Mediterranean Journal of Nutrition and Metabolism - Volume 1, issue 2
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Mediterranean Journal of Nutrition and Metabolism publishes original scientific papers on metabolism, including diabesity and eating disorders; nutrition (epidemiological, basic, clinical and artificial); dietary and nutritional practices and management and their impact on health from prevention to treatment.
The journal hosts the proceedings of relevant congresses and presents shorter notices focused on the original character of the Mediterranean nutritional civilisation. In addition, this journal is intended as a platform for scientific debate and knowledge-sharing among students and clinical practitioners, and between them and the broader scientific community, and finally as a tool for promoting and enhancing scientific cooperation.
Abstract: AGEs are produced by a nonenzymatic glycation process called the Maillard reaction which involves the condensation of a reducing sugar or an aldehydic group and a protein amino group, with the formation of a series of reactive intermediates leading to stable, irreversible, seldom fluorescent, compounds known as advanced glycation end-products (AGEs). The reaction occurs both in food during heating and in animal and human tissues. During the heating of food containing sugars, lipids and proteins, nonenzymatic protein browning reaction occurs, resulting in the formation of a large series of compounds, which include the melanoidins and other AGEs. Accumulation of AGEs…in the cells and in the extracellular matrix in animals is also observed; it is age-dependent, is related to cell or tissue turnover and is species-specific. These processes are accelerated in chronic diseases in which the production of pathogenetic AGEs and their accumulation rate are increased. The two research fields, the Maillard reaction in food chemistry and the glycation cascade in medicine, ran in parallel independently for a long time, but recently a new scientific society (the International Maillard Reaction Society, IMARS) has opened the way for an exciting fusion of knowledge. Pioneering studies resulted in concerns about the non-negligible bioavailability of dietary AGEs and related plasma concentrations in humans, and there are now claims that dietary AGEs may be toxic because of their bioreactivity in different chronic diseases. This has been confirmed by several studies in animals and in humans (AGEs-restricted diets resulted in a reduction of serum and tissue AGEs, related AGE receptors, inflammatory cells, and proatherosclerotic factors) and by in vitro studies on cells in culture. In view of the emerging evidence of a pathogenetic role of glycotoxins, an assessment of the benefits of a shift to a specific nutritional approach (the Mediterranean diet being the healthiest in terms of the low amount of AGEs and high amount of antioxidants) and an innovative therapeutic approach, aimed at directly breaking AGEs molecules or reversing their impaired gut absorption to favour their renal or faecal excretion, may be warranted. At any rate, a new scientific field is open for an interdisciplinary debate (involving chemists, geriatricians, and specialists in metabolic disorders, diabetes, and diet) paving the way for possible, remarkable clinical progress.
Abstract: Oxidative stress is in the basis of some diseases such as atherosclerosis, and is considered to be very important from the point of view of ageing. Biological membranes are very sensitive to oxidative stress because the presence of carbon–carbon double bonds in the lipid tails of their phospholipids. The type of dietary fat influences several biochemical parameters at the membrane level because membranes adapt their lipid composition to some extent in response to dietary fat. It is well know that dietary fat may modulate membrane susceptibility to oxidation, thus probably affecting in a direct or indirect way the susceptibility to…oxidative stress-related phenomena. In this review we summarize more than 15 years of research on the role of dietary fat, namely virgin olive oil, from the point of view of mitochondrial oxidative stress, ageing and atherosclerosis prevention.
Abstract: Different mixtures of higher aliphatic alcohols are on the market under the name “policosanol” claiming, without the support of independent data, the therapeutic efficacy and tolerability that former studies had demonstrated for the original policosanol. This name originally referred to a mixture of eight higher aliphatic primary alcohols obtained at the beginning of the 1990s from sugar-cane wax, and patented by Cuban researchers for its ability to lower blood cholesterol, and its antiplatelet and antioxidant properties. Analysis by GC-MS shows qualitative/ quantitative differences in policosanol-like preparations from different plant sources and origins. The anticholesterolaemic activity and some desirable pleiotropic effects…(decreased platelet aggregation, LDL oxidation, thromboxane production and foam-cell production) of the original policosanol have been confirmed by more than 50 clinical studies. However these results have recently been questioned by a few authors who have reported a modest or negligible activity of policosanol, whether from sugar cane or from other plant sources. A review of this important issue is therefore in order. Although the mechanism involved in the anticholesterolaemic effect has not been fully elucidated, there is clear evidence that policosanol induces AMP kinase phosphorylation and inhibits HMG-CoA reductase.
