-saturated-fat diet enhance the absorption of the most atherogenic fatty acids (lauric and myristic) after 1 week of treatment, as compared with the high-saturated-fat diet alone.

Plant sterol or stanol esters retard lesion formation in LDL receptor-deficient mice independent of changes in serum plant sterols

Statins do not always decrease coronary heart disease mortality, which was speculated based on increased serum plant sterols observed during statin treatment. To evaluate plant sterol atherogenicity, we fed low density lipoprotein-receptor deficient (LDLr(+/-)) mice for 35 weeks with Western diets (control) alone or enriched with atorvastatin or atorvastatin plus plant sterols or stanols. Atorvastatin decreased serum cholesterol by 22% and lesion area by 57%. Adding plant sterols or stanols to atorvastatin decreased serum cholesterol by 39% and 41%. Cholesterol-standardized serum plant sterol concentrations increased by 4- to 11-fold during sterol plus atorvastatin treatment versus stanol plus atorvastatin treatment. However, lesion size decreased similarly in the sterol plus atorvastatin (-99% vs. control) and the stanol plus atorvastatin (-98%) groups, with comparable serum cholesterol levels, suggesting that increased plant sterol concentrations are not atherogenic. Our second study confirms this conclusion. Compared with lesions after a 33 week atherogenic period, lesion size further increased in controls (+97%) during 12 more weeks on the diet, whereas 12 weeks with the addition of plant sterols or stanols decreased lesion size (66% and 64%). These findings indicate that in LDLr(+/-) mice 1) increased cholesterol-standardized serum plant sterol concentrations are not atherogenic, 2) adding plant sterols/stanols to atorvastatin further inhibits lesion formation, and 3) plant sterols/stanols inhibit the progression or even induce the regression of existing lesions.