RESUMO
Dietary plant sterols, such as campesterol and sitosterol, reduce plasma cholesterol concentrations, but any relationship to plaque development and CVD remains unclear. Some epidemiologic studies have suggested that elevated plasma plant sterol concentrations are atherogenic, including the Framingham Offspring Study that identified a positive association between plant sterol concentrations and CVD status. We hypothesized that this suggested atherogenicity relates to the oxidation status of plant sterols (i.e., concentrations of plasma oxyphytosterols). Therefore, in the Framingham Offspring Study cohort, we measured plasma oxyphytosterol concentrations in 144 patients with documented CVD and/or more than 50% carotid stenosis and 383 matched controls. We analyzed plasma oxyphytosterol concentrations by GC/MS/MS and performed conditional logistic regression analysis to determine associations between plasma plant sterol or oxyphytosterol concentrations and CVD status. We found that higher total cholesterol (TC)-standardized campesterol concentrations [odds ratio (OR): 2.36; 95% CI: 1.60, 3.50] and higher sitosterol concentrations (OR: 1.47; 95% CI: 1.09, 1.97) were significantly associated with increased CVD risk, as in the earlier study. However, the sum of absolute oxyphytosterol concentrations (OR: 0.99; 95% CI: 0.81, 1.21) and the sum of TC-standardized oxyphytosterol concentrations (OR: 0.98; 95% CI: 0.80, 1.19) were not associated with an increased CVD risk. Results were comparable for individual absolute and TC-standardized oxycampesterol and oxysitosterol concentrations. Plasma nonoxidized TC-standardized sitosterol and campesterol concentrations showed weak or no correlations with oxyphytosterol concentrations, while all individual plasma concentrations of oxyphytosterol correlated with each other. In conclusion, circulating plasma oxyphytosterols are not associated with CVD risk in the Framingham Offspring Study.
Assuntos
Doenças Cardiovasculares/sangue , Fitosteróis/sangue , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Fatores de RiscoRESUMO
PURPOSE: The primary and secondary objectives were to investigate the triglyceride (TG) and LDL-cholesterol (LDL-C) lowering effects of a spread with added plant sterols (PS) and fish oil as compared to a placebo spread. METHODS: This study had a randomized, double-blind, placebo-controlled, parallel group design with two intervention arms. Following a 2-week placebo run-in period, 260 healthy individuals with modestly elevated blood TG (≥ 1.4 mmol/L) and LDL-C (≥ 3.4 mmol/L) concentrations consumed either the placebo or intervention spread for 4 weeks. The intervention spread contained 2.0 g/day PS and 1.0 g/day eicosapentaenoic acid (EPA) + docosahexanoic acid (DHA) from fish oil. Fasting serum lipids and apolipoproteins (Apo) (exploratory) were measured at the end of the run-in and intervention phases. RESULTS: Four-week consumption of the intervention spread resulted in significantly lower TG (- 10.6%, 95% CI - 16.0 to - 4.9%; P < 0.001) and LDL-C concentrations (- 5.2%; 95% CI - 7.8 to - 2.4%) as compared to placebo. Total cholesterol (- 3.9%; 95% CI - 6.1 to - 1.5%), non-HDL-C (- 5.4%; 95% CI - 8.1 to - 2.7%), remnant-cholesterol (- 8.1%; 95% CI - 3.4 to - 12.5%), ApoAII (- 2.9%; 95% CI - 5.5 to - 0.2%), ApoCIII (- 7.7%; 95% CI - 12.1 to - 3.1%) and ApoB (- 3.2%; 95% CI - 5.9 to - 0.4%) concentrations were also significantly lower, as compared to placebo. No significant treatment effects were found for HDL-cholesterol, ApoAI, ApoCII, Apo E or ApoB/ApoAI. CONCLUSIONS: Four-week consumption of the intervention spread led to significant and clinically relevant decreases in serum TG, LDL-C and other blood lipid concentrations. The study was registered at clinicaltrials.gov (NCT02728583).
