Dose-response effects of different plant sterol sources in fat spreads on serum lipids and C-reactive protein and on the kinetic behavior of serum plant sterols

Phytosterol intake and risk of coronary artery disease: Results from 3 prospective cohort studies

BACKGROUND

Phytosterols are structurally similar to cholesterol and partially inhibit intestinal absorption of cholesterol, although their impact on coronary artery disease (CAD) risk remains to be elucidated.

OBJECTIVES

This study aimed to prospectively assess the associations between total and individual phytosterol intake and CAD risk in United States health professionals.

METHODS

The analysis included 213,992 participants from 3 prospective cohorts-the Nurses' Health Study (NHS), NHSII, and Health Professionals Follow-Up Study-without cardiovascular disease or cancer at baseline. Diet was assessed using a validated food frequency questionnaire every 2-4 y since baseline. Associations between phytosterol intake and the risk of CAD, such as nonfatal myocardial infarction and fatal CAD, were evaluated using Cox proportional hazards regression models.

RESULTS

More than 5,517,993 person-years, 8725 cases with CAD were documented. Comparing extreme quintiles, pooled hazard ratios (95% CIs) of CAD were 0.93 (0.86, 1.01; P-trend = 0.16) for total phytosterols, 0.89 (0.82, 0.96; P-trend = 0.05) for campesterol, 0.95 (0.88, 1.02; P-trend = 0.10) for stigmasterol, and 0.92 (0.85, 1.00; P-trend = 0.09) for β-sitosterol. Nonlinear associations were observed for total phytosterols, campesterol, and β-sitosterol: the risk reduction plateaued at intakes above ∼180, 30, and 130 mg/d, respectively (P-nonlinearity < 0.001). In a subset of participants (N range between 11,983 and 22,039), phytosterol intake was inversely associated with plasma concentrations of total cholesterol, triglycerides, high-density lipoprotein cholesterol, and IL-6 and positively associated with adiponectin, whereas no significant associations were observed for low-density lipoprotein cholesterol or C-reactive protein concentrations.

CONCLUSIONS

Higher long-term intake of total and major subtypes of phytosterols may be associated with a modest reduction in CAD risk, displaying a nonlinear relationship that plateau at moderate intake levels. The role of phytosterols in preventing CAD warrants further investigation.

Genosets for APOE and CYP7A1-rs3808607 variants do not predict LDL cholesterol lowering upon intervention with plant sterols in a randomized, double-blind, placebo-controlled trial

BACKGROUND

The consumption of 2 g/d plant sterols (PSs) reduces circulating LDL cholesterol by ≤10%. The degree of LDL cholesterol lowering was associated with specific apolipoprotein E [APOE, Reference SNP (rs)429358] and cholesterol 7α-hydroxylase (CYP7A1, rs3808607) genosets in previous post hoc analyses of randomized controlled trials. However, because post hoc analyses do not conform to the randomization model, there is a greater potential that the findings could be due to type I error, thus warranting validation through an a priori-designed intervention trial.

OBJECTIVES

The GenePredict Plant Sterol study (GPS) was designed to validate associations of LDL cholesterol lowering with specific APOE and CYP7A1 genosets through a priori recruitment of individuals carrying prespecified genosets.

METHODS

A 2-center, double-blind, placebo-controlled, randomized 2-period crossover dietary intervention with 2 g/d PS for 28 d with a minimum 28-d washout was undertaken from July 2017 to December 2019. A priori recruitment of individuals with slightly elevated LDL cholesterol was based on genosets of APOE isoforms and CYP7A1 rs3808607. Randomization was performed with stratification by sex and genoset.

RESULTS

The recruitment target of 64 participants with prespecified genosets could not be reached, despite the screening of 477 individuals; 42 participants completed the intervention trial. Reductions in LDL cholesterol were similar across all 3 genosets (-0.298 ± 0.164, -0.357 ± 0.115, -0.293 ± 0.109 mmol/L; P = 0.0002 overall; P = 0.9126 for treatment × genoset), providing evidence that the shortfall in recruitment might not have stopped the trial from meeting the objective.

CONCLUSIONS

APOE and CYP7A1 genotypes did not influence the efficacy of LDL cholesterol reductions upon dietary intervention with PSs. Findings of previous post hoc analyses could not be validated in a trial using a priori genotype-based recruitment. Obtaining adequate numbers of participants is challenging in trials using genoset-based recruitment, even for common variants.

Anti-diabetic Potential of a Stigmasterol From the Seaweed Gelidium spinosum and Its Application in the Formulation of Nanoemulsion Conjugate for the Development of Functional Biscuits

The seaweed Gelidium spinosum was selected for the extraction of phytosterol by the Soxhlet method. The extracted phytosterol was chemically characterized as stigmasterol using Fourier-transform infrared spectrometry and gas chromatography-mass spectrometry analysis. The antioxidant and α-amylase inhibitory activity of stigmasterol has been confirmed by in vitro assays. The in vivo studies demonstrated an anti-diabetic effect in streptozotocin (STZ)-induced hyperglycemic rats. Biochemical analysis showed administration of stigmasterol reduced the blood sugar, urea, and creatinine level. The stigmasterol was then nano-emulsified and incorporated into dough for biscuit formulation. The stigmasterol incorporated biscuit showed higher proximate values, low moisture content, lighter color and the textural property revealed lower hardness. Sensorial results showed acceptability when compared to the control. This study demonstrated the stigmasterol reduced hyperglycemic effects and therefore could be used as a supplement in diets for diabetic patients.

Current innovations in nutraceuticals and functional foods for intervention of non-alcoholic fatty liver disease

As innovations in global agricultural production and food trading systems lead to major dietary shifts, high morbidity rates from non-alcoholic fatty liver disease (NAFLD), accompanied by elevated risk of lipid metabolism-related complications, has emerged as a growing problem worldwide. Treatment and prevention of NAFLD and chronic liver disease depends on the availability of safe, effective, and diverse therapeutic agents, the development of which is urgently needed. Supported by a growing body of evidence, considerable attention is now focused on interventional approaches that combines nutraceuticals and functional foods. In this review, we summarize the pathological progression of NAFLD and discuss the beneficial effects of nutraceuticals and the active ingredients in functional foods. We also describe the underlying mechanisms of these compounds in the intervention of NAFLD, including their effects on regulation of lipid homeostasis, activation of signaling pathways, and their role in gut microbial community dynamics and the gut-liver axis. In order to identify novel targets for treatment of lipid metabolism-related diseases, this work broadly explores the molecular mechanism linking nutraceuticals and functional foods, host physiology, and gut microbiota. Additionally, the limitations in existing knowledge and promising research areas for development of active interventions and treatments against NAFLD are discussed.

