Article

Acute effects of high-fat meals enriched with walnuts or olive oil on postprandial endothelial function

Departament de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain.
Journal of the American College of Cardiology (Impact Factor: 15.34). 11/2006; 48(8):1666-71. DOI: 10.1016/j.jacc.2006.06.057
Source: PubMed

ABSTRACT We sought to investigate whether the addition of walnuts or olive oil to a fatty meal have differential effects on postprandial vasoactivity, lipoproteins, markers of oxidation and endothelial activation, and plasma asymmetric dimethylarginine (ADMA).
Compared with a Mediterranean diet, a walnut diet has been shown to improve endothelial function in hypercholesterolemic patients. We hypothesized that walnuts would reverse postprandial endothelial dysfunction associated with consumption of a fatty meal.
We randomized in a crossover design 12 healthy subjects and 12 patients with hypercholesterolemia to 2 high-fat meal sequences to which 25 g olive oil or 40 g walnuts had been added. Both test meals contained 80 g fat and 35% saturated fatty acids, and consumption of each meal was separated by 1 week. Venipunctures and ultrasound measurements of brachial artery endothelial function were performed after fasting and 4 h after test meals.
In both study groups, flow-mediated dilation (FMD) was worse after the olive oil meal than after the walnut meal (p = 0.006, time-period interaction). Fasting, but not postprandial, triglyceride concentrations correlated inversely with FMD (r = -0.324; p = 0.024). Flow-independent dilation and plasma ADMA concentrations were unchanged, and the concentration of oxidized low-density lipoproteins decreased (p = 0.051) after either meal. The plasma concentrations of soluble inflammatory cytokines and adhesion molecules decreased (p < 0.01) independently of meal type, except for E-selectin, which decreased more (p = 0.033) after the walnut meal.
Adding walnuts to a high-fat meal acutely improves FMD independently of changes in oxidation, inflammation, or ADMA. Both walnuts and olive oil preserve the protective phenotype of endothelial cells.

0 Bookmarks
 · 
127 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study assessed the postprandial effects of high fat, high protein meals containing either palmolein or olive oil on endothelial function in overweight/obese men. 28 men (32-65 yr; 25-35 kg/m(2)) consumed, in random order 1 wk apart, isocaloric high protein, high fat meals (2791 kJ, 40 g protein (∼3 g l-arginine), 44 g fat, 21 g carbohydrate) prepared with either 40 g palmolein or 40 g olive oil after an overnight fast. The SFA:MUFA:PUFA ratio of the oils were: palmolein, 42:47:12; olive oil, 17:76:7. Brachial artery flow-mediated dilatation (FMD), circulating endothelial function markers, nitrotyrosine (oxidative stress marker), triglycerides, glucose and insulin were assessed pre-meal and hourly for 5 h. Mixed model procedures were used to analyze the data. Meal consumption increased serum triglycerides (time effect, P < 0.001); with no meal differences (meal × time interaction, P = 0.93). Serum insulin peaked 1 h post-consumption and returned to pre-meal concentrations by 5 h with both meals (time effect, P < 0.001; meal × time effect, P = 0.68). FMD, serum intercellular adhesion molecule-1 (ICAM-1) and E-selectin did not change (meal × time effect, P > 0.4). Olive oil transiently increased plasma nitrotyrosine after 1 h compared to palmolein (meal × time interaction, P = 0.002) whereas both meals increased serum vascular cell adhesion molecule-1 (VCAM-1) after 1 h (time effect, P < 0.001; meal × time interaction, P = 0.98). Both nitrotyrosine and VCAM-1 returned to pre-meal concentrations after 2 h. In the context of a high protein meal, palmolein similarly to olive oil did not affect postprandial endothelial function in overweight/obese men. Australian New Zealand Clinical Trials Registry (ANZCTR) (http://www.anzctr.org.au/default.aspx). Trial ID: ACTRN12613000136707. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    Atherosclerosis 01/2015; 239(1):178-185. DOI:10.1016/j.atherosclerosis.2015.01.009 · 3.71 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A study was conducted to determine the effects of moisture content and energy of impact on the cracking characteristics of walnuts. A sample of fresh harvested walnuts was divided into four portions and conditioned under sunshine for different time durations to obtain different levels of moisture content [9.2-29.7%, wet basis (w. b.)]. An impact test apparatus was used to apply different impact energies in the range of 0.13-1.11 J to samples with different moisture content. Data obtained on the quantity of fully cracked and unbroken kernel, fully cracked but broken kernel and uncracked nuts were used in the computation of the nuts cracking characteristics. Results showed that moisture content, impact energy and interaction effects of these two variables have significant effect on the walnuts cracking characteristics. Full cracking of nuts increased with impact energy and decreasing moisture content. The optimum moisture content for cracking walnuts that gave the best result combination of high whole kernel yield and low kernel breakage was found to be about 16%. The optimum impact energy for cracking was found to be about 1.01 J (1.01 +/- 0.1 J). The results of this study show that development of a centrifugal impact cracker, which uses impact to crack walnuts, is possible. In the designing of the walnut cracker, the radius and speed of the cracker should be such that create impact energy and velocity of about 1.01 J and 11 m/s, respectively, and walnuts should be conditioned to the moisture content of about 16% for optimum efficiency.
    01/2014; 10(1). DOI:10.1515/ijfe-2012-0168
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Nuts are rich in many bioactive compounds that can exert beneficial effects on cardiovascular health. We reviewed the evidence relating nut consumption and the metabolic syndrome (MetS) and its components. Nuts reduce the postprandial glycemic response; however, long-term trials of nuts on insulin resistance and glycemic control in diabetic individuals are inconsistent. Epidemiologic studies have shown that nuts may lower the risk of diabetes incidence in women. Few studies have assessed the association between nuts and abdominal obesity, although an inverse association with body mass index and general obesity has been observed. Limited evidence suggests that nuts have a protective effect on blood pressure and endothelial function. Nuts have a cholesterol-lowering effect, but the relation between nuts and hypertriglyceridemia and high-density lipoprotein cholesterol is not well established. A recent pooled analysis of clinical trials showed that nuts are inversely related to triglyceride concentrations only in subjects with hypertriglyceridemia. An inverse association was found between the frequency of nut consumption and the prevalence and the incidence of MetS. Several trials evaluated the effect of nuts on subjects with MetS and found that they may have benefits in some components. Compared with a low-fat diet, a Mediterranean diet enriched with nuts could be beneficial for MetS management. The protective effects on metabolism could be explained by the modulation of inflammation and oxidation. Further trials are needed to clarify the role of nuts in MetS prevention and treatment.
    American Journal of Clinical Nutrition 06/2014; 100(Supplement_1). DOI:10.3945/ajcn.113.071530 · 6.92 Impact Factor

Full-text (2 Sources)

Download
18 Downloads
Available from
Jun 10, 2014