Responsiveness of plasma lipids and lipoproteins to plant stanol esters

Efficacy of Plant Sterol-Enriched Food for Primary Prevention and Treatment of Hypercholesterolemia: A Systematic Literature Review

Plant sterols/phytosterols (PSs) are molecules with a similar structure to cholesterol that have a recognized effect on elevated LDL concentrations (LDL-c). PSs are used as a natural therapy against elevated LDL-c in combination with a healthy diet and exercise. A systematic review was performed to evaluate the efficacy of PS-enriched foods in the treatment of hypercholesterolemia. Randomized controlled clinical studies reporting the use of PS-enriched foods to reduce LDL-c among adult individuals were retrieved and assessed for risk of bias. Meta-analyses were performed to assess changes in LDL-c by treatment, food matrix, LDL-c range, sterols dosage and risk of bias (RoB). In the 13 studies analyzed, LDL-c in PS-treated participants decreased by an average of 12.14 (8.98; 15.29) mg/dL. PS administration was statistically more effective in patients with LDL-c ≥ 140 mg/dL and for PS dosages > 2 g/day. It can be concluded that PSs can be used as an important primary prevention measure for hypercholesterolemia and as tertiary prevention for cardiovascular events in patients who already have mild to moderate LDL-c. However, in severe hypercholesterolemia and in cases of familial hypercholesterolemia, it is necessary to combine dietary treatment with the use of statins.

Plasma lathosterol measures rates of cholesterol synthesis and efficiency of dietary phytosterols in reducing the plasma cholesterol concentration

OBJECTIVES

Because the plasma campesterol/cholesterol ratio does not differ between groups that absorb different amounts of cholesterol, the authors investigated whether the plasma Phytosterols (PS) relate to the body's cholesterol synthesis rate measured as non-cholesterol sterol precursors (lathosterol).

METHOD

The authors studied 38 non-obese volunteers (58±12 years; Low-Density Lipoprotein Cholesterol ‒ LDL-C ≥ 130 mg/dL) randomly assigned to consume 400 mL/day of soy milk (Control phase) or soy milk + PS (1.6 g/day) for four weeks in a double-blind, cross-over study. PS and lathosterol were measured in plasma by gas chromatography coupled to mass spectrophotometry.

RESULTS

PS treatment reduced plasma total cholesterol concentration (-5.5%, p < 0.001), LDL-C (-7.6%, p < 0.001), triglycerides (-13.6%, p < 0.0085), and apolipoprotein B (apo B) (-6.3%, p < 0.008), without changing high density lipoprotein cholesterol (HDL-C concentration), but plasma lathosterol, campesterol and sitosterol expressed per plasma cholesterol increased.

CONCLUSIONS

The lathosterol-to-cholesterol plasma ratio predicted the plasma cholesterol response to PS feeding. The highest plasma lathosterol concentration during the control phase was associated with a lack of response of plasma cholesterol during the PS treatment period. Consequently, cholesterol synthesis in non-responders to dietary PS being elevated in the control phase indicates these cases resist to further synthesis rise, whereas responders to dietary PS, having in the control phase synthesis values lower than non-responders, expand synthesis on alimentary PS. Responders absorb more PS than non-responders, likely resulting from responders delivering into the intestinal lumen less endogenous cholesterol than non-responders do, thus facilitating greater intestinal absorption of PS shown as increased plasma PS concentration.

Plant sterol ester diet supplementation increases serum plant sterols and markers of cholesterol synthesis, but has no effect on total cholesterol levels

This double-blind, randomized, placebo-controlled, cross-over intervention-study was conducted in healthy volunteers to evaluate the effects of plant sterol ester supplemented margarine on cholesterol, non-cholesterol sterols and oxidative stress in serum and monocytes. Sixteen volunteers, average age 34 years, with no or mild hypercholesterolemia were subjected to a 4 week period of daily intake of 3g plant sterols per day supplied via a supplemented margarine on top of regular eating habits. After a wash-out period of one week, volunteers switched groups. Compared to placebo, a diet supplementation with plant sterols increased serum levels of plant sterols such as campesterol (+0.16±0.19mg/dL, p=0.005) and sitosterol (+0.27±0.18mg/dL, p<0.001) and increased markers of cholesterol synthesis such as desmosterol (+0.05±0.07mg/dL, p=0.006) as well as lathosterol (+0.11±0.16mg/dL, p=0.012). Cholesterol serum levels, however, were not changed significantly (+18.68±32.6mg/dL, p=0.052). These findings could not be verified in isolated circulating monocytes. Moreover, there was no effect on monocyte activation and no differences with regard to redox state after plant sterol supplemented diet. Therefore, in a population of healthy volunteers with no or mild hypercholesterolemia, consumption of plant sterol ester supplemented margarine results in increased concentrations of plant sterols and cholesterol synthesis markers without affecting total cholesterol in the serum, activation of circulating monocytes or redox state.

Effect of a plant sterol-enriched spread on biomarkers of endothelial dysfunction and low-grade inflammation in hypercholesterolaemic subjects

Plant sterols (PS) lower LDL-cholesterol, an established risk factor for CHD. Endothelial dysfunction and low-grade inflammation are two important features in the development of atherosclerosis. Whether PS affect biomarkers of endothelial function and low-grade inflammation is not well studied. The aim of the present study was to investigate the effect of regular intake of PS on biomarkers of endothelial dysfunction and low-grade inflammation. In a double-blind, randomised, placebo-controlled, parallel-group study, which was primarily designed to investigate the effect of PS intake on vascular function (clinicaltrials.gov: NCT01803178), 240 hypercholesterolaemic but otherwise healthy men and women consumed a low-fat spread with added PS (3 g/d) or a placebo spread for 12 weeks. Endothelial dysfunction biomarkers (both vascular and intracellular adhesion molecules 1 and soluble endothelial-selectin) and low-grade inflammation biomarkers (C-reactive protein, serum amyloid A, IL-6, IL-8, TNF-α and soluble intercellular adhesion molecule-1) were measured using a multi-array detection system based on electrochemiluminescence technology. Biomarkers were combined using z-scores. Differences in changes from baseline between the PS and the placebo groups were assessed. The intake of PS did not significantly change the individual biomarkers of endothelial dysfunction and low-grade inflammation. The z-scores for endothelial dysfunction (−0·02; 95 % CI −0·15, 0·11) and low-grade inflammation (−0·04; 95 % CI −0·16, 0·07) were also not significantly changed after PS intake compared with placebo. In conclusion, biomarkers of endothelial dysfunction and low-grade inflammation were not affected by regular intake of 3 g/d PS for 12 weeks in hypercholesterolaemic men and women.

