Plant sterol-enriched margarine lowers plasma LDL in hyperlipidemic subjects with low cholesterol intake: effect of fibrate treatment

Effects of phytosterol supplementation on lipid profiles in patients with hypercholesterolemia: a systematic review and meta-analysis of randomized controlled trials

Phytosterols (PSs) have been reported to improve blood lipids in patients with hypercholesterolemia for many years. However, meta-analyses of the effects of phytosterols on lipid profiles are limited and incomplete. A systematic search of randomized controlled trials (RCTs) published in PubMed, Embase, Cochrane Library, and Web of Science from inception to March 2022 was conducted according to the 2020 preferred reporting items of the guidelines for systematic reviews and meta-analysis (PRISMA) statement. These included studies of people with hypercholesterolemia, comparing foods or preparations containing PSs with controls. Mean differences with 95% confidence intervals were used to estimate continuous outcomes for individual studies. The results showed that in patients with hypercholesterolemia, taking a diet containing a certain dose of plant sterol significantly reduced total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) (TC: Weight Mean Difference (WMD) [95% CI] = -0.37 [-0.41, -0.34], p < 0.001; LDL-C: WMD [95% CI] = -0.34 [-0.37, -0.30], p < 0.001). In contrast, PSs had no effect on high density lipoprotein cholesterol (HDL-C) or triglycerides (TGs) (HDL-C: WMD [95% CI] = 0.00 [-0.01, 0.02], p = 0.742; TG: WMD [95% CI] = -0.01 [-0.04, 0.01], p = 0.233). Also, a significant effect of supplemental dose on LDL-C levels was observed in a nonlinear dose-response analysis (p-nonlinearity = 0.024). Our findings suggest that dietary phytosterols can help reduce TC and LDL-C concentrations in hypercholesterolemia patients without affecting HDL-C and TG concentrations. And the effect may be affected by the food substrate, dose, esterification, intervention cycle and region. The dose of phytosterol is an important factor affecting the level of LDL-C.

Diet and Cardiovascular Disease Risk Among Individuals with Familial Hypercholesterolemia: Systematic Review and Meta-Analysis

Background: Although a cholesterol-lowering diet and the addition of plant sterols and stanols are suggested for the lipid management of children and adults with familial hypercholesterolemia, there is limited evidence evaluating such interventions in this population. Objectives: To investigate the impact of cholesterol-lowering diet and other dietary interventions on the incidence or mortality of cardiovascular disease and lipid profile of patients with familial hypercholesterolemia. Search methods: Relevant trials were identified by searching US National Library of Medicine National Institutes of Health Metabolism Trials Register and clinicaltrials.gov.gr using the following terms: diet, dietary, plant sterols, stanols, omega-3 fatty acids, fiber and familial hypercholesterolemia. Selection criteria: Randomized controlled trials evaluating the effect of cholesterol-lowering diet or other dietary interventions in children and adults with familial hypercholesterolemia were included. Data collection and analysis: Two authors independently assessed the eligibility of the included trials and their bias risk and extracted the data which was independently verified by other colleagues. Results: A total of 17 trials were finally included, with a total of 376 participants across 8 comparison groups. The included trials had either a low or unclear bias risk for most of the assessed risk parameters. Cardiovascular incidence or mortality were not evaluated in any of the included trials. Among the planned comparisons regarding patients’ lipidemic profile, a significant difference was noticed for the following comparisons and outcomes: omega-3 fatty acids reduced triglycerides (mean difference (MD): −0.27 mmol/L, 95% confidence interval (CI): −0.47 to −0.07, p < 0.01) when compared with placebo. A non-significant trend towards a reduction in subjects’ total cholesterol (MD: −0.34, 95% CI: −0.68 to 0, mmol/L, p = 0.05) and low-density lipoprotein cholesterol (MD: −0.31, 95% CI: −0.61 to 0, mmol/L, p = 0.05) was noticed. In comparison with cholesterol-lowering diet, the additional consumption of plant stanols decreased total cholesterol (MD: −0.62 mmol/L, 95% CI: −1.13 to −0.11, p = 0.02) and low-density lipoprotein cholesterol (MD: −0.58 mmol/L, 95% CI: −1.08 to −0.09, p = 0.02). The same was by plant sterols (MD: −0.46 mmol/L, 95% CI: −0.76 to −0.17, p < 0.01 for cholesterol and MD: −0.45 mmol/L, 95% CI: −0.74 to −0.16, p < 0.01 for low-density lipoprotein cholesterol). No heterogeneity was noticed among the studies included in these analyses. Conclusions: Available trials confirm that the addition of plant sterols or stanols has a cholesterol-lowering effect on such individuals. On the other hand, supplementation with omega-3 fatty acids effectively reduces triglycerides and might have a role in lowering the cholesterol of patients with familial hypercholesterolemia. Additional studies are needed to investigate the efficacy of cholesterol-lowering diet or the addition of soya protein and dietary fibers to a cholesterol-lowering diet in patients with familial hypercholesterolemia.