Assuntos
LDL-Colesterol/sangue , Ácidos Graxos Ômega-3/farmacologia , Óleos de Peixe/farmacologia , Hipercolesterolemia/dietoterapia , Hipertrigliceridemia/dietoterapia , Fitosteróis/farmacologia , Triglicerídeos/sangue , Adolescente , Adulto , Idoso , LDL-Colesterol/efeitos dos fármacos , Método Duplo-Cego , Ácidos Graxos Ômega-3/administração & dosagem , Feminino , Óleos de Peixe/administração & dosagem , Humanos , Hipercolesterolemia/sangue , Hipertrigliceridemia/sangue , Masculino , Fitosteróis/administração & dosagem , Adulto JovemRESUMO
PURPOSE: Plant sterols and stanols interfere with intestinal cholesterol absorption, and it has been questioned whether absorption and plasma concentrations of fat-soluble vitamins and carotenoids are also affected. We conducted a meta-analysis to assess the effects of plant sterol and stanol consumption on plasma fat-soluble vitamin and carotenoid concentrations. METHODS: Forty-one randomized controlled trials involving 3306 subjects were included. Weighted absolute and relative changes of non-standardized and total cholesterol (TC)-standardized values (expressed as summary estimates and 95 % CIs) were calculated for three fat-soluble vitamins (α- and γ-tocopherol, retinol and vitamin D) and six carotenoids (ß-carotene, α-carotene, lycopene, lutein, zeaxanthin and ß-cryptoxanthin) using a random effects model. Heterogeneity was assessed using predefined subject and treatment characteristics. RESULTS: Average plant sterol or stanol intake was 2.5 g/d. Relative non-standardized and TC-standardized concentrations of ß-carotene decreased by, respectively, -16.3 % (95 % CI -18.3; -14.3) and -10.1 % (-12.3; -8.0), α-carotene by -14.4 % (-17.5; 11.3) and -7.8 % (-11.3; -4.3), and lycopene by -12.3 % (-14.6; -10.1) and -6.3 % (-8.6; -4.0). Lutein concentrations decreased by -7.4 % (-10.1; -4.8), while TC-standardized concentrations were not changed. For zeaxanthin, these values were -12.9 % (-18.9; -6.8) and -7.7 % (-13.8; -1.7) and for ß-cryptoxanthin -10.6 % (-14.3; -6.9) and -4.8 % (-8.7; -0.9). Non-standardized α-tocopherol concentrations decreased by -7.1 % (-8.0; -6.2) and γ-tocopherol by -6.9 % (-9.8; -3.9), while TC-standardized tocopherol concentrations were not changed. Non-standardized retinol and vitamin D concentrations were not affected. Results were not affected by baseline concentrations, dose, duration and type of plant sterols/stanols, except for significant effects of duration (≤4 vs. >4 weeks) on TC-standardized lutein concentrations (1.0 vs. -5.6 %) and type of plant sterol/stanol on TC-standardized ß-carotene concentrations (-8.9 vs. -14.2 %). CONCLUSIONS: Plant sterol and stanol intake lowers TC-standardized hydrocarbon carotenoid concentrations, differently affects TC-standardized oxygenated carotenoid concentrations, but does not affect TC-standardized tocopherol concentrations or absolute retinol and vitamin D concentrations. Observed concentrations remained within normal ranges.
Assuntos
Carotenoides/sangue , Fitosteróis/administração & dosagem , Vitaminas/sangue , Colesterol/sangue , Bases de Dados Factuais , Dieta , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Tocoferóis/sangue , Vitamina A/sangue , Vitamina D/sangueRESUMO
Plant sterols (PSs) lower LDL cholesterol (LDL-C) concentrations, whereas the n-3 (ω-3) fish fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) lower triglyceride (TG) concentrations. Incorporating both PSs and EPA+DHA from fish oil (FO) in a single food format was expected to beneficially affect 2 blood lipid risk factors. The aim of this study was to investigate the dose-response relation between low doses (<2 g/d) of EPA+DHA from FO, incorporated in a low-fat PS-enriched spread, and TG concentrations. In addition, effects on LDL-C were investigated. The study was designed as a randomized, double-blind, placebo-controlled parallel study. After a 4-wk run-in period, subjects were randomly assigned to consume either a control (C) spread (no PSs, no FO) or 1 of 4 intervention spreads containing a fixed amount of PSs (2.5 g/d) and varying amounts of FO (0.0, 0.9, 1.3, and 1.8 g/d of EPA+DHA) for 4 wk. Before and after the intervention, fasting blood samples were drawn for measuring serum lipids and EPA and DHA in erythrocyte membranes. In total, 85 hypercholesterolemic men and 247 women with a mean age of 57.9 y (range: 25-74 y) were included. Eighteen subjects dropped out during the study. At baseline, mean TG and LDL-C concentrations were 1.09 and 4.00 mmol/L, respectively. After the intervention, a significant dose-response relation for the TG-lowering effect of EPA+DHA [ßln (TG) = -0.07 mmol/L per gram of EPA+DHA; P < 0.01] was found. Compared with the C group, TG concentrations were 9.3-16.2% lower in the different FO groups (P < 0.05 for all groups). LDL-C concentrations were 11.5-14.7% lower in the different PS groups than in the C group (P < 0.01 for all groups). EPA and DHA in erythrocyte membranes were dose-dependently higher after FO intake than after the C spread, indicating good compliance. Consumption of a low-fat spread enriched with PSs and different low doses of n-3 fatty acids from FO decreased TG concentrations in a dose-dependent manner and decreased LDL-C concentrations. This trial was registered at clinicaltrials.gov as NCT01313988.