Keywords: Policosanol, High molecular weight alcohols, Clinical studies, Hypocholesterolaemic
Abstract: Numerous randomized clinical trials, systematic reviews and meta-analyses have confirmed the antidyslipidaemic activity of different dietary supplements, nutraceuticals and herbal remedies. International guidelines for cardiovascular disease prevention have begun to consider dietary supplements as an evidence-based approach to improve patients' plasma lipid levels. They already suggest to increasing or supplementing the dietary intake of soluble fibre (especially psyllium), soy proteins, plant sterols, niacin, and fish oil. Among the nutraceuticals, mevacoline and policosanol are both able to reduce plasma LDL-C by a mean of 20%. A preliminary clinical study of berberine has shown it to be the most powerful antihyperlipidaemic natural…compound, reducing plasma LDL-C by 25% and triglycerides by 35%. Among the herbal remedies, several placebo-controlled randomized clinical trials have confirmed the antihypercholesterolaemic, and antihypertriglyceridaemic properties of aged garlic powder, artichoke leaf extracts, guggul, and fenugreek. Single small clinical trials have also suggested that Korean ginseng, green tea, onion, yarrow, holy basil and arjun have an antihypercholesterolaemic effect.
Abstract: Malnutrition in patients with chronic heart failure (CHF) is not always as severe as muscle wasting in the same patients. Our data showed that 24% of patients with CHF had malnutrition (serum albumin < 3.5 g/dl) while 68% had muscle atrophy. This apparent discrepancy can be explained by considering the metabolic role of the striate muscle. The striate muscle maintains body metabolic performance by continuous exchange of fuel (amino acids) with other organs such as the liver. This happens when the subject is suffering from malnutrition or is starving, and it is regulated by the ratio of catabolic to anabolic…molecules such as hormones or cytokines. Glucose is produced when amino acids are metabolized in the liver by gluconeogenesis. Malnutrition, muscle wasting and the frequent progression to cachexia can be reduced by the use of specific therapeutic agents such as cytokines and/or catabolic hormone antagonists. This is because cytokines and catabolic hormones, with consequent insulin resistance (IR), can cause muscle wasting. An alternative and/or complementary therapy may be exogenous supplementation with amino acids. Amino acids: are rapidly absorbed independent of pancreatic activity, reduce IR, induce production in the liver of anabolic molecules such as growth hormone and insulin-like growth factor, and modulate catabolic hormone-mediated effects on adipocytes. Research on the most suitable qualitative and quantitative amino acid composition for an alternative and/or complementary therapy is being undertaken in different research centres.
Abstract: Weight loss and overweight/obesity – frequent consequences of malnutrition – may impair functional status and worsen concomitant morbidities in the elderly, often through changes in oxidative balance. In order to verify the relationships between these factors, a group of elderly people living on the island of Sardinia (Italy) underwent health and nutritional status assessment and oxidative balance evaluation. The elderly subjects had significantly higher d-ROMs test and body mass index (BMI) values than controls (d-ROMs 325.4 ± 66.3 vs. 295.4 ± 58.9 CARR U, p = 0.006; BMI 28.0 ± 4.6 vs. 21.7 ± 1.4 kg/m2 , p < 0.0001).…The risk of malnutrition in the elderly subjects was evaluated with the Mini Nutritional Assessment (MNA), which showed that 32 of the 111 elderly subjects (28.8%) were at risk of malnutrition, of whom 11 (34%) were overweight and 10 (31.2%) obese. Oxidative stress was negatively and significantly correlated with nutritional status. Oxidative stress may precede malnutrition, even in the absence of weight loss. Routine evaluation of nutritional status and oxidative balance in the elderly may help identify an early risk of malnutrition so that treatment can be personalized.
