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Copyright of Applied Physiology, Nutrition & Metabolism is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To determine the effect of diets low in saturated fatty acids and high in monounsaturated fatty acids (MUFA) or polyunsaturated fatty acids on body composition in participants at risk for metabolic syndrome (MetS).Methods: This study was a randomized, crossover, controlled feeding study. Participants (n = 101, ages 49.5 ± 1.2, BMI 29.4 ± 0.4 kg/m2 ) were randomized to five isocaloric diets containing treatment oils: Canola, CanolaOleic, CanolaDHA, Corn/Safflower, and Flax/Safflower. Each diet period was 4 weeks followed by a 2- to 4-week washout period.Results: Canola (3.1 kg, P = 0.026) and CanolaOleic oil diets (3.09 kg, P = 0.03) reduced android fat mass compared with the Flax/Saff oil diet (3.2 kg), particularly in men. The decrease in abdominal fat mass was correlated with the reduction in blood pressure after the Canola (systolic blood pressure: r = 0.26, P = 0.062; diastolic blood pressure: r = 0.38, P = 0.0049) and CanolaOleic oil diets (systolic blood pressure: r = 0.39 P = 0.004; diastolic blood pressure: r = 0.45, P = 0.0006). The decrease in abdominal fat mass also was associated with a reduction in triglyceride levels after the CanolaOleic oil diet (r = 0.42, P = 0.002).Conclusions: Diets high in MUFA (compared with PUFA) reduced central obesity with an accompanying improvement in MetS risk factors. Diets high in MUFA may be beneficial for treating and perhaps preventing MetS. [ABSTRACT FROM AUTHOR]

Oleic acid consumption is considered cardio-protective according to studies conducted examining effects of the Mediterranean diet. However, animal models have shown that oleic acid consumption increases LDL particle cholesteryl oleate content which is associated with increased LDL-proteoglycan binding and atherosclerosis. The objective was to examine effects of varying oleic, linoleic and docosahexaenoic acid consumption on human LDL-proteoglycan binding in a non-random subset of the Canola Oil Multi-center Intervention Trial (COMIT) participants. COMIT employed a randomized, double-blind, five-period, cross-over trial design. Three of the treatment oil diets: 1) a blend of corn/safflower oil (25:75); 2) high oleic canola oil; and 3) DHA-enriched high oleic canola oil were selected for analysis of LDL-proteoglycan binding in 50 participants exhibiting good compliance. LDL particles were isolated from frozen plasma by gel filtration chromatography and LDL cholesteryl esters quantified by mass-spectrometry. LDL-proteoglycan binding was assessed using surface plasmon resonance. LDL particle cholesterol ester fatty acid composition was sensitive to the treatment fatty acid compositions, with the main fatty acids in the treatments increasing in the LDL cholesterol esters. The corn/safflower oil and high-oleic canola oil diets lowered LDL-proteoglycan binding relative to their baseline values ( p = 0.0005 and p = 0.0012, respectively). At endpoint, high-oleic canola oil feeding resulted in lower LDL-proteoglycan binding than corn/safflower oil ( p = 0.0243) and DHA-enriched high oleic canola oil ( p = 0.0249), although high-oleic canola oil had the lowest binding at baseline ( p = 0.0344). Our findings suggest that high-oleic canola oil consumption in humans increases cholesteryl oleate percentage in LDL, but in a manner not associated with a rise in LDL-proteoglycan binding. [ABSTRACT FROM AUTHOR]

Abstract: Policosanols have been purported by one research group to act as effective agents for LDL-cholesterol (LDL-C) lowering in humans. However data from independent researchers have been contradicting results published by the laboratories originating these claims. The purpose of this commentary is therefore to briefly summarize the policosanol controversy and point out the potential explanations for inconsistencies in the policosanol literature, as well as to determine potential origins of the problem especially at the level of the reviewing and publishing process. Scrutiny and vigilance at all steps of the process are necessary in order to avoid such controversies in the field of natural product research. [Copyright &y& Elsevier]

