[Hospital feeding process]. / Proceso de alimentación hospitalaria.

INTRODUCTION: The Management Working Group of SENPE has among its objectives the development of evaluation processes in Clinical Nutrition. Previously, the document entitled "Process of nutritional care: self-evaluation guide" was prepared as a tool designed to help assess the quality of nutritional therapy in hospitalized patients, mainly from the perspective of artificial nutrition. Now a complementary text of the previous one is presented, that describes the process by which hospitalized patients are fed. We have divided the hospital feeding process into six sections, for which a general description is made and quality indicators are proposed. We hope that this work will serve to improve the quality of hospital food and to help hospital food professionals to make their work more satisfactory and effective.

INTRODUCCIÓN: El Grupo de Trabajo de Gestión de SENPE tiene entre sus objetivos el desarrollo de procesos de evaluación en Nutrición Clínica. Con anterioridad se elaboró el documento denominado "Proceso de atención nutricional: guía de autoevaluación", como una herramienta concebida para ayudar a evaluar la calidad de la terapia nutricional en pacientes hospitalizados, fundamentalmente desde la perspectiva de la nutrición artificial. Ahora se presenta un texto complementario del anterior, en el que se describe el proceso por el que alimenta a los pacientes hospitalizados. Hemos dividido el proceso de alimentación hospitalaria en seis secciones, para las que se hace una descripción general y se proponen indicadores de calidad para su evaluación. Confiamos en que este trabajo sirva para mejorar la calidad de las dietas de los hospitales y para ayudar a los profesionales de la alimentación de los hospitales a hacer su labor más satisfactoria y efectiva.

Nutritional and microbiological quality of commercial and homemade blenderized whole food enteral diets for home-based enteral nutritional therapy in adults.

BACKGROUND & AIMS: Serious nutritional and contamination risks may be involved in the preparation of blenderized tube-feeding diets and in the handling of commercial diets. Their nutritional and microbiological quality in home settings is unknown. The objective of this study was to assess the nutritional and microbiological quality of commercial enteral and homemade blenderized whole foods diets intended to adult patients in home nutritional therapy. METHODS: In a cross sectional study, 66 samples of commercial (CD) and noncommercial (NCD) enteral diets were collected at the homes of patients in home enteral nutritional therapy, 33 of each type. Commercial diets were either powder (PCD; n = 13) or liquid (LCD; n = 20). The samples were analyzed in laboratory to assess their nutritional and microbiological quality. Anthropometric data of mid upper arm circumference (MUAC) and triceps skinfold (TST) thickness were obtained from the patients' medical records. RESULTS: NCD presented significantly lower values for protein, fat, fiber, carbohydrate and energy while water content was significantly higher. PCD and LCD did not show any statistically significant differences between them. In the NCD, the values measured for macronutrients and energy corresponded to less than 50% of the prescribed values (except for fat). In CD, protein value was about 20% more than the prescribed value; fat and energy values corresponded to approximately 100% of the prescription, while carbohydrate corresponded to 92%. Regardless the type of the diet, prevalence of undernutrition was high in both groups though patients of the NCD presented a higher percentage. Samples of NCD complied significantly less with the microbiological standards; only 6.0% complied with the standard for coliform bacteria. Escherichia coli was detected in 10, 2, and 2 samples of NCD, PCD and LCD, respectively. CONCLUSIONS: Homemade blenderized enteral diets showed low values of energy and macronutrients, delivered less than 50% of the prescribed values and had high levels of bacterial contamination.

Ready-to-Use Supplementary Foods and Ready-to-Use Therapeutic Foods: Developing Product Standards.

The purpose of this commentary is to describe the current regulatory environment for the multitude of ready-to-use supplementary foods and ready-to-use therapeutic foods used in international feeding programs for undernourished and malnourished children. A perspective on the role of standards, their desirable scope, benefits and limitations as well as possible future developments of products in these categories also is provided.

Enteral nutrition formula selection: current evidence and implications for practice.