[Using plant sterols in clinical practice: From the chemistry to the clinic]

This paper describes what are plant sterols, the chemical structure to understand their mechanism of cholesterol-lowering action, and indications and contraindications in clinical practice.

Effects of plant stanol or sterol-enriched diets on lipid profiles in patients treated with statins: systematic review and meta-analysis

Efficacy and safety data from trials with suitable endpoints have shown that non-statin medication in combination with a statin is a potential strategy to further reduce cardiovascular events. We aimed to evaluate the overall effect of stanol- or sterol-enriched diets on serum lipid profiles in patients treated with statins by conducting a meta-analysis of randomized controlled trials (RCTs). We used the PubMed, Cochrane library and ClinicalTrials.gov databases to search for literature published up to December 2015. Trials were included in the analysis if they were RCTs evaluating the effect of plant stanols or sterols in patients under statin therapy that reported corresponding data on serum lipid profiles. We included 15 RCTs involving a total of 500 participants. Stanol- or sterol-enriched diets in combination with statins, compared with statins alone, produced significant reductions in total cholesterol of 0.30 mmol/L (95% CI −0.36 to −0.25) and low-density lipoprotein (LDL) cholesterol of 0.30 mmol/L (95% CI −0.35 to −0.25), but not in high-density lipoprotein cholesterol or triglycerides. These results persisted in the subgroup analysis. Our meta-analysis provides further evidence that stanol- or sterol-enriched diets additionally lower total cholesterol and LDL-cholesterol levels in patients treated with statins beyond that achieved by statins alone.

Effect of phytosterols and inulin-enriched soymilk on LDL-cholesterol in Thai subjects: a double-blinded randomized controlled trial

Background

Hypercholesterolemia, particularly high LDL-c and non-HDL-c levels, is a traditional risk for cardiovascular disease. Ingestion of diets containing phytosterols and inulin can reduce plasma LDL-c and triglyceride levels, respectively. Phytosterols and inulin-enriched soymilk may be an alternative for a supplemental diet to improve both LDL-c and non-HDL-c to reduce the risk of cardiovascular disease.

Methods

Two hundred and forty subjects who were 18 years old or older and had a baseline LDL-c of 130 mg/dl or higher were enrolled into the double-blinded randomized controlled trial study. Subjects were randomly assigned into the study group that received 2 g/day of phytosterols and 10 g/day of inulin-enriched soymilk or into the control group that received standard soymilk. The lipid profile was measured every 2 weeks for 8 weeks. Primary outcomes were 1) to determine the LDL-c reduction after consumption of phytosterols and inulin-enriched soymilk for 8 weeks and 2) to compare the difference of the LDL-c levels between the study and control groups. The secondary outcomes were to compare the difference of TC, TG and HDL-c between the study and control groups.

Results

At the end of the study, the median LDL-c levels decreased significantly from 165 (132, 254) mg/dl to 150 (105, 263) mg/dl in the study group (p < 0.001) and from 165 (130, 243) mg/dl to 159 (89, 277) mg/dl in the control group (p = 0.014). The LDL-c reduction was significantly better in the study group (−10.03 %, (−37.07, 36.00) vs −1.31 % (−53.40, 89.73), p < 0.001). TC also reduced significantly by 6.60 % in the study group while it reduced only by 1.76 % in the control group (p < 0.001). There were no statistical differences in TG and HDL-c levels between both study groups. The adverse events in the study group and the control groups were not different (RR 1.33 [0.871-2.030, 95 % CI]).

Conclusion

Daily consumption of soymilk containing 2 g of phytosterols and 10 g of inulin reduced TC and LDL-c better than standard soymilk. It had no effect on TG and HDL-c levels compared to standard soymilk. Both soymilk products were comparably safe.

Trial registration

Thai Clinical Trial Registry: TCTR20150417001 date: April 17, 2015

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-015-0149-4) contains supplementary material, which is available to authorized users.

Optimal Use of Plant Stanol Ester in the Management of Hypercholesterolemia

Plant stanol ester is a natural compound which is used as a cholesterol-lowering ingredient in functional foods and food supplements. The safety and efficacy of plant stanol ester have been confirmed in more than 70 published clinical studies and the ingredient is a well-established and widely recommended dietary measure to reduce serum cholesterol. Daily intake of 2 g plant stanols as plant stanol ester lowers LDL-cholesterol by 10%, on average. In Europe, foods with added plant stanol ester have been on the market for 20 years, and today such products are also available in many Asian and American countries. Despite the well-documented efficacy, the full potential in cholesterol reduction may not be reached if plant stanol ester is not used according to recommendations. This review therefore concentrates on the optimal use of plant stanol ester as part of dietary management of hypercholesterolemia. For optimal cholesterol lowering aiming at a lower risk of cardiovascular disease, plant stanol ester should be used daily, in sufficient amounts, with a meal and in combination with other recommended dietary changes.

Effects of pravastatin, phytosterols, and combination therapy on lipid profile in HIV-infected patients: an open-labelled, randomized cross-over study

BACKGROUND

To determine the effects of 40 mg of pravastatin, 2 g of phytosterols, and combination therapy on lipid profiles and to compare the reduction of LDL cholesterol between combination therapy and monotherapy.

