Effect of dietary antioxidants on postprandial endothelial dysfunction induced by a high-fat meal in healthy subjects

The effects of citrus flavonoids supplementation on endothelial function: A systematic review and dose-response meta-analysis of randomized clinical trials

The present systematic review and dose-response meta-analysis was conducted to synthesize existing data from randomized clinical trials (RCTs) concerning the impact of citrus flavonoids supplementation (CFS) on endothelial function. Relevant RCTs were identified through comprehensive searches of the PubMed, ISI Web of Science, and Scopus databases up to May 30, 2023. Weighted mean differences and their corresponding 95% confidence intervals (CI) were pooled utilizing a random-effects model. A total of eight eligible RCTs, comprising 596 participants, were included in the analysis. The pooled data demonstrated a statistically significant augmentation in flow-mediated vasodilation (FMD) (2.75%; 95% CI: 1.29, 4.20; I2 = 87.3%; p < 0.001) associated with CFS compared to the placebo group. Furthermore, the linear dose-response analysis indicated that each increment of 200 mg/d in CFS led to an increase of 1.09% in FMD (95% CI: 0.70, 1.48; I2 = 94.5%; p < 0.001). The findings from the nonlinear dose-response analysis also revealed a linear relationship between CFS and FMD (Pnon-linearity = 0.903, Pdose-response <0.001). Our findings suggest that CFS enhances endothelial function. However, more extensive RTCs encompassing longer intervention durations and different populations are warranted to establish more precise conclusions.

Effects of Nutrients on Platelet Function: A Modifiable Link between Metabolic Syndrome and Neurodegeneration?

Metabolic syndrome increases the risk of vascular dementia and other neurodegenerative disorders. Recent studies underline that platelets play an important role in linking peripheral with central metabolic and inflammatory mechanisms. In this narrative review, we address the activation of platelets in metabolic syndrome, their effects on neuronal processes and the role of the mediators (e.g., serotonin, platelet-derived growth factor). Emerging evidence shows that nutritional compounds and their metabolites modulate these interactions-specifically, long chain fatty acids, endocannabinoids and phenolic compounds. We reviewed the role of activated platelets in neurovascular processes and nutritional compounds in platelet activation.

Acute Freeze-Dried Mango Consumption With a High-Fat Meal has Minimal Effects on Postprandial Metabolism, Inflammation and Antioxidant Enzymes

Objective

Postprandial fluxes in oxidative stress, inflammation, glucose, and lipids, particularly after a high-fat meal (HFM), have been implicated in the development of cardiovascular disease (CVD). The aim of this study is to determine whether acute freeze-dried mango consumption modulates the postprandial response to an HFM. We hypothesized that the addition of mango, which is a rich source of many bioactive components, to an HFM would lower postprandial triglycerides, glucose, and inflammation, and increase antioxidant enzymes, compared to a standard HFM alone.

Methods

In a randomized cross-over study, 24 healthy adult males (18-25 years old) consumed a typical American breakfast (670 kcal; 58% fat) with or without the freeze-dried mango pulp (50 g). Lipids, glucose, antioxidant enzymes, and inflammatory markers were assessed at baseline/fasting and 1, 2, and 4 hours after the HFM.

Results

Addition of mango resulted in lower glucose (95.8 ± 4.4 mg/dL; P = .002) and higher high-density lipoprotein cholesterol (HDL-C; 58.4 ± 2.7 mg/dL; P = .01) 1 hour post-HFM compared to control (glucose: 104.8 ± 5.4 mg/dL; HDL-C: 55.2 ± 2.3 mg/dL), although no differences were observed in triglycerides (P = .88 for interaction). No significant meal × time interactions were detected in markers of inflammation (C-reactive protein, P = .17; interleukin-6, P = .30) or antioxidant enzymes (superoxide dismutase, P = .77; glutathione peroxidase, P = .36; catalase, P = .32) in the postprandial period.

Conclusions

When added to an HFM, acute mango consumption had modest beneficial effects on postprandial glucose and HDL-C responses, but did not alter triglyceride, inflammatory, or antioxidant enzymes.

Postprandial incorporation of EPA and DHA from transgenic Camelina sativa oil into blood lipids is equivalent to that from fish oil in healthy humans

EPA and DHA are important components of cell membranes. Since humans have limited ability for EPA and DHA synthesis, these must be obtained from the diet, primarily from oily fish. Dietary EPA and DHA intakes are constrained by the size of fish stocks and by food choice. Seed oil from transgenic plants that synthesise EPA and DHA represents a potential alternative source of these fatty acids, but this has not been tested in humans. We hypothesised that incorporation of EPA and DHA into blood lipids from transgenic Camelina sativa seed oil (CSO) is equivalent to that from fish oil. Healthy men and women (18-30 years or 50-65 years) consumed 450 mg EPA + DHA from either CSO or commercial blended fish oil (BFO) in test meals in a double-blind, postprandial cross-over trial. There were no significant differences between test oils or sexes in EPA and DHA incorporation into plasma TAG, phosphatidylcholine or NEFA over 8 h. There were no significant differences between test oils, age groups or sexes in postprandial VLDL, LDL or HDL sizes or concentrations. There were no significant differences between test oils in postprandial plasma TNFα, IL 6 or 10, or soluble intercellular cell adhesion molecule-1 concentrations in younger participants. These findings show that incorporation into blood lipids of EPA and DHA consumed as CSO was equivalent to BFO and that such transgenic plant oils are a suitable dietary source of EPA and DHA in humans.

Is Grassfed Meat and Dairy Better for Human and Environmental Health?

The health of livestock, humans, and environments is tied to plant diversity-and associated phytochemical richness-across landscapes. Health is enhanced when livestock forage on phytochemically rich landscapes, is reduced when livestock forage on simple mixture or monoculture pastures or consume high-grain rations in feedlots, and is greatly reduced for people who eat highly processed diets. Circumstantial evidence supports the hypothesis that phytochemical richness of herbivore diets enhances biochemical richness of meat and dairy, which is linked with human and environmental health. Among many roles they play in health, phytochemicals in herbivore diets protect meat and dairy from protein oxidation and lipid peroxidation that cause low-grade systemic inflammation implicated in heart disease and cancer in humans. Yet, epidemiological and ecological studies critical of red meat consumption do not discriminate among meats from livestock fed high-grain rations as opposed to livestock foraging on landscapes of increasing phytochemical richness. The global shift away from phytochemically and biochemically rich wholesome foods to highly processed diets enabled 2.1 billion people to become overweight or obese and increased the incidence of type II diabetes, heart disease, and cancer. Unimpeded, these trends will add to a projected substantial increase in greenhouse gas emissions (GHGE) from producing food and clearing land by 2050. While agriculture contributes one quarter of GHGE, livestock can play a sizable role in climate mitigation. Of 80 ways to alleviate climate change, regenerative agriculture-managed grazing, silvopasture, tree intercropping, conservation agriculture, and farmland restoration-jointly rank number one as ways to sequester GHG. Mitigating the impacts of people in the Anthropocene can be enabled through diet to improve human and environmental health, but that will require profound changes in society. People will have to learn we are members of nature's communities. What we do to them, we do to ourselves. Only by nurturing them can we nurture ourselves.