Phytosterols and Inflammation

Besides the well-characterized effect of foods and supplements enriched with plant sterols/stanols on serum LDL-C concentrations, evidence is now emerging that phytosterols exert beneficial effects on non-lipid variables such as inflammatory and oxidative stress markers, coagulation parameters and endothelial function. This makes sterols and stanols an attractive alternative for dietary interventions in cardiovascular disease prevention, particularly in populations at low or medium risk. This review aims to summarize the current knowledge derived from experimental studies and human data on the anti-inflammatory effects of phytosterols/stanols and their relevance in promoting atheroprotection and preventing cardiovascular disease. The anti-inflammatory effects induced by plant sterols/stanols have been demonstrated in in vitro studies and in experimental animal models. However, not all the beneficial effects seen at an experimental level have translated into clinical benefit. Indeed, clinical studies that evaluate the association between phytosterols consumption and inflammatory variables (CRP and cytokines) are inconsistent and have not yet provided a solid answer. Plant sterols have been proposed as useful adjuncts to statin therapy to further reduce the risk of cardiovascular disease. However, there is limited available data and more research needs to be done.

Combining Plant Sterols With Walking Lowers Postprandial Triacylglycerol More Than Walking Only in Chinese Men With Elevated Body Mass Index

This study examined if plant sterols and walking reduce postprandial triacylglycerol (TAG) concentrations in Chinese men with elevated body mass index (≥ 23.5 kg/m2). Fifteen Chinese men (mean [SD]: age = 25 [3] years and body mass index = 26.2 [1.5] kg/m2] completed four 10-day trials in random order with a 7- to 10-day washout between trials: (a) daily consumption of a control margarine while sedentary (C-S), (b) daily consumption of margarine containing 2 g/day of plant sterols while sedentary (PS-S), (c) daily consumption of a control margarine with 30-min daily walking (C-W), and (d) daily consumption of margarine containing 2 g/day of plant sterols with 30-min daily walking (PS-W). On Day 11 of each trial, postprandial TAG was measured after a high-fat milkshake. The 5-hr total area under the TAG curve was 22%, 25%, and 12% lower on PS-W (mean [SD]: 8.9 [4.3] mmol·5 hr/L) than C-S (11.4 [4.5] mmol·5 hr/L; p = .005; d = 0.56), PS-S (11.9 [4.9] mmol·5 hr/L; p = .004; d = 0.67), and C-W (10.1 [4.4] mmol·5 hr/L; p = .044; d = 0.27) trials, respectively. Similarly, 5-hr incremental area for PS-W (4.5 [2.7] mmol·5 hr/L) was 31%, 32%, and 18% lower than C-S (6.6 [3.3] mmol·5 hr/L; p = .005; d = 0.62), PS-S (6.6 [3.4] mmol·5 hr/L; p = .004; d = 0.64), and C-W (5.5 [2.8] mmol·5 hr/L; p = .032; d = 0.29). Ten days of daily plant sterol intake combined with walking presents an intervention strategy to lower postprandial TAG in Chinese men with elevated body mass index.

Serum Concentration of Plant Sterol Oxidation Products (POP) Compared to Cholesterol Oxidation Products (COP) after Intake of Oxidized Plant Sterols: A Randomised, Placebo-Controlled, Double-Blind Dose‒Response Pilot Study

Plant sterols (PS) are oxidized to PS oxidation products (POP). This study quantified the change in serum POP compared to cholesterol oxidation products (COP) after the intake of increasing POP doses. This was a double-blind, randomized, placebo-controlled, dose‒response pilot study with healthy individuals in four groups (15 per group). The control group received products with no added PS or POP and treatment groups received daily 20–25 g margarine with added PS (mean 3 g/d) and two cookies (~28 g) for six weeks. Cookies delivered 8.7 (low-dose), 15.2 (medium-dose), or 37.2 (high-dose) mg/d POP. Fasting serum POP and COP were measured at the baseline, days 14, 28, and 42 in all participants and days 7, 21, and 35 in a subset. Sixty individuals completed the study; 52 were included in per protocol analysis. Serum POP increased with increasing POP intake and plateaued at dose >15 mg/d. Stabilized POP concentrations were (mean ± SD) 38.9 ± 6.9, 91.0 ± 27.9, 144.4 ± 37.9 and 203.0 ± 63.7 nmol/L, for control, low-, medium-, and high-dose POP groups, respectively. For all groups, the serum COP ranged from 213 to 262 nmol/L and the average POP/COP ratio was <1. Serum POP concentrations increased non-linearly, reaching stabilized concentrations in <7 days, and remained below COP concentrations after the intake of increasing POP doses.

Dietary non-nutrients in the prevention of non-communicable diseases: Potentially related mechanisms

Among the 10 leading causes of death in developed countries are chronic non-communicable diseases (NCDs). The effect of these multifactorial diseases on public health has stimulated considerable research aimed at investigating their primary risk factors (genetic factors, stress, food intake, and amount of physical exercise). Thus, healthful foods (e.g., fruits, vegetables, oils, grains, and seeds) are sources of bioactive compounds that promote good health and disease prevention. Among their components are non-caloric substances identified as non-nutrients (polyphenols, phytosterols, saponins, and phytates), which have been found to have a role in modulating metabolic pathways, maintaining health, and preventing NCDs. The aim of this study is to demonstrate and review the performance of some non-nutrients, such as their antioxidant and anti-inflammatory action, modulation of the antiatherogenic lipid profile (higher high-density lipoprotein cholesterol, lower oxidized low-density lipoprotein, and triacylglycerols), reduction of glucose and fat intestinal absorption, increase in insulin sensitivity, and stimulation of nitic oxide synthesis.