Assuntos
Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácido Eicosapentaenoico/administração & dosagem , Óleos de Peixe/administração & dosagem , Hipercolesterolemia/sangue , Fitosteróis/administração & dosagem , Triglicerídeos/sangue , Adulto , Idoso , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Dieta , Relação Dose-Resposta a Droga , Método Duplo-Cego , Membrana Eritrocítica/metabolismo , Jejum , Feminino , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-IdadeRESUMO
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%.
Assuntos
Anticolesterolemiantes/uso terapêutico , Suplementos Nutricionais , Medicina Baseada em Evidências , Alimento Funcional , Hipercolesterolemia/dietoterapia , Fitosteróis/uso terapêutico , Adulto , Anticolesterolemiantes/administração & dosagem , Anticolesterolemiantes/química , LDL-Colesterol/sangue , Suplementos Nutricionais/análise , Alimento Funcional/análise , Humanos , Hipercolesterolemia/sangue , Fitosteróis/administração & dosagem , Fitosteróis/química , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
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.
Assuntos
Anticolesterolemiantes/administração & dosagem , Fitosteróis/administração & dosagem , Triglicerídeos/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Humanos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Plant sterol (PS)-supplemented foods are recommended to help in lowering serum LDL-cholesterol (LDL-C). Few studies have examined the efficacy of PS-enriched skimmed milk (SM) or semi-SM enriched with vegetable fat (PS-VFM). There is also insufficient information on factors predictive of LDL-C responses to PS. We examined the effects of PS-SM (0·1 % dairy fat) and PS-VFM (0·1 % dairy fat plus 1·5 % vegetable fat) on serum lipids and non-cholesterol sterols in hypercholesterolaemic individuals. In a placebo-controlled, crossover study, forty-three subjects with LDL-C>1300 mg/l were randomly assigned to three 4-week treatment periods: control SM, PS-SM and PS-VFM, with 500 ml milk with or without 3·4 g PS esters (2 g free PS). Serum concentrations of lipids and non-cholesterol sterols were measured. Compared to control, LDL-C decreased by 8·0 and 7·4 % (P < 0·015, both) in the PS-SM and PS-VFM periods, respectively. Serum lathosterol:cholesterol (C) ratios increased by 11-25 %, while sitosterol:C and campesterol:C ratios increased by 70-120 % with both the PS-fortified milk. Adjusted LDL-C reductions were variably enhanced in participants with basal low serum lathosterol/C or conversely high sitosterol/C and campesterol/C. Subjects with post-treatment serum PS:C ratios above the median showed mean LDL-C changes of - 5·9 to - 10·4 %, compared with 1·7 to - 2·9 % below the median. In conclusion, consumption of 2 g/d of PS as PS-SM and PS-VFM lowered LDL-C in hypercholesterolaemic subjects to a similar extent. Basal and post-treatment changes in markers of cholesterol metabolism indicating low cholesterol synthesis and high cholesterol absorption predicted improved LDL-C responses to PS.
