No description available.

Yes / Personalized nutrition has the potential to improve health, prevent disease and reduce healthcare expenditure. Whilst research hints at positive consumer attitudes towards personalized nutrition that draws upon lifestyle, phenotypic and genotypic data, little is known about the degree to which registered dietitians (RD) are engaged in the delivery of such services. This review sought to determine possible factors associated with the integration of the emerging science of Nutritional Genomics (NGx) into the clinical practice setting by practicing registered dietitians. Scope Search of online databases (Pubmed; National Library of Medicine; Cochrane Library; Ovid Medline) was conducted on material published from January 2000 to December 2014. Studies that sampled practicing dietitians and investigated integration or application of NGx and genetics knowledge into practice were eligible. Articles were assessed according to the American Dietetic Association Quality Criteria Checklist. Key findings Application of nutritional genomics in practice has been limited. Reluctance to integrate NGx into practice is associated with low awareness of NGx, a lack of confidence in the science surrounding NGx and skepticism toward Direct to consumer (DTC) products. Successful application to practice was associated with knowledge about NGx, having confidence in the science, a positive attitude toward NGx, access to DTC products, a supportive working environment, working in the clinical setting rather than the public health domain and being in private rather than public practice. Conclusions There is a need to provide RGs with a supportive working environment that provides ongoing training in NGx and which is integrated with clinical practice.

Thesis (MNutr)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Introduction: Nutritional genomics is a new and emerging field aimed at investigating the complex interactions between genetics and diet and the joint influence this has on disease prevention and health promotion. Research is accelerating at a rapid pace and although still in its infancy, it is important for registered dietitians (RDs) to be knowledgeable and keep abreast of these developments as it promises to revolutionize dietetic practice. International studies have demonstrated low confidence and involvement as well as poor knowledge of both genetics and nutritional genomics amongst RDs. To date no similar studies have been conducted amongst South African (SA) RDs. Methods: A cross-sectional descriptive study was conducted using a national survey of 1881 dietitians registered with the Health Professions Council of South Africa (HPCSA). Data was collected using an existing and validated questionnaire as developed for use in a similar study amongst RDs in the United Kingdom (UK). The self-administered questionnaire consisted of 4 sections to assess the following aspects: i) involvement and confidence in activities relating to genetics and nutritional genomics ii) knowledge of genetics and nutritional genomics iii) factors associated with knowledge and iv) demographic information. The main method of questionnaire distribution was via email (70%) using the Association of Dietetics in South Africa (ADSA) distribution service and questionnaires were posted to those RDs not registered with ADSA (30%). Results: The response rate was 15.2% (n = 279). Results showed low involvement in activities relating to genetics (n = 47, 17%) and nutritional genomics (n = 72, 25.8%). The majority of respondents indicated low confidence in performing activities relating to genetics (n = 161, 58.7%) and nutritional genomics (n = 148, 53.8%). However, a significant positive association was found between involvement and confidence for all activities (p < 0.001). The mean total knowledge score was 48.5 (±19%) and considered as low, with the mean genetics score of 58.5 (± 24%) being significantly higher than the nutritional genomics score of 31.9 (±23%), p < 0.001. Those respondents who reported involvement in discussing the genetic basis of a disease (p = 0.02); providing guidance to patients with genetic disorders (p = 0.01); providing training or education on human genetics (p = 0.01) and discussing with patients how diet may interact