METHODS

Thirty-six HIV-infected patients treated with ARVs who had high LDL cholesterol levels but no current usage of any lipid-lowering agents were enrolled into the open-labelled, randomized, cross-over study. All patients were assigned randomly into one of four intervention groups: (1) pravastatin 40 mg cross-over to the combination of pravastatin 40 mg and phytosterols 2 g (combination group), (2) the combination group cross-over to pravastatin 40 mg, (3) phytosterols 2 g cross-over to the combination group, and (4) the combination group cross-over to phytosterols 2 g. Each active treatment lasted 4 weeks with a wash-out period of 4 weeks.

RESULTS

The baseline mean TC, TG, HDL-c, and LDL-c levels in 36 HIV patients were 248.09 ± 34.73, 172.36 ± 125.44, 54.92 ± 16.67, and 175.13 ± 29.00 mg/dl, respectively. Pravastatin, phytosterols, and combination therapy reduced TC and LDL-c but TG and HDL-c were not significantly different from the baselines. The mean LDL-c reductions in the pravastatin, phytosterols, and the combination groups were 28.76 ± 9.32, 9.12 ± 7.84, and 27.08 ± 15.58%, respectively. The LDL-c levels in the pravastatin and combination groups were reduced more than in the phytosterols group (p < 0.01). There was no difference in the LDL-c reduction between the combination and pravastatin monotherapy groups (-25.61 ± 10.43 vs. -28.12 ± 14.07%, p = 0.555).

CONCLUSION

Pravastatin had moderate potency on LDL-c lowering in HIV patients but could not bring LDL-c to goal. Adding phytosterols to pravastatin for a 4-week duration could not demonstrate any additional lipid-lowering effect

TRIAL REGISTRATION

Thai Clinical Trial Registry: TCTR20150126002 date: January 23, 2015.

Serum cholesterol reduction efficacy of biscuits with added plant stanol ester

This study's aim was to test the low-density lipoprotein cholesterol- (LDL-c-) lowering efficacy of biscuits containing 2 g of plant stanols, which corresponded to 3.4 g of plant stanol esters. The biscuit is a new food format that can be consumed as a snack. In a double-blind, placebo-controlled parallel design study, 119 mildly to moderately hypercholesterolemic volunteers were randomized to plant stanol or control groups. Subjects were comparable in age, gender, lipid profiles, and body mass index. They consumed a control biscuit once a day for a two-week period, followed by a four-week intervention period that either had a plant stanol ester biscuit or a control. During the habitual diet, one biscuit per day was consumed at any time that subjects wished. Serum lipid profiles were measured at the first day of run-in, at baseline, and at the study's end. Compared to the control, the total cholesterol (TC), LDL-c, and the LDL-to-high-density lipoprotein (LDL/HDL) ratio had serum reductions of 4.9%, 6.1%, and 4.3%, respectively, and were observed after 4 weeks of biscuit consumption with added plant stanols (P < 0.05). A significantly higher reduction in LDL-c (8.9%) and LDL/HDL ratio (11.4%) was measured in those taking a plant stanol biscuit with a meal compared to those who consumed a plant stanol biscuit without other food. In conclusion, incorporating plant stanols into a biscuit is an attractive, convenient, and acceptable way to modestly lower elevated cholesterol concentrations. For optimal efficacy, biscuits should be consumed with a meal as part of a healthy diet.

Functional foods and cardiometabolic diseases* International Task Force for Prevention of Cardiometabolic Diseases

Mounting evidence supports the hypothesis that functional foods containing physiologically-active components may be healthful. Longitudinal cohort studies have shown that some food classes and dietary patterns are beneficial in primary prevention, and this has led to the identification of putative functional foods. This field, however, is at its very beginning, and additional research is necessary to substantiate the potential health benefit of foods for which the diet-health relationships are not yet scientifically validated. It appears essential, however, that before health claims are made for particular foods, in vivo randomized, double-blind, placebo controlled trials of clinical end-points are necessary to establish clinical efficacy. Since there is need for research work aimed at devising personalized diet based on genetic make-up, it seems more than reasonable the latter be modeled, at present, on the Mediterranean diet, given the large body of evidence of its healthful effects. The Mediterranean diet is a nutritional model whose origins go back to the traditional dietadopted in European countries bordering the Mediterranean sea, namely central and southern Italy, Greece and Spain; these populations have a lower incidence of cardiovascular diseases than the North American ones, whose diet is characterized by high intake of animal fat. The meeting in Naples and this document both aim to focus on the changes in time in these two different models of dietary habits and their fall out on public health.

Dietary modulators of statin efficacy in cardiovascular disease and cognition

Cardiovascular disease remains the leading cause of morbidity and mortality in the United States and other developed countries, and is fast growing in developing countries, particularly as life expectancy in all parts of the world increases. Current recommendations for the prevention of cardiovascular disease issued jointly from the American Academy of Cardiology and American Heart Association emphasize that lifestyle modification should be incorporated into any treatment plan, including those on statin drugs. However, there is a dearth of data on the interaction between diet and statins with respect to additive, complementary or antagonistic effects. This review collates the available data on the interaction of statins and dietary patterns, cognition, genetics and individual nutrients, including vitamin D, niacin, omega-3 fatty acids, fiber, phytochemicals (polyphenols and stanols) and alcohol. Of note, although the available data is summarized, the scope is limited, conflicting and disparate. In some cases it is likely there is unrecognized synergism. Virtually no data are available describing the interactions of statins with dietary components or dietary pattern in subgroups of the population, particularly those who may benefit most were positive effects identified. Hence, it is virtually impossible to draw any firm conclusions at this time. Nevertheless, this area is important because were the effects of statins and diet additive or synergistic harnessing the effect could potentially lead to the use of a lower intensity statin or dose.