Assuntos
LDL-Colesterol/sangue , Hipercolesterolemia/dietoterapia , Leite , Fitosteróis/uso terapêutico , Fitoterapia , Óleos de Plantas/uso terapêutico , Esteróis/sangue , Adulto , Animais , Anticolesterolemiantes/farmacologia , Anticolesterolemiantes/uso terapêutico , Estudos Cross-Over , Gorduras na Dieta/farmacologia , Gorduras na Dieta/uso terapêutico , Suplementos Nutricionais , Ésteres/farmacologia , Ésteres/uso terapêutico , Feminino , Alimentos Fortificados , Humanos , Hipercolesterolemia/sangue , Masculino , Pessoa de Meia-Idade , Fitosteróis/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Óleos de Plantas/farmacologiaRESUMO
BACKGROUND: The relationship between plant sterol (PS) absorption and circulatory concentrations with cholesterol absorption and biosynthesis during PS consumption has yet to be clearly elucidated in humans. It is therefore essential to examine campesterol, ß-sitosterol, and cholesterol absorption and cholesterol fractional synthesis rate (FSR) following PS consumption in individuals with high versus low basal circulatory PS concentrations. DESIGN: A randomized, crossover trial was conducted in 82 hypercholesterolemic men consuming spreads with or without 2 g/d of PS for two 4-week periods, each separated by a 4-week washout. Endpoint tracer enrichments after ingestion of (2)H-labeled campesterol or ß-sitosterol and (13)C-labeled cholesterol were determined by isotope ratio mass spectrometry. RESULTS: For both phases of dietary intervention, the endpoint cholesterol absorption index was positively correlated with campesterol (r = 0.5864, p < 0.0001) and ß-sitosterol (r = 0.4676, p < 0.0001) absorption indices; inversely, endpoint cholesterol FSR correlated negatively with the absorption indices of campesterol (r = -0.5004, p < 0.0009), ß-sitosterol (r = -0.4154, p < 0.05), and cholesterol (r = -0.4056, p < 0.0001). PS intervention reduced absorption indices of campesterol, ß-sitosterol, and cholesterol by 36.5% ± 2.7%, 39.3% ± 2.9%, and 34.3% ± 1.9%, respectively, but increased cholesterol FSR by 33.0% ± 3.3% relative to control. Endpoint circulatory PS levels (cholesterol adjusted) were positively associated with endpoint absorption indices of campesterol (r = 0.5586, p < 0.0001, for placebo; r = 0.6530, p < 0.0001, for PS intake) and cholesterol (r = 0.3683, p < 0.001 for placebo; r = 0.3469, p < 0.002, for PS intake) and were negatively associated with cholesterol FSR (r = -0.3551, p < 0.002, for placebo; r = -0.3643, p < 0.001, for PS intake). The cholesterol-lowering effect of PS was most pronounced among individuals falling within the 50th-75th percentiles of basal PS concentrations. CONCLUSION: These data suggest that basal PS concentrations indicate not only sterol absorption efficiency but also the extent of PS-induced cholesterol reduction and thus might be clinically useful to predict the extent of cholesterol response to PS intervention within a given individual.
Assuntos
Colesterol/análogos & derivados , Hipercolesterolemia/dietoterapia , Fitosteróis/farmacocinética , Sitosteroides/farmacocinética , Adulto , Idoso , Colesterol/farmacocinética , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Estudos Cross-Over , Determinação de Ponto Final , Humanos , Masculino , Pessoa de Meia-Idade , Triglicerídeos/sangueRESUMO
Hawthorn (Crataegus pinnatifida) is an edible fruit used in traditional Chinese medicine to lower plasma lipids. This study explored lipid-lowering compounds and underlying mechanisms of action of hawthorn. Hawthorn powder extracts inhibited acylCoA:cholesterol acyltransferase (ACAT) activity in Caco-2 cells. The inhibitory activity was positively associated with triterpenic acid (i.e., oleanolic acid (OA) and ursolic acid (UA)) contents in the extracts. Cholesterol lowering effects of hawthorn and its potential additive effect in combination with plant sterol esters (PSE) were further studied in hamsters. Animals were fed a semi-synthetic diet containing 0.08% (w/w) cholesterol (control) or the same diet supplemented with (i) 0.37% hawthorn dichloromethane extract, (ii) 0.24% PSE, (iii) hawthorn dichloromethane extract (0.37%) plus PSE (0.24%) or (iv) OA/UA mixture (0.01%) for 4 weeks. Compared to the control diet, hawthorn, PSE, hawthorn plus PSE and OA/UA significantly lowered plasma non-HDL (VLDL + LDL) cholesterol concentrations by 8%, 9%, 21% and 6% and decreased hepatic cholesterol ester content by 9%, 23%, 46% and 22%, respectively. The cholesterol lowering effects of these ingredients were conversely associated with their capacities in increasing fecal neutral sterol excretion. In conclusion, OA and UA are responsible for the cholesterol lowering effect of hawthorn by inhibiting intestinal ACAT activity. In addition, hawthorn and particularly its bioactive compounds (OA and UA) enhanced the cholesterol lowering effect of plant sterols.