with genes to influence risk (p = 0.03) also had higher total knowledge scores. Factors associated with knowledge were greater genetics content in university studies (p < 0.001); higher qualification (p = 0.01); participating in related continuous professional development (CPD) activities (p <0.001) and considering genetics of greater importance to dietetic practice (p = 0.03). Conclusions: The results of this study indicate that there is overall low involvement, confidence and knowledge of genetics and nutritional genomics amongst SA RDs and this compares well with international studies. Recommendations therefore include the development of a competency framework for genetics and nutritional genomics for undergraduate dietetic education as well as CPD activities in order to provide the driving force for the development of this field in SA. / AFRIKAANSE OPSOMMING: Inleiding: Voeding genomika is 'n nuwe en ontwikkelende veld wat die komplekse interaksies tussen dieet en genetika bestudeer, asook die gesamentlike invloed wat dit op gesondheids- bevordering en siekte voorkoming het. Navorsing is vinnig besig om uit te brei en alhoewel dit nog in die begin fase is, is dit belangrik vir geregistreerde dieetkundiges (GDs) om op hoogte te bly van die nuutste ontwikkelinge, aangesien dit die potensiaal het om 'n merkwaardige invloed op die dieetkunde praktyk te hê. Internasionale studies het lae selfvertroue en betrokkenheid, asook lae kennis van genetika en voeding genomika onder GDs bevind. Daar is tans geen studies beskikbaar onder Suid Afrikaanse (SA) GDs nie. Methodes: 'n Dwarssit studie is onderneem deur gebruik te maak van 'n nasionale opname van al 1881 dieetkundiges wat by die Health Professions Council of South Africa (HPCSA) geregistreer is. Data is ingesamel deur 'n gevalideerde self-geadministreerde vraelys wat ook begruik is vir 'n eenderse studie onder dieetkundiges in die Vereenigde Koninkryk (VK). Dit het bestaan uit vier afdelings om die volgende aspekte te evalueer: i) betrokkenheid en selfvertroue in aktiwiteite te make met genetika en voeding genomika ii) kennis van genetika en voeding genomika iii) faktore wat met kennis geassosieer word asook iv) demografiese inligting. Die hoof metode van data insameling was deur middel van epos (70%) met behulp van die Association for Dietetics in South Africa (ADSA) se epos databasis. Vraelyste is aan diegene gepos wat nie geregistreer was by ADSA nie (30%). Resultate: Vyftien persent (n = 279, 15.2%) van GDs het op die vraellys gereaggeer. Resultate het lae betrokkenheid in aktiwitiete met betrekking tot genetika (n = 47, 17%) en voeding genomika (n = 72, 25.8%) gewys. Die meerderheid van die deelnemers het lae selfvertroue gerapporteer in die uitvoering van aktiwiteite wat genetika (n = 161, 58.7%), asook voeding genomika (n = 148, 53.8%) behels. Daar was 'n statistiese beduidende positiewe assosiasie tussen betrokkenheid en selfvertroue vir alle aktiwiteite (p < 0.001). Die gemiddelde kennis telling was 48.5 (±19%) wat as laag beskou kan word. Die gemiddelde kennis vir genetika van 58.5 (± 24%) was statisties beduidend meer as die vir voeding genomika 31.9 (±23%), p < 0.001. Deelnemers wat betrokkenheid aangedui het in die bespreking van die genetiese basis van 'n siekte (p = 0.02); raadgewing aan pasiënte met genetiese siektes (p = 0.01); lewering van opleiding met betrekking tot genetika (p = 0.01) asook die bespreking van die interaksie van dieet en genetika met pasiënte en die invloed hiervan op risiko (p = 0.03), het ook beduidende hoër totale kennis gehad. Faktore wat met kennis geassosieer word is die genetika inhoud in voorgraadse studies (p < 0.001), hoër kwalifikasies (p = 0.01), voorgesette professionele onderrig (VPO) (p <0.001) asook diegene wat genetika as belangrik beskou vir dieetkunde praktyk (p = 0.03). Gevolgtrekking: Die resultate van hierdie studie wys dat daar oor die algemeen lae betrokkenheid, selfvertroue en kennis is van genetika en voeding genomika onder SA GDs. Dit vergelyk goed met international bevindinge. Aanbevelings is dat 'n raamwerk vir die kennis van genetika asook voeding genomika ontwikkel word vir voorgraadse dieetkunde studies, asook die ontwikkeling van VPO aktiwiteite wat die dryfkrag sal voorsien vir die ontwikkeling van hierdie veld in SA.