LDL-Cholesterol Lowering of Plant Sterols and Stanols-Which Factors Influence Their Efficacy?

The LDL-cholesterol (LDL-C) lowering effect of plant sterols/stanols (PSS) is summarized in several meta-analyses showing a dose-response relationship with intakes of 1.5 to 3 g/day lowering LDL-C by 7.5% to 12%. This review summarizes evidence for the impact of various factors potentially influencing the LDL-C-lowering efficacy of PSS. PSS are efficacious in all food formats and in food supplements. Some factors related to food format, e.g., solid vs. liquid foods, seem to impact efficacy, while there is no difference between free PSS and esters. Compared to multiple daily intakes, once-a-day intake of PSS, especially in the morning with light breakfast, leads to a sub-optimal LDL-C lowering. However, intake frequency seems influenced by intake occasion, i.e., with or without a meal, and time of day. Meal intake is a critical factor for an optimal LDL-C lowering efficacy of PSS. While age has no impact, gender is suggested to influence the LDL-C lowering effect of PSS with greater reductions reported for men than women; but overall evidence is inconclusive and larger studies show no gender by treatment interaction. In conclusion, PSS are efficacious in all foods and food supplements; for optimal efficacy they should be consumed with a (main) meal and twice daily.

Plant sterol-enriched soy milk consumption modulates 5-lipoxygenase, 12-lipoxygenase, and myeloperoxidase activities in healthy adults - a randomized-controlled trial

A randomized, double blind, placebo-controlled and crossover study was conducted to simultaneously measure the effects, after 3-h and 4-week daily exposure to plant sterols-enriched food product, on inflammation, oxidative status, 5-lipoxygenase, 12-lipoxygenase, and myeloperoxidase activities in healthy adults. Eighteen healthy participants (67% female, 35.3 (mean) ± 9.5 (SD) years, mean body mass index 22.8 kg m^-2) received two soy milk (20g) treatments daily: placebo and one containing 2.0 g free plant sterols equivalent of their palmitates (β-sitosterol, 55%; campesterol, 29%; stigmasterol, 23%). F₂-isoprostanes, leukotriene B₄, sitosterol, campesterol, and stigmasterol concentrations were measured in the blood plasma and urine, using stable isotope-labeled gas chromatography-mass spectrometry. High-sensitivity c-reactive protein, tumor necrosis factor-_α, and lipoxin A₄ concentrations in blood serum were measured using commercially available enzyme immunoassays. Myeloperoxidase activity, serum lipid hydroperoxides, plasma and urinary F₂-isoprostanes, plasma and urinary leukotriene B₄, and plasma high-sensitivity c-reactive protein concentrations were significantly reduced, while circulating lipoxin A₄ concentrations were significantly elevated after 4-week plant sterols treatment. Plant sterols treatment decreased plasma leukotriene B₄ and increased plasma lipoxin A₄ concentrations acutely. Total plant sterols, β-sitosterol, campesterol, and stigmasterol concentrations were significantly elevated after 4-week treatments compared with the pre-treatment concentrations. Our results suggest that dietary plant sterols, in the combination used, can alleviate lipid peroxidation and inflammatory events in vivo. These effects are possibly exerted via the modulation of myeloperoxidase, 5-lipoxygenase, and 12-lipoxygenase activities.

Cholesterol ester transfer protein polymorphism rs5882 is associated with triglyceride-lowering in response to plant sterol consumption

Recent work suggests that plant sterol (PS) consumption may lower triglyceride (TG) concentrations; however, human clinical trial evidence is inconsistent. We associated SNP r5882 in cholesteryl ester transfer protein with changes in TG concentrations following PS consumption (2 g/day for 4 weeks) in a dual-centre, single-blind, randomized, crossover trial. TG concentrations were lowered in homozygotes for the minor G-allele of rs5882 (-0.46 ± 0.13 mmol/L, p = 0.002, n = 10); there was no effect in the A-allele carriers.

Soya products and serum lipids: a meta-analysis of randomised controlled trials

Soya proteins and isoflavones have been reported to exert beneficial effects on the serum lipid profile. More recently, this claim is being challenged. The objective of this study was to comprehensively examine the effects of soya consumption on the lipid profile using published trials. A detailed literature search was conducted via MEDLINE (from 2004 through February 2014), CENTRAL (The Cochrane Controlled Clinical Trials Register) and ClinicalTrials.gov for randomised controlled trials assessing the effects of soya on the lipid profile. The primary effect measure was the difference in means of the final measurements between the intervention and control groups. In all, thirty-five studies (fifty comparisons) were included in our analyses. Treatment duration ranged from 4 weeks to 1 year. Intake of soya products resulted in a significant reduction in serum LDL-cholesterol concentration, -4.83 (95% CI -7.34, -2.31) mg/dl, TAG, -4.92 (95% CI -7.79, -2.04) mg/dl, and total cholesterol (TC) concentrations, -5.33 (95% CI -8.35, -2.30) mg/dl. There was also a significant increase in serum HDL-cholesterol concentration, 1.40 (95% CI 0.58, 2.23) mg/dl. The I² statistic ranged from 92 to 99%, indicating significant heterogeneity. LDL reductions were more marked in hypercholesterolaemic patients, -7.47 (95% CI -11.79, -3.16) mg/dl, than in healthy subjects, -2.96 (95% CI -5.28, -0.65) mg/dl. LDL reduction was stronger when whole soya products (soya milk, soyabeans and nuts) were used as the test regimen, -11.06 (95% CI -15.74, -6.37) mg/dl, as opposed to when 'processed' soya extracts, -3.17 (95% CI -5.75, -0.58) mg/dl, were used. These data are consistent with the beneficial effects of soya proteins on serum LDL, HDL, TAG and TC concentrations. The effect was stronger in hypercholesterolaemic subjects. Whole soya foods appeared to be more beneficial than soya supplementation, whereas isoflavone supplementation had no effects on the lipid profile.