Many new enteral nutrition (EN) formulas have been created over the past several decades with a variety of intended uses. Although each is intended to promote improved outcomes, research is often unclear and, in many cases, conflicting. It is important to note that EN products are considered medical foods by the U.S. Food and Drug Administration and therefore do not have to complete premarket review or approval and are not regulated to the same extent as pharmaceuticals. While standard EN formulas are designed to meet the basic macro- and micronutrient requirements of individuals who cannot meet nutrition needs orally, specialty EN products have been developed to exhibit pharmacologic properties, such as immune-enhancing formulas containing arginine, glutamine, nucleotides, and ω-3 fatty acids. With the vast number of products available, rising costs of healthcare, and the drive toward evidence-based practice, it is imperative that clinicians carefully consider research regarding use of specialty formulas, paying close attention to the quality, patient population, clinical end points, and cost to patient and/or facility.

Assessing copper status in pediatric patients receiving parenteral nutrition.

BACKGROUND: Copper is a trace mineral essential for numerous physiological processes. The purpose of this article is to provide data on copper levels in pediatric patients receiving parenteral nutrition (PN) that are useful to guide supplementation in PN formulation. METHOD: This is a retrospective review of hospitalized pediatric patients receiving PN supplemented and not supplemented with copper. In total, 751 supplemented pediatric patients and 90 pediatric patients not supplemented had serum copper levels measured. We assessed patient demographics, days on PN before copper level was drawn, serum copper levels, conjugated bilirubin levels, and C-reactive protein (CRP). RESULTS: The mean serum copper level was 80 mcg/dL at 20 days for supplemented patients and 64 mcg/dL at 14 days for the 90 nonsupplemented patients (P = .0002). In the supplemented patients, 50% of the levels were low and 45% were within the normal range. The remaining 5% of patients had high levels. In nonsupplemented patients, 71% were low and 29% within the normal range. There was no correlation between copper levels and conjugated bilirubin <2 mg/dL and >2 mg/dL (P = .3421). Copper levels correlated with CRP for CRP >4 mg/dL (P = .03). CONCLUSION: Pediatric patients receiving PN should be supplemented with copper to prevent deficiency. Serum copper levels should be assessed at 14 days. Assessment of copper status should not be determined by conjugated bilirubin levels. Serum copper levels may be elevated in patients with acute inflammation and may be falsely elevated when CRP is >4 mg/dL.

Specially formulated foods for treating children with moderate acute malnutrition in low- and middle-income countries.

