Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

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    Nutrition and cognition in older adults : studies on the role of glucose, sucrose, protein, vitamin B12 and folic acid
    Zwaluw, N.L. van der - \ 2014
    Wageningen University. Promotor(en): Lisette de Groot, co-promotor(en): Ondine van de Rest; Rosalie Dhonukshe-Rutten. - Wageningen : Wageningen University - ISBN 9789462571075 - 184
    ouderenvoeding - voeding - ouderen - kenvermogen - glucose - sucrose - eiwittoevoegingen - vitamine b12 - dementie - elderly nutrition - nutrition - elderly - cognition - glucose - sucrose - protein supplements - vitamin b12 - dementia

    The age-related cognitive decline and the increase in dementia patients are large problems in societies with growing ageing populations. No cure is present for dementia, while the available medication only focuses on alleviating symptoms. It is therefore of major importance to find risk factors that can modify the development of cognitive decline and dementia. Pre-clinical and observational studies suggest a role for nutrients. Evidence derived from randomized controlled trials (RCTs) is, however, limited and equivocal with most studies showing no effect and only a few studies showing a beneficial effect of a nutritional intervention. In the current thesis, we investigated the acute and longer-term effects of different nutrients, i.e. glucose and sucrose, protein, resistance-type exercise training with or without protein, and vitamin B12 and folic acid in order to optimize and preserve cognitive functions in non-demented elderly people.

    A comprehensive literature review was performed on the acute effects of glucose and sucrose on cognitive performance (Chapter 2). Glucose is the most important fuel for the brain, and as such, manipulation of the supply of glucose may affect cognitive functions. The main conclusion of our review was that a glucose load may have a short-term beneficial effect on episodic memory. Enhancing effects on other cognitive domains were less clear, partly due to the small number of studies examining these effects. Limited research was also done on the possible effects of sucrose on cognitive functions. Therefore, we investigated the acute effects of 50 g of glucose and 100 g of sucrose on a broad spectrum of cognitive functions reflecting performance on episodic memory, working memory, attention and information processing speed, and executive functions (Chapter 3). This was done by a cross-over study in 43 elderly participants who had self-reported memory complaints. In contrast to the conclusion of our review, we did not observe an effect of glucose or sucrose on episodic memory, though we showed a beneficial effect of sucrose on attention and information processing speed.

    Protein supplementation was the next nutritional intervention that was investigated. Several amino acids are precursors for neurotransmitters, and their supply may affect the synthesis and release of these neurotransmitters, and may consequently affect cognitive performance. A 24-week randomized placebo-controlled trial was carried out in 65 frail and pre-frail elderly people (Chapter 4). The protein supplementation included twice a day 15 grams of protein in the form of a drink. Reaction time improved more in the protein group compared to the placebo group, but the scores on the cognitive domains, i.e. episodic memory, attention and working memory, information processing speed, and executive functions, or the other single test scores, did not differ between treatment groups. In addition, we investigated the effects of 24 weeks resistance-type exercise training with and without protein supplementation in pre-frail and frail elderly people (Chapter 5). Exercise training without extra protein (n=62) improved performance on the domain attention and working memory. Exercise training together with protein supplementation (n=65) improved performance on information processing speed.

    Last, the role of vitamin B12 and folate on cognitive health was investigated. Low levels of these nutrients can increase homocysteine levels, which is a suggested risk factor for cognitive decline. The effect of daily supplementation with 500 µg vitamin B12 and 400 µg folic acid was investigated in 2,919 participants for two years (Chapter 6). Global cognitive function and episodic memory were assessed in the total study population, whereas extensive neuropsychological testing was done in a subpopulation (n=856). B-vitamin supplementation did not improve cognitive domain scores. Only a small, though significant, effect was observed on global cognitive performance, measured by the Mini-Mental State Examination, but this was suggested to be due to chance. Brain MRI scans were made in a subgroup (n=218) after two years of intervention to obtain volumetric measures of grey and white matter, and total brain volume (Chapter 7). We investigated the cross-sectional associations between follow-up levels of folate, homocysteine and three vitamin B12 status biomarkers, e.g. methylmalonic acid, holotranscobalamin and serum vitamin B12, and brain volumes. Fully adjusted regression models showed a borderline significant association between plasma homocysteine and total brain volume, with a stronger association in the group that received B-vitamin supplementation. Serum B12 and holotranscobalamin were not associated with brain volumes, whereas high methylmalonic acid levels were associated with lower brain volumes in the group that received B-vitamins. In contrast, higher folate levels were associated with lower total brain volumes. In addition, when comparing the group that received two years of B-vitamin supplementation and those who did not, we observed lower brain volumes in the B-vitamin group, which might be a result of a difference in age between the two groups.