Triglyceride-Lowering Response to Plant Sterol and Stanol Consumption

Phytosterols (PS) have long been recognized for their cholesterol-lowering action, however, recent work has highlighted triglyceride (TG)-lowering responses to PS that may have been overlooked in previous human interventions and mechanistic animal model studies. This review assesses the current state of knowledge regarding the effect of dietary PS supplementation on blood TG concentrations by examining the average therapeutic response, potential mechanisms, and metabolic and genetic factors that may contribute to inter-individual variability. Data from human intervention trials demonstrates that, compared to baseline concentrations, PS supplementation results in a variable TG-lowering response ranging from 0.8 to 28%. It is evident that hypertriglyceridemic individuals (>1.7 mmol/L) have a greater TG-lowering response to PS (11-28%) than subjects with normal plasma TG concentrations (0.8-7%). Although a genetic basis for the variable TG-lowering effects of PS is probable, there are only limited studies to draw on. The available data suggest that polymorphisms in the apolipoprotein E (apoE) gene may affect responsiveness, with PS-induced reductions in TG more readily evident in apoE2 than apoE3 or E4 subjects. Although only a minimal number of animal model studies have been conducted to specifically examine the mechanisms whereby PS may reduce blood TG concentrations, it appears that there may be multiple mechanisms involved including interruption of intestinal fatty acid absorption and modulation of hepatic lipogenesis and very low density lipoprotein packaging and secretion. In summary, the available data suggest that PS may be an effective therapy to lower blood TG, particularly in hypertriglyceridemic individuals. However, before PS can be widely recommended as a TG-lowering therapy, studies that are specifically powered and designed to fully access therapeutic responses and the mechanisms involved are required.

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%.

The food matrix and sterol characteristics affect the plasma cholesterol lowering of phytosterol/phytostanol

Foods with added phytosterols/phytostanols (PS) are recommended to lower LDL cholesterol (LDL-c) concentrations. Manufacturers have incorporated PS into a variety of common foods. Understanding the cholesterol-lowering impact of the food matrix and the PS characteristics would maximize their success and increase the benefit to consumers. This review systematically examines whether the PS characteristics and the fatty acid composition of foods with added PS affects serum LDL-c. A total of 33 studies published between the years 1998 and 2011 inclusive of 66 individual primary variables (strata) were evaluated. The functional food matrices included margarine, mayonnaise, yogurt, milk, cheese, meat, grain, juice, and chocolate. Consistently, ≥10% reductions in LDL-c were reported when the characteristics of the food matrix included poly- and monounsaturated fatty acids known to lower LDL-c. Also, >10% mean reductions in LDL-c were reported when β-sitostanol and campestanol as well as stanol esters were used. These characteristics allow both low-fat and high-fat foods to successfully incorporate PS and significantly lower LDL-c.

Consumption of plant sterol-enriched foods and effects on plasma plant sterol concentrations--a meta-analysis of randomized controlled studies

OBJECTIVE

Intake of plant sterol (PS)-enriched foods effectively lowers plasma total- and LDL-cholesterol concentrations while increasing plasma PS concentrations. The magnitude of this increase has not been systematically assessed. This study aimed to investigate the effect of PS-enriched foods on plasma PS concentrations by performing a meta-analysis of randomized controlled studies.

METHODS

Published PS intervention studies reporting plasma PS concentrations were searched through June 2012. Studies were selected that fulfilled pre-defined in- and exclusion criteria. Data were extracted, particularly on campesterol, sitosterol, total- and LDL-cholesterol. Random-effects models were used to calculate net effects while weighing each study by the inverse of its variance. Potential sources of heterogeneity were investigated.

RESULTS

The meta-analysis included data from 41 studies (55 strata) with in total 2084 subjects. The average dose of PS from enriched foods was 1.6 g/d (range: 0.3-3.2 g/d). Plasma sitosterol and campesterol concentrations were increased by on average 2.24 μmol/L (31%) and 5.00 μmol/L (37%), respectively, compared to control. Total- and LDL-cholesterol were reduced by on average 0.36 mmol/L (5.9%) and 0.33 mmol/L (8.5%), respectively. The increase in sitosterol and campesterol was impacted by the dose of PS, the baseline PS concentration and the PS composition of the test products. In the highest PS dose category (2.0-3.2 g/d), increases in sitosterol and campesterol were on average 3.56 and 7.64 μmol/L, respectively.

CONCLUSION

Intake of PS-enriched foods increases plasma sitosterol and campesterol concentrations. However, total PS remain below 1% of total sterols circulating in the blood.

A spread containing bioactive milk peptides Ile-Pro-Pro and Val-Pro-Pro, and plant sterols has antihypertensive and cholesterol-lowering effects

Lifestyle intervention is recommended as the primary treatment for mild hypertension and hypercholesterolemia. We studied the effects of a spread containing bioactive milk peptides IPP and VPP, as well as plant sterols, on cardiovascular risk factors in 104 hypertensive, hypercholesterolemic subjects in a randomised, placebo-controlled double-blind intervention. Middle-aged subjects consumed 20 g day⁻¹ of a spread containing 4.2 mg of IPP and VPP as well as 2 g of plant sterols for 10 weeks after a 2 week run-in period. Blood pressure was measured at home 3 times a week. Office blood pressure and 24 h ambulatory blood pressure measurements were performed at the end of the run-in and intervention periods. Blood samples were analysed for serum lipids, plasma glucose and inflammation markers. A significant decrease (-4.1 mmHg vs. -0.5 mmHg, p = 0.007) in systolic blood pressure was seen in the active group, compared to placebo at home measurements. Office blood pressure and 24 h nighttime or daytime ambulatory systolic or diastolic pressure did not differ between the groups. Total (-0.16 vs. 0.25 mmol l⁻¹, p = 0.005) and LDL cholesterol (-0.16 vs. 0.18 mmol l⁻¹, p = 0.006) decreased significantly in the active group compared to the placebo. No significant differences between groups were seen for plasma glucose or inflammation markers. The results thus suggest that milk peptides IPP and VPP and plant sterols, in a low-fat spread matrix, produce a clinically significant reduction in systolic blood pressure as well as serum total and LDL cholesterol without adverse effects. Functional foods that affect 2 major risk factors offer a safe and convenient way to reduce the risk of cardiovascular disease by supporting lifestyle intervention.