To help mitigate the escalating prevalence of Type 2 Diabetes (T2D) and alleviate society of its associated morbidity and economic burden on health care, it is crucial to understand its aetiology. Both genetic and the environmental risk factors are known to be involved. Healthy diets have been proven to reduce the risk of T2D in primary prevention trials, however, which components and exact mechanisms are involved is not fully understood, in particular, the role of macronutrient intake. Body weight, glycaemic markers and T2D are all to some extent genetically regulated. There may also be genetic influences on how people digest, absorb or metabolise macronutrients. This poses the possibility that the interplay between genes and our diet may help us unravel T2D’s aetiology. The aim of this PhD was to investigate gene-diet interactions on the risk of incident T2D, focusing primarily on macronutrient intake as the dietary factor. First, I systematically evaluated the current evidence before taking a step-wise approach (hypothesis driven to hypothesis-free) to interrogate gene-macronutrient interactions. This identified 13 publications, with 8 unique interactions reported between macronutrients (carbohydrate, fat, saturated fat, dietary fibre, and glycaemic load derived from self-report of dietary intake and circulating n-3 polyunsaturated fatty acids) and genetic variants in or near TCF7L2, GIPR, CAV2 and PEPD (p < 0.05) on T2D. All studies were observational with moderate to serious risk of bias and limitations that included lack of adequate adjustment for confounders, lack of reported replication and insufficient correction for multiple testing. Second, these reported interactions did not replicate in a large European multi-centre prospective T2D case-cohort study called EPIC-InterAct. We concluded that the heterogeneity between our results and those published could be explained by methodological differences in dietary measurement, population under study, study design and analysis but also by the possibility of spurious interactions. Third, given the paucity of gene-macronutrient interaction research using genetic risk scores (GRS), we examined the interaction between three GRS (for BMI (97 SNPs), insulin resistance (53 SNPs) and T2D (48 SNPs)) and macronutrient intake (quantity and quality indicators) in EPIC-InterAct. We did not identify any statistically significant interactions that passed multiple testing corrections (p≥0.20, with a p value threshold for rejecting the null hypothesis of 0.0015 (based on 0.05/33 tests)). We also examined 15 foods and beverages identified as being associated with T2D, and no significant interactions were detected. Lastly, we applied a hypothesis-free method to examine gene-macronutrient interactions and T2D risk by using a genome-environment-wide-interaction-study. Preliminary findings showed no significant interactions for total carbohydrate, protein, saturated fat, polyunsaturated fat and cereal fibre intake on T2D. In conclusion, the consistently null findings in this thesis using a range of statistical approaches to examine interactions between genetic variants and macronutrient intake on the risk of developing T2D have two key implications. One, based on the specific interactions examined, this research does not confirm evidence for gene-diet interactions in the aetiology of T2D and two, this research suggests that the association between macronutrient intake and the risk of developing T2D does not differ by genotype.

No description available.

INTRODUÇÃO: A exposição materna à frutose durante a gestação e lactação pode contribuir para o desenvolvimento de doenças crônicas na vida adulta da prole. OBJETIVO: Estudar os efeitos da ingestão de frutose durante a gestação e lactação sobre a vida pós-natal no que diz respeito às alterações metabólicas, de expressão gênica e ao comportamento alimentar em ratos machos. METODOLOGIA: Foram utilizados ratos Sprague-Dawley, provenientes de mães alimentadas com ração controle e de mães alimentadas com ração rica em frutose (60%), durante a gestação; a lactação e gestação/lactação. Após o desmame, a prole foi alimentada com ração controle até os 91 dias de vida. Foram analisados os parâmetros: biométricos, dietéticos, metabólicos quanto a glicemia, sensibilidade periférica à insulina, leptina e insulina (séricas e vias de sinalização), neuropeptídios envolvidos no controle do comportamento alimentar, e deposição hepática de gordura. RESULTADOS: Houve redução do índice de Lee no nascimento e hipoleptinemia aos 90 dias de vida, intolerância à glicose na vida pós-natal desde o desmame, concomitante com alterações na sensibilidade à ação da insulina na vida adulta, hiperinsulinemia, dislipidemia, deposição