The effect of plant sterols or stanols on lipid parameters in patients with type 2 diabetes: a meta-analysis

The effect of phytosterol supplementation on lipid profile: A critical umbrella review of interventional meta-analyses

Despite multiple investigations assessing the impact of phytosterol supplementation on serum lipid levels, there is still a great deal of debate regarding the benefits of this intervention in the management of dyslipidemia. Therefore, we aimed at clarifying this dilemma by conducting the present umbrella review of interventional meta-analyses. Scopus, PubMed, Web of Science, and EMBASE were used to search for pertinent publications on the effect of phytosterol supplementation on the lipid profile in humans up to June 2023. To compute the overall effect size (ES) and confidence intervals (CI), the random-effects model was used. The I2 statistic and Cochrane's Q-test were applied to estimate the heterogeneity among the studies. Seventeen meta-analyses with 23 study arms were included in the umbrella meta-analysis. Data pooled from the 23 eligible arms revealed that phytosterol supplementation reduces low-density lipoprotein cholesterol (LDL-C) (ES = -11.47 mg/dL; 95% CI: -12.76, -10.17, p < 0.001), total cholesterol (TC) (ES = -13.02 mg/dL; 95% CI: -15.68, -10.37, p < 0.001), and triglyceride (TG) (ES = -3.77 mg/dL; 95% CI: -6.04, -1.51, p = 0.001). Subgroup analyses showed that phytosterol administration with dosage ≥2 g/day and duration over 8 weeks and in hypercholesterolemic subjects was more likely to decrease LDL-C, TC, and TG. Phytosterol administration did not significantly modify HDL-C (ES = 0.18 mg/dL; 95% CI: -0.13, -0.51, p = 258) levels when compared to controls. The present umbrella meta-analysis confirms that phytosterol administration significantly reduces LDL-C, TC, and TG, with a greater effect with doses of ≥2 g/day and treatment duration >8 weeks, suggesting its possible application as a complementary therapy for cardiovascular risk reduction. Further studies are needed to determine the efficacy of phytosterols in patients with specific health conditions, as well as to ascertain the adverse effects, the maximum tolerable dose, and the maximum recommended duration of phytosterol administration.

Health outcomes associated with phytosterols: An umbrella review of systematic reviews and meta-analyses of randomized controlled trials

BACKGROUND

Phytosterols (PS), as a kind of plant active ingredients, have many benefits to human health. However, there is currently no comprehensive overview of the clinical evidence and an assessment of the evidence quality.

PURPOSE

We conducted an umbrella review, which incorporated verification spanning a number of meta-analyses and systematic reviews to clarify the link that existed between PS consuming and health outcomes.

METHODS

The databases PubMed, Embase, Web of Science and The Cochrane Library were searched for appropriate research and ultimately included 23 articles involving 79 results. Methodological quality and the validity of evidence received designation in the included meta-analyses leveraging the Assessment of Multiple Systematic Reviews (AMSTAR-2) and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE).

RESULTS

The consumption of PS makes a contribution to the alleviation of metabolic conditions such as hypercholesterolemia, diabetes, obesity, and hypertension. Its most essential function is to decrease cholesterol absorption, leading to dramatically reductions in total cholesterol and low density lipoprotein cholesterol. Furthermore, utilizing PS products can have a favorable impact on managing apolipoprotein levels along with decreasing the probability of obtaining atherosclerotic cardiovascular disease.

CONCLUSION

This umbrella review summarized a range of beneficial functions of PS to humans, highlighting the promising potential for the development of PS into functional foods.