Keywords: Elderly, Malnutrition, Mini Nutritional Assessment, Overweight, Oxidative stress, d-ROMs test
Abstract: The inclusion of whey protein concentrates (WPC) in the diet can lead to a decrease in food intake. Considering that excessive food intake and weight gain are correlated with increased oxidative stress and other risk factors, the anorectic action of WPC may have important clinical implications. The aims of the current study were to verify the effects of WPC in comparison with those of casein on food intake, weight, and oxidized glutathione (GSSG) and total glutathione (GSH) concentrations in the blood and liver with or without oxidative stress induced by oral carbon tetrachloride intoxication. Male Sprague-Dawley rats were fed a…balanced liquid diet for 3 weeks. Half of the rats received WPC (group P), while the control group received casein (group C). Group P rats ate significantly less than group C rats (p < 0.0001), and their weights decreased significantly. After carbon tetrachloride intoxication, there was a significant increase in GSH in rats of group P compared with the levels in rats of group C both in the liver (GSH group P 4,994 ± 652.6, group C 2,196 ± 323.2 nmol/mg, p < 0.01) and in the blood (GSH group P 1,368 ± 69.56, group C 1,088 ± 48.35 nmol/ml, p < 0.05). These findings indicate that WPC is effective in reducing food intake and preventing weight gain, and it may also play a protective role against oxidative stress by increasing glutathione synthesis in the liver.
Abstract: Osteocalcin (OC) is a bone Gla protein synthesized by osteoblasts which have a high affinity for calcium. To adequately carboxylate OC to form carboxylated OC (cOC), the osteoblasts require sufficient vitamin K. If vitamin K is deficient, under-carboxylated OC (ucOC) is produced. The ratio between ucOC and cOC (UCR) as well as the levels of circulating ucOC are used as indicators of the vitamin K status of bone. The aim of the present study was to compare the vitamin K status of bone by measuring the plasma levels of ucOC and UCR in healthy adult women before and after 3…weeks of oral supplementation with 20 ml/day Petrini Plus extra virgin olive oil. Petrini Plus is an organic olive oil enriched with vitamins D3 , K1 and B6 . Enrolled in the study were 15 healthy female volunteers (aged 25–40 years). Plasma levels of ucOC and cOC were measured by ELISA. ucOC was found to be reduced and UCR was reduced by 44% after Petrini Plus olive oil supplementation. Petrini Plus extra virgin olive oil might therefore be useful for bone protection as it was able to counteract bone loss in healthy volunteers.
Keywords: Osteocalcin, Osteoporosis, Petrini Plus extra virgin olive oil, Vitamin K
Abstract: Background and aims: Family history of type II diabetes appears to increase the risk of type II diabetes and of coronary heart disease. The aim of this study was to evaluate the effect of a first-degree family history of type II diabetes on fasting plasma concentrations of leptin and adiponectin in an outpatient clinical setting. Methods and results: The study included 46 nondiabetic premenopausal overweight and obese women, aged 22–50 years. A total of 22 subjects had no family history of type II diabetes until the third generation (FH−) and 24 subjects had a family history of type II diabetes…(FH+), defined as having one or both parents with type II diabetes. Fasting plasma leptin and adiponectin were measured by radioimmunoassay. Leptin concentrations were significantly higher (p < 0.05) in FH+ than in FH− subjects. Moreover, after multiple regression analyses, both leptin (positively, p < 0.01) and adiponectin (negatively, p < 0.05) maintained a significant association with family history of diabetes, independently of age, body mass index, insulin resistance (estimated by homeostasis model assessment, HOMAIR), glucose, lipids, and blood pressure levels. Conclusions: This study indicated that a genetic predisposition to type II diabetes is associated with higher leptin concentrations and lower adiponectin levels independently of insulin resistance, blood pressure and metabolic parameters, which thus possibly contribute to the higher risk of type II diabetes and cardiovascular disease in subjects with a family history of type II diabetes.
Keywords: Leptin, Adiponectin, Family history of type II diabetes, Insulin resistance