Christopher N. Blesso

Grape Polyphenols Reduce Blood Pressure and Increase Flow-Mediated Vasodilation in Men with Metabolic Syndrome

We evaluated the effects of grape polyphenols in individuals classified with metabolic syndrome (MetS). Men (n = 24) aged 30-70 y were randomly assigned to consume either a freeze-dried grape polyphenol powder (GRAPE) or a placebo for 30 d in a double-blind, crossover design, separated by a 3-wk washout period. Participants were asked to maintain their usual diet and physical activity during the study and abstain from consuming polyphenol-rich foods. MetS criteria including blood pressure (BP) and markers of vascular endothelial function including brachial artery flow-mediated vasodilation (FMD), plasma total nitrite + nitrate (NOx) to estimate NO production, plasma soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured at the end of each dietary period. Systolic BP (P < 0.0025) and plasma sICAM-1 concentrations (P < 0.025) were lower, whereas the FMD response was higher (P < 0.0001), during the GRAPE compared with the placebo period. In addition, changes in sVCAM-1 concentrations between periods were positively correlated with changes in systolic BP (r = 0.45; P < 0.05). Although NOx concentrations did not differ between periods, changes in systolic BP were negatively correlated with changes in NOx concentrations (r = -0.44; P < 0.05), indicating the vasodilating properties of NO. Other MetS variables did not differ between the GRAPE and placebo periods. These results suggest that GRAPE polyphenols may potentiate vasorelaxation and reduce BP and circulating cell adhesion molecules, resulting in improvements in vascular function.

Whole egg consumption improves lipoprotein profiles and insulin sensitivity to a greater extent than yolk-free egg substitute in individuals with metabolic syndrome

OBJECTIVE We investigated if daily egg feeding, along with carbohydrate restriction, would alter lipoprotein metabolism and influence atherogenic lipoprotein profiles and insulin resistance in men and women with metabolic syndrome (MetS). METHODS In a randomized, single-blind, parallel design, participants consumed either 3 whole eggs/day (EGG, n=20) or the equivalent amount of yolk-free egg substitute (SUB, n=17), as part of a moderately carbohydrate-restricted diet (25%-30% energy) for 12 weeks. Plasma lipids, apolipoproteins (apos), oxidized LDL (oxLDL), cholesteryl ester transfer protein (CETP) and lecithin-cholesterol acyltransferase (LCAT) activities were assessed at baseline and week 12. Lipoprotein particle concentrations and sizes were measured by nuclear magnetic resonance spectroscopy. RESULTS Atherogenic dyslipidemia improved for all individuals as evidenced by reductions in plasma triglycerides, apoC-III, apoE, oxLDL, VLDL particle diameter, large VDL, total IDL, small LDL, and medium LDL particles (P<0.05). Furthermore, there were increases in HDL-cholesterol, large LDL and large HDL particles (P<0.05) for all individuals. However, there were greater increases in HDL-cholesterol and large HDL particles, and reductions in total VLDL and medium VLDL particles for those consuming EGG compared to SUB (P<0.05). Plasma insulin and insulin resistance (HOMA-IR) were reduced, while LCAT activity, and both HDL and LDL diameters increased over time in the EGG group only (P<0.05). CONCLUSIONS Incorporating daily whole egg intake into a moderately carbohydrate-restricted diet provides further improvements in the atherogenic lipoprotein profile and in insulin resistance in individuals with MetS.

Effects of curcumin on HDL functionality.