In Silico Screening and Identification of Antidiabetic Inhibitors Sourced from Phytochemicals of Philippine Plants against Four Protein Targets of Diabetes (PTP1B, DPP-4, SGLT-2, and FBPase)

Current oral medications for type 2 diabetes target a single main physiological mechanism. They either activate or inhibit receptors to enhance insulin sensitivity, increase insulin secretion, inhibit glucose absorption, or inhibit glucose production. In advanced stages, combination therapy may be required because of the limited efficacy of single-target drugs; however, medications are becoming more costly, and there is also the risk of developing the combined side effects of each drug. Thus, identifying a multi-target drug may be the best strategy to improve treatment efficacy. This study sees the potential of 2657 Filipino phytochemicals as a source of natural inhibitors against four targets of diabetes: PTP1B, DPP-4, SGLT-2, and FBPase. Different computer-aided drug discovery techniques, including ADMET profiling, DFT optimization, molecular docking, MD simulations, and MM/PBSA energy calculations, were employed to elucidate the stability and determine the binding affinity of the candidate ligands. Through in silico methods, we have identified seven potential natural inhibitors against PTP1B, DPP-4, and FBPase, and ten against SGLT-2. Eight plants containing at least one natural inhibitor of each protein target were also identified. It is recommended to further investigate the plants' potential to be transformed into a safe and scientifically validated multi-target drug for diabetes therapies.

Comprehensive Approach to Medical Nutrition Therapy in Patients with Type 2 Diabetes Mellitus: From Diet to Bioactive Compounds

In the pathogenesis of type 2 diabetes mellitus (T2DM), diet plays a key role. Individualized medical nutritional therapy, as part of lifestyle optimization, is one of the cornerstones for the management of T2DM and has been shown to improve metabolic outcomes. This paper discusses major aspects of the nutritional intervention (including macro- and micronutrients, nutraceuticals, and supplements), with key practical advice. Various eating patterns, such as the Mediterranean-style, low-carbohydrate, vegetarian or plant-based diets, as well as healthy eating plans with caloric deficits have been proven to have beneficial effects for patients with T2DM. So far, the evidence does not support a specific macronutrient distribution and meal plans should be individualized. Reducing the overall carbohydrate intake and replacing high glycemic index (GI) foods with low GI foods have been shown as valid options for patients with T2DM to improve glycemic control. Additionally, evidence supports the current recommendation to reduce the intake of free sugars to less than 10% of total energy intake, since their excessive intake promotes weight gain. The quality of fats seems to be rather important and the substitution of saturated and trans fatty acids with foods rich in monounsaturated and polyunsaturated fats lowers cardiovascular risk and improves glucose metabolism. There is no benefit of supplementation with antioxidants, such as carotene, vitamins E and C, or other micronutrients, due to the lack of consistent evidence showing efficacy and long-term safety. Some studies suggest possible beneficial metabolic effects of nutraceuticals in patients with T2DM, but more evidence about their efficacy and safety is still needed.

Exogenous melatonin enhances the growth and production of bioactive metabolites in Lemna aequinoctialis culture by modulating metabolic and lipidomic profiles

BACKGROUND

Lemna species are cosmopolitan floating plants that have great application potential in the food/feed, pharmaceutical, phytoremediation, biofuel, and bioplastic industries. In this study, the effects of exogenous melatonin (0.1, 1, and 10 µM) on the growth and production of various bioactive metabolites and intact lipid species were investigated in Lemna aequinoctialis culture.

RESULTS

Melatonin treatment significantly enhanced the growth (total dry weight) of the Lemna aequinoctialis culture. Melatonin treatment also increased cellular production of metabolites including β-alanine, ascorbic acid, aspartic acid, citric acid, chlorophyll, glutamic acid, phytosterols, serotonin, and sucrose, and intact lipid species; digalactosyldiacylglycerols, monogalactosyldiacylglycerols, phosphatidylinositols, and sulfoquinovosyldiacylglycerols. Among those metabolites, the productivity of campesterol (1.79 mg/L) and stigmasterol (10.94 mg/L) were the highest at day 28, when 10 µM melatonin was treated at day 7.

CONCLUSION

These results suggest that melatonin treatment could be employed for enhanced production of biomass or various bioactive metabolites and intact lipid species in large-scale L. aequinoctialis cultivation as a resource for food, feed, and pharmaceutical industries.