RESUMO
The citrus flavonoids hesperidin and naringin have been suggested to lower blood total (TC) and LDL-cholesterol (LDL-C) both in animal models and humans. However, the evidence from previous studies in humans is not convincing. This study evaluated the LDL-C-lowering efficacy of pure hesperidin and naringin in moderately hypercholesterolemic individuals. A total of 204 healthy men and women with a serum TC concentration of 5.0-8.0 mmol/L participated in a randomized, placebo-controlled, parallel trial with 3 groups. A 4-wk preintervention period during which participants refrained from consuming hesperidin and naringin sources preceded the intervention. During the 4-wk intervention, the participants applied the same dietary restrictions and consumed 4 capsules/d providing either placebo (cellulose) or a daily dose of 800 mg hesperidin or 500 mg naringin. Blood samples to measure serum lipids were taken on 2 consecutive days at the beginning and end of the intervention phase. One hundred ninety-four participants completed the study. They maintained their prestudy body weights (mean changes lt 0.2 kg in all groups). In all groups, the mean consumption of scheduled capsules was gt 99%. Hesperidin and naringin did not affect TC or LDL-C, with endpoint LDL-C concentrations (adjusted for baseline) of 4.00 +/- 0.04, 3.99 +/- 0.04, and 3.99 +/- 0.04 mmol/L for control, hesperidin, and naringin groups, respectively. These citrus flavonoids also did not affect serum HDL-cholesterol and triglyceride concentrations. In conclusion, pure hesperidin and naringin consumed in capsules at mealtime do not lower serum TC and LDL-C concentrations in moderately hypercholesterolemic men and women.
Assuntos
Colesterol/sangue , Flavanonas/farmacologia , Hesperidina/farmacologia , Hipercolesterolemia/tratamento farmacológico , Hipolipemiantes/farmacologia , Idoso , Citrus/química , Feminino , Flavanonas/química , Hesperidina/química , Humanos , Hipercolesterolemia/sangue , Hipolipemiantes/química , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Ingestion of tea flavonoids found in both green and black tea is linked to cardiovascular health benefits such as lowering serum lipids. Evidence for a cholesterol-lowering benefit of green or black tea consumption from human intervention studies is, however, conflicting and active components responsible for the effect have not yet been clearly identified. AIM OF THE STUDY: In a randomized, double-blind, placebo-controlled, parallel design study the effects of ingesting a purified black tea theaflavins (TFs) powder alone or in combination with catechin (TFs/catechins) on lowering serum total (TC) and LDL-cholesterol (LDL-c) were assessed. METHODS: In total, 102 mildly to moderately hypercholesterolemic (TC and LDL-c: 5.70 +/- 0.74 and 3.97 +/- 0.61 mmol/L, respectively) subjects (67 men and 35 women) were randomly assigned to consume once daily one capsule of one of the 3 treatments: TFs (providing 77.5 mg), TFs/catechins (providing 75.0 mg TFs plus 150.0 mg catechins and 195.0 mg of other polyphenols), or placebo (cellulose). RESULTS: Serum TC and LDL-c concentrations did not differ significantly among the 3 treatments as assessed at 4, 8, and 11 weeks using analysis of covariance (p = 0.1187 and p = 0.1063, respectively). Although changes over time from baseline to week 11 were significant for TC and LDL-c (p = 0.0311 and p = 0.0269, respectively), this decrease over time was seen in the TFs and placebo groups. CONCLUSION: In this human intervention study, no statistically significant LDL-c lowering effect was seen with either TFs alone or the TFs/catechins combination as compared to placebo. Based on these findings it cannot be concluded that tea flavonoids such as theaflavins and catechins are responsible for a putative cholesterol-lowering effect of black tea, at least not with the daily dose applied in the present study.