Cranberries improve postprandial glucose excursions in type 2 diabetes

Recent research supports a favorable role of cranberries on cardiometabolic health. Postprandial metabolism, especially hyperglycemia, has been shown to be an independent cardiovascular risk and few clinical studies have reported the role of berries in improving postprandial dysmetabolism. We investigated the postprandial effects of dried cranberries following a high-fat breakfast challenge in obese participants with type 2 diabetes (T2DM), in a randomized crossover trial. Blood draw and vascular measurements were conducted at fasting, 1, 2 and 4 hours (h), following the consumption of a fast-food style high-fat breakfast (70 g fat, 974 kcal) with or without cranberries (40 g). Analyses of our data (n = 25; BMI (kg m^-2) (mean ± s.d.) = 39.5 ± 6.5; age (years) = 56 ± 6) revealed that postprandial increases in glucose were significantly lower in the cranberry vs. control at 2 & 4 h (p < 0.05). No significant differences were noted in insulin, insulin resistance evaluated by homeostasis model assessment, lipid profiles and blood pressure between the cranberry and control groups. Among the biomarkers of inflammation and oxidation, postprandial serum interleukin-18 and malondialdehyde were significantly lower at 4 h, and serum total nitrite was higher at 2 h in the cranberry vs. control group (all p < 0.05). No effects were noted on C-reactive protein or interlukin-6. Overall, dietary cranberries had notable effects in improving high-fat breakfast induced postprandial glucose and selected biomarkers of inflammation and oxidation in participants with T2DM. These findings provide evidence that adding whole cranberries to a high-fat meal may improve postprandial blood glucose management and warrant further investigation.

Metabolic and inflammatory responses to the common sweetener stevioside and a glycemic challenge in horses with equine metabolic syndrome

Extracts derived from the leaves of the stevia plant (stevioside) are commonly used as sweeteners for humans and horses. Stevioside appears to be safe for human consumption, including for individuals with insulin dysregulation. In the horse, the safety or metabolic effects of stevioside on normal animals or on those with metabolic dysfunction are unknown. Furthermore, the inflammatory response to a glycemic challenge or to stevioside in horses is not well defined. Therefore, the objective of this study was to measure the effects of stevioside and a glycemic challenge on insulin, glucose, and inflammatory responses in horses with a common metabolic dysfunction (equine metabolic syndrome or EMS) compared with non-EMS controls. To accomplish this, 15 horses were selected; 8 EMS and 7 age-matched controls. An oral sugar test was performed using Karo corn syrup (karo) or stevioside in a random crossover design. Horses were given 0.15 mL/kg body weight of karo or its equivalent grams of sugar in stevia dissolved in water. Blood samples were collected by jugular venipuncture before administration of either stevia or karo and at 60 and 240 min after administration. Serum was used for glucose and insulin determination and plasma for isolation of peripheral blood mononuclear cells (PBMCs) for inflammatory cytokine analysis via flow cytometry and reverse transcription PCR (RT-PCR). Stevia appeared to stimulate lower glycemic and insulinemic responses when compared to karo, in particular in EMS horses. EMS and control horses had inverse inflammatory responses to administration of either stevia or karo with EMS horses having a proinflammatory response (P ≤ 0.05). These data provide evidence as to why horses with EMS may be predisposed to developing laminitis, potentially as a result of an exaggerated inflammatory response to glycemic and insulinemic responses. Furthermore, the data provide new avenues for exploring mechanisms behind the syndrome, in particular when using a glycemic challenge.

Post-prandial systemic 8-isoprostane increases after consumption of moderate and high-fat meals in insufficiently active males

A single high-fat meal (HFM) leads to an increase in triglycerides and oxidative stress. Oxidative stress can be assessed via 8-isoprostane generation, which is associated with the development of asthma and cardiovascular disease. No previous research has investigated whether airway and systemic 8-isoprostane increases postprandially in nonasthmatic participants according to the energy and fat content of a meal. Our purpose was to assess airway and systemic 8-isoprostane after a HFM and a true-to-life moderate-fat meal (MFM). We hypothesized that airway and systemic 8-isoprostane would increase after a HFM and a MFM, with the greatest increase in the HFM condition. Eight nonasthmatic men (25.8±6.9years) completed the HFM and MFM trials in a randomized crossover design. After a 10-hour fast, participants consumed either a HFM (71.13kJ/kg body mass, 60% fat, 23% CHO) or a MFM (35.56kJ/kg body mass, 30% fat, 52% CHO). Exhaled breath condensate to assess airway 8-isoprostane was collected at baseline and at 3 and 6hours postmeal. Venous blood samples were collected at baseline and hourly until 6hours postmeal to assess triglycerides, and every 3hours for systemic 8-isoprostane. Airway 8-isoprostane responses were not significant as a main effect of time (P=.072), between conditions (P=.365), or between time and condition (P=.319) postmeal. Systemic 8-isoprostane increased over time (P<.001), but not between conditions (P=.124) or between time and condition (P=.649) postmeal. Triglyceride incremental area under the curve was different in the HFM compared to the MFM condition (P=.013). After a HFM and a MFM, 8-isoprostane increases systemically; however, airway 8-isoprostane does not change.

Healthful Dietary Patterns and the Risk of Hypertension Among Women With a History of Gestational Diabetes Mellitus: A Prospective Cohort Study

Women who developed gestational diabetes mellitus represent a high-risk population for hypertension later in life. The role of diet in the progression of hypertension among this susceptible population is unknown. We conducted a prospective cohort study of 3818 women with a history of gestational diabetes mellitus in the Nurses' Health Study II as part of the ongoing Diabetes & Women's Health Study. These women were followed-up from 1989 to 2011. Incident hypertension was identified through self-administered questionnaires that were validated previously by medical record review. Adherence scores for the alternative Healthy Eating Index 2010, the alternative Mediterranean diet, and the Dietary Approaches to Stop Hypertension were computed for each participant. Cox proportional hazard models were used to evaluate the associations between dietary scores and hypertension while adjusting for major risk factors for hypertension. We documented 1069 incident hypertension cases during a median of 18.5 years of follow-up. After adjustment for major risk factors for hypertension, including body mass index, alternative Healthy Eating Index 2010, alternative Mediterranean diet, and Dietary Approaches to Stop Hypertension scores were significantly inversely associated with the risk of hypertension; hazard ratio and 95% confidence interval comparing the extreme quartiles (highest versus lowest) were 0.76 (0.61-0.94; P for linear trend =0.03) for AHEI score, 0.72 (0.58-0.90; P for trend =0.01) for Dietary Approach to Stop Hypertension score, and 0.70 (0.56-0.88; P for trend =0.002) for alternative Mediterranean diet score. Adherence to a healthful dietary pattern was related to a lower subsequent risk of developing hypertension among women with a history of gestational diabetes mellitus.

Acute Thermotherapy Prevents Impairments in Cutaneous Microvascular Function Induced by a High Fat Meal

We tested the hypothesis that a high fat meal (HFM) would impair cutaneous vasodilation, while thermotherapy (TT) would reverse the detrimental effects. Eight participants were instrumented with skin heaters and laser-Doppler (LD) probes and tested in three trials: control, HFM, and HFM + TT. Participants wore a water-perfused suit perfused with 33°C (control and HFM) or 50°C (HFM + TT) water. Participants consumed 1 g fat/kg body weight. Blood samples were taken at baseline and two hours post-HFM. Blood pressure was measured every 5-10 minutes. Microvascular function was assessed via skin local heating from 33°C to 39°C two hours after HFM. Cutaneous vascular conductance (CVC) was calculated and normalized to maximal vasodilation (%CVCmax). HFM had no effect on initial peak (48 ± 4 %CVCmax) compared to control (49 ± 4 %CVCmax) but attenuated the plateau (51 ± 4 %CVCmax) compared to control (63 ± 4 %CVCmax, P < 0.001). Initial peak was augmented in HFM + TT (66 ± 4 %CVCmax) compared to control and HFM (P < 0.05), while plateau (73 ± 3 % CVCmax) was augmented only compared to the HFM trial (P < 0.001). These data suggest that HFM negatively affects cutaneous vasodilation but can be minimized by TT.