Phytosterols supplementation decreases plasma small and dense LDL levels in metabolic syndrome patients on a westernized type diet

BACKGROUND AND AIMS

Several studies have observed a hypocholesterolemic effect of plant sterols in hypercholesterolemic patients on a balanced diet. The aim of this study was to examine the effect of phytosterol supplementation on risk factors of coronary artery disease in metabolic syndrome patients on a Westernized type diet.

METHODS AND RESULTS

In a randomized placebo-controlled design 108 patients with metabolic syndrome were assigned to consume either 2 plant sterol-enriched yogurt mini drink which provided 4 g phytosterols per day, or a yogurt beverage without phytosterols (control). The duration of the study was 2 months and the patients in both groups followed their habitual westernized type diet and recording it on food diaries. Blood samples were drawn at baseline and after 2 months of intervention. After 2 months supplementation with phytosterols, a significant reduction in total cholesterol, LDL-cholesterol, small and dense LDL (sdLDL) levels, as well as, apoB and triglycerides concentrations were observed in the intervention group (P < 0.05) compared to the control group. In addition, phytosterol supplementation lowered serum total cholesterol by 15.9%, LDL-cholesterol by 20.3% and triglyceride levels by 19.1% (P = 0.02, P < 0.001 and P < 0.001, respectively), although the patients kept their habitual westernized type diet. No differences were observed in HDL cholesterol, apoA1, glucose, C-reactive protein, fibrinogen levels and blood pressure.

CONCLUSIONS

Phytosterol supplementation improves risk factors of coronary artery disease even if the diet is a westernized type.

The effect of plant sterols on serum triglyceride concentrations is dependent on baseline concentrations: a pooled analysis of 12 randomised controlled trials

PURPOSE

Plant sterols (PS) are well known for their low-density lipoprotein cholesterol-lowering effect. Until recently, they were believed to have little or no impact on blood triglycerides (TG). However, studies taken individually were possibly lacking statistical power to detect modest TG decreases. This study was performed to quantify the TG-lowering effect of PS by pooling individual subject data from 12 randomised controlled trials that investigated the effects of PS on blood lipids.

METHODS

The main outcome variable was the control-adjusted PS effect on relative (%) and absolute (mmol/L) changes in TG. The relative and absolute changes in high-density lipoprotein cholesterol (HDL-C) were also assessed. Differences in changes of serum lipid concentrations between PS and control treatments were estimated by an ANCOVA using a random effect model which included PS intake (active or control), study and predefined subject characteristics.

RESULTS

The twelve randomised controlled trials included in total 935 hypercholesterolaemic subjects not preselected based on their baseline TG concentrations. In most studies, the PS dose ranged between 1.6 and 2.5 g/day. PS intake significantly lowered serum TG by 6.0% (95% CI: -10.7, -1.2) or 0.12 mmol/L (95% CI: -0.20, -0.04). No significant interaction was observed between PS intake and baseline TG concentrations on relative changes, but, on absolute changes, interaction was significant with larger TG decreases observed with higher TG concentrations at baseline. No effects were observed on HDL-C concentrations.

CONCLUSIONS

These results show that PS exert a modest TG-lowering effect which is dependent on baseline concentrations.

Nutritional biomarkers and foodomic methodologies for qualitative and quantitative analysis of bioactive ingredients in dietary intervention studies

Traditional dietary assessment methods, such as 24-h recalls, weighted food diaries and food frequency questionnaires (FFQs) are highly subjective and impair the assessment of successfully accomplished dietary interventions. Foodomic technologies offer promising methodologies for gathering scientific evidence from clinical trials with sensitive methods (e.g., GC-MS, LC-MS, CE, NMR) to detect and quantify markers of nutrient exposure or subtle changes in dietary patterns. This review provides a summary of recently developed foodomic methodologies for the detection of suggested biomarkers, including the food specificity for each suggested biomarker and a brief description of the key aspects of 24-h recalls that may affect marker detection and stability, such as mixed nutrients and cooking processes. The primary aim of this review is to contribute to the assessment of the metabolic effects of active ingredients and foods using cutting-edge methods to improve approaches to future nutritional programs tailored for health maintenance and disease prevention.

The metabolic effects of omega-3 plant sterol esters in mixed hyperlipidemic subjects

PURPOSE

The aim of the current study was to evaluate the therapeutic effects of omega-3 plant sterol esters (n-3-PSE) on lipid profile and other coronary heart disease risk factors in subjects with mixed hyperlipidemia.

METHODS

Ninety-one patients with mixed hyperlipidemia were randomized in a double blind fashion to receive either placebo (corn oil) or n-3-PSE. Twenty four patients dropped out or were excluded from the efficacy analysis due to protocol violation. The primary efficacy endpoint was mean change in plasma low-density lipoprotein cholesterol (LDL-C) levels after 12 weeks of treatment. Other efficacy measures included plasma lipids, lipoproteins, and high-sensitivity C-reactive protein (hsCRP) levels. Participants who completed the double-blind study were given the option to continue into an open-label, 12-weeks follow up phase.

RESULTS

n-3-PSE treatment did not result in a significant change in LDL-C levels. Triglyceride levels were reduced significantly by 19% (51 mg/dL, p < 0.0001) in the n-3-PSE group in comparison with the placebo group (p = 0.025). Diastolic blood pressure and hsCRP were reduced by 7% (5.9 mmHg) and 7.8% (0.6 mg/L), respectively, and were significantly different from the placebo group (p = 0.036 and p = 0.018, respectively).

CONCLUSIONS

In patients with mixed hyperlipidemia, n-3-PSE treatment may offer a safe and effective therapy for triglyceride level reduction while avoiding the typical increase in LDL-C levels associated with n-3 fatty acid treatment. The observed reduction in blood pressure and inflammation markers warrants further evaluation. The positive effect of n-3-PSE treatment was preserved at the end of the follow up phase.

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.

