Beta-glucan- or rice bran-enriched foods : a comparative crossover clinical trial on lipidic pattern in mildly hypercholesterolemic men

Background/ Objectives:There has been growing interest in using dietary intervention to improve the lipid profile. This work aims at analyzing the effects and the comparison of the enrichment of a diet with beta-glucans or rice bran in mildly hypercholesterolemic men.Subjects/Methods:The subjects initially consumed a 3-week Step 1 American Heart Association diet with rice bran-enriched foods. After this adaptation period, volunteers were randomly assigned to follow a crossover, controlled trial that consisted of two treatment with beta-glucan- or rice bran-enriched foods, each of 4 weeks, with a 3-week wash-out, like the adaptation period, between periods. Fasted blood samples were collected on days 0, 21, 49, 70 and 98 in both study arms for measuring low-density lipoprotein (LDL)-cholesterol (primary outcome), total cholesterol, high-density lipoprotein (HDL)-cholesterol, triglycerides, apolipoprotein (apo) A-I, apo B and glucose levels.Results:Twenty-four men (mean age: 50.3\ub15.3, mean body mass index: 24.9\ub11.9) completed the 14-week trial. Subjects in the 3-week adaptation period experienced significant reductions in the mean level of LDL cholesterol, total cholesterol, total cholesterol/HDL cholesterol, LDL cholesterol/HDL cholesterol, apo A-I, apo A-I/apo B and glucose. During the intervention diet periods, a difference was found between treatment groups for the mean change in LDL (0.21 (95% confidence interval (CI): 0.02-0.40), P=0.033) and total cholesterol (0.34 (95% CI: 0.20-0.47), P<0.001). Other parameters evaluated were not significantly affected by the diet consumed.Conclusions:The results of the present crossover clinical trial showed that beta-glucan-enriched foods are more effective in lowering serum LDL levels, compared with rice bran-enriched foods

Effect of Polyglucosamine on Weight Loss and Metabolic Parameters in Overweight and Obesity : A Systemic Review and Meta-Analysis

The use of dietary supplements for weight loss has gained significant momentum. Polyglucosamine, a chitosan derivative, is a dietary supplement increasingly used for weight loss. In this meta-analysis, we systematically summarized and quantified the key findings of four randomized, placebo-controlled clinical trials examining the effects of polyglucosamine supplementation and caloric restriction, and physical activity on body weight, body mass index (BMI), and waist circumference in subjects with overweight and obesity. The control group was set with a physical activity from 6\u20137 MET-h/week activity and up to 21 MET-h/week activity with caloric restriction. Compliance in the latter trials was reported via a follow-up questionnaire with the individual participants. The analysis included 399 subjects followed for a period ranging from 12 weeks to one year. Subjects\u2019 age ranged from 21\u201375 years, BMI from 26\u201345 kg/m2, and all were white European or Caucasian in ethnicity. The meta-analyzed mean differences for random effects showed that polyglucosamine supplementation improves weight loss by 121.78 kg [ 122.78, 120.79], BMI by 121.52 kg/m2 [ 123.58, 0.54], and improves waist circumference reduction by 121.45 cm [ 122.77, 120.12]. In conclusion, the use of polyglucosamine supplementation in conjunction with lifestyle behavioral therapies can be effective for weight reduction. Further studies are needed to examine the long-term effects of polyglucosamine supplementation on weight loss and other metabolic parameters