Potential antidiabetic phytochemicals in plant roots: a review of in vivo studies

Background

Medicinal plants are used to treat various disorders, including diabetes, globally in a range of formulations. While attention has mainly been on the aerial plant parts, there are only a few review studies to date that are focused on the natural constituents present in the plant roots with health benefits. Thus, the present study was performed to review in vivo studies investigating the antidiabetic potential of the natural compounds in plant roots.

Methods

We sorted relevant data in 2001-2019 from scientific databases and search engines, including Web of Knowledge, PubMed, ScienceDirect, Medline, Reaxys, and Google Scholar. The class of phytochemicals, plant families, major compounds, active constituents, effective dosages, type of extracts, time of experiments, and type of diabetic induction were described.

Results

In our literature review, we found 104 plants with determined antidiabetic activity in their root extracts. The biosynthesis pathways and mechanism of actions of the most frequent class of compounds were also proposed. The results of this review indicated that flavonoids, phenolic compounds, alkaloids, and phytosteroids are the most abundant natural compounds in plant roots with antidiabetic activity. Phytochemicals in plant roots possess different mechanisms of action to control diabetes, including inhibition of α-amylase and α-glucosidase enzymes, oxidative stress reduction, secretion of insulin, improvement of diabetic retinopathy/nephropathy, slow the starch digestion, and contribution against hyperglycemia.

Conclusion

This review concludes that plant roots are a promising source of bioactive compounds which can be explored to develop against diabetes and diabetes-related complications.

Graphical abstract

Effect of phytosterols on reducing low-density lipoprotein cholesterol in dogs

Hyperlipidemia is described as an increase in serum and/or plasma levels of triglycerides, cholesterol, or both. This disturbance can be primary in some cases, or combined with other comorbidities such as endocrinopathies, liver diseases, or specific drug use. Among the various ways to control dyslipidemia are specific diets, omega-3 fatty acid supplementation, or hypolipemiant treatment. Herbal medicine has been used in the human clinical routine to reduce cholesterol circulation. With an aim to expand its application in veterinary medicine, we analyzed the use of phytosterols in dogs as a potential alternative to control hypercholesterolemia. We performed lipidogram analysis in healthy dogs to examine the possible adverse effects during the treatment. Eight Beagle dogs received orally two 650 mg capsules of phytosterols (Collestra, Aché), for 15 consecutive d, along with the 2 usual meals. All animals remained clinically stable during the trial. There were significant alterations in low-density lipoprotein (LDL) and high-density lipoprotein (HDL) levels during the trial. LDL was reduced (86.8 ± 29.89 mg/dL [D0], 74.45 ± 31.58 mg/dL [D8], and 58.91 ± 18.65 mg/dL [D15]; P = 0.0442) and HDL was elevated (83.40 ± 12.05 mg/dL [D0], 86.46 ± 13.05 mg/dL [D8], and 101.5 ± 10.52 [D15]; P = 0.0141), while total cholesterol and triglyceride concentrations remained constant and within the normal range for canine species. Thus, a 1300 mg dose of phytosterols, administrated orally and fractionated along with the 2 usual meals, was capable of reducing LDL and increasing HDL concentration in healthy nondyslipidemic dogs, which makes them candidates to be included on the list of hypolipemiant drugs for clinical use in dogs with hypercholesterolemia.

How should we judge edible oils and fats? An umbrella review of the health effects of nutrient and bioactive components found in edible oils and fats