The extent to which sterols and stanols modulate LDL particle size is unknown. We examined the effects of supplementation with unesterified plant sterols and stanols on several LDL electrophoretic characteristics. Healthy hypercholesterolemic subjects (n = 14) consumed each of four experimental diets contained plant sterols (S), plant stanols (SN), a 50:50 mixture of sterols and stanols (SSN), or cornstarch (control) in a randomized crossover design. The butter component of the diet was blended with unesterified sterols and stanols at a dose of 1.8 g/d. The LDL particles were characterized by polyacrylamide gradient gel electrophoresis of whole plasma. LDL cholesterol (LDL-C) concentrations decreased by 8.8, 13.6, and 13.1% in the S, SN, and SSN groups, respectively (P < 0.01) with a significant increase of 4.3% in the control group. None of the treatments with sterols and stanols induced significant changes in LDL peak particle diameter or in the cholesterol levels of the small LDL subfraction (<25.5 nm). The reduction in plasma LDL-C levels with SN consumption was due mainly to a decrease (P < 0.05) in the concentration of cholesterol in the large subfraction (>26.0 nm). The significant reduction in plasma LDL-C concentrations by sterol and stanol consumption in subjects was not paralleled by any beneficial changes in LDL electrophoretic characteristics. [ABSTRACT FROM AUTHOR]

Medium-chain triglycerides (MCT) have been proposed as weight-lowering agents, although there is some concern regarding their hyperlipidemic effect. This study evaluates the effects of a combination of MCT oil, phytosterols and flaxseed oil [functional oil (FctO)] on plasma lipid concentrations and LDL particle size. Twenty-four healthy overweight men (body mass index 28.2 +/- 0.4 kg/m(2)) consumed controlled diets designed to maintain weight for two periods of 29 d each. Diets contained 40% of energy as fat, 75% of which was added fat, either FctO or olive oil (OL). Body composition and blood samples were analyzed at the baseline and the endpoint of each period. Total cholesterol concentration decreased 12.5% (-0.68 mmol/L; P < 0.05) when subjects consumed FctO and 4.7% when they consumed OL. Similarly, FctO consumption lowered LDL cholesterol concentrations by 13.9%, whereas OL consumption did not. There was no difference in absolute change in LDL-cholesterol between FctO and OL consumption. Peak LDL particle size was greater in those who consumed FctO than in those who consumed OL (P < 0.05), with no effect of diet on proportion of large, medium or small particles. We conclude that those who consume a diet containing FctO have a better lipid profile than those who consume a diet rich in OL, which also leads to a larger lipoprotein particle size. Functional oil consumption can therefore help reduce the risk of cardiovascular disease. [ABSTRACT FROM AUTHOR]

Abstract: Plant sterols/stanols-enriched foods possess well-documented low-density lipoprotein (LDL)-cholesterol−lowering effect. However, the relative efficacy of plant sterols/stanols as supplements (tablets/capsules) compared with other dietary forms still needs to be determined. Our aim was to precisely identify and quantify the LDL-cholesterol−lowering effect of plant sterols/stanols as supplements in contrast to food-based approaches. Eight eligible clinical trials published from January 1992 to April 2013 were identified from five databases. A random effect model was used to calculate weighted mean effect sizes for net differences in LDL-cholesterol concentrations. Among the included trials with the duration between 4 and 6 weeks, plant sterol/stanol dose ranged from 1.0 to 3.0 g/day administrated mainly with the main meals (2 or 3 times/day). Intake of plant sterol/stanol supplements decreased LDL-cholesterol concentrations by 12 mg/dL (0.31 mmol/L) (95% CI −0.39 to −0.23; P<0.000) compared with placebo. The test of heterogeneity was not significant (χ2 , P=0.50, I 2=0%). Further analysis showed no significant difference between the LDL-cholesterol−lowering action of plant sterols/stanols supplements (−12 mg/dL [−0.31 mmol/L]; 95% CI −0.39 to −0.24; P<0.0001) vs foods enriched with plant sterols/stanols (−12 mg/dL [−0.31 mmol/L]; 95% CI −0.35 to −0.27; P<0.0001). Plant sterol/stanol supplements as part of a healthy diet represent an effective means of delivering LDL-cholesterol−lowering similar to plant sterols/stanols delivered in various food formats. [Copyright &y& Elsevier]