    To conclude, the nutritional intervention studies showed little evidence for a beneficial effect on cognitive performance in relatively healthy older adults. Given the large problem of dementia, research on modifiable risk factors, including nutrition, should continue, with well thought out research methods, including large and long-term observational and intervention studies with high-sensitive study populations and early biomarkers (e.g. imaging techniques) for cognitive decline in combination with neuropsychological tests. In this way, nutrition can be added to the list of lifestyle factors that can fight dementia.

    Voeding en beweging ter preventie van cognitieve achteruitgang
    Severs, A. ; Rest, O. van de; Groot, C.P.G.M. de; Loon, L.J.C. van - \ 2014
    VoedingsMagazine 27 (2014)1. - ISSN 0922-8012 - p. 18 - 20.
    ouderen - ouderenvoeding - eiwittoevoegingen - dementie - kenvermogen - lichaamsbeweging - voeding en gezondheid - voedingsstoffen - elderly - elderly nutrition - protein supplements - dementia - cognition - exercise - nutrition and health - nutrients
    Dementie wordt een steeds groter en kostbaarder probleem door de vergrijzing. Wetenschappers zijn naarstig op zoek naar mogelijkheden om het tij te keren. Zo ook Ondine van de Rest, onderzoeker aan Wageningen University. Haar onderzoek is gericht op de rol van voeding bij leeftijdsgerelateerde cognitieve achteruitgang. Samen met prof. dr.Lisette de Groot, hoogleraar voeding voor de oudere mens aan Wageningen Universiteit, en Prof. Dr. Luc van Loon, hoogleraar fysiologie van inspanning aan Maastricht Universiteit, voerde ze binnen het Top Instituut Food and Nutrition (TIFN) een interventiestudie uit bij ouderen naar het effect van eiwitsuppletie en beweging op de cognitie.
    Dietary strategies to augment muscle mass in the elderly
    Tieland, C.A.B. - \ 2013
    Wageningen University. Promotor(en): Lisette de Groot; L.J.C. van Loon. - S.l. : s.n. - ISBN 9789461735676 - 150
    eiwittoevoegingen - lichaamsbeweging - spiergewicht - lichamelijke fitheid - ouderen - maatregel op voedingsgebied - protein supplements - exercise - muscle weight - physical fitness - elderly - nutritional intervention

    Background: The world population is aging rapidly. This growth of the aging population is accompanied by an increased number of frail elderly people who are at risk of adverse health outcomes such as disability, co-morbidity and mortality. A dominant feature of frailty is the age related loss of muscle mass, strength and performance, also called sarcopenia. Resistance-type exercise training and dietary protein supplementation are considered promising strategies to reverse sarcopenia and subsequent frailty. However, strong evidence for the impact of protein supplementation with or without resistance exercise in frail elderly people is scarce. Well-designed intervention studies in frail elderly people are needed to define new leads for the development of nutritional and exercise interventions to effectively prevent or treat the progressive loss of muscle mass, strength and physical performance with aging. Therefore, the aims of this thesis are to study 1) the impact of protein supplementation and 2) the impact of protein supplementation during prolonged resistance-type exercise training on muscle mass, strength and physical performance in frail elderly people.