LDL-cholesterol-lowering effect of plant sterols and stanols across different dose ranges: a meta-analysis of randomised controlled studies

Phytosterols (PS, comprising plant sterols and plant stanols) have been proven to lower LDL-cholesterol concentrations. The dose-response relationship for this effect has been evaluated in several meta-analyses by calculating averages for different dose ranges or by applying continuous dose-response functions. Both approaches have advantages and disadvantages. So far, the calculation of averages for different dose ranges has not been done for plant sterols and stanols separately. The objective of the present meta-analysis was to investigate the combined and separate effects of plant sterols and stanols when classified into different dose ranges. Studies were searched and selected based on predefined criteria. Relevant data were extracted. Average LDL-cholesterol effects were calculated when studies were categorised by dose, according to random-effects models while using the variance as weighing factor. This was done for plant sterols and stanols combined and separately. In total, 124 studies (201 strata) were included. Plant sterols and stanols were administered in 129 and fifty-nine strata, respectively; the remaining used a mix of both. The average PS dose was 2.1 (range 0.2-9.0) g/d. PS intakes of 0.6-3.3 g/d were found to gradually reduce LDL-cholesterol concentrations by, on average, 6-12%. When plant sterols and stanols were analysed separately, clear and comparable dose-response relationships were observed. Studies carried out with PS doses exceeding 4 g/d were not pooled, as these were scarce and scattered across a wide range of doses. In conclusion, the LDL-cholesterol-lowering effect of both plant sterols and stanols continues to increase up to intakes of approximately 3 g/d to an average effect of 12%.

Dose-dependent LDL-cholesterol lowering effect by plant stanol ester consumption: clinical evidence

Elevated serum lipids are linked to cardiovascular diseases calling for effective therapeutic means to reduce particularly LDL-cholesterol (LDL-C) levels. Plant stanols reduce levels of LDL-C by partly blocking cholesterol absorption. Accordingly the consumption of foods with added plant stanols, typically esterified with vegetable oil fatty acids in commercial food products, are recommended for lowering serum cholesterol levels. A daily intake of 1.5 to 2.4 g of plant stanols has been scientifically evaluated to lower LDL-C by 7 to 10% in different populations, ages and with different diseases. Based on earlier studies, a general understanding is that no further reduction may be achieved in intakes in excess of approximately 2.5 g/day. Recent studies however suggest that plant stanols show a continuous dose–response effect in serum LDL-C lowering. This review discusses the evidence for a dose-effect relationship between plant stanol ester consumption and reduction of LDL-C concentrations with daily intakes of plant stanols of 4 g/day or more. We identified five such studies and the overall data demonstrate a linear dose-effect relationship with the most pertinent LDL-Cholesterol lowering outcome, 18%, achieved by a daily intake of 9 to 10 g of plant stanols. Along with reduction in LDL-C, the studies demonstrated a decrease in cholesterol absorption markers, the serum plant sterol to cholesterol ratios, by increasing the dose of plant stanol intake. None of the studies with daily intakes up to 10 g of plant stanols reported adverse clinical or biochemical effects from plant stanols. In a like manner, the magnitude of decrease in serum antioxidant vitamins was not related to the dose of plant stanols consumed and the differences between plant stanol ester consumers and controls were minor and insignificant or nonexisting. Consumption of plant stanols in high doses is feasible as a range of food products are commercially available for consumption including spreads and yoghurt type drinks. In conclusion, a dose-effect relationship of plant stanols in higher doses than currently recommended has been demonstrated by recent clinical studies and a meta-analysis. Further studies are called for to provide confirmatory evidence amenable for new health claim applications and dietary recommendations.

Inhibition of cholesterol absorption: targeting the intestine

Atherosclerosis, the gradual formation of a lipid-rich plaque in the arterial wall is the primary cause of Coronary Artery Disease (CAD), the leading cause of mortality worldwide. Hypercholesterolemia, elevated circulating cholesterol, was identified as a key risk factor for CAD in epidemiological studies. Since the approval of Mevacor in 1987, the primary therapeutic intervention for hypercholesterolemia has been statins, drugs that inhibit the biosynthesis of cholesterol. With improved understanding of the risks associated with elevated cholesterol levels, health agencies are recommending reductions in cholesterol that are not achievable in every patient with statins alone, underlying the need for improved combination therapies. The whole body cholesterol pool is derived from two sources, biosynthesis and diet. Although statins are effective at reducing the biosynthesis of cholesterol, they do not inhibit the absorption of cholesterol, making this an attractive target for adjunct therapies. This report summarizes the efforts to target the gastrointestinal absorption of cholesterol, with emphasis on specifically targeting the gastrointestinal tract to avoid the off-target effects sometimes associated with systemic exposure.

A comparison of the LDL-cholesterol lowering efficacy of plant stanols and plant sterols over a continuous dose range: results of a meta-analysis of randomized, placebo-controlled trials

PURPOSE

To determine if plant stanols and plant sterols differ with respect to their low-density lipoprotein cholesterol (LDL-CH) lowering efficacies across a continuous dose range.

METHODS

Dose-response relationships were evaluated separately for plant stanols and plant sterols and reductions in LDL-CH, using a first-order elimination function.

RESULTS

Altogether, 113 publications and 1 unpublished study report (representing 182 strata) complied with the pre-defined inclusion and exclusion criteria and were included in the assessment. The maximal LDL-CH reductions for plant stanols (16.4%) and plant stanol ester (17.1%) were significantly greater than the maximal LDL-CH reductions for plant sterols (8.3%) and plant sterol ester (8.4%). These findings persisted in several additional analyses.

DISCUSSION AND CONCLUSIONS

Intakes of plant stanols in excess of the recommended 2g/day dose are associated with additional and dose-dependent reductions in LDL-CH, possibly resulting in further reductions in the risk of coronary heart disease (CHD).

Beyond cholesterol-lowering effects of plant sterols: clinical and experimental evidence of anti-inflammatory properties

Inflammation is a strong risk factor for cardiovascular disease. Dietary plant sterols are known to reduce plasma cholesterol levels and thereby reduce cardiovascular risk. Recent observations from animal and human studies have demonstrated anti-inflammatory effects of phytosterols. For example, several animal and human studies report reductions in the levels of proinflammatory cytokines, including C-reactive protein, after consumption of dietary plant sterols. Although the cholesterol-lowering effects of phytosterols in humans are well documented, studies on the effects of phytosterols on inflammatory markers have produced inconsistent results. This review summarizes and discusses findings from recent animal and human studies with regard to the potential anti-inflammatory effects of dietary phytosterols. Findings on the effects of plant sterols on inflammation remain limited and confounding. Future research using better-designed and well-controlled laboratory studies and clinical trials are needed to fully understand the mechanisms through which phytosterols influence inflammation. Additional well-designed placebo-controlled studies are needed to better understand how and to what extent dietary plant sterols may modify the immune system and the production of inflammatory markers.