Getting personal: considering variable interindividual responsiveness to dietary lipid-lowering therapies

PURPOSE OF REVIEW

There is substantial interindividual variation in the response of blood lipids to dietary therapies. The purpose of this review is to highlight recent developments in identifying patient-specific factors that contribute to the significant heterogeneity of responsiveness in lipids to dietary changes and consumption of dietary bioactive compounds.

RECENT FINDINGS

Recent findings suggest that a variety of patient-specific physiological, pathological, environmental, and genetic factors influence the effectiveness of dietary lipid-lowering therapies.

SUMMARY

Although genetic markers of responsiveness will revolutionize future personalized nutrition therapies, current research priorities should emphasize the identification of readily accessible metabolic biomarkers of responsiveness in patient subgroups.

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.

Consumption of plant sterols reduces plasma and hepatic triglycerides and modulates the expression of lipid regulatory genes and de novo lipogenesis in C57BL/6J mice

To investigate emerging clinical data suggesting a triglyceride (TAG)-lowering response to plant sterol (PS) therapy, we characterized changes in TAG metabolism in 16 C57BL/6J mice fed a basal control diet (CON) or the CON diet supplemented with 2% PS for 6 wk. PS consumption reduced (p<0.05) plasma (-28%) and hepatic (-30%) TAG concentrations compared with CON mice. PS consumption increased (p<0.05) hepatic lipogenic gene expression (sterol-regulatory-element-binding protein 1c, 2.4-fold of CON; fatty acid synthase, 6.5-fold of CON) and de novo lipogenesis (4.51+/-0.72 versus 2.82+/-0.61%/day) compared with CON. PS consumption increased (p<0.05) fecal palmitate and stearate excretion and reduced body weight gain compared with CON mice. Although no change in the transcription of intestinal fatty acid absorptive genes was observed, peroxisome proliferator-activated receptor alpha mRNA was reduced (p<0.05, 2.0-fold of CON) in the PS-fed mice. In conclusion, PS-fed C57BL/6J mice showed pronounced reductions in plasma and hepatic TAG concentrations despite increases in hepatic lipogenic gene expression and de novo lipogenesis. Interference with intestinal fatty acid/TAG metabolism as suggested by increased fecal fatty acid loss and reduced weight gain may be associated with the TAG-lowering response to PS consumption.

Phytosterol ester constituents affect micellar cholesterol solubility in model bile

Plant sterols and stanols (phytosterols) and their esters are nutraceuticals that lower LDL cholesterol, but the mechanisms of action are not fully understood. We hypothesized that intact esters and simulated hydrolysis products of esters (phytosterols and fatty acids in equal ratios) would differentially affect the solubility of cholesterol in model bile mixed micelles in vitro. Sodium salts of glycine- and taurine-conjugated bile acids were sonicated with phosphatidylcholine and either sterol esters or combinations of sterols and fatty acids to determine the amount of cholesterol solubilized into micelles. Intact sterol esters did not solubilize into micelles, nor did they alter cholesterol solubility. However, free sterols and fatty acids altered cholesterol solubility independently (no interaction effect). Equal contents of cholesterol and either campesterol, stigmasterol, sitosterol, or stigmastanol (sitostanol) decreased cholesterol solubility in micelles by approximately 50% compared to no phytosterol present, with stigmasterol performing slightly better than sitosterol. Phytosterols competed with cholesterol in a dose-dependent manner, demonstrating a 1:1 M substitution of phytosterol for cholesterol in micelle preparations. Unsaturated fatty acids increased the micelle solubility of sterols as compared with saturated or no fatty acids. No differences were detected in the size of the model micelles. Together, these data indicate that stigmasterol combined with saturated fatty acids may be more effective at lowering cholesterol micelle solubility in vivo.

Review article: effects of plant sterols and stanols beyond low-density lipoprotein cholesterol lowering

Consumption of foods and supplements enriched with plant sterols/stanols (PS) may help reduce low-density lipoprotein cholesterol (LDL-C) levels. In this review, we consider the effects of PS beyond LDL-C lowering. Plant sterols/stanols exert beneficial effects on other lipid variables, such as apolipoprotein (apo) B/apoAI ratio and, in some studies, high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG). Plant sterols/stanols may also affect inflammatory markers, coagulation parameters, as well as platelet and endothelial function. Evidence also exists about a beneficial effect on oxidative stress, but this does not seem to be of greater degree than that expected from the LDL-C lowering. Many of these effects have been demonstrated in vitro and animal models. Some in vitro effects cannot be seen in vivo or in humans at usual doses. The epidemiological studies that evaluated the association of plasma PS concentration with cardiovascular disease (CVD) risk do not provide a definitive answer. Long-term randomized placebo-controlled studies are required to clarify the effects of supplementation with PS on CVD risk and progression of atherosclerosis.

Dietary phytosterols and phytostanols decrease cholesterol levels but increase blood pressure in WKY inbred rats in the absence of salt-loading

Background

There are safety concerns regarding widespread consumption of phytosterol and phytostanol supplemented food products. The aim of this study was to determine, in the absence of excess dietary salt, the individual effects of excess accumulation of dietary phytosterols and phytostanols on blood pressure in Wistar Kyoto (WKY) inbred rats that have a mutation in the Abcg5 gene and thus over absorb phytosterols and phytostanols.

Methods

Thirty 35-day old male WKY inbred rats (10/group) were fed a control diet or a diet containing phytosterols or phytostanols (2.0 g/kg diet) for 5 weeks. The sterol composition of the diets, plasma and tissues were analysed by gas chromatography. Blood pressure was measured by the tail cuff method. mRNA levels of several renal blood pressure regulatory genes were measured by real-time quantitative PCR.