Dietary guidelines for many Western countries base their edible oil and fat recommendations solely on saturated fatty acid content. This study aims to demonstrate which nutritional and bioactive components make up commonly consumed edible oils and fats; and explore the health effects and strength of evidence for key nutritional and bioactive components of edible oils. An umbrella review was conducted in several stages. Food composition databases of Australia and the United States of America, and studies were examined to profile nutrient and bioactive content of edible oils and fats. PUBMED and Cochrane databases were searched for umbrella reviews, systematic literature reviews of randomized controlled trials or cohort studies, individual randomized controlled trials, and individual cohort studies to examine the effect of the nutrient or bioactive on high-burden chronic diseases (cardiovascular disease, type 2 diabetes mellitus, obesity, cancer, mental illness, cognitive impairment). Substantial systematic literature review evidence was identified for fatty acid categories, tocopherols, biophenols, and phytosterols. Insufficient evidence was identified for squalene. The evidence supports high mono- and polyunsaturated fatty acid compositions, total biophenol content, phytosterols, and possibly high α-tocopherol content as having beneficial effects on high-burden health comes. Future dietary guidelines should use a more sophisticated approach to judge edible oils beyond saturated fatty acid content.

Nutraceuticals: Reviewing their Role in Chronic Disease Prevention and Management

Over half the adult population in many Western countries consume nutraceuticals because of their purported therapeutic benefits, accessibility and convenience. Several studies have demonstrated that they may also serve as a useful adjunct to pharmaceuticals to better manage chronic conditions or offset negative side effects. Individuals are advised to consult their physician before using nutraceuticals, but this advice is often overlooked. Thus, the community pharmacist plays an increasingly important role in assisting consumers with selecting a nutraceutical that is safe and for which there is evidence of therapeutic efficacy. Therefore, the aim of this review is to summarise the clinical evidence, safety and purported mechanisms of action for selected nutraceuticals in the management of chronic diseases, including obesity, diabetes, hypertension, hypercholesterolemia and inflammatory-based diseases.

The Impact of Phytosterols on the Healthy and Diseased Brain

The central nervous system (CNS) is the most cholesterol-rich organ in mammals. Cholesterol homeostasis is essential for proper brain functioning and dysregulation of cholesterol metabolism can lead to neurological problems. Multiple sclerosis (MS) and Alzheimer's disease (AD) are examples of neurological diseases that are characterized by a disturbed cholesterol metabolism. Phytosterols (PS) are plant-derived components that structurally and functionally resemble cholesterol. PS are known for their cholesterol-lowering properties. Due to their ability to reach the brain, researchers have started to investigate the physiological role of PS in the CNS. In this review, the metabolism and function of PS in the diseased and healthy CNS are discussed.

Plant sterols lower LDL-cholesterol and triglycerides in dyslipidemic individuals with or at risk of developing type 2 diabetes; a randomized, double-blind, placebo-controlled study

Background

Managing cardiovascular disease (CVD) risk factors, e.g., dyslipidemia in type-2 diabetes mellitus (T2DM) is critically important as CVD is the most common cause of death in T2DM patients. This study aimed to investigate the effect of plant sterols (PS) on lowering both elevated low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG).

Methods

In a double-blind, randomized, placebo-controlled, parallel study, 161 individuals at increased risk of and with established T2DM, consumed low-fat spreads without or with added PS (2 g/d) for 6 weeks after a 2-week run-in period. Increased risk of developing T2DM was defined by the Australian T2DM Risk Assessment Tool (AUSDRISK). Fasting serum/plasma total cholesterol (TC), LDL-C, TG, high-density lipoprotein cholesterol (HDL-C), glucose and insulin were measured at baseline and after 6 weeks. Effects on acute and chronic postprandial blood lipids, glucose and insulin were measured over 4-h in 39 individuals with T2DM following a mixed meal challenge without and with added 2 g/d PS at week 6. The study was registered at clinicaltrials.gov (NCT02288585).

Results

Hundred fifty-one individuals completed the study and 138 (57% men, 43% women; 44 with and 94 at risk of T2DM) were included in per protocol analysis. Baseline LDL-C and TG were 3.8 ± 1.0 and 2.5 ± 0.8 mmol/l, respectively. PS intake significantly lowered fasting LDL-C (−4.6%, 95%CI −1.2; −8.0; p = 0.009), TC (−4.2%, 95%CI −1.2; −7.1; p = 0.006) and TG (−8.3%, 95% −1.1, −15.0; p = 0.024) with no significant changes in HDL-C, glucose or insulin. Postprandial lipid (TG, TC, LDL-C, HDL-C, remnant cholesterol), glucose and insulin responses did not differ.