    Methods: First, we studied various characteristics of dietary protein intake, including the distribution of dietary protein intake throughout the day, and the use of protein-containing food sources in various elderly populations. With this knowledge, we designed two large intervention trials to study the impact of dietary protein supplementation with or without prolonged resistance-type exercise training on muscle mass, strength and physical performance in frail elderly people. In addition, we assessed the usefulness of handgrip strength as a measure of post exercise strength differences and studied the association of vitamin D status and vitamin D intake on muscle mass, strength and physical performance in a frail elderly population.

    Results: Dietary protein intake in frail and institutionalized elderly people were especially low at breakfast and lunch. Supplementing protein at breakfast and lunch did not increase muscle mass but improved physical performance in frail elderly people. Resistance-type exercise training improved muscle leg strength and physical performance, but not handgrip strength. Supplementing protein at breakfast and lunch was required to significantly increase muscle mass during prolonged resistance-type exercise training in frail elderly people. Furthermore, low vitamin D status and vitamin D intake were associated with impaired physical performance.

    Conclusions: Although dietary protein supplementation does not increase muscle mass, it represents a promising strategy to improve physical performance in frail elderly people. Prolonged resistance-type exercise training represents an effective strategy to improve strength and physical performance, but dietary protein supplementation is required to allow muscle mass gain during exercise training in frail elderly people.

    Lagekostenbedrijf: bijsturen aan voerhek
    Remmelink, G. - \ 2000
    Praktijkonderzoek Rundvee, Schapen en Paarden. Praktijkonderzoek 13 (2000)5. - ISSN 1386-8470 - p. 28 - 29.
    melkveehouderij - melkvee - rundveevoeding - voeropname - melkproductie - eiwittoevoegingen - concentraten - productiekosten - dairy farming - dairy cattle - cattle feeding - feed intake - milk production - protein supplements - concentrates - production costs
    De koeien op het Lagekostenbedrijf hebben in de stalperiode 1999/2000 meer melk geproduceerd dan in de voorgaande stalperiode. Er is tijdelijk extra krachtvoer verstrekt en er werd een hoge ruwvoeropname gerealiseerd.
    Nitrogen utilization in pigs as affected by dietary induced losses of ileal endogenous nitrogen
    Grala, W. - \ 1998
    Agricultural University. Promotor(en): M.W.A. Verstegen; S. Tamminga; T. Zebrowska; J. Huisman. - S.l. : Grala - ISBN 9789054858164 - 179
    voer - verteerbaarheid - eiwitten - varkens - dierlijke meststoffen - drijfmest - stikstof - stikstofmetabolisme - eiwittoevoegingen - darmen - spijsvertering - feeds - digestibility - proteins - pigs - animal manures - slurries - nitrogen - nitrogen metabolism - protein supplements - intestines - digestion

    The results of this thesis showed that various protein sources (feedstuffs) have different values for apparent and true ileal digestibilities of protein and thus also of ileal endogenous nitrogen losses (ENL; determined with the 15 N-isotope dilution technique). It was initially hypothesized that increased ENL may induce an increased recycling of endogenous proteins. As a result of the latter, increased nitrogen (N) losses may occur in urine because of inefficiency of metabolic processes. Furthermore, the increased ENL may lead to a decreased utilization of small intestinal dietary N for retention in pigs. In this context, when using feedstuffs that led to a distinctly different ENL, the results of N balance in pigs were in agreement with the starting hypothesis. Further, it was found that feedstuffs with protease inhibitor-related ENL reduced the dietary N utilization and increased urinary N loss. For feedstuffs with various ENL related to fibre per se, the urinary N loss and dietary N utilization for retention did not differ significantly. It means that ENL- and N metabolism differ depending on the feed factors to which the ENL are related. These results indicated that (1) total secretion of endogenous N may not be related to the level of ENL, and (2) the reabsorption ratio of the secreted endogenous N may vary for different feedstuffs. Based on that, the starting hypothesis was modified to: mainly, the magnitude of ENL (i.e., first- limiting amino acids) determines the inefficiency of dietary N utilization rather than the magnitude of total recycled endogenous N. Thus, increased urinary N losses may depend on the extent of amino acid oxidation resulting from the amino acid imbalance caused by the ENL In the particular experimental conditions (restricted protein/AA intake), extra supplementation with crystalline amino acids of a diet with high protease inhibitor-related ENL improved the utilization of the dietary N and decreased extra urinary N loss. It seems, therefore, that extra amino acid addition can compensate for the ENL by improving the profile of amino acids available for endogenous protein re- synthesis. As a result, the remaining dietary amino acids are in a better balance for the body protein retention. Further results showed that the total amounts of endogenous N secretions were approximately similar for different dietary factors that induce the ENL Therefore, the magnitude of the ENL rather than the magnitude of total secreted and reabsorbed endogenous N mainly determines the efficiency of dietary N utilization and extra urinary N loss. These results were in agreement with the adjusted hypothesis. Supplementation with extra amino acids may decrease environmental N losses, caused by increased ENL and increase the efficiency of dietary N utilization in pig production.