The position of functional foods and supplements with a serum LDL-C lowering effect in the spectrum ranging from universal to care-related CVD risk management

A wealth of data demonstrates a causal link between serum low-density lipoprotein cholesterol (LDL-C) concentrations and cardiovascular disease (CVD). Any decrease in serum LDL-C concentrations is associated with a decreased CVD risk, and this benefit is similar to a comparable LDL-C reduction after drug treatment and dietary intervention. Moreover, life-long reductions in serum LDL-C levels have a large impact on CVD risk and a long-term dietary enrichment with functional foods or supplements with a proven LDL lowering efficacy is therefore a feasible and efficient approach to decrease future CVD risk. Functional foods with an LDL-C lowering effect can improve health and/or a reduce the risk of disease. However, it has not been mentioned specifically whether this concerns mainly universal prevention or whether this can also be applied to the hierarchy towards care related prevention. Therefore, we here describe the effects of a list of interesting functional food ingredients with proven benefit in LDL-C lowering. In addition, we pay particular attention to the emerging evidence that the addition of these functional ingredients and supplements is advisable as universal and selective prevention in the general population. Moreover, functional ingredients and supplements are also helpful in care related prevention, i.e. in patients with elevated LDL-C concentrations who are statin-intolerant or are not able to achieve their LDL-C target levels. Furthermore, we will highlight practical aspects regarding the use of functional foods with an LDL-C lowering effect, such as the increasing importance of shared decision making of medical doctors and dieticians with patients to ensure proper empowerment and better adherence to dietary approaches. In addition, we will address costs issues related to the use of these functional foods, which might be a barrier in some populations.

Impact of phytosterol supplementation on plasma lipoprotein(a) and free fatty acid (FFA) concentrations: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Although some earlier studies have indicated the effect of phytosterol (PS) supplementation on serum lipoprotein(a) (Lp(a)) and free fatty acid (FFA) concentration, findings are still conflicting. We aimed to assess the impact of PS supplementation on serum Lp(a) and FFA concentration through a systematic review and meta-analysis of available RCTs.

METHODS AND RESULTS

We performed a systematic search of all available RCTs conducted up to 21 February 2019 in the following databases: PubMed, Scopus, and Cochrane. The choice of fixed- or random-effect model for analysis was determined according to the I² statistic. Effect sizes were expressed as weighted mean difference (WMD) and 95% confidence interval (CI). Pooling of 12 effect sizes from seven articles revealed a significant reduction of Lp(a) levels following PS supplementation (MD: -0.025 mg/dl, 95% CI: -0.045, -0.004, p = 0.017) without significant heterogeneity among the studies (I² = 0.0%, p = 0.599). Also, PS supplementation significantly lowered FFA (MD: -0.138 mg/dl, 95% CI: -0.195, -0.081, p = 0.000) without significant heterogeneity among the studies (I² = 0.0%, p = 0.911). The results for meta-regression and sensitivity analysis were not significant.

CONCLUSION

The meta-analysis suggests that oral PS supplementation could cause a significant reduction in serum Lp(a) and FFA.

Phytosterol Supplementation Could Improve Atherogenic and Anti-Atherogenic Apolipoproteins: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials

Phytosterol and phytostanol (PS) supplementation is reported to improve atherogenic and anti-atherogenic apolipoproteins (Apo). The purpose of the present study is to critically investigate the effectiveness of PS supplementation on Apo in adults.A comprehensive search was conducted of all randomized controlled trials (RCTs) conducted up to September 2018 in the following databases: PubMed, Web of Science, Cochrane Library, and Scopus. Mean difference with 95% confidence intervals (CIs) were pooled using a random-effects model (DerSimonian-Laird method).Fifty-one arms from 37 RCTs were included in the present meta-analysis. Findings showed that PS supplementation and fortification increased Apo-AI (weighted mean difference [WMD]: 0.014 mg/dl, 95% CI: 0.001, 0.028, p = 0.042) and Apo-CII (WMD: 0.303 mg/dl, 95% CI: 0.084, 0.523, p = 0.007) and lowered Apo-B (WMD: -0.063 mg/dl, 95% CI: -0.075, -0.051, p < 0.001), Apo-B/Apo-A-I ratio (WMD: -0.044 mg/dl, 95% CI: -0.062, -0.025, p < 0.001), and Apo-E (WMD: -0.255 mg/dl, 95% CI: -0.474, -0.036, p = 0.023). However, PS supplementation did not have significant effects on Apo-AII and Apo-CIII. PS supplementation or fortification significantly changes Apo-E (r = -0.137, p nonlinearity = 0.006) and Apo-CIII (r = 1.26, p nonlinearity = 0.028) based on PS dosage (mg/d) and Apo-CIII (r = 3.34, p nonlinearity = 0.013) and Apo-CII (r = 1.09, p nonlinearity = 0.017) based on trial duration (weeks) in a nonlinear fashion.Based on our findings, supplements or fortified foods containing PS might have a considerable favorite effect in achieving Apo profile target; however, due to high heterogeneity among included studies, results must be interpreted with caution.KEY TEACHING POINTSCardiovascular diseases (CVDs) recognized as main public health concern worldwide with considerable mortality of all global deaths.Apo-lipoproteins are amphipathic molecules involved in the lipoprotein metabolism which introduced as biomarkers in the evaluation of CVD risk.Phytosterols bioactive components of plants have important biological functions in cholesterol metabolism in humans.Here we showed that phytosterols and phytostanols improve apo-lipoproteins profile of humans; finding from meta-analysis of randomized controlled trials.Phytosterols supplementation lowered atherogenic apo-lipoproteins (Apo-B and Apo-E) and increased anti-atherogenic apo-lipoproteins (Apo-AI, Apo-CII).