Conclusions

In individuals at risk of and with established T2DM and with elevated TG and LDL-C, 2 g/d of PS results in dual LDL-C plus TG lowering. Postprandial lipid or glycemic responses did not differ between PS and control treatment.

Interindividual variability in the cholesterol-lowering effect of supplementation with plant sterols or stanols

Low-density lipoprotein cholesterol (LDL-C) plays a causal role in atherosclerosis. One way to reduce LDL-C levels is to inhibit cholesterol absorption. Plant sterols and stanols compete with cholesterol for absorption in the intestine and induce an average decrease in LDL-C by 5% to 15% in a dose-dependent manner, but not in all individuals. This review focuses on the interindividual variability in response to dietary supplementation with plant sterols and stanols. Dietary plant sterols and stanols have no significant effects on LDL-C in substantial numbers of individuals. Higher responses, in absolute value and percentage of LDL-C, are observed in individuals with higher cholesterol absorption and a lower rate of cholesterol synthesis. Some data provide evidence of the influence of genetics on the response to plant sterols and stanols. Further studies in large populations are required to extend these conclusions about genetic influences.

Functional foods and dietary supplements for the management of dyslipidaemia

Dyslipidaemia is characterized by increased blood levels of total or LDL cholesterol and triglycerides, or decreased HDL cholesterol levels, and is a risk factor for cardiovascular disease. Dyslipidaemia has a high worldwide prevalence, and many patients are turning to alternatives to pharmacotherapy to manage their lipid levels. Lifestyle modification should be emphasized in all patients to reduce cardiovascular risk and can be initiated before pharmacotherapy in primary prevention of cardiovascular disease. Many functional foods and natural health products have been investigated for potential lipid-lowering properties. Those with good evidence for a biochemical effect on plasma lipid levels include soy protein, green tea, plant sterols, probiotic yogurt, marine-derived omega-3 fatty acids and red yeast rice. Other products such as seaweed, berberine, hawthorn and garlic might confer some limited benefit in certain patient groups. Although none of these products can reduce lipid levels to the same extent as statins, most are safe to use in addition to other lifestyle modifications and pharmacotherapy. Natural health products marketed at individuals with dyslipidaemia, such as policosanol, guggulsterone and resveratrol, have minimal definitive evidence of a biochemical benefit. Additional research is required in this field, which should include large, high-quality randomized controlled trials with long follow-up periods to investigate associations with cardiovascular end points.

Joint position statement on "Nutraceuticals for the treatment of hypercholesterolemia" of the Italian Society of Diabetology (SID) and of the Italian Society for the Study of Arteriosclerosis (SISA)

AIM

Evidence showed that LDL-cholesterol lowering is associated with a significant cardiovascular risk reduction. The initial therapeutic approach to hypercholesterolemia includes dietary modifications but the compliance to recommendations is often inadequate. Some dietary components with potential cholesterol-lowering activity are present in small amounts in food. Therefore, in recent years the use of "nutraceuticals" (i.e., nutrients and/or bioactive compounds with potential beneficial effects on human health) has become widespread. Such substances may be added to foods and beverages, or taken as dietary supplements (liquid preparations, tablets, capsules). In the present manuscript, the cholesterol-lowering activity of some nutraceuticals (i.e. fiber, phytosterols, soy, policosanol, red yeast rice and berberine) will be discussed along with: 1) the level of evidence on the cholesterol-lowering efficacy emerging from clinical trial; 2) the possible side effects associated with their use; 3) the categories of patients who could benefit from their use.

DATA SYNTHESIS

Based on the current literature, the cholesterol-lowering effect of fiber, phytosterols and red yeast rice is consistent and supported by a good level of evidence. Over berberine, there is sufficient evidence showing significant cholesterol-lowering effects, although the results come from studies carried out almost exclusively in Asian populations. Data on the effects of soy are conflicting and, therefore, the strength of recommendation is quite low. The evidence on policosanol is inconclusive.