Assuntos
Biflavonoides/administração & dosagem , Catequina/administração & dosagem , Hipercolesterolemia/sangue , Lipídeos/sangue , Chá/química , Adulto , Colesterol/sangue , LDL-Colesterol/sangue , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Humanos , Hipercolesterolemia/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Fitoterapia , PlacebosRESUMO
The cholesterol-lowering effect of phytosterols has been extensively studied, and consumption of phytosterols is among the recommendations to lower LDL-cholesterol concentrations. Due to their structural similarity with cholesterol, phytosterols may undergo oxidative processes comparable to those involved in cholesterol oxidation. Consumption of phytosterols could therefore lead to increased systemic concentrations of oxidized phytosterols (oxyphytosterols) via increased dietary intake or in vivo formation from non-oxidized phytosterols. While the biological effects of oxidized cholesterol (oxycholesterol) have been well studied, the amount of biological research on oxyphytosterols is scarce. Most reports on oxyphytosterols cover their quantitative analysis. Whether oxyphytosterols may play similar biological roles as compared to oxycholesterol has not been fully elucidated. The usual perception about oxyphytosterols is that these components present a concern in terms of food quality and health. This perception originates from the parallel that is made with oxycholesterol. Yet, in line with results for oxycholesterol, recent data suggest that oxyphytosterols--depending on the type of oxidation product--may also have beneficial biological properties. Therefore, the objective of this review is to summarise the current understanding of the biological effects, next to identifying future research needs that will help to clarify the possible impact of oxyphytosterols on human health.
Assuntos
Anticolesterolemiantes/metabolismo , Colesterol na Dieta/administração & dosagem , Hipercolesterolemia/metabolismo , Fitosteróis/metabolismo , Antagonistas de Androgênios/farmacologia , Animais , Anticolesterolemiantes/farmacologia , Colesterol/metabolismo , Humanos , Hipercolesterolemia/tratamento farmacológico , Imunossupressores/farmacologia , Fígado/metabolismo , Medicina Tradicional , Oxirredução , Fitosteróis/farmacologiaRESUMO
Convincing evidence supports the intake of specific food components, food groups, or whole dietary patterns to positively influence dyslipidemia and to lower risk of cardiovascular diseases (CVD). Specific macro- and micro-components of a predominantly plant-based dietary pattern are vegetable fats, dietary fibers, and phytonutrients such as phytosterols. This review summarizes the current knowledge regarding effects of these components on lowering blood lipids, i.e., low-density lipoprotein cholesterol (LDL-C) and on reducing CVD risk. The beneficial role of a plant-based diet on cardiovascular (CV) health has increasingly been recognized. Plant-based dietary patterns include a Mediterranean and Nordic diet pattern, the dietary approaches to stop hypertension (DASH), and Portfolio diet, as well as vegetarian- or vegan-type diet patterns. These diets have all been found to lower CVD-related risk factors like blood LDL-C, and observational study evidence supports their role in lowering CVD risk. These diet patterns are not only beneficial for dyslipidemia management and prevention of CVD but further contribute to reducing the impact of food choices on environmental degradation. Hence, the CV health benefits of a predominantly plant-based diet as a healthy and environmentally sustainable eating pattern are today recommended by many food-based dietary as well as clinical practice guidelines.
Assuntos
Doenças Cardiovasculares/prevenção & controle , Dieta Saudável/métodos , Dieta Vegetariana/métodos , Dislipidemias/dietoterapia , LDL-Colesterol/sangue , Dislipidemias/sangue , Fatores de Risco de Doenças Cardíacas , HumanosRESUMO
To better understand the level of knowledge and interest in 'diet and lifestyle' for cholesterol management and CVD prevention, European Atherosclerosis Society (EAS) members were invited to take part in an online survey. In total, 269 EAS members participated of which 64 (24%) were students/postdocs, 102 (38%) researchers involved with CVD-related research and 103 (38%) doctors and clinicians who directly interact with patients. All (99%) of the participants either agreed or strongly agreed that 'diet and lifestyle' have a role to play in cholesterol management, with 80% indicating that 'diet and lifestyle' is very or extremely important. Of the clinicians, 75% indicated that their patients voluntarily ask for 'diet and lifestyle' advice and over 80% said they continuously provide 'diet and lifestyle advice' to their patients. Of the surveyed clinicians, 91% feel sufficiently educated and confident to provide expert advice and over 90% recommend medication, diet change, frequent exercise and smoking cessation to their patients. In view of more specific dietary advice, clinicians reportedly recommend a 'Mediterranean diet', and advise to avoid high-fat foods, and to increase intake of high-fibre foods. Interestingly, smoking cessation and alcohol avoidance were mentioned less frequently. In view of educational needs, over half of the surveyed EAS members use the internet and 'guidelines' to learn about 'diet and lifestyle' in relation to cholesterol and CVD risk management. Clinicians tend to use 'guidelines' more often, while students/postdocs tend to use the internet significantly more than clinicians and CVD researchers. Regarding unmet needs for educational tools addressing specifically 'diet and lifestyle', clinicians feel that patient-oriented leaflets and pocket guidelines would be most beneficial materials to introduce, while students/postdocs would prefer an app. In summary, the role of 'diet and lifestyle' as a cornerstone of cholesterol management and CVD risk prevention seems well recognised amongst EAS members surveyed.