Significant improvement of erectile function after Roux-en-Y gastric bypass surgery in obese Chinese men with erectile dysfunction

BACKGROUND

We aimed to examine the effect of Roux-en-Y gastric bypass surgery (RYGB) on erectile dysfunction (ED), cavernosal morphological vasculopathy, and carotid wall alterations in severely obese Chinese men.

METHODS

We performed a retrospective cohort study of 39 obese men with ED who underwent RYGB between 2011 and 2012. Erectile function was assessed by the International Index of Erectile Function-5 (IIEF-5) before and 1 year after surgery. Intima-media thickness of carotid and cavernosal arteries and cavernosal peak systolic velocity (PSV) were investigated by color Doppler ultrasound. Endothelial function was assessed with the L-arginine test.

RESULTS

Eighteen (46.2%) men had cavernosal vasculopathy and 21 (53.8%) had carotid vasculopathy before surgery, and these proportions decreased to 15.4% and 23.1% after surgery, respectively. There was a significant improvement in carotid and cavernosal intima-media thickness postoperatively. IIEF-5 (17.3 to 23.8, P < 0.05), PSV (23 to 37, P < 0.05), and endothelial scores (6.1 to 8.2, P < 0.05) were all improved after RYGB. The increase in endothelial function scores was positively associated with changes in pre- to postoperative IIEF-5 scores (r = 0.438, P = 0.017). Younger age, being married, and lower preoperative IIEF-5 scores were independently related to greater improvement in erectile function.

CONCLUSIONS

ED can be relieved after RYGB in obese Chinese patients, accompanied by the improvement of cavernosal morphological vasculopathy and carotid wall alterations. Changes in endothelial function may contribute to this improvement, while preoperative body mass index and the amount of weight loss do not.

Secoiridoids delivered as olive leaf extract induce acute improvements in human vascular function and reduction of an inflammatory cytokine: a randomised, double-blind, placebo-controlled, cross-over trial

The leaves of the olive plant (Olea europaea) are rich in polyphenols, of which oleuropein and hydroxytyrosol (HT) are most characteristic. Such polyphenols have been demonstrated to favourably modify a variety of cardiovascular risk factors. The aim of the present intervention was to investigate the influence of olive leaf extract (OLE) on vascular function and inflammation in a postprandial setting and to link physiological outcomes with absorbed phenolics. A randomised, double-blind, placebo-controlled, cross-over, acute intervention trial was conducted with eighteen healthy volunteers (nine male, nine female), who consumed either OLE (51 mg oleuropein; 10 mg HT), or a matched control (separated by a 4-week wash out) on a single occasion. Vascular function was measured by digital volume pulse (DVP), while blood collected at baseline, 1, 3 and 6 h was cultured for 24 h in the presence of lipopolysaccharide in order to investigate effects on cytokine production. Urine was analysed for phenolic metabolites by HPLC. DVP-stiffness index and ex vivo IL-8 production were significantly reduced (P< 0.05) after consumption of OLE compared to the control. These effects were accompanied by the excretion of several phenolic metabolites, namely HT and oleuropein derivatives, which peaked in urine after 8-24 h. The present study provides the first evidence that OLE positively modulates vascular function and IL-8 production in vivo, adding to growing evidence that olive phenolics could be beneficial for health.

Postprandial metabolism and inflammatory markers in overweight adolescents

Lifestyle changes have an impact on lipid metabolism. The overload of circulating lipids may lead to endothelial dysfunction, oxidative stress and exaggerated inflammatory response, which may be further aggravated in the presence of overweight. This study aims to describe the postprandial metabolism and inflammatory response in overweight and normal-weight adolescents. Sixty-two adolescents aged 11–18 years were divided into two groups: overweight (OW; n=38) and normal weight (NW; n=24). Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), glucose, insulin, high-sensitivity C-reactive protein (hs-CRP), fibrinogen and leukocytes were collected for fasting and 4 and 6 h after a oral fat tolerance test (OFTT) consisting of a high-fat meal with 1.000 Kcal, 27.4% carbohydrates, 14.7% protein and 57.8% lipids (30.4% saturated, 32.7% monounsaturated, 26.5% polyunsaturated fatty acids and 288 mg TC). Data were analyzed with repeated measures ANOVA, multiple linear regression, and Pearson, Spearman and partial correlations. OW adolescents showed significantly higher fasting values of TC (P=0.036), LDL-C (P=0.010), fibrinogen (P=0.036) and hs-CRP (P=0.004). All variables, except for glucose, increased in response to OFTT, but there were no interactions between group and time. body mass index z-score was positively correlated to LDL-C, TG, fibrinogen and hs-CRP, and inversely correlated to HDL-C. In conclusion, adolescents with OW showed higher TC, LDL-C and inflammatory markers levels than NW adolescents. These findings have clinical implications for prevention of chronic diseases, as we spend most of our days in a postprandial state.

Nutritionally mediated oxidative stress and inflammation

There are many sources of nutritionally mediated oxidative stress that trigger inflammatory cascades along short and long time frames. These events are primarily mediated via NF κ B. On the short-term scale postprandial inflammation is characterized by an increase in circulating levels of IL-6 and TNF- α and is mirrored on the long-term by proinflammatory gene expression changes in the adipocytes and peripheral blood mononuclear cells (PBMCs) of obese individuals. Specifically the upregulation of CCL2/MCP-1, CCL3/MIP-1 α , CCL4/MIP-1 β , CXCL2/MIP-2 α , and CXCL3/MIP-2 β is noted because these changes have been observed in both adipocytes and PBMC of obese humans. In comparing numerous human intervention studies it is clear that pro-inflammatory and anti-inflammatory consumption choices mediate gene expression in humans adipocytes and peripheral blood mononuclear cells. Arachidonic acid and saturated fatty acids (SFAs) both demonstrate an ability to increase pro-inflammatory IL-8 along with numerous other inflammatory factors including IL-6, TNF α , IL-1 β , and CXCL1 for arachidonic acid and IGB2 and CTSS for SFA. Antioxidant rich foods including olive oil, fruits, and vegetables all demonstrate an ability to lower levels of IL-6 in PBMCs. Thus, dietary choices play a complex role in the mediation of unavoidable oxidative stress and can serve to exacerbate or dampen the level of inflammation.