Graphical abstract Heterogeneity, metabolism and biological activities of normal functional HDL (A) and of HDL with defective antiatherogenic function in the dyslipidemia of metabolic diseases (B). Interconversion between lipid‐free apolipoprotein AI, discoid lipid‐poor pre‐&bgr;‐HDL, spherical small, dense HDL3, and large, light HDL2 mediated by lecithin:cholesterol acyltransferase, cholesteryl ester transfer protein, phospholipid transfer protein, hepatic lipase, endothelial lipase, ABCA1 and scavenger receptor type BI is schematically shown in either solid (A) or dotted (B) lines. In panel (B), key pathways leading to the formation of functionally deficient HDL (elevated hepatic production of serum amyloid A, shedding of apolipoprotein AI and other HDL proteins from HDL particles, enrichment of small HDL3 in triglycerides and depletion in cholesteryl esters mediated by cholesteryl ester transfer protein, and oxidation and glycation of HDL proteins) are shown in solid lines. Biological activities of HDL particles are indicated. Deficient biological activities of small, dense HDL3 are marked in red. HDL components are underlined. Figure. No Caption available. ABSTRACT Curcumin, a bioactive polyphenol, is a yellow pigment of the Curcuma longa (turmeric) plant. Curcumin has many pharmacologic effects including antioxidant, anti‐carcinogenic, anti‐obesity, anti‐angiogenic and anti‐inflammatory properties. Recently, it has been found that curcumin affects lipid metabolism, and subsequently, may alleviate hyperlipidemia and atherosclerosis. Plasma HDL cholesterol (HDL‐C) is an independent negative risk predictor of cardiovascular disease (CVD). However, numerous clinical and genetic studies have yielded disappointing results about the therapeutic benefit of raising plasma HDL‐C levels. Therefore, research efforts are now focused on improving HDL functionality, independent of HDL‐C levels. The quality of HDL particles can vary considerably due to heterogeneity in composition. Consistent with its complexity in composition and metabolism, a wide range of biological activities is reported for HDL, including antioxidant, anti‐glycation, anti‐inflammatory, anti‐thrombotic, anti‐apoptotic and immune modulatory activities. Protective properties of curcumin may influence HDL functionality; therefore, we reviewed the literature to determine whether curcumin can augment HDL function. In this review, we concluded that curcumin may modulate markers of HDL function, such as apo‐AI, CETP, LCAT, PON1, MPO activities and levels. Curcumin may subsequently improve conditions in which HDL is dysfunctional and may have potential as a therapeutic drug in future. Further clinical trials with bioavailability‐improved formulations of curcumin are warranted to examine its effects on lipid metabolism and HDL function.

Effects of carbohydrate restriction and dietary cholesterol provided by eggs on clinical risk factors in metabolic syndrome

BACKGROUND There are a limited number of clinical interventions evaluating the effects of dietary cholesterol in individuals at elevated risk for type 2 diabetes and cardiovascular disease. OBJECTIVE To investigate the effects of whole egg intake in adults with metabolic syndrome (MetS). METHODS Men (n = 12) and women (n = 25) with MetS were instructed to follow a moderate carbohydrate-restricted diet (<30% energy) and randomly assigned to consume either three whole eggs (EGG, n = 20) or egg substitute (SUB, n = 17)/d for 12 weeks. Dietary intake, MetS parameters, and body composition were assessed at baseline and post-intervention. RESULTS Total carbohydrate (P < .001) intake decreased in all participants over time. The EGG group consumed more dietary cholesterol (P < .001) and choline (P < .001) than the SUB group. MetS was reduced in both groups, with improvements noted in dyslipidemia and decreases in waist circumference (P < .01), weight (P < .001), and percent body fat (P < .001). Reductions in plasma tumor necrosis factor-α (P < .001) and serum amyloid A (P < .05) were seen in the EGG group only. Notably, increases in dietary cholesterol were associated with reductions in plasma tumor necrosis factor-α (r = -0.340, P = .04). Plasma C-reactive protein, adiponectin, interleukin-6 interleukin-10, and cell adhesion molecules were unaffected by the intervention. CONCLUSIONS These results demonstrate that on a moderate carbohydrate background diet, accompanied by weight loss, the inclusion of whole eggs improves inflammation to a greater extent than yolk-free egg substitute in those with MetS.