Ubiquinol-induced gene expression signatures are translated into altered parameters of erythropoiesis and reduced low density lipoprotein cholesterol levels in humans

Studies in vitro and in mice indicate a role for Coenzyme Q(10) (CoQ(10) ) in gene expression. To determine this function in relationship to physiological readouts, a 2-week supplementation study with the reduced form of CoQ(10) (ubiquinol, Q(10) H(2) , 150 mg/d) was performed in 53 healthy males. Mean CoQ(10) plasma levels increased 4.8-fold after supplementation. Transcriptomic and bioinformatic approaches identified a gene-gene interaction network in CD14-positive monocytes, which functions in inflammation, cell differentiation, and peroxisome proliferator-activated receptor-signaling. These Q(10) H(2) -induced gene expression signatures were also described previously in liver tissues of SAMP1 mice. Biochemical and NMR-based analyses showed a reduction of low density lipoprotein (LDL) cholesterol plasma levels after Q(10) H(2) supplementation. This effect was especially pronounced in atherogenic small dense LDL particles (19-21 nm, 1.045 g/L). In agreement with gene expression signatures, Q(10) H(2) reduces the number of erythrocytes but increases the concentration of reticulocytes. In conclusion, Q(10) H(2) induces characteristic gene expression patterns, which are translated into reduced LDL cholesterol levels and altered parameters of erythropoiesis in humans.

Plant stanol esters lower LDL cholesterol level in statin-treated subjects with type 1 diabetes by interfering the absorption and synthesis of cholesterol

OBJECTIVE

We investigated the effects of plant stanol esters (STAEST) on serum cholesterol and lipoprotein lipid concentrations and serum non-cholesterol sterols in patients with type 1 diabetes who were on statin treatment.

METHODS

In a randomized, double-blind, parallel study the intervention group (n=12) consumed vegetable oil-based spread enriched with STAEST (3.0 g/d of plant stanols), and the control group (n=12) consumed the same spread containing no added plant stanols for 4 weeks.

RESULTS

Serum total, LDL and non-HDL cholesterol concentrations were decreased by 9.6, 16.4 and 15.3% compared with the baseline concentrations in the STAEST group (P<0.05 for all). The respective reductions were 7.8, 14.8 and 12.2% compared with the controls (P<0.05 for all). No effects on HDL cholesterol or serum triglyceride concentrations were found. The STAEST consumption significantly decreased serum plant sterol concentrations and the ratios to cholesterol by 30-32 and 25-27% (P<0.05 for all) compared with the baseline levels, respectively. Cholesterol synthesis markers were not increased in the STAEST group, but serum lathosterol to campesterol ratio was significantly increased by 57% compared with the baseline levels indicating increased cholesterol synthesis at least to some extent in compensation for decreased cholesterol absorption. However, cholesterol homeostasis, intact at baseline and in the control group also during the intervention was lost in the STAEST group.

CONCLUSION

STAEST significantly decreased serum total, LDL and non-HDL cholesterol concentrations and thus offers an additional benefit to cholesterol lowering in patients with type 1 diabetes who are on statin treatment.

Phytosterols and phytosterolemia: gene-diet interactions

Phytosterol intake is recommended as an adjunctive therapy for hypercholesterolemia, and plant sterols/stanols can reduce cholesterol absorption at the intestinal lumen through the Niemann-Pick C1 Like 1 (NPC1L1) transporter pathway by competitive solubilization in mixed micelles. Phytosterol absorption is of less magnitude than cholesterol and is preferably secreted in the intestinal lumen by ABCG5/G8 transporters. Therefore, plasma levels of plant sterols/stanols are negligible compared with cholesterol, under an ordinary diet. The mechanisms of cholesterol and plant sterols absorption and the whole-body pool of sterols are discussed in this chapter. There is controversy about treatment with statins inducing further increase in plasma non-cholesterol sterols raising concerns about the safety of supplementation of plant sterols to such drugs. In addition, increase in plant sterols has also been reported upon consumption of plant sterol-enriched foods, regardless of other treatments. Rare mutations on ABCG5/G8 transporters affecting cholesterol/non-cholesterol extrusion, causing sitosterolemia with xanthomas and premature atheroslerotic disease are now known, and cholesterol/plant sterols absorption inhibitor, ezetimibe, emerges as the drug that reduces phytosterolemia and promotes xanthoma regression. On the other hand, common polymorphisms affecting the NPC1L1 transporter can interfere with the action of ezetimibe. Gene-diet interactions participate in this intricate network modulating the expression of genetic variants on specific phenotypes and can also affect the individual response to the hypolipidemic treatment. These very interesting aspects promoted a great deal of research in the field.

The effect of adding plant sterols or stanols to statin therapy in hypercholesterolemic patients: systematic review and meta-analysis

OBJECTIVE

To characterize the effect of plant sterols/stanols on serum lipids in hypercholesterolemic patients on concurrent statin therapy, we conducted a meta-analysis of randomized controlled trials.

METHODS

A systematic literature search of MEDLINE, EMBASE, Cochrane CENTRAL, and the Natural Medicines Comprehensive Database was conducted from the earliest possible date through May 2008. Trials were included in the analysis if they were randomized controlled trials evaluating the use of plant sterols/stanols in combination with statins in hypercholesterolemic patients that reported efficacy data on total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, or triglycerides. The weighted mean difference (WMD) of the change from baseline (in mg/dL) with 95% confidence interval (CI) was calculated as the difference between the mean in the plant sterol/stanol groups and the control groups, using a random-effects model.