    Het effect van bloedplasma in speenvoeders met verschillende eiwitbronnen op de opfokresultaten van biggen
    Peet-Schwering, C.M.C. van der; Binnendijk, G.P. - \ 1995
    Rosmalen : Praktijkonderzoek varkenshouderij (Proefverslag / Praktijkonderzoek Varkenshouderij P1.137) - 24
    diervoedering - samenstelling - experimenten - biggen - eiwittoevoegingen - spenen - animal feeding - composition - experiments - piglets - protein supplements - weaning
    Methionine-behoefte van Peking-eenden
    Buisonjé, F.E. de; Vahl, H.A. ; Getkate, J.A. ; Pieterse, C. - \ 1994
    Praktijkonderzoek voor de Pluimveehouderij 5 (1994)4. - ISSN 0924-9087 - p. 26 - 28.
    cysteïne - cystine - eenden - voer - methionine - eiwittoevoegingen - eiwitten - cysteine - cystine - ducks - feeds - methionine - protein supplements - proteins
    Onderzocht is het effect van verschillende gehalten verteerbare methionine + cystine in het voer op de technische resultaten en slachtrendementen van Peking-eenden.
    Lysine-behoefte van Peking-eenden
    Buisonjé, F.E. de; Vahl, H.A. ; Getkate, J.A. ; Pieterse, C. - \ 1994
    Praktijkonderzoek voor de Pluimveehouderij 5 (1994)3. - ISSN 0924-9087 - p. 35 - 38.
    dierlijke producten - china - samenstelling - eenden - voer - vleesproductie - eiwittoevoegingen - eiwitten - kwaliteit - animal products - china - composition - ducks - feeds - meat production - protein supplements - proteins - quality
    In een proef met Peking-eenden werd het effect getest van verschillende lysine-gehalten in het voer op de technische resultaten en de slachtkwaliteit.
    Enzym Lyxasan verbetert verteerbaarheid tarwe
    Klis, J.D. van der; Ruesink, E.W. - \ 1993
    De Pluimveehouderij 23 (1993)35. - ISSN 0166-8250 - p. 19 - 19.
    vleeskuikens - samenstelling - verteerbaarheid - voer - eiwittoevoegingen - triticum aestivum - tarwe - broilers - composition - digestibility - feeds - protein supplements - triticum aestivum - wheat
    Tarwe heeft verschillende nadelen. De voederwaarde kan sterk varieren en is moeilijk voorspelbaar. Bovendien kunnen bij hoge verwerkingspercentages de produktieresultaten teleurstellend zijn, wanneer slechte partijen tarwe in het voer worden opgenomen. Een nieuw enzym beperkt deze nadelen
    Effekt van plantaardig en mikrobieel fytase op de verteerbaarheid van Weende analyse-komponenten, Ca en P bij oude fokzeugen in diverse reproduktiestadia = Effect of plant and microbial phytase on the digestibilities of proximate components, Ca and P in the diets for older breeding sows in various stagen of the reproduction cycle
    Kemme, P.A. ; Jongbloed, A.W. - \ 1993
    Lelystad : IVVO-DLO (Rapport IVVO-DLO no. 251) - 31
    calcium - verteerbaarheid - voer - mineralen - fosfor - biggen - eiwittoevoegingen - calcium - digestibility - feeds - minerals - phosphorus - piglets - protein supplements
    Goede resultaten met fytase bij slachtkuikenmoederdieren
    Haar, J. van de; Meijerhof, R. - \ 1991
    De Pluimveehouderij 21 (1991)50. - ISSN 0166-8250 - p. 12 - 13.
    dierlijke meststoffen - samenstelling - enzymen - glycosidasen - eiwittoevoegingen - drijfmest - vleeskuikenouderdieren - animal manures - composition - enzymes - glycosidases - protein supplements - slurries - broiler breeders