BACKGROUND: Moderate acute malnutrition, also called moderate wasting, affects around 10% of children under five years of age in low- and middle-income countries. There are different approaches to addressing malnutrition with prepared foods in these settings; for example, providing lipid-based nutrient supplements or blended foods, either a full daily dose or in a low dose as a complement to the usual diet. There is no definitive consensus on the most effective way to treat children with moderate acute malnutrition. OBJECTIVES: To evaluate the safety and effectiveness of different types of specially formulated foods for children with moderate acute malnutrition in low- and middle-income countries, and to assess whether foods complying or not complying with specific nutritional compositions, such as the WHO technical specifications, are safe and effective. SEARCH METHODS: In October 2012, we searched CENTRAL, MEDLINE, LILACS, CINAHL, BIBLIOMAP, POPLINE, ZETOC, ICTRP, mRCT, and ClinicalTrials.gov. In August 2012, we searched Embase. We also searched the reference lists of relevant papers and contacted nutrition-related organisations and researchers in this field.     SELECTION CRITERIA: We planned to included any relevant randomised controlled trials (RCTs), controlled clinical trials (CCTs), controlled before-and-after studies (CBAs), and interrupted time series (ITS) that evaluated specially formulated foods for the treatment of moderate acute malnutrition in children aged between six months and five years in low- and middle-income countries. DATA COLLECTION AND ANALYSIS: Two authors assessed trial eligibility and risk of bias, and extracted and analysed the data. We summarised dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses using the random-effects model and assessed heterogeneity. The quality of evidence was assessed using GRADE methods. MAIN RESULTS: Eight randomised controlled trials, enrolling 10,037 children, met our inclusion criteria. Seven of the trials were conducted in Africa. In general, the included studies were at a low risk of bias. There may have been a risk of performance bias as trial participants were aware which intervention group they were in, but we did not consider this likely to have biased the outcome measurement. We were unable to assess the risk of reporting bias in half of the trials and two trials were at high risk of attrition bias. Any specially formulated food versus standard care - the provision of food increased the recovery rate by 29% (RR 1.29, 95% CI 1.20 to 1.38; 2152 children, two trials; moderate quality evidence), decreased the number dropping out by 70% (RR 0.30, 95% CI 0.22 to 0.39; 1974 children, one trial; moderate quality evidence), and improved weight-for-height (MD 0.20 z-score, 95% CI 0.03 to 0.37; 1546 children, two trials; moderate quality evidence). The reduction in mortality did not reach statistical significance (RR 0.44; 95% CI 0.14 to 1.36; 1974 children, one trial; low quality evidence). Lipid-based nutrient supplements versus any blended foods (dry food mixtures, without high lipid content), at full doses - there was no significant difference in mortality (RR 0.93, 95% CI 0.54 to 1.62; 6367 children, five trials; moderate quality evidence), progression to severe malnutrition (RR 0.88, 95% CI 0.72 to 1.07; 4537 children, three trials; high quality evidence), or the number of dropouts from the nutritional programme (RR 1.14, 95% CI 0.62 to 2.11; 5107 children, four trials; moderate quality evidence). However, lipid-based nutrient supplements significantly increased the number of children recovered (RR 1.10, 95% CI 1.04 to 1.16; 6367 children, five trials; moderate quality evidence), and decreased the number of non-recovering children (RR 0.53, 95% CI 0.40 to 0.69; 4537 children, three trials; high quality evidence). LNS also improved weight gain, weight-for-height, and mid-upper arm circumference, although for these outcomes, the improvement was modest (moderate quality evidence). One trial observed more children with vomiting in the lipid-based nutrient supplements group compared to those receiving blended food (RR 1.43, 95% CI 1.11 to 1.85; 2712 children, one trial; low quality evidence). Foods at complementary doses - no firm conclusion could be drawn on the comparisons between LNS at complementary dose and blended foods at complementary or full dose (low quality evidence). Lipid-based nutrient supplements versus specific types of blended foods - a recently developed enriched blended food (CSB++) resulted in similar outcomes to LNS (4758 children, three trials; moderate to high quality evidence). Different types of blended foods - in one trial, CSB++ did not show any significant benefit over locally made blended food, for example, Misola, in number who recovered, number who died, or weight gain (moderate to high quality evidence). Improved adequacy of home diet - no study evaluated the impact of improving adequacy of local diet, such as local foods prepared at home according to a given recipe or of home processing of local foods (soaking, germination, malting, fermentation) in order to increase their nutritional content. AUTHORS' CONCLUSIONS: In conclusion, there is moderate to high quality evidence that both lipid-based nutrient supplements and blended foods are effective in treating children with MAM. Although lipid-based nutrient supplements (LNS) led to a clinically significant benefit in the number of children recovered in comparison with blended foods, LNS did not reduce mortality, the risk of default or progression to SAM. It also induced more vomiting. Blended foods such as CSB++ may be equally effective and cheaper than LNS. Most of the research so far has focused on industrialised foods, and on short-term outcomes of MAM. There are no studies evaluating interventions to improve the quality of the home diet, an approach that should be evaluated in settings where food is available, and nutritional education and habits are the main determinants of malnutrition. There are no studies from Asia, where moderate acute malnutrition is most prevalent.

Characterization of NIST food-matrix Standard Reference Materials for their vitamin C content.

The vitamin C concentrations in three food-matrix Standard Reference Materials (SRMs) from the National Institute of Standards and Technology (NIST) have been determined by liquid chromatography (LC) with absorbance detection. These materials (SRM 1549a Whole Milk Powder, SRM 1849a Infant/Adult Nutritional Formula, and SRM 3233 Fortified Breakfast Cereal) have been characterized to support analytical measurements made by food processors that are required to provide information about their products' vitamin C content on the labels of products distributed in the United States. The SRMs are primarily intended for use in validating analytical methods for the determination of selected vitamins, elements, fatty acids, and other nutrients in these materials and in similar matrixes. They can also be used for quality assurance in the characterization of test samples or in-house control materials, and for establishing measurement traceability. Within-day precision of the LC method used to measure vitamin C in the food-matrix SRMs characterized in this study ranged from 2.7% to 6.5%.

Economical and financial analysis of lamb finishing fed with diets formulated according to the NRC (1985) and the NRC (2007).