Moderate-intensity, premeal cycling blunts postprandial increases in monocyte cell surface CD18 and CD11a and endothelial microparticles following a high-fat meal in young adults

High-fat meals promote transient increases in proatherogenic factors, implicating the postprandial state in cardiovascular disease (CVD) progression. Although low-grade inflammation is associated with CVD, little research has assessed postprandial inflammation. Because of its anti-inflammatory properties, premeal exercise may counteract postprandial inflammation. The purpose of this study was to determine postprandial alterations in monocytes and circulating markers of endothelial stress and inflammation following a high-fat meal in young adults with or without premeal cycle exercise. Each subject completed two trials and was randomized to rest or cycle at a moderate intensity prior to eating a high-fat meal. Flow cytometry was used to assess monocyte cell surface receptor expression and concentration of endothelial microparticles (EMP). Plasma cytokines were assessed using Luminex MagPix. Statistical analysis was completed using separate linear mixed models analyses with first-order autoregressive (AR(1)) heterogeneous covariance structure. Significance was set at P ≤ 0.05. Percentage increases in classic monocyte CD11a and CD18 were greater overall in the postprandial period in the meal-only condition compared with the meal + exercise condition (P < 0.05). EMP concentration was 47% greater 3 h after the meal compared with premeal values in the meal-only condition (P < 0.05); no significant increase was observed in the meal + exercise condition. Premeal cycling blunted postprandial increases in EMP and CD11a and CD18. Acute, moderate-intensity exercise may help counteract possibly deleterious postprandial monocyte and endothelial cell activation.

Effects of acute ingestion of different fats on oxidative stress and inflammation in overweight and obese adults

Background

Studies show that obese individuals have prolonged elevations in postprandial lipemia and an exacerbated inflammatory response to high fat meals, which can increase risk for cardiovascular diseases. As epidemiological studies indicate an association between type of fat and circulating inflammatory markers, the purpose of this study was to investigate the acute effect of different fat sources on inflammation and oxidative stress in overweight and obese individuals.

Methods

Eleven overweight and obese subjects consumed three high fat milkshakes rich in monounsaturated fat (MFA), saturated fat (SFA), or long-chain omega 3 polyunsaturated fat (O3FA) in random order. Blood samples collected at baseline, 1, 2, 4, and 6 hours postprandial were analyzed for markers of inflammation (soluble intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), tumor necrosis factor- α (TNF-α), and C-reactive protein (CRP)), oxidative stress (8-epi-prostaglandin-F2α (8-epi) and nuclear factor-κB (NF-κB)), and metabolic factors (glucose, insulin, non-esterified free fatty acids, and triglycerides (TG)).

Results

O3FA enhanced NF-kB activation compared to SFA, but did not increase any inflammatory factors measured. Conversely, SFA led to higher ICAM-1 levels than MFA (p = 0.051), while MFA increased TG more than SFA (p < 0.05). CRP increased while TNF-α and 8-epi decreased with no difference between treatments.

Conclusions

While most of the inflammatory factors measured had modest or no change following the meal, ICAM-1 and NF-κB responded differently by meal type. These results are provocative and suggest that type of fat in meals may differentially influence postprandial inflammation and endothelial activation.

Differential effects of low-carbohydrate and low-fat diets on inflammation and endothelial function in diabetes

OBJECTIVE

To characterize acute (postprandial) and chronic (after a 6-month period of weight loss) effects of a low-carbohydrate vs. a low-fat diet on subclinical markers of cardiovascular disease (CVD) in adults with type 2 diabetes.

DESIGN

At baseline and 6 months, measures of C-reactive protein (CRP), interleukin-6 (IL-6), soluble intercellular adhesion molecule (sICAM) and soluble E-selectin were obtained from archived samples (n = 51) of participants randomized in a clinical trial comparing a low-carbohydrate and a low-fat diet. In a subset of participants (n = 27), postprandial measures of these markers were obtained 3 h after a low-carbohydrate or low-fat liquid meal. Endothelial function was also measured by reactive hyperemic peripheral arterial tonometry during the meal test. Paired t tests and unpaired t tests compared within- and between-group changes.

RESULTS

There were no significant differences observed in postprandial measures of inflammation or endothelial function. After 6 months, CRP (mean ± S.E.) decreased in the low-fat arm from 4.0 ± 0.77 to 3.0 ± 0.77 (P = .01). In the low-carbohydrate arm, sICAM decreased from 234 ± 22 to 199 ± 23 (P = .001), and soluble E-selectin decreased from 93 ± 10 to 82 ± 10 (P = .05.) A significant correlation between change in high-density lipoprotein and change in soluble E-selectin (r = -0.33, P = .04) and with the change in ICAM (r = -0.43, P = .01) was observed.

CONCLUSIONS

Low-carbohydrate and low-fat diets both have beneficial effects on CVD markers. There may be different mechanisms through which weight loss with these diets potentially reduces CVD risk.

Genetic effects on postprandial variations of inflammatory markers in healthy individuals

Circulating levels of inflammatory markers predict the risk of cardiovascular disease (CVD), mediated perhaps in part by dietary fat intake, through mechanisms only partially understood. To evaluate post-fat load changes in inflammatory markers and genetic influences on these changes, we administered a standardized high-fat meal to 838 related Amish subjects as part of the Heredity and Phenotype Intervention (HAPI) Heart Study and measured a panel of inflammatory markers, including C-reactive protein (CRP), interleukin-1beta (IL-1beta), matrix metalloproteinase-1 and -9 (MMP-1 and MMP-9), and white blood cell (WBC) count, before and 4 h after fat challenge (CRP prechallenge only). Heritabilities (h(2) +/- s.d.) of basal inflammatory levels ranged from 16 +/- 8% for MMP-9 (P = 0.02) to 90 +/- 7% for MMP-1 (P < 0.0001). Post-fat load, circulating levels of WBC, MMP-1, and MMP-9 increased by 16, 32, and 43% (all P < 0.0001), with no significant changes in IL-1beta. Postprandial changes over the 4-h period were modestly heritable for WBC (age- and sex-adjusted h(2) = 14 +/- 9%, P = 0.04), but the larger MMP-1 and MMP-9 changes appeared to be independent of additive genetic effects. These results reveal that a high-fat meal induces a considerable inflammatory response. Genetic factors appear to play a significant role influencing basal inflammatory levels but to have minimal influence on post-fat intake inflammatory changes.

The tsim tsoum approaches for prevention of cardiovascular disease

The Tsim Tsoum Concept means that humans evolved on a diet in which nature recommends to ingest fatty acids in a balanced ratio (polyunsaturated(P) : saturated(S) =w-6 : w-3 = 1 : 1)as part of dietary lipid pattern where monounsaturated fatty acids(MUFA) is the major fatty acid(P : M : S = 1 : 6 : 1) in the background of other dietary factors; antioxidants, vitamins, minerals and fiber as well as physical activity and low mental stress. Several hundred years ago, our diet included natural foods; fruits, vegetables, green vegetables, seeds, eggs and honey. Fish, and wild meat were also available to pre-agricultural humans which shaped modern human genetic nutritional requirement. Cereal grains (refined), and vegetable oils that are rich in w-6 fatty acids are relatively recent addition to the human diet that represent dramatic departure from those foods to which we are adapted. Excess of linoleic acid, trans fatty acids (TFA), saturated and total fat as well as refined starches and sugar are proinflammatory. Low dietary MUFA and n-3 fatty acids and other long chain polyunsarurated fatty acids (LCPUFA) are important in the pathogenesis of metabolic syndrome. Increased sympathetic activity with greater secretion of neurotransmitters in conjunction of underlying long chain PUFA deficiency, and excess of proinflammatory nutrients, may damage the neurons via proinflammatory cytokines, in the ventromedial hypothalamus and insulin receptors in the brain.Since, 30–50% of the fatty acids in the brain are LCPUFA, especially omega-3 fatty acids, which are incorporated in the cell membrane phospholipids, it is possible that their supplementation may be protective.Blood lipid composition does reflect one's health status: (a) circulating serum lipoproteins and their ratio provide information on their atherogenicity to blood vessels and (b) circulating plasma fatty acids, such as w-6/w-3 fatty acid ratio, give indication on proinflammatory status of blood vessels, cardiomyocytes, liver cells and neurones; (a) and (b) are phenotype-related and depend on genetic, environmental and developmental factors. As such, they appear as universal markers for holistic health and these may be important in the pathogenesis of cardiovascular diseases and cancer, which is the main consideration of Tsim Tsoum concept.