A combination of omega-3 and plant sterols regulate glucose and lipid metabolism in individuals with impaired glucose regulation: a randomized and controlled clinical trial

Background

Lipid metabolism imbalance has been recognized as one of the major drivers of impaired glucose metabolism in the context of type 2 diabetes mellitus (T2DM), the rates of which are steadily increasing worldwide. Impaired glucose regulation (IGR) plays a vital role in the prevention and treatment of T2DM. The goal of this study was to further clarify whether the combination of plant sterols (PS) and omega-3 fatty acids yields any synergistic effect that enhances the prevention and treatment of IGR.

Methods

A total of 200 participants were randomized to receive PS and omega-3 fatty acids (n = 50), PS alone (n = 50), omega-3 fatty acids alone (n = 50), or placebo soy bean powder plus placebo capsules (n = 50) for 12 weeks. Patient characteristics including body composition, blood pressure, glucose metabolism (Fasting plasma glucose (FPG), fasting insulin (FINS), glycosylated hemoglobin (HbA1c), Homeostasis Model Assessment of Insulin Resistance (HOMA-IR)), lipid metabolism (TG, TC, HDL-C, LDL-C) and inflammatory factors (Hs-CRP, IL-6) were all monitored in these IGR individuals.

Results

Compared to the placebo group, the group receiving the combined intervention exhibited significantly decreased TG, HDL-C, FBG, HOMA-IR and HbA1c. Omega-3 fatty acids alone were associated with significant reductions in waistline, TG, FBG, HOMA-IR and Hs-CRP. PS alone was only associated with decreased TG and Hs-CRP. No interventions produced significant changes in body weight, BMI, blood pressure, FINS, body fat percentage, visceral fat rating, TC, LDL-C or IL-6.

Conclusions

In summary, this study has demonstrated for the first time that PS, omega-3 fatty acids or the combination thereof significantly improved inflammation, insulin resistance, as well as glucose and lipid metabolism in IGR individuals. These findings may provide a scientific basis for the development of nutritional products incorporating PS and omega-3 fatty acids, and also for the development of nutritional supplement strategies aimed at preventing the development of disease in the IGR population.

Dietary natural products as emerging lipoprotein(a)-lowering agents

Elevated plasma lipoprotein(a) (Lp(a)) levels are associated with an increased risk of cardiovascular disease (CVD). Hitherto, niacin has been the drug of choice to reduce elevated Lp(a) levels in hyperlipidemic patients but its efficacy in reducing CVD outcomes has been seriously questioned by recent clinical trials. Additional drugs may reduce to some extent plasma Lp(a) levels but the lack of a specific therapeutic indication for Lp(a)-lowering limits profoundly reduce their use. An attractive therapeutic option is natural products. In several preclinical and clinical studies as well as meta-analyses, natural products, including l-carnitine, coenzyme Q ₁₀ , and xuezhikang were shown to significantly decrease Lp(a) levels in patients with Lp(a) hyperlipoproteinemia. Other natural products, such as pectin, Ginkgo biloba, flaxseed, red wine, resveratrol and curcuminoids can also reduce elevated Lp(a) concentrations but to a lesser degree. In conclusion, aforementioned natural products may represent promising therapeutic agents for Lp(a) lowering.

Effect of dietary cholesterol and plant sterol consumption on plasma lipid responsiveness and cholesterol trafficking in healthy individuals

Dietary cholesterol and plant sterols differentially modulate cholesterol kinetics and circulating cholesterol. Understanding how healthy individuals with their inherent variabilities in cholesterol trafficking respond to such dietary sterols will aid in improving strategies for effective cholesterol lowering and alleviation of CVD risk. The objectives of this study were to assess plasma lipid responsiveness to dietary cholesterolv. plant sterol consumption, and to determine the response in rates of cholesterol absorption and synthesis to each sterol using stable isotope approaches in healthy individuals. A randomised, double-blinded, crossover, placebo-controlled clinical trial (n49) with three treatment phases of 4-week duration were conducted in a Manitoba Hutterite population. During each phase, participants consumed one of the three treatments as a milkshake containing 600 mg/d dietary cholesterol, 2 g/d plant sterols or a control after breakfast meal. Plasma lipid profile was determined and cholesterol absorption and synthesis were measured by oral administration of [3, 4-13C] cholesterol and2H-labelled water, respectively. Dietary cholesterol consumption increased total (0·16 (sem0·06) mmol/l,P=0·0179) and HDL-cholesterol (0·08 (sem0·03) mmol/l,P=0·0216) concentrations with no changes in cholesterol absorption or synthesis. Plant sterol consumption failed to reduce LDL-cholesterol concentrations despite showing a reduction (6 %,P=0·0004) in cholesterol absorption. An over-compensatory reciprocal increase in cholesterol synthesis (36 %,P=0·0026) corresponding to a small reduction in absorption was observed with plant sterol consumption, possibly resulting in reduced LDL-cholesterol lowering efficacy of plant sterols. These data suggest that inter-individual variability in cholesterol trafficking mechanisms may profoundly impact plasma lipid responses to dietary sterols in healthy individuals.

Phytosterol nutritional supplement improves pregnancy and neonatal complications of gestational diabetes mellitus in a double-blind and placebo-controlled clinical study

Gestational diabetes mellitus (GDM) is an increasingly serious health problem among pregnant women.