This study compares both versions of the nutritional requirement system determined by the National Research Council (NRC) version 1985 (NRC85) and NRC version 2007 (NRC07), for finishing lambs in feedlots. Nineteen crossbred lambs were divided in four groups representing four experimental treatments: one diet according to NRC85 and three diets according to NRC07. The diets recommended by NRC07 considers crude protein intake relative to ruminal undegradable protein at 20, 40, and 60 % levels (NRC07/20, NRC07/40, and NRC07/60). Diets were composed of Brazilian semi-arid native grass silage, soybean meal, corn, annatto byproduct, and limestone. Purchases and sales of lambs were done according to average market prices in Brazil. The economic indicators considered pointed that all treatments were viable but NRC07/20 and NRC07/60 were more profitable with similar net present values (NPVs) and internal return rates (IRRs). NRC07/20 was the best option showing an IRR of 17.20 % and a payback period (PP) of 5.07 considering a fixed annual interest rate of 6 %. Sensitivity analysis considering a 10 % raise in variable costs showed negative NPVs, IRRs inferior to the opportunity cost rates adopted and PPs that exceeded the planning horizon of 7 years for both NRC85 and NRC07/40.

Systematic review of safety and tolerability of a complex micronutrient formula used in mental health.

BACKGROUND: Theoretically, consumption of complex, multinutrient formulations of vitamins and minerals should be safe, as most preparations contain primarily the nutrients that have been in the human diet for millennia, and at safe levels as defined by the Dietary Reference Intakes. However, the safety profile of commercial formulae may differ from foods because of the amounts and combinations of nutrients they contain. As these complex formulae are being studied and used clinically with increasing frequency, there is a need for direct evaluation of safety and tolerability. METHODS: All known safety and tolerability data collected on one complex nutrient formula was compiled and evaluated. RESULTS: Data were assembled from all the known published and unpublished studies for the complex formula with the largest amount of published research in mental health. Biological safety data from 144 children and adults were available from six sources: there were no occurrences of clinically meaningful negative outcomes/effects or abnormal blood tests that could be attributed to toxicity. Adverse event (AE) information from 157 children and adults was available from six studies employing the current version of this formula, and only minor, transitory reports of headache and nausea emerged. Only one of the studies permitted a direct comparison between micronutrient treatment and medication: none of the 88 pediatric and adult participants had any clinically meaningful abnormal laboratory values, but tolerability data in the group treated with micronutrients revealed significantly fewer AEs and less weight gain. CONCLUSIONS: This compilation of safety and tolerability data is reassuring with respect to the broad spectrum approach that employs complex nutrient formulae as a primary treatment.

The role of the Codex Alimentarius process in support of new products to enhance the nutritional health of infants and young children.

The Codex Alimentarius is a collection of internationally recognized standards, codes of practice, guidelines, and other recommendations relating to foods, food production, and food safety. Among other functions, it is responsible for setting international standards for safety and hygiene. Codex food standards and guidelines directed at foods produced primarily for young infants and children have important implications for maintaining nutritional status and health, especially given the positioning of these products as components of established World Health Organization (WHO)/UNICEF-recommended feeding strategies. Recently, new products targeted at this age group (e.g., lipid-based nutrient supplements and micronutrient powders) have been produced and used, but these are not totally covered under existing Codex guidelines or standards. The objective of this paper is to review the role of the Codex process and specifically to suggest revisions to existing Codex guidelines on formulated complementary foods (Guidelines for Formulated Supplementary Foods for Older Infants and Young Children, CAC/GL 08-1991) to encompass this new category of fortified complementary foods and home fortificants. In reviewing the existing guidelines, potential areas for revision included the sections on the recommended nutrients in these foods and their intended use. Updating the Codex guidelines provides the opportunity to encourage production and use of new products for children and help ensure that such foods, when used as directed, do not interfere with breastfeeding. The revised guidelines would help governments develop national regulations covering all forms of formulated complementary foods. They would also lessen impediments to international trade by providing clear guidance for foods used in feeding programs and for young children, particularly in developing countries.

[Experimental rationale for approaches to the development and evaluation of new functional foodstuffs].

This comprehensive experimental study had the objective to determine the optimum ratio of calcium and vitamin D used as additives in food compositions and provide an experimentally-based rationale for the use of new functional dairy products and evaluation of their nutritional value. Experimental medico-biological assessment was conducted using growing male Wistar rats by balance and biochemical methods. It was shown that the calcium/vitamin D ratio in foodstuffs determines their functional efficiency. High nutritive and biological value was documented for some new cottage cheese products rich in calcium (240 mg%) and vitamin D (1 mg%). Results of the study were used to develop guidelines for the enrichment of various food compositions with calcium and vitamin D and substantiate methods for the assessment of their real functional effectiveness.