Fruit and vegetable consumption and proinflammatory gene expression from peripheral blood mononuclear cells in young adults: a translational study

BACKGROUND

Fruits and vegetables are important sources of fiber and nutrients with a recognized antioxidant capacity, which could have beneficial effects on the proinflammatory status as well as some metabolic syndrome and cardiovascular disease features. The current study assessed the potential relationships of fruit and vegetable consumption with the plasma concentrations and mRNA expression values of some proinflammatory markers in young adults.

METHODS

One-hundred and twenty healthy subjects (50 men/70 women; 20.8 +/- 2.6 y; 22.3 +/- 2.8 kg/m2) were enrolled. Experimental determinations included anthropometry, blood pressure and lifestyle features as well as blood biochemical and inflammatory measurements. The mRNA was isolated from peripheral blood mononuclear cells (PBMC) and the gene expression concerning selected inflammatory markers was assessed by quantitative real-time PCR. Nutritional intakes were estimated by a validated semi-quantitative food-frequency questionnaire.

RESULTS

The highest tertile of energy-adjusted fruit and vegetable consumption (>660 g/d) was associated with lower plasma concentrations of C-reactive protein (CRP) and homocysteine and with lower ICAM1, IL1R1, IL6, TNFalpha and NFkappaB1 gene expression in PBMC (P for trend < 0.05), independently of gender, age, energy intake, physical activity, smoking, body mass index, systolic blood pressure and circulating non-esterified fatty acids. In addition, plasma CRP, homocysteine and TNFalpha concentrations and ICAM1, TNFalpha and NFkappaB1 gene expression in PBMC showed a descending trend as increased fiber intake (>19.5 g/d) from fruits and vegetables (P for trend < 0.05). Furthermore, the participants within the higher tertile (>11.8 mmol/d) of dietary total antioxidant capacity showed lower plasma CRP and mRNA values of ICAM1, IL1R1, IL6, TNFalpha and NFkappaB1 genes (P for trend < 0.05). The inverse association between fruit and vegetable consumption and study proinflammatory markers followed the same trend and remained statistically significant, after the inclusion of other foods/nutrients in the linear regression models.

CONCLUSION

A higher fruit and vegetable consumption was independently associated not only with reduced CRP and homocysteine concentrations but also with a lower mRNA expression in PBMC of some relevant proinflammatory markers in healthy young adults.

Stress, food, and inflammation: psychoneuroimmunology and nutrition at the cutting edge

Inflammation is the common link among the leading causes of death. Mechanistic studies have shown how various dietary components can modulate key pathways to inflammation, including sympathetic activity, oxidative stress, transcription factor nuclear factor-kappaB activation, and proinflammatory cytokine production. Behavioral studies have demonstrated that stressful events and depression can also influence inflammation through these same processes. If the joint contributions of diet and behavior to inflammation were simply additive, they would be important. However, several far more intriguing interactive possibilities are discussed: stress influences food choices; stress can enhance maladaptive metabolic responses to unhealthy meals; and diet can affect mood as well as proinflammatory responses to stressors. Furthermore, because the vagus nerve innervates tissues involved in the digestion, absorption, and metabolism of nutrients, vagal activation can directly and profoundly influence metabolic responses to food, as well as inflammation; in turn, both depression and stress have well-documented negative effects on vagal activation, contributing to the lively interplay between the brain and the gut. As one example, omega-3 fatty acid intake can boost mood and vagal tone, dampen nuclear factor-kappaB activation and responses to endotoxin, and modulate the magnitude of inflammatory responses to stressors. A better understanding of how stressors, negative emotions, and unhealthy meals work together to enhance inflammation will benefit behavioral and nutritional research, as well as the broader biomedical community.

Postprandial vascular reactivity in obese and normal weight young adults

As humans spend a significant amount of time in the postprandial state, we examined whether vascular reactivity (a key indicator of cardiovascular health) was different after a high-fat meal in 11 obese (median BMI 46.4, age 32.1 +/- 6.3 years, 7 men) and 11 normal weight (median BMI 22.6) age- and sex-matched controls. At baseline and 1 and 3 h postmeal, blood pressure (BP), heart rate (HR), reactive hyperemia peripheral artery tonometry (RH-PAT) index, radial augmentation index adjusted for HR (AIx75), brachial pulse wave velocity (PWV(b)), glucose, insulin, total and high-density lipoprotein (HDL) cholesterol, and triglycerides were measured. Brachial flow-mediated dilatation (FMD) and, by venous plethysmography, resting and hyperemic forearm blood flows (FBFs) were measured at baseline and 3 h. At baseline, obese subjects had higher systolic BP, HR, resting FBF, insulin and equivalent FMD, RH-PAT, hyperemic FBF, AIx75, PWV(b), glucose, total cholesterol, triglycerides, and lower HDL cholesterol. In obese and lean subjects, FMD at baseline and 3 h was not significantly different (6.2 +/- 1.7 to 5.8 +/- 4.3% for obese and 4.7 +/- 4.1 to 4.3 +/- 3.9% for normal weight, P = 0.975 for group x time). The meal did not produce significant changes in RH-PAT, hyperemic FBF, and PWV(b) in either group (P > 0.1 for the effect of time and for group x time interactions). In conclusion, the vascular responses to a high-fat meal are similar in obese and normal weight young adults. An exaggerated alteration in postprandial vascular reactivity is thus unlikely to contribute importantly to the increased cardiovascular risk of obesity.

Acute and long-term effects of grape and pomegranate juice consumption on vascular reactivity in paediatric metabolic syndrome

OBJECTIVES

This study, which to the best of our knowledge is the first of its kind, aimed to determine the acute and long-term effects of the consumption of grape and pomegranate juices on endothelium function in adolescents with metabolic syndrome, and to compare the effects of these two kinds of juices.

METHODS

This randomised controlled clinical trial was conducted in 2008 among 30 adolescents, aged 12-15 years, with metabolic syndrome. Participants were randomly assigned to two groups of equal number; one group was asked to drink 18 millilitre per kilogram per day of natural grape juice and the other group was asked to drink 240 millilitre per day of natural pomegranate juice once daily for 1 month. Juices were homemade without any added sweetener. Basal brachial artery dimension and flow-mediated dilation as an index of endothelial function and endothelial-dependent dilation after receiving nitoglycerin spray were evaluated by high-resolution B mode ultrasonography before juice consumption, 4 hours and 30 days after regular daily consumption.

RESULTS

Flow-mediated dilation at 90 seconds and after nitoglycerin significantly improved at 4 hours and at 1 month after drinking both kinds of juices, without significant difference between the two groups. The change at 1 month versus 4 hours was significant only in the grape juice group.

CONCLUSION

Daily consumption of diets rich in antioxidants might improve endothelial function in adolescents with metabolic syndrome. These effects began as soon as 4 hours after juice consumption. Such beneficial effects should be considered in dietary recommendations for the paediatric age group, notably in obese individuals.