A Phytosterol-Enriched Spread Improves Lipid Profile and Insulin Resistance of Women with Gestational Diabetes Mellitus: A Randomized, Placebo-Controlled Double-Blind Clinical Trial

BACKGROUND

Gestational diabetes mellitus (GDM) has become a serious health risk among pregnant women throughout the world. Phytosterol-enriched margarines are capable of lowering total cholesterol (TC) and low-density lipoprotein (LDL), but little is known about its effects on GDM. We aimed to examine the effects of daily consumption of a phytosterol-enriched spread on insulin resistance and lipid profile in pregnant GDM women.

METHODS

Pregnant women suffering from GDM in their second trimester were recruited and randomly assigned to consume a margarine spread either with or without phytosterols daily for 16 weeks. Serum lipid profile and glucose and insulin metabolisms were assessed at week 0 (baseline) and week 16 (end of trial).

RESULTS

After 16 weeks, levels of triacylglycerol, TC, and LDL were significantly decreased, while high-density lipoprotein was significantly increased, compared with the baseline in the phytosterol group. In addition, in the same treatment group, glucose metabolic parameters, including fasting plasma glucose, serum insulin levels, the quantitative insulin check index, homeostasis model of assessment of insulin resistance, and β-cell function, were also significantly improved.

CONCLUSION

Daily consumption of a phytosterol-enriched spread improved insulin resistance and lipid profile in women with GDM.

Advances in Microalgae-Derived Phytosterols for Functional Food and Pharmaceutical Applications

Microalgae contain a variety of bioactive lipids with potential applications in aquaculture feed, biofuel, food and pharmaceutical industries. While microalgae-derived polyunsaturated fatty acid (PUFA) and their roles in promoting human health have been extensively studied, other lipid types from this resource, such as phytosterols, have been poorly explored. Phytosterols have been used as additives in many food products such as spread, dairy products and salad dressing. This review focuses on the recent advances in microalgae-derived phytosterols with functional bioactivities and their potential applications in functional food and pharmaceutical industries. It highlights the importance of microalgae-derived lipids other than PUFA for the development of an advanced microalgae industry.

Dietary interventions (plant sterols, stanols, omega-3 fatty acids, soy protein and dietary fibers) for familial hypercholesterolaemia

BACKGROUND

A cholesterol-lowering diet and several other dietary interventions have been suggested as a management approach either independently or as an adjuvant to drug therapy in children and adults with familial hypercholesterolaemia (FH). However, a consensus has yet to be reached on the most appropriate dietary treatment. Plant sterols are commonly used in FH although patients may know them by other names like phytosterols or stanols.

OBJECTIVES

To examine whether a cholesterol-lowering diet is more effective in reducing ischaemic heart disease and lowering cholesterol than no dietary intervention in children and adults with familial hypercholesterolaemia. Further, to compare the efficacy of supplementing a cholesterol-lowering diet with either omega-3 fatty acids, soya proteins, plant sterols or plant stanols.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Inborn Errors of Metabolism Trials Register, which is compiled from electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (updated with each new issue of The Cochrane Library), quarterly searches of MEDLINE and the prospective handsearching of one journal - Journal of Inherited Metabolic Disease. Most recent search of the Group's Inborn Errors of Metabolism Trials Register: 22 August 2013. We also searched PubMed to 05 February 2012.

SELECTION CRITERIA

Randomised controlled trials, both published and unpublished, where a cholesterol-lowering diet in children and adults with familial hypercholesterolaemia has been compared to other forms of dietary treatment or to no dietary intervention were included.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the trial eligibility and risk of bias and one extracted the data, with independent verification of data extraction by a colleague.

MAIN RESULTS

In the 2014 update of the review, 15 trials have been included, with a total of 453 participants across seven comparison groups. The included trials had either a low or unclear risk of bias for most of the parameters used for risk assessment. Only short-term outcomes could be assessed due to the short duration of follow up in the included trials. None of the primary outcomes, (incidence of ischaemic heart disease, number of deaths and age at death) were evaluated in any of the included trials. No significant differences were noted for the majority of secondary outcomes for any of the planned comparisons. However, a significant difference was found for the following comparisons and outcomes: for the comparison between plant sterols and cholesterol-lowering diet (in favour of plant sterols), total cholesterol levels, mean difference 0.30 mmol/l (95% confidence interval 0.12 to 0.48); decreased serum LDL cholesterol, mean difference -0.60 mmol/l (95% CI -0.89 to -0.31). Fasting serum HDL cholesterol levels were elevated, mean difference -0.04 mmol/l (95% CI -0.11 to 0.03) and serum triglyceride concentration was reduced, mean difference -0.03 mmol/l (95% CI -0.15 to -0.09), although these changes were not statistically significant. Similarly, guar gum when given as an add on therapy to bezafibrate reduced total cholesterol and LDL levels as compared to bezafibrate alone.

AUTHORS' CONCLUSIONS

No conclusions can be made about the effectiveness of a cholesterol-lowering diet, or any of the other dietary interventions suggested for familial hypercholesterolaemia, for the primary outcomes: evidence and incidence of ischaemic heart disease, number of deaths and age at death,due to the lack of data on these. Large, parallel, randomised controlled trials are needed to investigate the effectiveness of a cholesterol-lowering diet and the addition of omega-3 fatty acids, plant sterols or stanols, soya protein, dietary fibers to a cholesterol-lowering diet.