    De milieuproblematiek vereist dat er minder mineralen in de mest terechtkomen. Ook bij slachtkuikenmoederdieren is het mogelijk om via de voeding de uitscheiding van fosfaat te beperken met behoud van goede technische resultaten. Dit blijkt uit onderzoek uitgevoerd op het Pluimveeteeltproefbedrijf Delden
    Verhoging lysinegehalte voer zogende zeugen zinvol?
    Everts, H. ; Sebek, L.B.J. ; Plagge, J.G. - \ 1991
    Praktijkonderzoek varkenshouderij 5 (1991)1. - ISSN 1382-0346 - p. 17 - 19.
    diervoedering - eiwittoevoegingen - voortplanting - zeugen - animal feeding - protein supplements - reproduction - sows
    Tijdens de zoogperiode moeten de meeste zeugen hun lichaamsreserves aan vet en eiwit behoorlijk aanspreken, omdat ze in verhouding tot hun melkproduktie te weinig energie en eiwit opnemen. De vraag is nu of een verhoging van het Iysine-/eiwitgehalte van het voer voor lacterende zeugen een gunstig effect kan hebben op de volgende reproduktiecyclus.
    Ontsloten gerst en Borcilac in voer voor gespeende biggen
    Plagge, G. - \ 1990
    Praktijkonderzoek varkenshouderij 4 (1990)1. - ISSN 1382-0346 - p. 21 - 22.
    gerst - hordeum vulgare - melkproducten - biggen - eiwittoevoegingen - voedersystemen - barley - hordeum vulgare - milk products - piglets - protein supplements - feeding systems
    Het ontsluiten van gerst in biggenvoeders leidt niet tot een duidelijke verbetering van de technische resultaten en tot een betere gezondheid van de dieren. Ook opname van extra Borcilac (een eiwitrijke weipoeder) en vetten heeft geen positieve invloed op de technische resultaten
    Supplementation of plant protein with amino acids for broiler production
    Al-Azzawi, I.I. - \ 1964
    Wageningen University. Promotor(en): S. Iwema. - Oosterbeek : Viking - 118
    eiwittoevoegingen - pluimvee - kippen - voer - eiwitten - protein supplements - poultry - fowls - feeds - proteins
    A diet of sesame oilmeal, maize and barley supplemented with adequate lysine 0.50-0.78 (in total 1.18%-1.23% of the diet) was a suitable diet for fast growing chickens to produce broilers weighing approximately 1 kg in 7 weeks. The average feed intake per unit gain in the 7th week was 2.149 for chickens which had received plant protein and high energy level and 2.312 for those which had received about 2700 kcal. The gain achieved with sesame, corn and barley was approximately 95 % of that with the best animal-protein diets used in the Netherlands. Adding up to 10 % of sesame oil did not improve weight but it did improve feed efficiency and produced good quality meat. The response of pullets to lysine was better than that of cockerels. The plant protein varied in value, so it was much more accurate to deal with the digestible value than the crude value.

    The high methionine content of sesame should inspire the agricultural offices in the Middle East to encourage farmers to produce soya bean, to make a high quality feed for broiler production. Soya bean lacked methionine, but it was rich in lysine and would make a good combination with sesame. In practice in the Middle East the supplement of lysine would diminish the cost of high quality feed by about 22.5 %, if it was used instead of animal protein.

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