Fluidit\ue0 di membrana, ossidazione delle lipoproteine ed invecchiamento

In the past 20 years evidence has been accumulated suggesting that oxidative stress and damage to cellular components from reactive oxygen species (ROS) play an integral role in the age-related deterioration of biochemical and physiologic processes and in the incidence of age-related disease. Mitochondria are the primary site for ROS generation as a by product of aerobic metabolism and the accumulation of mitochondrial oxidative damage over time diminishes the cellular efficiency in energy production (ATP). Moreover, oxidative stress contributes to functional and structural alterations of tissues and blood vessels that decrease the supply of oxygen and nutrients to the various organs and body systems, thus further reducing energy production. The deficiency of ATP decreases the bioavailability of all the molecules whose biosynthesis requires the intervention of ATP itself and slows down the process of repair and replacement of the various lipid or glycoprotein molecules, which make up the bilayer structural organization of the cell membrane. Current evidence suggests that the processe at the cell surface seem to be of comparable importance for the life of an individual as the nucleus for the preservation of the species. Oxidative stress leads to progressive structural alteration of membranes manifested by a progressive reduction of membrane fluidity that causes a secondary metabolic damage to the cells. The membrane hardening, in fact, limits the capacity of membrane proteins to collide with their ligands, thus reducing the activity of enzymes, receptors for hormone or neurotransmitter, ion channels and the trans-membrane carriers for amino acids and glucose. There is thus a spiral of structural and functional damage to cells and tissues, starting with the reduced efficiency in ATP synthesis which is further amplified by the decreased rate of synthesis of membrane macromolecules and lipids, the increase in intracellular calcium and potassium, and the increase in ROS-induced peroxidation processes. Moreover, significant correlations have been found between lipoprotein susceptibility to peroxidation, the degree of obesity, the peripheral resistance to insulin, and the risk to developing atherosclerosis and cardiovascular diseases. In particular, in the case of HDL it has been demonstrated that these lipoproteins serve as an acceptor of cholesterol efflux from foam cells by a mechanism similar to that of \u201creverse cholesterol transport\u201d and that their oxidation significantly reduces the cholesterol efflux from macrophage-derived foam cells. In a previous work we demonstrated that pyrene derivatives can be used to selectively follow the kinetics of Cu++-catalyzed peroxidation in the hydrophilic envelope (pyrene dodecanoyl sulfatide) and in the hydrophobic core (cholesteryl pyrenyl hexanoate) of human LDL and HDL. With the aim to provide more detailed information on the correlation between lipoprotein susceptibility to peroxidation, membrane fluidity, obesity and risk of developing atherosclerosis, we performed a study in which the different envelope and core susceptibility to peroxidation of both LDL and HDL and membrane fluidity were measured in two adult female groups: overweight and obese patients and lean healthy subjects. The response of the hydrophobic core to oxidative stress induced by Cu++ in LDL and HDL was quite similar in both groups, whereas the envelope, and in particular that one of HDL lipoproteins, was by far more rapidly peroxidized in overweight and obese patients. The higher oxidability of the HDL envelope of obese patients could depend on several factors, including the concentration of envelope-specific antioxidants, the levels of peroxidable substrates, and the different catalyzing capacity of copper. How both the onset of this ROS-induced spiral and the membrane hardening in the obese patients could be kept under control with either an adequate diet or a supply of appropriate functional food will be the main issue of this presentation

Red wine polyphenols protect n 123 more than n 126 polyunsaturated fatty acid from lipid peroxidation

Moderate red wine consumption is associated with decreased risk for cardiovascular disease; however, the underlying mechanisms are not completely understood. The main aim of this study was to investigate the effects of red wine polyphenols (WP) on the oxidizability of human plasma fatty acids, in particular those most involved in the inflammatory response \u2014 archidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The oxidizability of the major fatty acids of plasma was determined by measuring their loss gaschromatographycally during peroxidation kinetics induced by 2\u2032-azobis(2-methylpropionamidine)-dihydrochloride. The capacity of WP to scavenge 1,1,diphenyl-2-picryl-hydrazyl (DPPH), superoxide anion and hydroxyl radicals, and trap total peroxyl radicals in plasma (TRAP) was also measured. WP (1.75\u20135 \u3bcg/mL) inhibited DPPH, superoxide anion and hydroxyl radicals and increased TRAP in a dose-dependent manner. WP (1.75 \u3bcg/mL) significantly protected all plasma PUFA from peroxidation but the protection of EPA and DHA was higher than that of AA. These results suggest that the association of WP to apolipoproteins makes EPA and DHA less accessible to hydro-soluble radicals than AA, thus providing a biochemical rationale for future \u2018in vivo\u2019 studies on the benefits to health of moderate red wine consumption