Trillin, a steroidal saponin isolated from the rhizomes of Dioscorea nipponica, exerts protective effects against hyperlipidemia and oxidative stress

ETHNOPHARMACOLOGICAL EVIDENCE

Numerous efforts have been conducted in searching for effective agents against cardiovascular diseases, in particular from herbal medicines. The rhizome of Dioscorea nipponica (Dioscoreae Nipponicae Rhizoma) is a traditional Chinese herb being prescribed to improve the blood circulation. Here, we identified a steroidal saponin trillin from Dioscorea nipponica, which showed robust anti-hyperlipidemic effects.

MATERIALS AND METHODS

Rats were induced for hyperlipidemia and subjected to the drug treatment. The anti-hyperlipidemic effects of trillin were evaluated by different biochemical assays.

RESULTS

In hyperlipidemic rat model, fed with high-fat diet, the blood levels of cholesterol, triglyceride, low density lipoprotein (LDL) and high density lipoprotein (HDL) were increased. The intra-peritoneal administration of trillin into those rats significantly improved the bleeding and blood coagulation time, and in parallel the treatment restored the levels of cholesterol, glyceride, LDL and HDL back to the normal condition. In addition, the administration of trillin in rats exerted beneficial effects in improving the levels of lipid peroxidation and superoxide dismutase activity.

CONCLUSION

This was the first time to reveal the anti-hyperlipidemic and anti-oxidative effects of trillin. These results would be important in developing food supplements for health improvements and therapeutic drugs against hyperlipidemia and cardiovascular diseases in future.

Medicinal halophytes: potent source of health promoting biomolecules with medical, nutraceutical and food applications

Salt-tolerant plants grow in a wide variety of saline habitats, from coastal regions, salt marshes and mudflats to inland deserts, salt flats and steppes. Halophytes living in these extreme environments have to deal with frequent changes in salinity level. This can be done by developing adaptive responses including the synthesis of several bioactive molecules. Consequently, several salt marsh plants have traditionally been used for medical, nutritional, and even artisanal purposes. Currently, an increasing interest is granted to these species because of their high content in bioactive compounds (primary and secondary metabolites) such as polyunsaturated fatty acids, carotenoids, vitamins, sterols, essential oils (terpenes), polysaccharides, glycosides, and phenolic compounds. These bioactive substances display potent antioxidant, antimicrobial, anti-inflammatory, and anti-tumoral activities, and therefore represent key-compounds in preventing various diseases (e.g. cancer, chronic inflammation, atherosclerosis and cardiovascular disorder) and ageing processes. The ongoing research will lead to the utilisation of halophytes as a new source of healthy products as functional foods, nutraceuticals or active principles in several industries. This contribution focuses on the ethnopharmacological uses of halophytes in traditional medicine and reviews recent investigations on their biological activities and nutraceuticals. The work is distributed according to the different families of nutraceuticals (lipids, vitamins, proteins, glycosides, phenolic compounds, etc.) discussing the analytical techniques employed for their determination. Information about the claimed health promoting effects of the different families of nutraceuticals is also provided together with data on their application.

Effect of plant sterols on the lipid profile of patients with hypercholesterolaemia. Randomised, experimental study

BACKGROUND

Studies have been conducted on supplementing the daily diet with plant sterol ester-enriched milk derivatives in order to reduce LDL-cholesterol levels and, consequently, cardiovascular risk. However, clinical practice guidelines on hypercholesterolaemia state that there is not sufficient evidence to recommend their use in subjects with hypercholesterolaemia. The main objective of this study is to determine the efficacy of the intake of 2 g of plant sterol esters a day in lowering LDL-cholesterol levels in patients diagnosed with hypercholesterolaemia. The specific objectives are: 1) to quantify the efficacy of the daily intake of plant sterol esters in lowering LDL-cholesterol, total cholesterol and cardiovascular risk in patients with hypercholesterolaemia; 2) to evaluate the occurrence of adverse effects of the daily intake of plant sterol esters; 3) to identify the factors that determine a greater reduction in lipid levels in subjects receiving plant sterol ester supplements.

METHODS/DESIGN

Randomised, double-blind, placebo controlled experimental trial carried out at family doctors' surgeries at three health centres in the Health Area of Albacete (Spain). The study subjects will be adults diagnosed with "limit" or "defined" hypercholesterolaemia and who have LDL cholesterol levels of 130 mg/dl or over. A dairy product in the form of liquid yoghurt containing 2 g of plant sterol ester per container will be administered daily after the main meal, for a period of 24 months. The control group will receive a daily unit of yogurt not supplemented with plant sterol esters that has a similar appearance to the enriched yoghurt. The primary variable is the change in lipid profile at 1, 3, 6, 12, 18 and 24 months. The secondary variables are: change in cardiovascular risk, adherence to the dairy product, adverse effects, adherence to dietary recommendations, frequency of food consumption, basic physical examination data, health problems, lipid-lowering medication, physical activity, smoking habits and socio-demographic variables.

DISCUSSION

If plant sterol ester supplements were effective a sounder recommendation for the consumption of plant sterols in subjects with hypercholesterolaemia could be made.

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).

Lowering LDL cholesterol with margarine containing plant stanol/sterol esters: is it still relevant in 2011?