Assuntos
Atitude do Pessoal de Saúde , Competência Clínica , Dieta , Dislipidemias/terapia , Estilo de Vida , Padrões de Prática Médica , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/prevenção & controle , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação das Necessidades , Comportamento de Redução do Risco , Sociedades Médicas , Inquéritos e Questionários , Adulto JovemRESUMO
BACKGROUND: Functional food ingredients and natural health products have been demonstrated to reduce disease risk and thereby help to lower health care costs across populations at risk for chronic or degenerative diseases. However, typically a wide range of interindividual variability exists in response across individuals to nutritional and natural health product bioactives, such as plant sterols (PS). This study aims to determine and utilize information on the associations between genosets and the degree of responsiveness to dietary PS intervention, with a long-term objective of developing genetic tests to predict responses to PS. METHODS: This clinical trial is designed as a double-blind, placebo controlled, randomized two-period crossover study. Sixty-four eligible participants with the specific a priori-determined single nucleotide polymorphisms (SNPs) associated with a responsiveness to PS will consume PS or a placebo treatment for two 4-week periods. The PS treatment consists of two daily single portions of margarine, each providing 1 g PS during the PS period (2.0 g/day of PS in total). The placebo will be an identical margarine containing no added PS. Low-density lipoprotein cholesterol (LDL-C) responsiveness to the controlled administration of PS will be investigated as the primary outcome, and the associations between interindividual genoset variabilities and response to PS consumption will be determined. DISCUSSION: This research will provide further insight into whether the associations between previously identified SNPs and the response of LDL-C to PS consumption can be used in a predictive manner. It will also provide insight into the complexities of undertaking a nutrigenetic trial with prospective recruitment based on genotype. TRIAL REGISTRATION: ClinicalTrials.gov: Identifier: NCT02765516. Registered on 6 May 2016.
Assuntos
LDL-Colesterol/sangue , LDL-Colesterol/genética , Fitosteróis/administração & dosagem , Estudos Cross-Over , Método Duplo-Cego , Variação Genética , Humanos , Polimorfismo de Nucleotídeo Único , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Varying the macronutrient composition of meals alters acute postprandial responses, but the effect sizes for specific macronutrient exchanges have not been quantified by systematic reviews. Therefore the aim is to quantify the effect size of exchanging fat for carbohydrates in mixed meals on postprandial glucose (PPG), insulin (PPI), triglycerides (PPTG), and free fatty acids (PPFFA) responses by performing a systematic review and meta-analysis of randomized controlled trials. A systematic literature search was undertaken on randomized controlled trials comparing isocaloric high fat with high carbohydrate meals, with comparable protein contents and at least one postprandial glycemic- and one lipid outcome. The outcome data were extracted and expressed as mean postprandial levels over 2 h. Ten studies involving 14 comparisons met the eligibility criteria. Data were available for meta-analysis from 347 participants, consuming mixed meals containing 250-1003 kcal, and total fat contents of 33.3-75.6 percentage of energy (en%) (intervention) versus 0-31.7 en% (control). Each 10en% increase in fat, replacing carbohydrates produced a mean reduction in PPG of 0.32 mmol/l (95% CI -0.64 to -0.00, p = 0.047), a reduction in PPI of 18.2 pmol/l (95% CI -24.86 to -11.54), an increase in PPTG of 0.06 mmol/l (95% CI 0.02 to 0.09, p = 0.004), with no statistically significant effect on PPFFA. Modest exchange of carbohydrates for fats in mixed meals significantly reduces PPG and PPI and increases PPTG responses. The quantitative relationships derived here may be applied to predict responses, and to design and optimize meal macronutrient compositions in dietary intervention studies.