Milk sphingomyelin improves lipid metabolism and alters gut microbiota in high fat diet-fed mice

High dietary fat intake can cause elevated serum and hepatic lipids, as well as contribute to gut dysbiosis, intestinal barrier dysfunction and increased circulating lipopolysaccharide (LPS). Dietary milk sphingomyelin (SM) has been shown to inhibit lipid absorption in rodents. We evaluated the effects of milk SM on lipid metabolism and LPS levels in C57BL/6J mice fed a high-fat diet for 4weeks and compared it with egg SM. Mice were fed a high-fat diet (45%kcal from fat) (CTL, n=10) or the same diet modified to contain 0.25% (wt/wt) milk SM (MSM, n=10) or 0.25% (wt/wt) egg SM (ESM, n=10). After 4weeks, MSM had gained significantly less weight and had reduced serum cholesterol compared to CTL. ESM had increases in serum cholesterol, triglycerides, phospholipids and SM compared to CTL. MSM significantly decreased, while ESM increased, hepatic triglycerides. This may have been related to induction of hepatic stearoyl-CoA desaturase-1 mRNA observed in ESM. MSM displayed intestinal and hepatic gene expression changes consistent with cholesterol depletion. MSM had significantly lower serum LPS compared to CTL, which may have been due to altered distal gut microbiota. Fecal Gram-negative bacteria were significantly lower, while fecal Bifidobacterium were higher, in MSM. These results suggest that milk SM is more effective than egg SM at combating the detrimental effects of a high-fat diet in mice. Additionally, distal gut microbiota is altered with milk SM and this may have contributed to the lower serum LPS observed.

Egg Phospholipids and Cardiovascular Health

Eggs are a major source of phospholipids (PL) in the Western diet. Dietary PL have emerged as a potential source of bioactive lipids that may have widespread effects on pathways related to inflammation, cholesterol metabolism, and high-density lipoprotein (HDL) function. Based on pre-clinical studies, egg phosphatidylcholine (PC) and sphingomyelin appear to regulate cholesterol absorption and inflammation. In clinical studies, egg PL intake is associated with beneficial changes in biomarkers related to HDL reverse cholesterol transport. Recently, egg PC was shown to be a substrate for the generation of trimethylamine N-oxide (TMAO), a gut microbe-dependent metabolite associated with increased cardiovascular disease (CVD) risk. More research is warranted to examine potential serum TMAO responses with chronic egg ingestion and in different populations, such as diabetics. In this review, the recent basic science, clinical, and epidemiological findings examining egg PL intake and risk of CVD are summarized.

Grape Consumption Increases Anti-Inflammatory Markers and Upregulates Peripheral Nitric Oxide Synthase in the Absence of Dyslipidemias in Men with Metabolic Syndrome

We evaluated the effects of grape consumption on inflammation and oxidation in the presence or absence of dyslipidemias in metabolic syndrome (MetS). Men with MetS (n = 24), 11 with high triglycerides and low HDL and 13 with no dyslipidemia were recruited and randomly allocated to consume daily either 46 g of lyophilized grape powder (GRAPE), equivalent to 252 g fresh grapes, or placebo with an identical macronutrient composition and caloric value as GRAPE for four weeks. After a three-week washout, participants followed the alternate treatment. We measured changes between placebo and GRAPE periods in inflammatory and oxidative stress markers both in circulation and in gene expression. Changes in plasma adiponectin (p < 0.05), interleukin (IL)-10 (p < 0.005) and in mRNA expression of the inducible isoform of nitric oxide synthase (iNOS) (p < 0.25) were increased in the GRAPE compared to the placebo period only in those individuals without dyslipidemia. Additionally, plasma IL-10 was negatively correlated with NOX2 expression, a marker of oxidative stress (r = −0.55, p < 0.01), while iNOS expression was positively correlated with the expression of superoxide dismutase 2 (r = 0.642, p < 0.01), a key anti-oxidative enzyme. Grape consumption displayed anti-oxidative and increased anti-inflammatory markers in the absence of the inflammatory milieu associated with dyslipidemias.

Dietary sphingomyelin attenuates hepatic steatosis and adipose tissue inflammation in high-fat-diet-induced obese mice☆