Recommendations about the use of plant stanol/sterol esters have not been updated since 2001. There have been many developments in medicines for lipid-lowering since 2001. In this review, the use of margarines containing stanol or sterol esters, to lower LDL cholesterol is considered in the 2011 setting. Firstly, there is a brief overview of the effects of the stanols/sterols on LDL cholesterol, which shows that these agents have a modest ability to lower LDL cholesterol, and are not effective in all conditions. Secondly, the relevance of the stanols/sterols in 2010/1 is questioned, given they have not been shown to reduce clinical endpoints, and have no effects on HDL cholesterol or triglyceride levels. Finally, there is a section comparing the stanols/sterols with the present day prescription lipid lowering medicines. Prescription drugs (statins, ezetimibe, and niacin) have a much greater ability to lower LDL cholesterol than the stanol/sterol esters, and also increase levels of HDL cholesterol and decrease levels of triglycerides. The statins and niacin have been shown to reduce cardiovascular clinical endpoints. Except in borderline normo/hypercholesterolemia, prescription drugs should be preferred to stanol/sterol esters for lowering LDL cholesterol in 2011.

Functional food ingredients as adjunctive therapies to pharmacotherapy for treating disorders of metabolic syndrome

Abstract Information regarding the use of functional foods and nutraceuticals (FFN) in combating disease is rarely communicated to health care practitioners as medicinal strategies for patients. Metabolic syndrome (MetS) is an ideal paradigm for demonstrating the therapeutic properties of FFN. Encompassing multiple etiologies, including atherogenic dyslipidemia, insulin resistance, and hypertension, MetS affects over a third of American adults. However, as disease-related risk factors accumulate over time, guidelines for treating disorders of MetS progressively de-emphasize the use of FFN. Using marine omega-3 fatty acids, plant sterols, fiber, and tomato extract as examples, the purpose of this review is to endorse FFN as long-term adjunctive therapies to pharmaceutical treatment for disorders and risk factors for MetS. An additional goal is to compare physiological and molecular targets of FFN against corresponding prescription medications. Results reveal that FFN are viable treatment strategies for disorders of MetS, complementing pharmacological interventions by targeting and improving the biological processes that foster the development of disease. Thus, efficacious FFN therapies should be emphasized throughout all stages of treatment as adjuncts to pharmacotherapy for disorders of MetS. Accordingly, new developments in FFN research must be implemented into clinical guidelines with the prospect of improving disease prognoses as accessories to prescription medications.

Phytosterols: physiologic and metabolic aspects related to cholesterol-lowering properties

The aim of this review is to give a general contemporary overview of the physiologic effects of phytosterols and their role in cholesterol uptake in the intestinal tract. The mechanism of phytosterols action is based on its ability to reduce cholesterol absorption. Doses of 0.8 to 4.0 g/d of phytosterols were used to reduce low-density lipoprotein cholesterol concentrations by 10% to 15%, although most of the studies described used 2 g/d of phytosterol to achieve a reduction of 10% in low-density lipoprotein cholesterol concentrations. Although some studies point to the possibility that elevated plasma phytosterol concentrations could contribute to the development of premature coronary artery diseases, extensive safety evaluation studies have been conducted for these compounds, and they have been considered safe.

Anti-hyperlipidemic effect of an edible brown algae, Ecklonia stolonifera, and its constituents on poloxamer 407-induced hyperlipidemic and cholesterol-fed rats

We conducted this study to isolate novel anti-hyperlipidemic agents derived from natural marine products. To accomplish this, we investigated the effects of ethanolic (EtOH) extracts of Ecklonia stolonifera and its phlorotannin constituents, eckol and dieckol, on serum lipid levels in rats with hyperlipidemia that was induced by a high-cholesterol diet or poloxamer 407. Treatment with the EtOH extracts of E. stolonifera and its phlorotannin-rich ethyl acetate (EtOAc) and n-butanol (n-BuOH) fractions induced a significant reduction in triglycerides (TG), total cholesterol (TC), and low-density lipoprotein-cholesterol (LDL-C) levels, as well as a significant increase in the high-density lipoprotein-cholesterol (HDLC) level in hyperlipidemic rats. However, treatment with the water (H(2)O) fraction did not exert any significant effects on the serum levels of hyperlipidemic rats. In addition, eckol and dieckol isolated from the active EtOAc fraction induced a significant reduction in serum TG, TC, and LDL-C levels, as well as in the atherogenic index (A.I.). Furthermore, treatment with dieckol induced a greater decrease in the serum TG, TC, and LDL-C levels of hyperlipidemic rats than eckol or lovastatin, as well as an increase in the serum HDL-C levels. Taken together, these results suggest that phlorotannins such as eckol and dieckol have the potential for use for the prevention of hyperlipidemic atherosclerosis.

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.

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.

L’ézétimibe comme complément des statines ?

Ezetimibe is the first cholesterol absorption inhibitor, a novel class of lipopenic drugs that inhibit intestinal absorption of biliary and dietary cholesterol. From a pathophysiological point of view, combining complementary drugs that act on different cholesterol metabolism pathways is particularly interesting. This interest has been confirmed in clinical studies combining ezetimibe and statins, which inhibit cholesterol synthesis in the liver. Adding ezetimibe (10 mg/d) to statin therapy decreased LDL cholesterol by as much as an additional 20%. It may thus be especially useful in patients who are unable to reach the LDL cholesterol target with diet and statins alone. Ezetimibe is well tolerated and is indicated alone in statin-intolerant patients.