Discriminated benefits of a Mediterranean dietary pattern within a hypocaloric diet program on plasma RBP4 concentrations and other inflammatory markers in obese subjects

Personalized nutritional strategies to treat obesity may specifically influence inflammatory markers, in addition to reduce body weight. In the present study, we evaluated the effect of a hypocaloric diet based on a Mediterranean dietary pattern (MDP) on nutritional status as well as on plasma concentrations of retinol binding protein-4 (RBP4) and other proinflammatory markers. Fourty-one subjects (24F/17M; age: 37 ± 7 years; BMI: 32.2 ± 3.9 kg/m²) were assigned to follow a MDP within a caloric-restricted diet over an 8-week period. Anthropometrical, clinical, and biochemical variables were measured at baseline and endpoint after the nutritional program. Dietary intervention resulted in a mean weight loss of -4.4 ± 2.5 kg (P < 0.001) and marked reductions (P < 0.05) in plasma concentrations of RBP4, leptin, C-reactive protein, complement C3, and tumor necrosis factor-alpha (TNFα). Individuals with a higher adherence to the MDP during the nutritional intervention presented differentially higher reductions (P < 0.05) in plasma RBP4, IL6, and TNFα. In addition, the increase in the Mediterranean diet score from baseline was a significant and independent predictor factor for the decrease in plasma RBP4 concentration (P < 0.05). In conclusion, our findings suggest that following a hypocaloric diet accompanying a high adherence to a MDP resulted in specific reductions on proinflammatory markers, in addition to a significant improvement in some metabolic syndrome features induced by weight loss, which could be a good combined strategy to treat obesity as well as related metabolic and inflammatory disorders.

Vascular health in children and adolescents: effects of obesity and diabetes

The foundations for cardiovascular disease in adults are laid in childhood and accelerated by the presence of comorbid conditions, such as obesity, diabetes, hypertension, and dyslipidemia. Early detection of vascular dysfunction is an important clinical objective to identify those at risk for subsequent cardiovascular morbidity and events, and to initiate behavioral and medical interventions to reduce risk. Typically, cardiovascular screening is recommended for young adults, especially in people with a family history of cardiovascular conditions. Children and adolescents were once considered to be at low risk, but with the growing health concerns related to sedentary lifestyle, poor diet and obesity, cardiovascular screening may be needed earlier so that interventions to improve cardiovascular health can be initiated. This review describes comorbid conditions that increase cardiovascular risk in youth, namely obesity and diabetes, and describes noninvasive methods to objectively detect vascular disease and quantify vascular function and structure through measurements of endothelial function, arterial compliance, and intima-media thickness. Additionally, current strategies directed toward prevention of vascular disease in these populations, including exercise, dietary interventions and pharmacological therapy are described.

Impacto hormonal e inflamatório de diferentes composições dietéticas: ênfase em padrões alimentares e fatores dietéticos específicos

A adoção de um padrão alimentar saudável, caracterizado pelo consumo de frutas, hortaliças, carnes magras, lácteos desnatados, frutos secos e moderada ingestão de óleos vegetais e álcool, é um fator determinante para um menor risco de doenças crônicas como a obesidade, a síndrome metabólica e as doenças cardiovasculares. Esse efeito benéfico pode ser explicado, pelo menos em parte, por seu papel modulador sobre biomarcadores da sensibilidade insulínica, da aterogênese, bem como os de inflamação e de função endotelial. Por outra parte, a ingestão de componentes específicos da dieta como os ácidos graxos insaturados (oleico e alfa-linolênico) e os micronutrientes com propriedades antioxidantes (vitaminas A, E e C; selênio e zinco) vêm sendo discutida, em razão de sua potencial ação protetora perante a ocorrência das doenças crônicas e possíveis benefícios na regulação hormonal, metabólica e inflamatória que esses fatores dietéticos podem proporcionar dentro de um tratamento nutricional para a obesidade e a síndrome metabólica.

Dietary saturated and unsaturated fats as determinants of blood pressure and vascular function

The amount and type of dietary fat have long been associated with the risk of CVD. Arterial stiffness and endothelial dysfunction are important risk factors in the aetiology of CHD. A range of methods exists to assess vascular function that may be used in nutritional science, including clinic and ambulatory blood pressure monitoring, pulse wave analysis, pulse wave velocity, flow-mediated dilatation and venous occlusion plethysmography. The present review focuses on the quantity and type of dietary fat and effects on blood pressure, arterial compliance and endothelial function. Concerning fat quantity, the amount of dietary fat consumed habitually appears to have little influence on vascular function independent of fatty acid composition, although single high-fat meals postprandially impair endothelial function compared with low-fat meals. The mechanism is related to increased circulating lipoproteins and NEFA which may induce pro-inflammatory pathways and increase oxidative stress. Regarding the type of fat, cross-sectional data suggest that saturated fat adversely affects vascular function whereas polyunsaturated fat (mainly linoleic acid (18 : 2n-6) and n-3 PUFA) are beneficial. EPA (20 : 5n-3) and DHA (22 : 6n-3) can reduce blood pressure, improve arterial compliance in type 2 diabetics and dyslipidaemics, and augment endothelium-dependent vasodilation. The mechanisms for this vascular protection, and the nature of the separate physiological effects induced by EPA and DHA, are priorities for future research. Since good-quality observational or interventional data on dietary fatty acid composition and vascular function are scarce, no further recommendations can be suggested in addition to current guidelines at the present time.

Effect of diet on the low-grade and chronic inflammation associated with obesity and metabolic syndrome

Adipose tissue is an active endocrine and paracrine organ that releases a large number of cytokines and biomarkers, which are involved in the development of chronic diseases. These effects have been attributed to direct or indirect mechanisms acting on insulin resistance, inflammation and endothelial dysfunction. In addition, the expression and secretion of these biomarkers in various tissues can be influenced by dietary patterns, with an effect on inflammatory status. In this context, following an energy-balanced diet, moderate in carbohydrates, high in oleic and omega-3 fatty acids, and low in saturated and trans fatty acids, with high intake of fruits and legumes and moderate alcohol consumption, appears to have beneficial effects on the inflammatory state associated with obesity and the manifestations of metabolic syndrome. However, the long-term impact of habitual intake and the mechanisms involved in distinct physiological and pathological conditions remain unclear.

Association of retinol-binding protein-4 with dietary selenium intake and other lifestyle features in young healthy women

OBJECTIVE

This study specifically assessed plasma retinol-binding protein-4 (RBP4), an inflammatory marker, in young healthy women, with emphasis on its potential relations to dietary intake and lifestyle features.

METHODS

Seventy-four women with a mean age of 20.5 +/- 2.5 y and body mass index of 21.3 +/- 2.3 kg/m(2) were enrolled. Anthropometric, blood pressure, glucose, lipid profile, RBP4, and insulin concentrations were determined. Nutritional intakes were estimated by a validated semiquantitative food-frequency questionnaire. Physical activity and smoking status were evaluated with appropriate tools.

RESULTS

Regarding anthropometric and biochemical variables, only triacylglycerol concentration had a positive and significant association with plasma RBP4 concentrations (P < 0.001). Trans fatty acid intake, vitamin A intake, and smoking time showed positive and significant correlations with RBP4 concentrations (P < 0.05). Furthermore, individuals with a higher selenium intake (P = 0.027), non-smoking participants (P = 0.032), and subjects who self-declared to practice some physical activity (P = 0.030) presented significantly lower RBP4 concentrations. Interestingly, selenium intake was inversely and significantly associated with RBP4 concentration (P = 0.018) when adjusted for smoking status, energy intake, and vitamin C, vitamin E, and zinc intakes. Plasma RBP4 concentrations were also associated with smoking status (P = 0.035), adjusted for potential confounding factors.