Long-term efficacy of 'ready-to-drink' protein substitute in phenylketonuria.

BACKGROUND: In phenylketonuria (PKU), protein substitute is an essential part of dietary treatment. Short-term studies have demonstrated that liquid protein substitutes (LPS) are efficacious, and improve compliance in teenagers and adults with PKU, although there are no data available to demonstrate that their effectiveness is sustained over time. The present retrospective study aimed to evaluate the long-term efficacy of ready-to-drink protein substitute in a group of people with PKU. METHODS: Thirty-four patients (17 females and 17 males, median age 14.9 years, range 7.2-53.8 years) with PKU on dietary management were recruited from Birmingham Children's Hospital. All patients who were taking a LPS for a median of 2.4 years (range 6 months to 4.1 years), had their plasma phenylalanine concentrations, anthropometric and nutritional biochemical markers reviewed, both before and when taking the LPS. RESULTS: There was a significant improvement in median plasma phenylalanine (P < 0.05), vitamin B(12) (P < 0.01), calcium (P < 0.05) and albumin (P < 0.05) concentrations in subjects (n = 13) aged >18 years when taking the LPS. In the children aged 7-18 years (n = 21), median plasma phenylalanine concentrations were maintained on LPS. Their plasma selenium concentrations (P < 0.05) deteriorated, but calcium (P < 0.05), albumin (P < 0.01), haemoglobin (P < 0.01) and haematocrit (P < 0.01) significantly improved. CONCLUSIONS: This retrospective review suggested that, in adult patients, the long-term use of LPS is associated with better compliance by lowering blood phenylalanine and improving nutritional biochemical markers.

Formulas de soja / Soy formulae

Hoy en día se podrían considerar únicamente tres indicaciones claras de las fórmulas de soja: las alteraciones del metabolismo hidrocarbonado, como la galactosemia y el déficit de lactasa congénita, ambas con una incidencia mínima; los hijos de padres que por motivos religiosos o de otra índole prefieren evitar el aporte de proteínas animales y aquellos lactantes con alergia robada a las proteínas vacunas que rechazan las fórmulas hidrolizadas o las fórmulas a base de aminoácidos. Igualmente hay que puntualizar que todos los comités y grupos relacionados exhortan a la industria a disminuir en su proceso de fabricación las cantidades de fitatos, aluminio, fitoestrógenos y otros componentes de seguridad a corto y largo plazo no comprobada (AU)

Currently, only three clear indications of the soy formulae could be considered: hydrocarbon metabolism alterations, such as galactosemia, and congenital lactase deficit, both having a mínimum incidence. Children of parents who, for any religious or other type of reason prefer to avoid animal protein intake and those infants with proven allergy to cow protein who reject the hydrolyzed formulae or amino acid based formulae. In addition, it should be stressed that all of the related committees and groups urge the industries to decrease the amounts of phylates, aluminum, phytoestrogens and other unproven short and long term safety components in their manufacturing process (AU)

Natural endogenous ligands for benzodiazepine receptors in hepatic encephalopathy.

Benzodiazepines of natural origin (NBZDs) have been found in human blood and brains as well as in medicinal plants and foods. In plasma and brain tissue there are i.e. diazepam and nordiazepam equal to commercial drugs but there are also other benzodiazepine-like compounds termed "endozepines", which act as agonists at the benzodiazepine receptors of central type (CBR). A synthetic pathway for the production of NBZDs has not yet been found, but it has been suggested that micro-organisms may synthesize molecules with benzodiazepine-like structures. Hence NBZDs could be of both endogenous and exogenous source and be considered as natural anxyolitic and sedative. Interestingly there are also natural compounds, such as the polypeptide Diazepam Binding Inhibitor (DBI) acting as an "inversive agonist" implicated in fair and panic disorders. It has been suggested that NBZDs may play a role in the pathogenesis of hepatic encephalopathy (HE). Multidirectional studies evaluated NBZDs levels (1) in the blood of normal subjects, of cirrhotic with or without HE and in commercial benzodiazepine consumers; (2) in the blood of cirrhotic treated or not with a non-absorbable antibiotic; (3) in several constituents of our diet. In conclusion, NBZDs increase sometime in cirrhotics with or without HE but they reach concentrations not higher than those found in commercial benzodiazepines consumers. Hence NBZDs must be considered as occasional precipitating factor of HE and benzodiazepine antagonists only symptomatic drugs. The finding that NBZDs may be in part synthesized by intestinal bacterial flora and in part constituent of our diet underlines the importance to feed cirrhotic patients with selected food.