hepática de TAG, estímulo hedônico do comportamento alimentar alterado aos 14 dias de vida pós-natal via núcleo accumbens shell com maior expressão de CART. CONCLUSÃO: As proles possuem possível marca epigenética que pode contribuir para o prejuízo na produção e ação da insulina, ocasionando alterações na homeostase do metabolismo glicídico e lipídico hepáticos, levando a deposição hepática de gordura e alterações no perfil lipídico, com redução da leptinemia na vida adulta, e no controle hedônico central do comportamento alimentar apenas aos 14 dias de vida pós-natal. / INTRODUCTION: Maternal exposure to fructose during gestation and lactation can contribute to the development of chronic diseases in the adult life of offspring. OBJECTIVE: To study the effects of ingestion of fructose during gestation and lactation on postnatal life with respect to metabolic changes, gene expression and feeding behavior in male rats. METHODS: Male Sprague-Dawley rats from mothers fed with control rat chow (AIN-93) and from mothers fed a high fructose diet (60%). Both isocaloric, during gestation; lactation and gestation/lactation. After weaning, the offspring were fed with control rat chow until the 91st days of life. The following parameters were analyzed: biometric, dietary, metabolic for glycaemia, peripheral insulin sensitivity, leptin and insulin (serum and signaling pathways), neuropeptides involved in food behavior control, and hepatic deposition of fat. RESULTS: Reduction in the Lee index at birth and hypoleptinemia at 90 days of age (only in the offspring that the mothers consumed fructose during pregnancy), glucose intolerance in postnatal life since with changes in insulin sensitivity in adult life, hyperinsulinemia, dyslipidemia, hepatic deposition of GAD, hemodialysis of altered eating behavior at 14 days of age). CONCLUSION: The offspring from mothers who consumed fructose rat chow during gestation and lactation have a possible epigenetic mark that may contribute to the impairment in the production and action of insulin, leading to changes in hepatic glucose and lipid metabolism homeostasis, leading to hepatic fat deposition and alterations in the lipid profile, with reduction of leptinemia in adult life, and in the central hedonic control of dietary behavior only at the 14 days postnatal life.

Thesis (PhD (Physiological Sciences))--University of Stellenbosch, 2011. / Includes bibliography. / ENGLISH ABSTRACT: Genetic screening to improve obesity treatment outcomes is available despite the lack of conclusive evidence, specifically for Caucasian South Africans, in this regard. The aim of this study was to investigate the association between genotype (seven polymorphisms) and body mass index (BMI), health and lifestyle indicators in a cross-sectional sample of overweight/obese Caucasian adults (n=133), as well as the association between genotype and weight loss outcomes following an intervention (n=88) using a quasi experimental study design (time-series). The intervention consisted of a 24-week conservative weight loss programme that included dietary, physical activity and behavioural components. The primary null hypothesis for the cross-sectional sample, namely that there is no association between genotype and BMI, has not been rejected. A number of the secondary/exploratory hypotheses were rejected of which the most plausible associations (based on support by the literature and a physiological basis for the findng) are: 1) the mutant TT homozygotes of the GNB3 C825T polymorphism may have a higher risk to develop the metabolic syndrome (MetS) as they had significantly higher fasting triglyceride and glucose levels, a higher number of traits that met the diagnostic cut-off criteria for MetS and higher number of these subjects was diagnosed with MetS compared to the wild-type C-allele carriers; and 2) subjects with mutant alleles of either the FTO rs1421085 or rs17817449 polymorphisms may have poorer eating behaviours (a higher rigid control, habitual and emotional disinhibition, perceived hunger and internal locus for hunger) and higher intake of high-fat foods. The primary null hypothesis for the intervention sample, namely that there is no association between genotype and weight loss outcome, was not rejected for the FABP2 Ala54Thr, INSIG2 rs7566605, FTO rs1421085, ADRB3 Trp64Arg and GNB3 C825T polymorphisms. However, it was rejected in some instances indicating the following associations: 1) The wild-type TT homozygotes of the FTO rs17817449 polymorphism lost significantly more weight during the first two months of the program compared to the mutant allele carriers (this is a novel finding); 2) The wild-type Arg16Arg homozygotes of the ADRB2 Arg16Gly