Anti-oxidant, anti-glycant, and inhibitory activity against \u3b1-amylase and \u3b1-glucosidase of selected spices and culinary herbs

Aqueous and methanol extracts of dry sage, rosemary, basil, parsley, chili, garlic and onion were analyzed to investigate their anti-oxidant and anti-glycant activities and in vitro inhibitory potential against enzymes involved in glycemic regulation. The aqueous extracts of rosemary and sage were the richest in phenolic compounds and showed the highest ability in binding iron and inhibiting DPPH, superoxide radicals and advanced glycation end-product production, lipid peroxidation, and the activity of a-glucosidase and a-amylase. On the other hand, the methanol extracts of both these Labiatae were less efficient than those of garlic, onion, parsley and chili in scavenging hydroxyl radicals. As far as protein glycation is concerned, methanol extracts were more effective in inhibiting the production of Amadori compounds and the aqueous ones in preventing advanced glycation endproduct formation. Therefore these spices may be preventive not only against cardiovascular diseases but also type 2 diabetes

Palm oil: health risks and benefits

Recently, there has been growing discussion on the use of palm oil in the preparation of food products. In this review, we first examine the criticism of palm oil, in particular the supposed contribution to increase cardiovascular disease risk factors because of the high content in saturated fatty acid and the content of potential toxic compound formed during the refining processes, such as glycidols and chloropropanediols. The results of the main publications on these topics demonstrate that the massive attack against palm oil is largely unjustified if palm oil is assumed within the limits of a balanced diet. Finally, we discuss the possible benefits on health of the minor components of palm oil, such as tocopherols, tocotrienols and carotenoids

Palm oil: health risks and benefits

Recently, there has been growing discussion on the use of palm oil in the preparation of food products. In this review, we first examine the criticism of palm oil, in particular the supposed contribution to increase cardiovascular disease risk factors because of the high content in saturated fatty acid and the content of potential toxic compound formed during the refining processes, such as glycidols and chloropropanediols. The results of the main publications on these topics demonstrate that the massive attack against palm oil is largely unjustified if palm oil is assumed within the limits of a balanced diet. Finally, we discuss the possible benefits on health of the minor components of palm oil, such as tocopherols, tocotrienols and carotenoids

Effects of weight loss on erythrocyte membrane composition and fluidity in overweight and moderately obese women

A previous study showed chemical and physical impairment of the erythrocyte membrane of overweight and moderately obese women. The present study investigated the effects of a low-calorie diet (800 kcal/day deficit for 8 weeks) on erythrocyte membrane properties in 70 overweight and moderately obese (body mass index, 25-33 kg/m(2)) normotensive, nondiabetic women. At the end of dietary intervention, 24.3% of women dropped out, 45.7% lost less than 5% of their initial weight (Group I) and only 30% of patients lost at least 5% of their initial body weight (Group II). Group I showed no significant changes in erythrocyte membrane composition and function. The erythrocyte membranes of Group II showed significant reductions in malondialdehyde, lipofuscin, cholesterol, sphingomyelin, palmitic acid and nervonic acid and an increase in di-homo-gamma-linolenic acid, arachidonic acid and membrane fluidity. Moreover, Group II showed an improvement in total cholesterol, low-density lipoprotein cholesterol, glycemia and insulin resistance. These changes in erythrocyte membrane composition could reflect a virtuous cycle resulting from the reduction in insulin resistance associated with increased membrane fluidity that, in turn, results in a sequence of metabolic events that concur to further improve membrane fluidity