Testing the effect of specific orders to provide oral liquid nutritional supplements to nursing home residents: a quality improvement project.

OBJECTIVES: To improve nursing home (NH) staff delivery of oral liquid nutritional supplements between meals to residents with a history of weight loss. DESIGN: Pre-Post intervention study. SETTING: Two skilled nursing homes. PARTICIPANTS: Eighteen long term care residents. INTERVENTION: At baseline all participants had a non-specific physician's order to receive a nutritional supplement. The intervention consisted of specifying the physician's order as follows: "Give 4 oz high protein supplement at 10 am, 2 pm, and 7 pm". MEASUREMENTS: Research staff conducted direct observations for two days during and between meals for a total of 4 days, or 12 possible observation periods per participant before and one week following the intervention. Research staff documented NH staff delivery of snacks (including high protein supplements) and amount consumed (fluid ounces) for the high protein supplements using a standardized protocol during each observation period. RESULTS: Before the specific order was written participants were offered any type of snack an average of 1.82 times per day and a high protein supplement 0.59 times per day. After the specific order was written participants were offered any type of snack an average of 1.59 times per day and a high protein supplement 0.91 times per day. There were no statistically significant differences in the average number of times snacks or supplements were offered before and after the specific order was written. The proportion of snacks offered that were high protein supplements did increase after the specific order was written (p<0.001). When a high protein supplement was provided, most residents consumed 100% of it. CONCLUSIONS: Oral liquid nutritional supplements were not provided consistent with orders in NH practice. The specificity of the order related to type of supplement and time of delivery did not influence when and how often supplements are provided to residents but it did influence the type of nutritional supplement offered.

Oral nutritional supplements and taste preferences: 545 days of clinical testing in malnourished in-patients.

BACKGROUND & AIMS: Acceptability and intake of oral nutritional supplements are often suboptimal, partly because patients dislike flavour, texture or smell. We assessed the taste preferences about milk-based and fruit-juice typed supplements in malnourished in-patients. METHODS: One hundred and nine in-patients requiring oral nutritional support were assigned to consume four given supplements on four consecutive days, to answer a questionnaire based on a 10-point visual analogue scale (VAS) on acceptance/tolerance, and to choose their preferred product for the fifth day. RESULTS: Overall pleasantness was significantly better for milk-based supplements than for sweet and salty fruit-juice typed products (on VAS: 6.2+/-3.1 versus 4.4+/-3.9, p<0.01 and 3.5+/-3.4, p<0.0001, respectively, when 1 meant "not at all" and 10 "very much"), whereas digestive tolerance was comparable. When offered together on day 5, milk-based products were more frequently preferred (81.6%) than fruit-juice typed supplements (18.4%, p<0.001). Among milk-based products, vanilla, coffee and strawberry had comparable good results, whereas chocolate was less chosen and neutral never. For fruit-juice typed products, tomato obtained better results than orange or apple. CONCLUSIONS: Oral nutritional supplements are globally well-accepted and tolerated, but with variations according to categories and flavours that must be considered to improve compliance.

Hormetic dietary phytochemicals.