Plant sterols are efficacious in lowering plasma LDL and non-HDL cholesterol in hypercholesterolemic type 2 diabetic and nondiabetic persons

BACKGROUND

Because of hyperglycemia and hyperinsulinemia, diabetic persons have higher cholesterol synthesis and lower cholesterol absorption rates than do nondiabetic persons. Differences in plant sterol efficacy between diabetic and nondiabetic persons have not been examined.

OBJECTIVE

The objective was to compare the degree of response of plasma lipid concentrations and glycemic control to plant sterol consumption in a controlled diet between hypercholesterolemic type 2 diabetic and nondiabetic subjects.

DESIGN

Fifteen nondiabetic subjects and 14 diabetic subjects participated in a double-blinded, randomized, crossover, placebo-controlled feeding trial. The diet included 1.8 g/d of either plant sterols or cornstarch placebo over 21 d, separated by a 28-d washout period.

RESULTS

Plant sterol consumption significantly reduced (P < 0.05) LDL-cholesterol concentrations from baseline in both nondiabetic and diabetic subjects by 15.1% and 26.8%, respectively. The diabetic subjects had significantly (P < 0.05) lower absolute concentrations of total cholesterol after treatment than did the nondiabetic subjects; however, there was no significant difference in the percentage change from the beginning to the end of the trial. There was also a significant decrease (P < 0.05) in absolute non-HDL-cholesterol concentrations after treatment in both groups.

CONCLUSIONS

The results showed that plant sterols are efficacious in lowering LDL cholesterol and non-HDL cholesterol in both diabetic and nondiabetic persons. Plant sterol consumption may exist as a dietary management strategy for hypercholesterolemia in persons with type 2 diabetes.

The effect of adlay oil on plasma lipids, insulin and leptin in rat

This study was designed to investigate the effect of dietary adlay oil on plasma lipids, insulin and lipid peroxidation levels in rats. Twenty-four male Wistar rats fed diet containing adlay oil and cholesterol were studied for 4 weeks. The animals were divided into three groups: (1) 10% lard (control) group; (2) 5% lard + 5% adlay oil (5% adlay oil) group; and (3) 10% adlay oil group. Although there was no significant difference in body weight at the end of the feeding study, rats fed a diet containing adlay oil showed a significant decrease in adipose tissue weight and relative adipose weight. In addition, the rats fed the adlay oil showed significantly decreased low-density lipoprotein cholesterol (LDL-C), insulin, leptin and thiobarbituric acid reactive substance (TBARS) concentrations after 4 weeks of the feeding study. Although a significant decrease in total plasma cholesterol was observed in rats fed the 5% adlay oil diet, no significant difference was observed between the 10% adlay oil and control groups, and neither was a significant difference in liver TBARS concentration found between the dietary groups. Results from this study suggest that dietary adlay oil can reduce leptin, adipose tissue and LDL-C levels in rats.

Plant stanol and sterol esters in prevention of cardiovascular diseases

Statin trials have indicated that effective reduction of serum cholesterol should last up to one year before reduced risk of cardiovascular diseases can be detected. This observation can be applied most probably also to the use of plant stanol/sterol ester spreads for the treatment of hypercholesterolemia. However, despite the fact that the two spreads lower serum cholesterol similarly in short term studies, a comparison of one year results reveals an inconsistent effect of plant sterol spread as compared with that of plant stanol spread on cholesterol concentration in both men and women. This favors the use of plant stanol ester spread for long-term lowering of serum cholesterol. Doses of about 2 g/day of plant stanols as fatty acid ester spread enhances fecal elimination of cholesterol, but not of bile acids, through inhibition of cholesterol absorption by about 40%. This lowers serum total and low density lipoprotein (LDL) cholesterol despite enhanced compensatory increase in cholesterol synthesis by about 10% and 15% as compared with control spread, respectively, and by up to 20% as compared with the baseline diet. About one-third of mildly hypercholesterolemic subjects reach an accepted cholesterol level. A small dose of statin should be added to treatment in individuals resistant to monotherapy with plant stanol ester spread. A life-long consumption of plant stanol ester spread has been predicted to lower coronary events by about 20%.

Efficacy and safety of plant stanols and sterols in the management of blood cholesterol levels

Foods with plant stanol or sterol esters lower serum cholesterol levels. We summarize the deliberations of 32 experts on the efficacy and safety of sterols and stanols. A meta-analysis of 41 trials showed that intake of 2 g/d of stanols or sterols reduced low-density lipoprotein (LDL) by 10%; higher intakes added little. Efficacy is similar for sterols and stanols, but the food form may substantially affect LDL reduction. Effects are additive with diet or drug interventions: eating foods low in saturated fat and cholesterol and high in stanols or sterols can reduce LDL by 20%; adding sterols or stanols to statin medication is more effective than doubling the statin dose. A meta-analysis of 10 to 15 trials per vitamin showed that plasma levels of vitamins A and D are not affected by stanols or sterols. Alpha carotene, lycopene, and vitamin E levels remained stable relative to their carrier molecule, LDL. Beta carotene levels declined, but adverse health outcomes were not expected. Sterol-enriched foods increased plasma sterol levels, and workshop participants discussed whether this would increase risk, in view of the marked increase of atherosclerosis in patients with homozygous phytosterolemia. This risk is believed to be largely hypothetical, and any increase due to the small increase in plasma plant sterols may be more than offset by the decrease in plasma LDL. There are insufficient data to suggest that plant stanols or sterols either prevent or promote colon carcinogenesis. Safety of sterols and stanols is being monitored by follow-up of samples from the general population; however, the power of such studies to pick up infrequent increases in common diseases, if any exist, is limited. A trial with clinical outcomes probably would not answer remaining questions about infrequent adverse effects. Trials with surrogate end points such as intima-media thickness might corroborate the expected efficacy in reducing atherosclerosis. However, present evidence is sufficient to promote use of sterols and stanols for lowering LDL cholesterol levels in persons at increased risk for coronary heart disease.