CONCLUSION

This translational research revealed that dietary intake of a nutrient with an impact on oxidative stress such as selenium and lifestyle features such as smoking habit can modulate RBP4 concentrations. Our results suggest that plasma RBP4 values could be a valuable tool to screen potential nutrient and inflammation interactions.

Effect of raisin consumption on oxidative stress and inflammation in obesity

AIM

Oxidative stress can initiate increased inflammation that elevates risk for cardiovascular disease. The objective of this study was to determine the effects of daily consumption of raisins on markers of oxidative stress, inflammation and endothelial activation in response to an acute high-fat meal in overweight individuals.

METHODS

Seventeen overweight men and women consumed 90 g raisins or isocaloric placebo (264 kcal/day) for 14 days in a randomized, crossover design while following a low-flavonoid diet. The oxidative [urinary 8-iso-prostaglandin-F(2alpha) (8-epi PGF(2alpha)) and serum oxygen radical absorbance capacity (ORAC)], inflammatory (serum C-reactive protein and interleukin-6), endothelial (serum soluble intercellular adhesion molecule-1 and soluble vascular cell adhesion molecule-1, sVCAM-1) and metabolic [free fatty acids (FFAs), triacylglycerol, glucose and insulin] response to four high-fat (53%) meals was tested pre- and postintervention.

RESULTS

Urinary 8-epi PGF(2alpha) decreased (-22%) and fasting ORAC increased (+3%) after both interventions combined. Fasting protein-free ORAC was modestly (+3.5%) higher during the raisin than the placebo intervention. Neither the meals nor the raisins consistently induced fasted markers of inflammation or endothelial dysfunction. Gender influenced postprandial metabolic responses in that males responded with higher serum FFAs, sVCAM-1 and glucose compared with females.

CONCLUSIONS

Serum antioxidant capacity was modestly increased by daily raisin consumption, but this did not alter fasted or postprandial inflammatory response in these relatively healthy but overweight individuals. Providing all food in regular pattern reduced measures of oxidative stress.

Effect of short-term lycopene supplementation and postprandial dyslipidemia on plasma antioxidants and biomarkers of endothelial health in young, healthy individuals

The objective of this study was to test the hypothesis that the effect of a high-fat meal (HFm) on plasma lipid-soluble antioxidants and biomarkers of vascular oxidative stress and inflammation would be attenuated by short-term lycopene supplementation in young healthy subjects. Following restriction of lycopene-containing foods for 1-wk (LYr), blood was collected in a fasting state and 3 h after a HFm and a low-fat meal (LFm) in N = 18 men aged 23 ± 2 years, and after a HFm only in N = 9 women aged 23 ± 1 years. Blood was also sampled pre- and post-meals following 1-wk of 80 mg/day lycopene supplementation (LYs) under continued dietary LYr. In the fasting state, LYs compared with LYr not only evoked a >2-fold increase in plasma lycopene but also increased plasma β-carotene and α-tocopherol (p < 0.01), though LYs did not affect plasma nitrate/nitrite (biomarker of nitric oxide), malondialdehyde (biomarker of lipid oxidative stress), vascular- and intercellular-adhesion molecules or C-reactive protein (biomarkers of inflammation). Contrary to the hypothesis, the HFm-induced dyslipidemic state did not affect plasma malondialdehyde, C-reactive protein, or adhesion molecules in either LYr or LYs. Both the HFm and LFm were associated with decreases in the nitric oxide metabolites nitrate/nitrite and lipid-soluble antioxidants (p < 0.05). The data revealed that 1-wk of LYs increased plasma lycopene, β-carotene, and α-tocopherol yet despite these marked changes to the plasma lipid-soluble antioxidant pool, biomarkers of vascular oxidative stress and inflammation were unaffected in the fasted state as well as during dyslipidemia induced by a HFm in young healthy subjects.

Apple polyphenols and fibers attenuate atherosclerosis in apolipoprotein E-deficient mice

Atherosclerosis, which is closely linked to nutritional habits, is a major cause of mortality in Western countries. Most of the previous investigations carried out on health effects of apples have been focused on their capacity to lower lipid concentration as well as on their antioxidant effects. The aim of the present study was to investigate the antiatherosclerotic effects of apple polyphenols and fibers. A crude apple polyphenol extract and low-viscosity apple fibers isolated from cider apples were administered separately or in association with the diet of apo E-deficient mice. After 4 months of supplementation, lipemia and oxidative stress biomarkers were measured and atheroslerotic lesions assessed by histomorphometry. Total plasmatic cholesterol and triacylgycerol levels were not affected by supplementation, and hepatic cholesterol level was lower in the group supplemented with both fibers and polyphenols. Uric acid concentrations and antioxidant capacity (FRAP) in plasma were reduced in all groups supplemented with polyphenols or fibers. The mean lesion area was reduced by 17, 38, and 38%, respectively, for the polyphenol, fiber, and polyphenol + fiber groups. Apple constituents supplied at nutritional doses therefore limit the development of atherosclerotic lesions in the aorta of apo E-deficient mice. On the basis of the results, we hypothesize that apple fibers and polyphenols may play a role in preventing atherosclerosis disease by decreasing uric acid plasma level.

[The role of post-prandial lipids in atherogenesis: particularities of diabetes mellitus]

Atherosclerosis is a complex and multifactorial disease, which determines clinical events that cause significant morbidity-mortality, represented by acute myocardial infarction, angina and sudden death. It is associated with lipid disturbances, platelet activation, thrombosis, endothelial dysfunction, inflammation, oxidative stress, altered matrix metabolism, among other disturbances. All these abnormalities are usual and more pronounced in diabetic patients, as well as in the post-prandial state. Among the coronary artery disease risk factors that are not usually employed in clinical practice in the whole population, postprandial hyperlipemia plays a major role, being a possible early marker of metabolic abnormalities and vascular dysfunction not yet seen in the fasting state. Recent results showed that post-oral lipid overload changes are negatively associated with endothelial dysfunction, and vascular reactivity abnormalities are strongly related to atherosclerosis progression and cardiovascular events. These abnormalities could disclose a lipid intolerance state that can be detected in apparently healthy subjects even before fasting abnormalities are seen. This review will deal with the pathophysiology changes involved in post-prandial hyperlipemia and its relationship with atherogenesis, with particular emphasis to diabetes mellitus.

Supplements of l-arginine attenuate the effects of high-fat meal on endothelial function and oxidative stress

BACKGROUND

Postprandial hypertriglyceridemia is known to cause endothelial dysfunction and increased oxidative stress. Oral supplements of l-arginine have been found to improve endothelial function. However, the effects of supplements of l-arginine on the influences of postprandial hypertriglyceridemia were not studied before.

METHODS

Forty young healthy men without any risk factors were equally divided into two groups. l-arginine group (age 22+/-1 years, body mass index 23.5+/-1.2 kg/m(2)) received a standard high-fat meal with 15 g oral l-arginine. Control group (age 22+/-1 years, body mass index 23.8+/-0.9 kg/m(2)) received a standard high-fat meal with placebo. A standard high-fat meal consisted of 900 kcal and 50 g of fat. Flow-mediated vasodilation (FMD), von Willebrand factor (vWF), p-Selectin, and glutathione peroxidase (GSH-Px) were measured before and 2 h after the high-fat meal.