Western-type diets can induce obesity and related conditions such as dyslipidemia, insulin resistance and hepatic steatosis. We evaluated the effects of milk sphingomyelin (SM) and egg SM on diet-induced obesity, the development of hepatic steatosis and adipose inflammation in C57BL/6J mice fed a high-fat, cholesterol-enriched diet for 10 weeks. Mice were fed a low-fat diet (10% kcal from fat) (n=10), a high-fat diet (60% kcal from fat) (HFD, n=14) or a high-fat diet modified to contain either 0.1% (w/w) milk SM (n=14) or 0.1% (w/w) egg SM (n=14). After 10 weeks, egg SM ameliorated weight gain, hypercholesterolemia and hyperglycemia induced by HFD. Both egg SM and milk SM attenuated hepatic steatosis development, with significantly lower hepatic triglycerides (TGs) and cholesterol relative to HFD. This reduction in hepatic steatosis was stronger with egg SM supplementation relative to milk SM. Reductions in hepatic TGs observed with dietary SM were associated with lower hepatic mRNA expression of PPARγ-related genes: Scd1 and Pparg2 in both SM groups, and Cd36 and Fabp4 with egg SM. Egg SM and, to a lesser extent, milk SM reduced inflammation and markers of macrophage infiltration in adipose tissue. Egg SM also reduced skeletal muscle TG content compared to HFD. Overall, the current study provides evidence of dietary SM improving metabolic complications associated with diet-induced obesity in mice. Further research is warranted to understand the differences in bioactivity observed between egg and milk SM.

Immune modulation by curcumin: The role of interleukin-10

ABSTRACT Cytokines are small secreted proteins released by different types of cells with specific effects on cellular signaling and communication via binding to their receptors on the cell surface. IL-10 is known to be a pleiotropic and potent anti-inflammatory and immunosuppressive cytokine that is produced by both innate and adaptive immunity cells including dendritic cells, macrophages, mast cells, natural killer cells, eosinophils, neutrophils, B cells, CD8+ T cells, and TH1, TH2, and TH17 and regulatory T cells. Both direct and indirect activation of the stress axis promotes IL-10 secretion. IL-10 deregulation plays a role in the development of a large number of inflammatory diseases such as neuropathic pain, Parkinsons disease, Alzheimers disease, osteoarthritis, rheumatoid arthritis, psoriasis, systemic lupus erythematosus, type 1 diabetes, inflammatory bowel disease, and allergy. Curcumin is a natural anti-inflammatory compound able to induce the expression and production of IL-10 and enhancing its action on a large number of tissues. In vitro and in pre-clinical models curcumin is able to modulate the disease pathophysiology of conditions such as pain and neurodegenerative diseases, bowel inflammation, and allergy, but also of infections and cancer through its effect on IL-10 secretion. In humans, at least one part of the positive effects of curcumin on health could be related to its ability to enhance IL-10 -mediated effects.

Black elderberry extract attenuates inflammation and metabolic dysfunction in diet-induced obese mice.

Dietary anthocyanins have been shown to reduce inflammation in animal models and may ameliorate obesity-related complications. Black elderberry is one of the richest sources of anthocyanins. We investigated the metabolic effects of anthocyanin-rich black elderberry extract (BEE) in a diet-induced obese C57BL/6J mouse model. Mice were fed either a low-fat diet (n 8), high-fat lard-based diet (HFD; n 16), HFD+0·25 % (w/w) BEE (0·25 %-BEE; n 16) or HFD+1·25 % BEE (1·25 %-BEE; n 16) for 16 weeks. The 0·25 % BEE (0·034 % anthocyanin, w/w) and 1·25 % BEE (0·17 % anthocyanin, w/w) diets corresponded to estimated anthocyanin doses of 20-40 mg and 100-200 mg per kg of body weight, respectively. After 16 weeks, both BEE groups had significantly lower liver weights, serum TAG, homoeostasis model assessment and serum monocyte chemoattractant protein-1 compared with HFD. The 0·25 %-BEE also had lower serum insulin and TNFα compared with HFD. Hepatic fatty acid synthase mRNA was lower in both BEE groups, whereas PPARγ2 mRNA and liver cholesterol were lower in 1·25 %-BEE, suggesting decreased hepatic lipid synthesis. Higher adipose PPARγ mRNA, transforming growth factor β mRNA and adipose tissue histology suggested a pro-fibrogenic phenotype that was less inflammatory in 1·25 %-BEE. Skeletal muscle mRNA expression of the myokine IL-6 was higher in 0·25 %-BEE relative to HFD. These results suggest that BEE may have improved some metabolic disturbances present in this mouse model of obesity by lowering serum TAG, inflammatory markers and insulin resistance.