CONCLUSION

Although health benefits may arise from the use of nutraceuticals with cholesterol-lowering activity, their use might be also associated with possible risks and pitfalls, some of which are common to all nutraceuticals whereas others are related to specific nutraceuticals.

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

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

Effect of fermented milk product containing lactotripeptides and plant sterol esters on haemodynamics in subjects with the metabolic syndrome – a randomised, double-blind, placebo-controlled study

We investigated the effects of fermented milk product containing isoleucine–proline–proline, valine–proline–proline and plant sterol esters (Pse) on plasma lipids, blood pressure (BP) and its determinants systemic vascular resistance and cardiac output. In a randomised, double-blind, placebo-controlled study, 104 subjects with the metabolic syndrome (MetS) were allocated to three groups in order to receive fermented milk product containing (1) 5 mg/d lactotripeptides (LTP) and 2 g/d plant sterols; (2) 25 mg/d LTP and 2 g/d plant sterols; (3) placebo for 12 weeks. Plasma lipids and home BP were monitored. Haemodynamics were examined in a laboratory using radial pulse wave analysis and whole-body impedance cardiography in the supine position and during orthostatic challenge. There were no differences between the effects of the two treatments and placebo on the measurements of BP at home or on BP, systemic vascular resistance index and cardiac index in the laboratory, neither in the supine nor in the upright position. The changes in plasma LDL-cholesterol concentration were − 0·1 (95 % CI − 0·3, 0·1 and − 0·3, 0·0) mmol/l in the 5 and 25 mg/d LTP groups, respectively, and +0·1 (95 % CI − 0·1, 0·3) mmol/l during placebo (P= 0·024). Both at baseline and at week 12, the increase in systemic vascular resistance during head-up tilt was lower in the 25 mg/d LTP group than in the 5 mg/d LTP group (P< 0·01), showing persistent differences in cardiovascular regulation between these groups. In subjects with the MetS, intake of LTP and Pse in fermented milk product showed a lipid-lowering effect of borderline significance, while no antihypertensive effect was observed at home or in the laboratory.

The effect of nutritional supplements on serum high-density lipoprotein cholesterol and apolipoprotein A-I

One of the factors contributing to the increased risk of developing premature atherosclerosis is low plasma concentrations of high-density lipoprotein (HDL) cholesterol. Multiple potential mechanisms account for the cardioprotective effects of HDL and its main protein apolipoprotein A-I (apo A-I). Diet has an important role in modulating HDL cholesterol level. The widespread use of nutritional supplements may also alter the biology of HDL. In this review, we discuss the effect of select nutritional supplements on serum HDL cholesterol and apo A-I levels. Some nutritional supplements, such as phytosterols, soy proteins, and black seed extracts, may increase HDL cholesterol levels, while others such as cholic acid and high doses of commonly used antioxidant vitamins may downregulate HDL cholesterol levels and reduce its cardioprotection. Multiple mechanisms are involved in the regulation of HDL levels, so changes in production and clearance of HDL may have different clinical implications. The clinical relevance of the changes in HDL and apo A-I caused by nutrient supplementation needs to be tested in controlled clinical trials.

Efficient solvent-free synthesis of phytostanyl esters in the presence of acid-surfactant-combined catalyst

An efficient approach based on the synthesis of phytostanyl esters with an acid-surfactant-combined catalyst in a solvent-free system was developed. The effect of catalyst dose, substrate molar ratio, reaction temperature, and acyl donor was considered. The reaction conditions were further optimized by response surface methodology, and a high yield of phytostanyl laurate (>92%) was obtained under optimum conditions: 3.17:1 molar ratio of lauric acid to plant stanols, 4.01% catalyst dose (w/w), 119 °C, and 4.1 h. FT-IR, MS, and NMR were adopted to confirm the chemical structure of phytostanyl laurate. Meanwhile, the physiochemical properties of different phytostanyl esters were investigated. Compared with phytostanols, the prepared phytostanyl esters had much lower melting temperature and higher oil solubility. There was no obvious difference in melting and solidification properties between sunflower oil with phytostanyl laurate (<5%) or oleate (<10%) and the original sunflower oil, suggesting that the esterification of phytostanols greatly facilitated their corporation into oil-based foods.