polymorphism lost significantly more weight during the first month of the program compared to the mutant allele carriers (this finding is supported by one other intervention study); 3) Subjects with a mutant C-allele of the INSIG2 rs7566605 polymorphism and a mutant Gly16-allele of the ADRB2 Arg16Gly polymorphism lost significantly less weight over the six month intervention period (this is a novel genegene interaction finding). A number of secondary/exploratory hypotheses were rejected, of which the most plausible finding include that the improvement in emotional disinhibition in the wild-type TT subjects of the FTO rs1421085 polymorphism was associated with a more pronounced decrease in BMI over the six month weight loss period. The integration of the results from this study with the literature indicates that there is insufficient evidence at this stage for genetic screening of the polymorphisms investigated in this study and the provision of evidence-based personalized recommendations for weight loss in obese individuals. It is recommended that these associations should be viewed as priority in future research. / AFRIKAANSE OPSOMMING: Genetiese sifting om die resultate van vetsug behandeling te verbeter is beskikbaar ten spyte van ‘n tekort aan genoegsame bewyse, spesifiek ten opsigte van Kaukasiërs van Suid-Afrika. Die doel van hierdie studie was om die assosiasie tussen genotipe (sewe polimorfismes) en liggaamsmassa indeks (LMI), gesondheid en lewenstyl indikatore in ‘n dwarssnit (cross-sectional) steekproef van oorgewig/vetsugtige Kaukasiër volwassenes (n=133) te ondersoek, asook die assosiasie tussen genotipe en gewigsverlies uitkomste na afloop van ‘n intervensie (n=88) in ‘n kwasi-eksperimentele studie ontwerp (tydreeks). Die intervensie het bestaan uit ‘n 24-week konserwatiewe gewigsverlies program met dieet, fisieke aktiwiteit en gedragskomponente. Die primêre nul hipotese vir die dwarsnit steekproef, naamlik dat daar geen assosiasie tussen genotipe en LMI is nie, is nie verwerp nie. ‘n Aantal sekondêre/spekulatiewe hipotesis is verwerp waarvan die mees geloofwaardige assosiasies (gebasseer op ondersteuning van die literatuur en ‘n fisiologiese basis vir die bevinding) die volgende insluit: 1) die mutante TT homosigote van die GNB3 C825T polimorfisme het moontlik ‘n hoër risiko vir die ontwikkeling van die metaboliese sindroom (MetS) aangesien hulle betekenisvolle hoër vastende trigliseriede en glukose vlakke gehad het, ‘n grooter aantal kenmerke gehad het wat aan die diagnostiese afsnykriteria vir MetS voldoen en ‘n grooter aantal van hierdie persone was met MetS gediagnoseer in vergelyking met die wilde-tipe C-alleel draers; en 2) persone met die mutante allele van die FTO rs1421085 of rs17817449 polimorfismes het moontlik ‘n swakker eetgedrag (‘n hoër rigiede kontrole, gewoonte en emosionele disinhibisie, waarneembare honger en interne lokus van honger) en ‘n hoër inname van hoë-vet voedsel. Die primêre nul hipotese vir die intervensie steekproef, naamlik dat daar geen assosiasie tussen genotipe en gewigsverlies uitkomste is nie, is nie vir die FABP2 Ala54Thr, INSIG2 rs7566605, FTO rs1421085, ADRB3 Trp64Arg en GNB3 C825T polimorfismes verwerp nie. Dit was egter in sommige gevalle vir die volgende assosiasies verwerp: 1) Die wilde-tipe TT homosigote van die FTO rs17817449 polimorfisme het betekenisvol meer gewig in die eerste twee maande van die program verloor in vergelyking met die mutante alleel draers (dit is ‘n nuwe bevinding); 2) Die wilde-tipe Arg16Arg homosigote van die ADRB2 Arg16Gly polimorfisme het betekenisvol meer gewig gedurende die eerste maand van die program verloor in vergelyking met die mutante alleel draers (hierdie bevinding word ondersteun deur een ander intervensie studie); 3) Persone met ‘n mutante C-alleel van die INSIG2 rs7566605 polimorfisme en ‘n mutante Gly16-allele van die ADRB2 Arg16Gly polimorfisme het minder gewig tydens die ses maande intervensie periode verloor (dit is ‘n nuwe geen-geen interaksie bevinding). ‘n Aantal sekondêre/ spekulatiewe hipoteses is verwerp, waarvan die mees geloofwaardigste bevinding insluit dat ‘n verbetering in emosionele disinhibisie van die wild-tipe TT persone van die FTO rs1421085 polimorfisme geassosieer was met ‘n meer prominente daling in LMI oor die ses maande gewigsverlies periode. Die integrasie van die resultate van hierdie navorsing met die literatuur dui aan dat daar op hierdie stadium onvoldoende bewyse vir genetiese sifting en die voorsiening van bewys-gebasseerde persoonlike aanbevelings vir gewigsverlies in vetsugtig individue bestaan vir die polimorfismes wat ondersoek is. Dit word aanbeveel dat hierdie assosiasies as prioriteit in toekomstige navorsing beskou moet word.