RESULTS

Eight studies (n = 306 patients) met the inclusion criteria. Upon meta-analysis, the use of plant sterols/stanols in combination with statin therapy significantly lowered total cholesterol (WMD, -14.01 mg/dL [95% CI, -18.66 to -9.37], p < 0.0001) and LDL cholesterol (WMD, -13.26 mg/dL [95% CI, -17.34 to -9.18], p < 0.0001) but not HDL cholesterol or triglycerides.

CONCLUSIONS

Based upon the current literature, we can only say that plant sterols/stanols, when administered in addition to statins, favorably affect total and LDL cholesterol with 95% confidence. Randomized trials examining the impact of plant sterols/stanols in combinatation with statins on patient morbidity and mortality are needed.

Functional foods for dyslipidaemia and cardiovascular risk prevention

A food can be regarded as ‘functional’ if it can demonstrate a beneficial efficacy on one or more target functions in the body in a convincing way. Beyond adequate nutritional qualities, functional foods should either improve the state of health and wellbeing and/or reduce the risk of disease. Functional foods that are marketed with claims of heart disease reduction focus primarily on the major risk factors, i.e. cholesterol, diabetes and hypertension. Some of the most innovative products are designed to be enriched with ‘protective’ ingredients, believed to reduce risk. They may contain, for example, soluble fibre (from oat and psyllium), useful both for lowering cholesterol and blood pressure, or fructans, effective in diabetes. Phytosterols and stanols lower LDL-cholesterol in a dose-dependent manner. Soya protein is more hypocholesterolaemic in subjects with very high initial cholesterol and recent data indicate also favourable activities in the metabolic syndrome.n-3 Fatty acids appear to exert significant hypotriacylglycerolaemic effects, possibly partly responsible for their preventive activity. Dark chocolate is gaining much attention for its multifunctional activities, useful both for the prevention of dyslipidaemia as well as hypertension. Finally, consensus opinions about tea and coffee have not emerged yet, and the benefits of vitamin E, garlic, fenugreek and policosanols in the management of dyslipidaemia and prevention of arterial disease are still controversial.

The effect of a very high daily plant stanol ester intake on serum lipids, carotenoids, and fat-soluble vitamins

BACKGROUND & AIMS

Intake of 2-3 g/d of plant stanols as esters lowers LDL cholesterol level, but there is no information about the efficacy and safety of a respective very high daily intake. We studied the effects of 8.8 g/d of plant stanols as esters on serum lipids and safety variables in subjects with mild to moderate hypercholesterolemia.

METHODS

In a randomized, double-blind, placebo-controlled study the intervention (n=25) and control (n=24) groups consumed spread and drink enriched or not with plant stanol esters for 10 weeks.

RESULTS

Plant stanols reduced serum total and LDL cholesterol concentrations by 12.8 and 17.3% from baseline and by 12.0 and 17.1% from controls (P<0.01 for all). Liver enzymes, markers of hemolysis, and blood cells were unchanged. Serum vitamins A, D, and gamma-tocopherol concentrations, and the ratios of alpha-tocopherol to cholesterol were unchanged. Serum beta-carotene concentrations decreased significantly from baseline and were different from controls even when adjusted for cholesterol. Serum alpha-carotene concentration and alpha-carotene/cholesterol ratio were not different from controls.

CONCLUSIONS

High intake of plant stanols reduced LDL cholesterol values without any other side effects than reduction of serum beta-carotene concentration. However, the end product, serum vitamin A levels, were unchanged. The results suggest that plant stanol ester intake can be increased to induce a greater cholesterol lowering effect.

Consumption of oat beta-glucan with or without plant stanols did not influence inflammatory markers in hypercholesterolemic subjects

We have earlier demonstrated that muesli enriched with oat beta-glucan effectively lowered serum LDL cholesterol. Addition of plant stanols further lowered LDL cholesterol. Besides these hypocholesterolemic effects, beta-glucan and plant stanol esters (PSE) may also affect inflammatory processes. Forty-two mildly hypercholesterolemic subjects randomly consumed for 4 wk (crossover design) control muesli (4.8 g control fiber), beta-glucan muesli (4.8 g oat beta-glucan), or combination muesli (4.8 g oat beta-glucan plus 1.4 g stanol as PSE). Changes in cytokine production (IL-6, IL-8, and TNF-alpha) of LPS-stimulated peripheral blood mononuclear cells (PBMC) and whole blood were evaluated, as well as changes in plasma high-sensitivity (hs)-CRP. Additionally, changes in expression profiles of 84 genes involved in atherosclerosis metabolism were assessed in isolated PBMC. IL-6, IL-8, and TNF-alpha production by PBMC and whole blood after LPS stimulation did not differ between the treatments. Also high-sensitivity C-reactive protein (hs-CRP) levels were similar. beta-Glucan consumption did not change gene expression, while only 3 genes (ADFP, CDH5, CSF2) out of the 84 genes from the atherosclerotic risk panel were differentially expressed (p < 0.05) after consumption of PSE. Consumption of beta-glucan with or without PSE did not influence inflammatory parameters in mildly hypercholesterolemic subjects.

A plant stanol yogurt drink alone or combined with a low-dose statin lowers serum triacylglycerol and non-HDL cholesterol in metabolic syndrome patients

We evaluated the effects of 2 commonly available strategies (plant stanol ester drink and 10 mg simvastatin) on coronary heart disease (CHD) risk variables in participants with metabolic syndrome. Metabolic syndrome patients are at increased risk to develop CHD, partly due to high triacylglycerol (TAG) and low HDL cholesterol (HDL-C) concentrations and a low-grade inflammatory profile. Effects of plant stanol esters on TAG concentrations in these participants are unknown. After a 3-wk run-in period in which individuals consumed placebo yogurt drinks and placebo capsules, participants were randomly divided into 4 groups: placebo (n = 9), simvastatin + placebo drink (n = 10), placebo + stanol drink (n = 9), and simvastatin + stanol drink (n = 8). After 9 wk, we evaluated the effects on serum lipids, low-grade inflammation, and endothelial dysfunction markers. In metabolic syndrome patients, stanol esters (2.0 g/d), simvastatin, or the combination lowered non-HDL-C by 12.8% (P = 0.011), 30.7% (P < 0.001), and 35.4% (P < 0.001), respectively, compared with placebo. TAG were lowered by 27.5% (P = 0.044), 21.7% (P = 0.034), and 32.7% (P < 0.01), respectively. The total-:HDL-C ratio was significantly lowered in all 3 intervention groups. We found no treatment effects on the apolipoprotein CII:CIII ratio, cholesterol ester transfer protein mass, FFA concentrations, and markers for low-grade inflammation or endothelial dysfunction. This study shows that in metabolic syndrome patients, plant stanol esters lower not only non-HDL-C, but also TAG. Effects on TAG were also present in combination with statin treatment, illustrating an additional benefit of stanol esters in this CHD risk population.