Compelling evidence from epidemiological studies suggests beneficial roles of dietary phytochemicals in protecting against chronic disorders such as cancer, and inflammatory and cardiovascular diseases. Emerging findings suggest that several dietary phytochemicals also benefit the nervous system and, when consumed regularly, may reduce the risk of disorders such as Alzheimer's and Parkinson's diseases. The evidence supporting health benefits of vegetables and fruits provide a rationale for identification of the specific phytochemicals responsible, and for investigation of their molecular and cellular mechanisms of action. One general mechanism of action of phytochemicals that is emerging from recent studies is that they activate adaptive cellular stress response pathways. From an evolutionary perspective, the noxious properties of such phytochemicals play an important role in dissuading insects and other pests from eating the plants. However at the subtoxic doses ingested by humans that consume the plants, the phytochemicals induce mild cellular stress responses. This phenomenon has been widely observed in biology and medicine, and has been described as 'preconditioning' or 'hormesis.' Hormetic pathways activated by phytochemicals may involve kinases and transcription factors that induce the expression of genes that encode antioxidant enzymes, protein chaperones, phase-2 enzymes, neurotrophic factors, and other cytoprotective proteins. Specific examples of such pathways include the sirtuin-FOXO pathway, the NF-kappaB pathway, and the Nrf-2/ARE pathway. In this article, we describe the hormesis hypothesis of phytochemical actions with a focus on the Nrf2/ARE signaling pathway as a prototypical example of a neuroprotective mechanism of action of specific dietary phytochemicals.

Effects of short-term and long-term treatment with medium- and long-chain triglycerides ketogenic diet on cortical spreading depression in young rats.

The ketogenic diet (KD) is a high fat and low carbohydrate and protein diet. It is used in the clinical treatment of epilepsy, in order to decrease cerebral excitability. KD is usually composed by long-chain triglycerides (LCT) while medium-chain triglycerides (MCT) diet is beginning to be used in some clinical treatment of disorders of pyruvate carboxylase enzyme and long-chain fatty acid oxidation. Our study aimed to analyze the effects of medium- and long-chain KD on cerebral electrical activity, analyzing the propagation of the phenomenon of cortical spreading depression (CSD). Three groups of weaned rats (21 days old) received, for 7 weeks, either a control (AIN-93G diet), or a MCT-KD (rich in triheptanoin oil), or a LCT-KD (rich in soybean oil). They were compared to another three groups (21 days old) receiving the same diets for just 10 days. CSD propagation was evaluated just after ending the dietary treatments. Results showed that short-term KD treatment resulted in a significant reduction of the CSD velocity of propagation (control group: 4.02+/-1.04mm/min; MCT-KD: 0.81+/-1.46mm/min and LCT-KD: 2.26+/-0.41mm/min) compared to the control group. However, long-term treatment with both KDs had no effect on the CSD velocity (control group: 3.10+/-0.41mm/min, MCT-KD: 2.91+/-1.62mm/min, LCT-KD: 3.02+/-2.26mm/min) suggesting that both short-term KDs have a positive effect in decreasing brain cerebral excitability in young animals. These data show for the first time that triheptanoin has an effect on central nervous system.

Diet and Alzheimer's disease.

Alzheimer's disease (AD) is increasing in prevalence. There are no known preventive or curative measures. There is evidence that oxidative stress, homo-cysteine-related vitamins, fats, and alcohol have a role in the pathogenesis of AD. Some epidemiologic studies suggest that higher dietary intake of antioxidants, vitamins B(6), B(12), and folate, unsaturated fatty acids, and fish are related to a lower risk of AD, but reports are inconsistent. Modest to moderate alcohol intake, particularly wine, may be related to a lower risk of AD. The Mediterranean diet may also be related to lower AD risk. However, randomized clinical trials of supplements of vitamins E, B(12), B(6), and folate have shown no cognitive benefit, and randomized trials for other nutrients or diets in AD are not available. The existing evidence does not support the recommendation of specific supplements, foods, or diets for the prevention of AD.

Towards a nutritional approach for prevention of Alzheimer's disease: biochemical and cellular aspects.

Alzheimer's disease (AD) is a major public health concern in all countries. Although the precise cause of AD is still unknown, a growing body of evidence supports the notion that soluble amyloid beta-peptide (Abeta) may be the proximate cause of synaptic injuries and neuronal death early in the disease. AD patients display lower levels of docosahexaenoic acid (DHA, C22:6 ; n-3) in plasma and brain tissues as compared to age-matched controls. Furthermore, epidemiological studies suggest that high DHA intake might have protective properties against neurodegenerative diseases. These observations are supported by in vivo studies showing that DHA-rich diets limits the synaptic loss and cognitive defects induced by Abeta peptide. Although the molecular basis of these neuroprotective effects remains unknown, several mechanisms have been proposed such as (i) regulation of the expression of potentially protective genes, (ii) activation of anti-inflammatory pathways, (iii) modulation of functional properties of the synaptic membranes along with changes in their physicochemical and structural features.