Results

Compared to the control diet, the phytosterol diet resulted in 3- to 4-fold increases in the levels of phytosterols in plasma, red blood cells, liver, aorta and kidney of WKY inbred rats (P < 0.05). The phytostanol diet dramatically increased (> 9-fold) the levels of phytostanols in plasma, red blood cells, liver, aorta and kidney of these rats (P < 0.05). The phytosterol diet decreased cholesterol levels by 40%, 31%, and 19% in liver, aorta and kidney, respectively (P < 0.05). The phytostanol diet decreased cholesterol levels by 15%, 16%, 20% and 14% in plasma, liver, aorta and kidney, respectively (P < 0.05). The phytostanol diet also decreased phytosterol levels by 29% to 54% in plasma and tissues (P < 0.05). Both the phytosterol and phytostanol diets produced significant decreases in the ratios of cholesterol to phytosterols and phytostanols in plasma, red blood cells, liver, aorta and kidney. Rats that consumed the phytosterol or phytostanol diets displayed significant increases in systolic and diastolic blood pressure compared to rats that consumed the control diet (P < 0.05). The phytosterol diet increased renal angiotensinogen mRNA levels of these rats.

Conclusion

These data suggest that excessive accumulation of dietary phytosterols and phytostanols in plasma and tissues may contribute to the increased blood pressure in WKY inbred rats in the absence of excess dietary salt. Therefore, even though phytosterols and phytostanols lower cholesterol levels, prospective clinical studies testing the net beneficial effects of dietary phytosterols and phytostanols on cardiovascular events for subgroups of individuals that have an increased incorporation of these substances are needed.

Independent and interactive effects of plant sterols and fish oiln-3 long-chain polyunsaturated fatty acids on the plasma lipid profile of mildly hyperlipidaemic Indian adults

The present study was designed to evaluate the independent and interactive effects of a once-a-day yoghurt drink providing 2 g plant sterols/d and capsules providing 2 g fish oiln-3 long-chain (LC) PUFA/d on plasma lipids, apolipoproteins and LDL particle size. Following a 2-week run-in period, 200 mildly hypercholesterolaemic Indian adults aged 35–55 years were randomised into one of four groups of a 2 × 2 factorial, double-blind controlled trial. The 4-week treatments consisted of (1) control yoghurt drink and control capsules, (2) control yoghurt drink and fish oil capsules, (3) plant sterol-enriched yoghurt drink and control capsules, or (4) plant sterol-enriched yoghurt drink and fish oil capsules. Blood was drawn before and after the 4-week intervention. Changes in health status, lifestyle and dietary habits, and daily compliance were recorded. The main effects of plant sterols were a 4·5 % reduction in LDL-cholesterol and a 15 % reduction in TAG without a significant change in HDL-cholesterol. Overall, fish oiln-3 LC-PUFA did not significantly affect cholesterol concentrations but reduced TAG by 15 % and increased HDL-cholesterol by 5·4 %. The combination significantly lowered TAG by 15 %v.control. No significant interaction between plant sterols andn-3 LC-PUFA was observed on plasma cholesterol concentrations. In conclusion, once-a-day intake of 2 g plant sterols/d in a yoghurt drink, 2 g fish oiln-3 LC-PUFA/d in capsules, and their combination had beneficial effects on the lipid profile of mildly hypercholesterolaemic Indian adults. The potent hypotriacylglycerolaemic effect of plant sterols observed in the present study and this population warrants additional investigation.

Stearate-enriched plant sterol esters lower serum LDL cholesterol concentration in normo- and hypercholesterolemic adults

Studies in our laboratory have previously demonstrated in hamsters a superior cholesterol-lowering ability of plant sterol (PS) esters enriched in stearate compared with linoleate. We therefore conducted a randomized, double-blind, 2-group parallel, placebo-controlled study to test the cholesterol-lowering properties of stearate-enriched PS esters in normo- and hypercholesterolemic adults. Thirty-two adults, 16 per group with equal number of males and females in each group, participated in the 4-wk study. Participants consumed 3 g/d (1 g three times per day with meals) of either PS esters or placebo delivered in capsules. Serum LDL cholesterol concentration significantly decreased 0.42 mmol/L (11%) and the LDL:HDL cholesterol ratio decreased 10% with PS ester supplementation, whereas LDL particle size and lipoprotein subclass particle concentrations (as measured by NMR) were not affected. The percent change in LDL cholesterol was positively correlated with baseline lathosterol concentration (r = 0.729; P = 0.0014), indicating an association between the magnitude of LDL change and the rate of whole-body cholesterol synthesis. Serum campesterol (but not sitosterol) concentration significantly increased in the PS ester group. Serum tocopherol, retinol, and beta-carotene concentrations were not affected by PS ester supplementation. Thus, our findings demonstrate the usefulness of a novel stearate-enriched PS ester compound in decreasing LDL cholesterol in both normo- and hypercholesterolemic adults. The extent to which PS ester fatty acid composition affects intestinal micelle formation and cholesterol absorption in humans requires further study.

Lifestyle approaches and dietary strategies to lower LDL-cholesterol and triglycerides and raise HDL-cholesterol

This article discusses specific dietary factors as well as dietary patterns that affect the major coronary heart disease (CHD) lipid risk factors (ie, LDL-C, HDL-C, and TG). Based on a very large evidence base, it is clear that diet and lifestyle practices can markedly affect these major CHD lipid risk factors, and consequently decrease CHD risk substantively.

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.

Influence of dietary phytosterols and phytostanols on diastolic blood pressure and the expression of blood pressure regulatory genes in SHRSP and WKY inbred rats

The aim of the present study was to determine the impact of increased consumption of phytosterols or phytostanols on blood pressure and renal blood pressure regulatory gene expression in stroke-prone spontaneously hypertensive (SHRSP) and normotensive Wistar–Kyoto (WKY) inbred rats. SHRSP and WKY inbred rats (10/group) were fed a control diet or a diet supplemented with phytosterols or phytostanols (2·0 g/kg diet). After 5 weeks, SHRSP rats demonstrated higher systolic and diastolic blood pressures than WKY inbred rats. SHRSP rats that consumed the phytosterol or phytostanol supplemental diets displayed a 2- or 3-fold respective increase in the diastolic blood pressure than those that consumed the control diet. Angiotensinogen (Agt), angiotensin I-converting enzyme 1 (Ace1), nitric oxide synthase (Nos) 1,Nos3, cyclooxygenase 2 (Cox2) and THUMP domain containing 1 were expressed at higher levels in SHRSP compared with WKY inbred rats.Reninand angiotensin II receptor type 1a were expressed at lower levels in SHRSP than WKY inbred rats. Phytostanol supplementation up-regulated the expression ofAce1andNos3in SHRSP rats. Phytosterol supplementation increased the mRNA levels ofNos1and spondin 1 (Spon1) in SHRSP and WKY inbred rats.Cox2mRNA levels were elevated in both phytosterol- and phytostanol-supplemented SHRSP and WKY inbred rats. Therefore, the increased blood pressure in SHRSP rats may be partly due to altered renal expression of blood pressure regulatory genes. Specifically, up-regulation ofAce1,Nos1,Nos3,Cox2andSpon1were associated with the increased diastolic blood pressure observed in phytosterol- or phytostanol-supplemented SHRSP rats.