Continuous dose-response relationship of the LDL-cholesterol-lowering effect of phytosterol intake

Phytosterols (plant sterols and stanols) are well known for their LDL-cholesterol (LDL-C)-lowering effect. A meta-analysis of randomized controlled trials in adults was performed to establish a continuous dose-response relationship that would allow predicting the LDL-C-lowering efficacy of different phytosterol doses. Eighty-four trials including 141 trial arms were included. A nonlinear equation comprising 2 parameters (the maximal LDL-C lowering and an incremental dose step) was used to describe the dose-response curve. The overall pooled absolute (mmol/L) and relative (%) LDL-C-lowering effects of phytosterols were also assessed with a random effects model. The pooled LDL-C reduction was 0.34 mmol/L (95% CI: -0.36, -0.31) or 8.8% (95% CI: -9.4, -8.3) for a mean daily dose of 2.15 g phytosterols. The impacts of subject baseline characteristics, food formats, type of phytosterols, and study quality on the continuous dose-response curve were determined by regression or subgroup analyses. Higher baseline LDL-C concentrations resulted in greater absolute LDL-C reductions. No significant differences were found between dose-response curves established for plant sterols vs. stanols, fat-based vs. non fat-based food formats and dairy vs. nondairy foods. A larger effect was observed with solid foods than with liquid foods only at high phytosterol doses (>2 g/d). There was a strong tendency (P = 0.054) towards a slightly lower efficacy of single vs. multiple daily intakes of phytosterols. In conclusion, the dose-dependent LDL-C-lowering efficacy of phytosterols incorporated in various food formats was confirmed and equations of the continuous relationship were established to predict the effect of a given phytosterol dose. Further investigations are warranted to investigate the impact of solid vs. liquid food formats and frequency of intake on phytosterol efficacy.

Phytosterols dissolved in diacylglycerol oil reinforce the cholesterol-lowering effect of low-dose pravastatin treatment

BACKGROUND AND AIMS

Dietary therapy using phytosterols can reinforce statin treatment; however the value of a low-dose combination of those agents remains to be investigated. Plant sterols (PS), dissolved in diacylglycerol (DAG) oil, (PS/DAG) can be effective at a relatively low dose. The objective of the present study was to examine the effect of PS/DAG oil on blood cholesterol concentrations in hypercholesterolemic outpatients on low-dose pravastatin (10 mg/day).

METHODS AND RESULTS

The patients (n=61) were randomly assigned to one of three groups, who consumed TAG (control), DAG or PS/DAG oil. The average intake of PS from the PS/DAG oil during the test period was significantly higher than that for TAG and DAG oils (502 vs. 49 and 38 mg/day, P<0.05). Significant cholesterol-lowering effects from the baseline were observed in the case of the PS/DAG oil treatment alone. Changes in low-density lipoprotein (LDL) cholesterol were inversely correlated with baseline serum campesterol concentrations (r=-0.560, P<0.05), but not baseline LDL cholesterol concentrations. In addition, serum apolipoprotein B concentrations were reduced to a greater extent in subjects with high versus low levels of baseline campesterol (-13.2 mg/dL vs. -3.1 mg/dL, P<0.05). Furthermore, there was a mild, but significant reduction in serum lipoprotein (a) concentration from the baseline (-5.9 mg/dL), which was correlated with the reduction in serum apolipoprotein B concentration (r=0.596, P<0.05).

CONCLUSION

A low-dose combination of PS/DAG oil and pravastatin may be a useful strategy for further ameliorating blood cholesterol and lipoprotein (a) concentrations for hypercholesterolemic patients with a low response to pravastatin.

Plant sterols/stanols as cholesterol lowering agents: A meta-analysis of randomized controlled trials

BACKGROUND

Consumption of plant sterols has been reported to reduce low density lipoprotein (LDL) cholesterol concentrations by 5-15%. Factors that affect plant sterol efficacy are still to be determined.

OBJECTIVES

To more precisely quantify the effect of plant sterol enriched products on LDL cholesterol concentrations than what is reported previously, and to identify and quantify the effects of subjects' characteristics, food carrier, frequency and time of intake on efficacy of plant sterols as cholesterol lowering agents.

DESIGN

Fifty-nine eligible randomized clinical trials published from 1992 to 2006 were identified from five databases. Weighted mean effect sizes were calculated for net differences in LDL levels using a random effect model.

RESULTS

Plant sterol containing products decreased LDL levels by 0.31 mmol/L (95% CI, -0.35 to -0.27, P= < 0.0001) compared with placebo. Between trial heterogeneity was evident (Chi-square test, P = <0.0001) indicating that the observed differences between trial results were unlikely to have been caused by chance. Reductions in LDL levels were greater in individuals with high baseline LDL levels compared with those with normal to borderline baseline LDL levels. Reductions in LDL were greater when plant sterols were incorporated into fat spreads, mayonnaise and salad dressing, milk and yoghurt comparing with other food products such as croissants and muffins, orange juice, non-fat beverages, cereal bars, and chocolate. Plant sterols consumed as a single morning dose did not have a significant effect on LDL cholesterol levels.

CONCLUSION

Plant sterol containing products reduced LDL concentrations but the reduction was related to individuals' baseline LDL levels, food carrier, and frequency and time of intake.