Assuntos
Ácidos Graxos não Esterificados , Insulina , Glicemia , Estudos Cross-Over , Carboidratos da Dieta , Gorduras na Dieta , Glucose , Humanos , Refeições , Período Pós-Prandial , TriglicerídeosRESUMO
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.
Assuntos
LDL-Colesterol/sangue , Fitosteróis/administração & dosagem , Adulto , Relação Dose-Resposta a Droga , Humanos , Fitosteróis/farmacologiaRESUMO
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, doseâresponse 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.
Assuntos
Colesterol/sangue , Alimento Funcional , Metabolismo dos Lipídeos , Margarina , Fitosteróis/administração & dosagem , Fitosteróis/sangue , Adulto , Idoso , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Culinária , Método Duplo-Cego , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Oxirredução , Projetos Piloto , Fatores de Tempo , Triglicerídeos/sangueRESUMO
The National Cholesterol Education Program Adult Treatment Panel III guidelines advocate effective combinations of cholesterol-lowering dietary components. This approach (dietary portfolio) produces large reductions in serum cholesterol, but the contribution of individual components remains to be established. We therefore assessed the effect of eliminating one out of the 4 dietary portfolio components. Plant sterols were selected because at 2 g/d, they have been reported to reduce low-density lipoprotein cholesterol (LDL-C) by 9% to 14%. Forty-two hyperlipidemic subjects were prescribed diets high in soy protein (22.5 g/1000 kcal), viscous fibers (10 g/1000 kcal), and almonds (23 g/1000 kcal) for 80 weeks. Subjects were instructed to take these together with plant sterols (1.0 g/1000 kcal) except between weeks 52 and 62. While taking the full dietary portfolio, including plant sterols, mean LDL-C reduction from baseline was 15.4% +/- 1.6% (P < .001). After sterol elimination, mean LDL-C reduction was 9.0% +/- 1.5% (P < .001). Comparable LDL-C reductions were also seen for the 18 subjects with a complete data set: on plant sterols, 16.7% +/- 3.1% (P < .001) and off plant sterols, 10.3% +/- 2.6% (P < .001), resulting in a 6.3% +/- 2.0% (P = .005) difference attributable to plant sterols. Compliance in this group of 18 was 67.0% +/- 5.9% for plant sterols and 61.9% +/- 4.8% for the other components. In combination with other cholesterol-lowering foods and against the background of a low-saturated fat diet, plant sterols contributed over one third of the LDL-C reduction seen with the dietary portfolio after 1 year of following dietary advice.
Assuntos
Anticolesterolemiantes , Colesterol na Dieta , Dieta , Fitosteróis/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Fibras na Dieta , Ingestão de Energia , Feminino , Humanos , Masculino , Carne , Pessoa de Meia-Idade , Educação de Pacientes como Assunto , Proteínas de Soja , VerdurasRESUMO
ATP-binding cassette hetero-dimeric transporters G5 and G8 (ABCG5/G8) have been postulated to mediate intestinal cholesterol efflux, whereas Niemann-Pick C1 Like 1 (NPC1L1) protein is believed to be essential for intestinal cholesterol influx. The individual or combined genetic markers, such as single nuclear polymorphisms (SNPs), of these two transporter genes may explain inter-individual variations in plasma cholesterol response following plant sterol (PS) intervention. The present study was aimed at investigating the association between ABCG5/G8 and NPC1L1 genotype SNPs with sterol absorption and corresponding plasma concentrations. The study used a 4-week crossover design with 82 hypercholesterolemic men characterized by high vs. low basal plasma PS concentrations consuming spreads with or without 2 g/day of PS. For the ABCG8 1289 C > A (T400 K) polymorphism, the A allele carriers with high basal plasma PS concentrations demonstrated a 3.9-fold greater reduction (p < 0.05) in serum low density lipoprotein cholesterol (LDL-C) than their low basal plasma PS counterparts. For the NPC1L1 haplotype of 872 C > G (L272L) and 3929 G > A (Y1291Y), individuals carrying mutant alleles showed a 2.4-fold greater (p < 0.05) reduction in LDL-C levels, compared to wild type counterparts. Results suggest that genetic and metabolic biomarkers together may predict inter-individual lipid level responsiveness to PS-intervention, and thus could be useful in devising individualized cholesterol lowering strategies.