Stability of sterols in phytosterol-enriched milk under different heating conditions

Commercially available phytosterol-enriched milk was subjected to usual and drastic heating conditions to evaluate the stability of the sterols at different treatments. Products showed 422.2 mg of phytosterols/100 g of milk and 132 microg of sterol oxidation products (SOPs)/g of fat (277 microg of SOPs/100 g of milk). Schaal oven conditions (24 h/65 degrees C, equivalent to 1 month of storage at room temperature) reduced the phytosterol content by only 4%. Drastic heating treatments (2 min of microwave heating at 900 W or 15 min of electrical heating at 90 degrees C) led to a 60% decrease of total phytosterol content, with a significant increase of TBARs. The oxysterol amount under those conditions (which was higher in microwave-treated samples) was lower than expected, probably because of the degradation of the oxidation products. Usual heating conditions (1.5 min of microwaves) maintained phytosterol content on physiologically active values (301 mg/100 g of milk) with oxidation percentages around 0.12-0.40% for phytosterols and 1.13% for cholesterol.

The lipid-lowering effects of phytosterols and (n-3) polyunsaturated fatty acids are synergistic and complementary in hyperlipidemic men and women

Fish oils rich in (n-3) long-chain PUFA (LCPUFA) can reduce circulating triglycerides and raise HDL-cholesterol. Phytosterols have been shown to reduce total cholesterol and LDL-cholesterol in normocholesterolemic and hyperlipidemic populations. We investigated the combined effects of phytosterols and (n-3) LCPUFA on plasma lipid profile in hyperlipidemic individuals. This study was a 3-wk randomized, double-blind, placebo-controlled, 2 x 2 factorial trial in 4 parallel groups of 60 hyperlipidemic individuals. Subjects were randomized to receive either sunola oil or 1.4 g/d (n-3) LCPUFA capsules with or without 2 g phytosterols per day while maintaining their habitual diet. The combination of phytosterols and (n-3) LCPUFA reduced plasma total cholesterol by 13.3% (P = 0.001), which differed from (n-3) LCPUFA alone (P < 0.001). LDL-cholesterol concentrations followed the same pattern as that of plasma cholesterol with a 12.5% decrease (P = 0.002) in the combination group. The HDL-cholesterol concentration was increased by (n-3) LCPUFA (7.1%; P = 0.01) alone and in combination with phytosterols (8.6%; P = 0.04), whereas phytosterol treatment alone had no effect. Plasma triglyceride concentration was lowered by (n-3) LCPUFA (22.3%; P = 0.004) alone and in combination with phytosterols (25.9%; P = 0.005), whereas phytosterol treatment alone had no effect. In conclusion, the combined supplementation with phytosterols and (n-3) LCPUFA has both synergistic and complementary lipid-lowering effects in hyperlipidemic men and women.

Fish-oil esters of plant sterols differ from vegetable-oil sterol esters in triglycerides lowering, carotenoid bioavailability and impact on plasminogen activator inhibitor-1 (PAI-1) concentrations in hypercholesterolemic subjects

BACKGROUND

Consumption of plant sterol (PS) esters lower low-density lipoprotein (LDL)-cholesterol levels by suppressing intestinal absorption of cholesterol. Commercially available PS are mainly esterified to omega-6 fatty acid (FA), such as sunflower oil (SO) FA. Emerging trends include using other sources such as olive oil (OO) or omega-3 FA from fish oil (FO), known to exert potent hypotriglyceridemic effects. Our objective was to compare the actions of different FA esterified to PS on blood lipids, carotenoid bioavailability as well as inflammatory and coagulation markers.

METHODS

Twenty-one moderately overweight, hypercholesterolemic subjects consumed experimental isoenergetic diets enriched with OO (70% of fat), each lasting 28-day and separated by 4-week washout periods, using a randomized crossover design. Diets were supplemented with three PS esters preparations, PS-FO, PS-SO, or PS-OO. All PS treatments contained an equivalent of 1.7 PS g/d, and the PS-FO provided a total of 5.4 g/d FO FA (eicosapentaenoic and docosahexaenoic acids).

RESULTS

There were no differences between PS-containing diet effects on total cholesterol, LDL-cholesterol, or high-density lipoprotein (HDL)-cholesterol levels. However, PS-FO consumption resulted in markedly lower (P < 0.0001) fasting and postprandial triglyceride concentrations compared with PS-SO and PS-OO. These treatments affected plasma beta-carotene (P = 0.0169) and retinol (P = 0.0244), but not tocopherol (P = 0.2108) concentrations. Consumption of PS-FO resulted in higher beta-carotene (P = 0.0139) and retinol (P = 0.0425) levels than PS-SO and PS-OO, respectively. Plasma TNF-alpha, IL-6, C-reactive protein, prostate specific antigen, and fibrinogen concentrations were unaffected by the PS-interventions. In contrast, plasminogen activator inhibitor 1 (PAI-1) concentrations were lower (P = 0.0282) in the PS-FO-fed than the PS-SO, but not the PS-OO (P = 0.7487) groups.

CONCLUSION

Our findings suggest that, in hypercholesterolemic subjects consuming an OO-based diet, PS-FO results in lowered blood triglyceride and PAI-1 concentrations, and higher fat-soluble vitamin levels in comparison to the vegetable oil FA esters of PS (PS-SO and PS-OO). Thus, PS-FO may offer hyperlipidemic subjects a more comprehensive lipid lowering approach while reducing the potential risk of decreased plasma carotenoid concentrations.