Moderately elevated plant sterol levels are associated with reduced cardiovascular risk—The LASA study

Functional foods with supplementation of plant sterols are already used by millions of people. However, at the same time it is current scientific thinking that elevation of plant sterols in the circulation causes coronary heart disease. Therefore, this study aimed to define the risk for coronary heart disease associated with moderately high plant sterol plasma levels in a cohort of elderly. In this study, we evaluated the association between plant sterols and coronary heart disease in a cohort of 1242 subjects older than 65 years, participating at the Longitudinal Aging Study Amsterdam (LASA). Concentrations of sitosterol, campesterol, brassicasterol and stigmasterol were assessed using highly sensitive and specific gas chromatography-mass spectrometry-selected ion-monitoring. Plant sterol concentrations (and their ratios to cholesterol) were slightly, however, significantly lower in patients with coronary heart disease. Moreover, high plasma concentrations of a marker plant sterol, sitosterol, were associated with a markedly reduced risk for coronary heart disease (OR 0.78, CI 0.62-0.98, p<0.05). In contrast neither plant stanols (sitostanol or campestanol) nor the cholesterol synthesis markers (lathosterol, lanosterol and desmosterol) nor their ratios to cholesterol were significantly different in the study groups. These data suggest that plant sterols could have neutral or even protective effects on development of coronary heart disease, which have to be confirmed in interventional trials.

Effect of low-fat, fermented milk enriched with plant sterols on serum lipid profile and oxidative stress in moderate hypercholesterolemia

BACKGROUND

Plant sterol (PS)-enriched foods have been shown to reduce plasma LDL-cholesterol concentrations. In most studies, however, PSs were incorporated into food products of high fat content.

OBJECTIVE

We examined the effect of daily consumption of PS-supplemented low-fat fermented milk (FM) on the plasma lipid profile and on systemic oxidative stress in hypercholesterolemic subjects.

DESIGN

Hypercholesterolemic subjects (LDL-cholesterol concentrations >or=130 and <or= 190 mg/dL; n = 194) consumed 2 low-fat portions of FM in the same meal daily for 6 wk. Subjects were randomly assigned to 2 groups: low-fat FM enriched with 0.8 g PS ester per portion or control FM. Plasma concentrations of lipids, oxidized LDL, beta-carotene, beta-sitosterol, campesterol, and high-sensitivity C-reactive protein were measured during the trial.

RESULTS

Plasma LDL-cholesterol concentrations were reduced by 9.5% and 7.8% after 3 and 6 wk, respectively, in the 1.6-g/d PS group compared with the control group, whereas plasma triacylglycerol and HDL-cholesterol concentrations were not significantly affected. In addition, there were no significant changes in serum beta-carotene on normalization to LDL cholesterol during the study period in both groups, whereas plasma concentrations of oxidized LDL were reduced significantly in the PS group compared with the control group (-1.73 compared with 1.40 U/L, respectively; P < 0.05). Plasma sitosterol concentrations were increased by 35% (P < 0.001 compared with control); however, campesterol concentrations did not change during the study period.

CONCLUSION

Daily consumption of 1.6 g PS in low-fat FM efficiently lowers LDL cholesterol in subjects with moderate hypercholesterolemia without deleterious effects on biomarkers of oxidative stress.

Reduced-calorie orange juice beverage with plant sterols lowers C-reactive protein concentrations and improves the lipid profile in human volunteers

BACKGROUND

Dietary plant sterols effectively reduce LDL cholesterol when incorporated into fat matrices. We showed previously that supplementation with orange juice containing plant sterols (2 g/d) significantly reduced LDL cholesterol. Inflammation is pivotal in atherosclerosis. High-sensitivity C-reactive protein (hs-CRP), the prototypic marker of inflammation, is a cardiovascular disease risk marker; however, there is a paucity of data on the effect of plant sterols on CRP concentrations.

OBJECTIVE

The aim of this study was to examine whether plant sterols affect CRP concentrations and the lipoprotein profile when incorporated into a reduced-calorie (50 calories/240 mL) orange juice beverage.

DESIGN

Seventy-two healthy subjects were randomly assigned to receive a reduced-calorie orange juice beverage either without (Placebo Bev) or with (1 g/240 mL; Sterol Bev) plant sterols twice a day with meals for 8 wk. Fasting blood was obtained at baseline and after 8 wk of Placebo Bev or Sterol Bev supplementation.

RESULTS

Sterol Bev supplementation significantly reduced total cholesterol (5%; P < 0.01) and LDL cholesterol (9.4%; P < 0.001) compared with both baseline and Placebo Bev (P < 0.05). HDL cholesterol increased significantly with Sterol Bev (P < 0.02). No significant changes in triacylglycerol, glucose, or liver function tests were observed with Sterol Bev. Sterol Bev supplementation resulted in no significant change in vitamin E and carotenoid concentrations. Sterol Bev supplementation resulted in a significant reduction of CRP concentrations compared with baseline and Placebo Bev (median reduction: 12%; P < 0.005).

CONCLUSION

Supplementation with a reduced-calorie orange juice beverage containing plant sterols is effective in reducing CRP and LDL cholesterol and could be incorporated into the dietary portion of therapeutic lifestyle changes.

The role of dietary supplementation with plant sterols and stanols in the prevention of cardiovascular disease

Several studies have shown that increased levels of low-density lipoprotein (LDL) cholesterol predict cardiovascular events. The Adult Treatment Panel II (ATP II) introduced the principle of therapeutic lifestyle changes, including plant sterols/stanols for the management of LDL cholesterol. Plant sterols and stanols in fat matrices effectively lower LDL cholesterol levels in hypercholesterolemic, diabetic, and healthy human volunteers. Recent studies also show that sterols (2 g/d) lower LDL cholesterol even when incorporated in nonfat matrices. In addition, they may reduce biomarkers of oxidative stress and inflammation. Plant sterols and stanols exert their hypocholesterolemic effects possibly by interfering with the uptake of both dietary and biliary cholesterol from the intestinal tract. Present evidence is accumulating to promote their use for lowering LDL cholesterol levels, as a first line of therapy (as well as adjunctive therapy) in patients on statin therapy.