RESULTS

Serum triglyceride levels were significantly increased 2 h after the high-fat meal in both groups. In the control group, FMD (10.5+/-1.2% vs. 6.8+/-1.4%, p<0.001) and GSH-Px (23.5+/-6.2 vs. 21.9+/-5.0 mug/ml, p=0.029) were significantly decreased after the high-fat meal. P-Selectin (20.0+/-7.7 vs. 25.9+/-10.5 mg/l, p=0.025) and vWF (731.2+/-131.5 vs. 934.9+/-133.8 mU/ml, p<0.001) were significantly increased after the high-fat meal. In the l-arginine group, FMD (10.3+/-1.3 vs. 9.3+/-0.9%, p<0.001) was slightly but significantly decreased after the high-fat meal but not GSH-Px (23.6+/-3.6 vs. 23.0+/-4.8%, p=0.468). P-Selectin (20.1+/-5.9 vs. 25.7+/-10.2 mg/l, p=0.001) and vWF (793.2+/-146.0 vs. 944.4+/-136.8 mU/ml, p<0.001) were significantly increased after the high-fat meal. Degree of FMD attenuation following the high-fat meal was significantly less in the l-arginine group (1.0+/-0.9 vs. 3.8+/-1.5%, p<0.001).

CONCLUSIONS

Concomitant supplements of l-arginine improved endothelial dysfunction and oxidative stress induced by postprandial hypertriglyceridemia. However, changes of p-Selectin and vWF were not affected by supplements of l-arginine with the high-fat meal.

Inflammation, obesity, and fatty acid metabolism: influence of n-3 polyunsaturated fatty acids on factors contributing to metabolic syndrome

Metabolic syndrome (MetS) comprises an array of metabolic risk factors including abdominal obesity, dyslipidemia, hypertension, and glucose intolerance. Individuals with MetS are at elevated risk for diabetes and cardiovascular disease. Central to the etiology of MetS is an interrelated triad comprising inflammation, abdominal obesity, and aberrations in fatty acid metabolism, coupled with the more recently recognized changes in metabolism during the postprandial period. We review herein preliminary evidence regarding the role of dietary n-3 polyunsaturated fatty acids in modulating each of the components of the triad of adiposity, inflammation, and fatty acid metabolism, with particular attention to the role of the postprandial period as a contributor to the pathophysiology of MetS.

Both alpha- and beta-carotene, but not tocopherols and vitamin C, are inversely related to 15-year cardiovascular mortality in Dutch elderly men

The role of beta-carotene, alpha-tocopherol, and vitamin C in the prevention of cardiovascular diseases (CVD) is controversial. Prospective studies on gamma-tocopherol and carotenoids other than beta-carotene are sparse. We assessed relations between the intake of different carotenoids, alpha- and gamma-tocopherol, and vitamin C with 15-y CVD mortality in elderly men who participated in the Zutphen Elderly Study. Information on diet and potential confounding factors was collected in 1985, 1990, and 1995. In 1985, 559 men (mean age approximately 72 y) free of chronic diseases were included in the current analysis. After 15 y of follow-up, comprising 5744 person-years, 197 men had died from CVD. After adjustment for age, smoking, and other potential lifestyle and dietary confounders, relative risks (RR) (95% CI) of CVD death for a 1-SD increase in intake were 0.81 (0.66-0.99) for alpha-carotene and 0.80 (0.66-0.97) for beta-carotene. Carrots were the primary source of alpha- and beta-carotene and their consumption was related to a lower risk of death from CVD (adjusted RR, 0.83; 95% CI = 0.68-1.00). Intakes of carotenoids other than alpha- and beta-carotene were not associated with CVD mortality, nor were vitamin C and alpha- and gamma tocopherol. In conclusion, dietary intakes of alpha-carotene and beta-carotene are inversely associated with CVD mortality in elderly men. This study does not indicate an important role for other carotenoids, tocopherols, or vitamin C in lowering the risk of CVD death.

A high-fat meal enriched with eicosapentaenoic acid reduces postprandial arterial stiffness measured by digital volume pulse analysis in healthy men

Diets rich in eicosapentaenoic acid [EPA; 20:5(n-3)] are associated with decreased arterial stiffness, but postprandial effects on vascular function are unknown. We investigated whether an EPA-enriched high-fat meal could improve postprandial vascular function. Seventeen healthy men ingested 2 test meals (51 g fat), 1 wk apart, in random order: 5 g EPA plus high-oleic sunflower oil (HOS) vs. HOS only. A second high-fat meal (44 g fat), the same on both study days, was provided 4 h later. Blood pressure and arterial function were measured using digital volume pulse (DVP) to derive a stiffness index (DVP-SI) and reflection index in fasting subjects at 3 and 6 h following the test meal. Blood samples were taken following the test meal for plasma 8-isoprostane F2alpha, nitric oxide (NO) metabolites (NOx), glucose, insulin, triacylglycerol, and fatty acid analysis. The plasma EPA concentration (mean +/- SD) reached a peak of 2.10 +/- 0.99 mmol/L following the EPA meal (5 h) and did not rise above 0.27 +/- 0.16 mmol/L 1 h following the placebo meal. DeltaDVP-SI did not differ between the 2 test meals at 3 h but was greater at 6 h following EPA (6 h -0.65 +/- 0.65 m/s) compared with placebo (6 h -0.33 +/- 1.26 m/s). Plasma 8-isoprostane F2alpha concentrations increased by 48% at 6 h compared with baseline following the EPA meal and plasma NOx decreased following both meals, with no differences between the meals in the changes. Changes in other variables measured also did not differ after subjects consumed the 2 meals. In conclusion, adding EPA to a high-fat meal results in acute changes in vascular tone, independent of changes in oxidative stress.

Reduced venous endothelial responsiveness after oral lipid overload in healthy volunteers

The aim of this study was to investigate endothelial venous function, inflammatory markers, and systemic oxidative stress after an oral lipid overload (OLO). We studied 18 healthy adults (9 men; age, 29.2 +/- 0.9 years; body mass index, 22.3 +/- 0.4 kg/m(2)). Blood samples were collected in the fasting state and 3, 4, and 5 hour after the OLO (1000 kcal, 58% fat) for metabolic variables, oxidative stress, inflammatory markers, adiponectin, and resistin. Changes in vein diameter to phenylephrine, acetylcholine, and sodium nitroprusside (dorsal hand vein technique) were measured before and after the OLO. Oral lipid overload increased triglycerides (61 +/- 6 vs 134 +/- 17 mg/dL, P < .001), insulin (7.2 +/- 0.8 vs 10.7 +/- 1.3 muU/mL, P < .05), and resistin (5.38 +/- 0.5 vs 6.81 +/- 0.7 ng/mL, P < .05) and reduced antioxidant capacity (plasma total antioxidant capacity: 186.7 +/- 56 vs 161.8 +/- 50 U Trolox per microliter plasma, P < .01), vascular reactivity (171.3 +/- 85 vs 894.4 +/- 301 ng/mL, P < .001), and maximum acetylcholine venodilation (105.9% +/- 9% vs 61.0% +/- 7%, P < .05). No changes were observed for sodium nitroprusside. Post-OLO triglycerides were positively correlated with phenylephrine dose (rho = 0.38, P < .05) and resistin (rho = 0.43, P < .01) and negatively correlated with the maximum acetylcholine venodilation (rho = -0.36, P < .05). In conclusion, an OLO impaired venoconstriction responsiveness in healthy subjects, probably because of a reduction in the antioxidant capacity.