Association of natural intake of dietary plant sterols with carotid intima-media thickness and blood lipids in Chinese adults: a cross-section study

BACKGROUND

Many studies showed a moderate cholesterol-lowering effect of plant sterols (PS), but increased circulating PS might be atherogenic. We evaluated the associations between natural dietary intake of PS and carotid intima-media thickness (IMT) and serum lipids.

METHODOLOGY/PRINCIPAL FINDINGS

This community-based cross-sectional study included 1160 men and 2780 women aged 31-75 years. Dietary intakes were assessed using a food-frequency questionnaire. The IMTs at the common, bifurcation and internal carotid artery segments, and fasting serum total (TC), LDL (LDLc) and HDL (HDLc) cholesterol, and triglycerides (TG) were determined. After adjusting for potential covariates, multivariate analysis showed a dose-dependent inverse association of total PS intake with serum TC, LDLc, non-HDLc in women (P<0.001) and in men (P<0.05). As compared to the lowest quartile of PS intake (<206 mg/d), the multivariate-adjusted means of TC, LDLc and non-HDLc in the highest quartile of PS intake (447 mg/d) decreased by 5.0%, 6.2% and 6.5% in women (P<0.005), and by 6.4%, 7.1% and 6.7% (P>0.05) in men. Although the IMTs tended to be lower with greater intake of dietary PS, only small differences in the left internal IMT between the highest and lowest groups were observed among men (-7.6%) and women (-5.1%) (P<0.05). The multivariate analysis showed no significant mean differences among the PS groups in HDLc, TG and IMTs at other studied sites among men and women (all P>0.05).

CONCLUSIONS

Greater PS consumption from natural diets is associated with lower serum total, LDL, non-HDL cholesterol and with thinner left internal IMT in women and men.

Databases on food phytochemicals and their health-promoting effects

Considerable information on the chemistry and biological properties of dietary phytochemicals has accumulated over the past three decades. The scattering of the data in tens of thousands publications and the diversity of experimental approaches and reporting formats all make the exploitation of this information very difficult. Some of the data have been collected and stored in electronic databases so that they can be automatically updated and retrieved. These databases will be particularly important in the evaluation of the effects on health of phytochemicals and in facilitating the exploitation of nutrigenomic data. The content of over 50 databases on chemical structures, spectra, metabolic pathways in plants, occurrence and concentrations in foods, metabolism in humans and animals, biological properties, and effects on health or surrogate markers of health is reviewed. Limits of these databases are emphasized, and needs and recommendations for future developments are underscored. More investments in the construction of databases on phytochemicals and their effects on health are clearly needed. They should greatly contribute to the success of future research in this field.

Role of phytosterols in lipid-lowering: current perspectives

The cholesterol-lowering effect of plant sterols was first discovered in the early 1950s. However, it is only recently that plant sterols have become clinically important, when advances in food-technology have made it possible to combine sterols with a variety of food products including margarines, yogurts, fruit juices and cereal bars. We review the clinical trial evidence of lipid-lowering efficacy of plant sterols and discuss their implications in routine clinical practice. To generate the evidence we searched the Pubmed database for English language literature, using relevant keywords and medical subject heading (MeSH) terms, and extracted the findings from recently published studies and meta-analyses on this topic. Our findings suggest that the short-term use of food supplements rich in plant sterols is a safe and effective strategy; to maximize the benefits of dietary and lifestyle therapy, either with or without statin therapy, among majority of dyslipidemic patients with need for additional lipid-lowering.