Plant sterol-enriched spread enhances the cholesterol-lowering potential of a fat-reduced diet

OBJECTIVE

To determine the effect of a plant sterol-enriched spread on plasma cholesterol concentrations when replacing butter or a standard polyunsaturated spread in a diet containing 30% of energy fat.

DESIGN

Parallel butter phase followed by double-blind, randomized, cross-over polyunsaturated spread phases.

SETTING

General community.

SUBJECTS

Volunteer sample of 50 free-living men and women with mean age (s.d.) 46.7 y (10.5), moderately elevated plasma total cholesterol 5.95 mmol/l (0.78), and body mass index 26.0 (3.9) kg/m(2).

INTERVENTION

Participants ate a moderately low-fat diet (30% of energy) for the 11-week intervention. During the first 3 weeks the diet included 20 g per day of butter. Participants were then randomized to replace the butter with 25 g of polyunsaturated spread with or without 2 g of plant sterols for 4 weeks, crossing over in the last 4 weeks to the alternate spread.

MAIN OUTCOME MEASURES

Plasma cholesterol and fatty acids.

RESULTS

Replacing butter with a standard polyunsaturated fat spread reduced mean plasma total cholesterol concentrations by 4.6% (from 6.09 (0.82) to 5.81 (0.77) mmol/l, P<0.01) and low-density lipoprotein cholesterol by 5.5% (from 3.98 (0.76) to 3.76 (0.74) mmol/l, P<0.05). Replacing butter with a polyunsaturated spread containing plant sterols reduced plasma total cholesterol by 8.9% (from 6.09 (0.82) to 5.55 (0.76) mmol/l, P<0.01) and low density lipoprotein cholesterol by 12.3% (from 3.98 (0.76) to 3.49 (0.72) mmol/l, P<0.01). Plasma high density lipoprotein cholesterol concentration was the same on the three diets.

CONCLUSION

In people with moderately raised plasma cholesterol concentrations consuming reduced-fat diets the reduction in plasma total and low-density lipoprotein cholesterol concentrations achieved by replacing butter with a polyunsaturated spread is enhanced by addition of plant sterols.

Phytosterols, phytostanols, and their conjugates in foods: structural diversity, quantitative analysis, and health-promoting uses

Phytosterols (plant sterols) are triterpenes that are important structural components of plant membranes, and free phytosterols serve to stabilize phospholipid bilayers in plant cell membranes just as cholesterol does in animal cell membranes. Most phytosterols contain 28 or 29 carbons and one or two carbon-carbon double bonds, typically one in the sterol nucleus and sometimes a second in the alkyl side chain. Phytostanols are a fully-saturated subgroup of phytosterols (contain no double bonds). Phytostanols occur in trace levels in many plant species and they occur in high levels in tissues of only in a few cereal species. Phytosterols can be converted to phytostanols by chemical hydrogenation. More than 200 different types of phytosterols have been reported in plant species. In addition to the free form, phytosterols occur as four types of "conjugates," in which the 3beta-OH group is esterified to a fatty acid or a hydroxycinnamic acid, or glycosylated with a hexose (usually glucose) or a 6-fatty-acyl hexose. The most popular methods for phytosterol analysis involve hydrolysis of the esters (and sometimes the glycosides) and capillary GLC of the total phytosterols, either in the free form or as TMS or acetylated derivatives. Several alternative methods have been reported for analysis of free phytosterols and intact phytosteryl conjugates. Phytosterols and phytostanols have received much attention in the last five years because of their cholesterol-lowering properties. Early phytosterol-enriched products contained free phytosterols and relatively large dosages were required to significantly lower serum cholesterol. In the last several years two spreads, one containing phytostanyl fatty-acid esters and the other phytosteryl fatty-acid esters, have been commercialized and were shown to significantly lower serum cholesterol at dosages of 1-3 g per day. The popularity of these products has caused the medical and biochemical community to focus much attention on phytosterols and consequently research activity on phytosterols has increased dramatically.

Cholesterol absorption

Cholesterol absorption is a key regulatory point in human lipid metabolism because it determines the amount of endogenous biliary as well as dietary cholesterol that is retained, thereby influencing whole body cholesterol balance. Plant sterols (phytosterols) and the drug ezetimibe reduce cholesterol absorption and low-density lipoprotein cholesterol in clinical trials, complementing the statin drugs, which inhibit cholesterol biosynthesis. The mechanism of cholesterol absorption is not completely known but involves the genes ABC1, ABCG5, and ABCG8, which are members of the ATP-binding cassette protein family and appear to remove unwanted cholesterol and phytosterols from the enterocyte. ABC1 is upregulated by the liver X (LXR) and retinoid X (RXR) nuclear receptors. Acylcholesterol acytransferase-2 is an intestinal enzyme that esterifies absorbed cholesterol and increases cholesterol absorption when dietary intake is high. New clinical treatments based on better understanding of absorption physiology are likely to substantially improve clinical cholesterol management in the future.