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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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    Fish fatty acids and mental health in older people
    Rest, O. van de - \ 2009
    Wageningen University. Promotor(en): Lisette de Groot; Frans Kok, co-promotor(en): Marianne Geleijnse. - [S.l. : S.n. - ISBN 9789085854715 - 200
    geestelijke gezondheid - mentale vaardigheid - depressie - visoliën - meervoudig onverzadigde vetzuren - ouderen - verouderen - omega-3 vetzuren - mental health - mental ability - depression - fish oils - polyenoic fatty acids - elderly - aging - omega-3 fatty acids
    Background
    It has been suggested that the intake of fish and marine n-3 polyunsaturated fatty acids could protect against age-related cognitive decline and impaired mental well-being. However, results from observational studies are inconclusive and data from randomized controlled trials in older people without clinical dementia or depression are scarce. The objective of this thesis was to investigate the effect of daily supplementation with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on cognitive performance and mental well-being in an older non-clinical population. We also examined the effect of fish oil on gene expression profiles in white blood cells to identify early changes in pathways possibly related to mental health. Furthermore, we assessed the association of fish and EPA+DHA intake with mental health in different aging populations.

    Methods
    The effect of low and high doses of EPA+DHA (400 and 1,800 mg per day, respectively) on cognitive performance, several measures of mental well-being, and gene expression was examined in a 26-week randomized, double-blind, placebo-controlled trial. This study was conducted in 302 individuals aged 65 years or older with no clinical diagnosis of dementia or depression. Furthermore, the cross-sectional association between fatty fish and EPA+DHA intake with cognitive performance and the association with cognitive change during 6 years of follow-up was assessed in 1,025 aging US men who participated in the Veterans Affairs Normative Aging Study (NAS). In addition, the associations of EPA+DHA and fish intake with depressive symptoms and dispositional optimism were assessed in 644 free-living Dutch subjects with a history of myocardial infarction.

    Results
    Daily intake of low or high doses of EPA+DHA did not affect cognitive performance, mental well-being, anxiety, or quality of life, after 13 or 26 weeks of intervention. However, treatment with EPA+DHA for 26 weeks altered gene expression in white blood cells to a more anti-inflammatory and more anti-atherogenic profile. In elderly US men we found no association of fatty fish or EPA+DHA intake with cognitive performance or 6-year cognitive change. Intake of EPA+DHA was positively associated with dispositional optimism in subjects with a history of myocardial infarction. There was also a tendency for less depressive symptoms with a higher EPA+DHA or fish intake, but this association was no longer statistically significant after controlling for confounders.

    Conclusion
    Supplemental intake of EPA+DHA is unlikely to have a short-term impact on cognitive performance or mental well-being of older people without a clinical diagnosis of dementia or depression. Whether long-term intake of EPA+DHA and fish could be beneficial to the maintenance of cognitive performance or mental well-being of older people in Western populations still needs to be established.
    Micronutrients, omega-3 fatty acids and cognitive performance in Indian schoolchildren
    Eilander, J.H.C. - \ 2009
    Wageningen University. Promotor(en): Frans Kok, co-promotor(en): S.J.M. Osendarp; S. Muthayya. - [S.l. : S.n. - ISBN 9789085854708 - 175
    sporenelementen - meervoudig onverzadigde vetzuren - cognitieve ontwikkeling - mentale vaardigheid - minerale supplementen - fortificatie - ondervoeding - schoolkinderen - india - omega-3 vetzuren - kenvermogen - trace elements - polyenoic fatty acids - cognitive development - mental ability - mineral supplements - fortification - undernutrition - school children - india - omega-3 fatty acids - cognition

    In developing countries, approximately 30-40% of school-age children suffer from iodine and iron deficiencies. Poverty and consumption of monotonous diets are underlying causes of inadequate intakes of micronutrients and omega-3 fatty acids and may have severe consequences for children’s cognitive development. Multiple micronutrient interventions have shown to benefit mental performance of children, but a systematic evaluation of the evidence is currently lacking. The omega-3 fatty acid, -linolenic acid (ALA) is converted into docosahexaenoic acid (DHA), a major structural component of the brain, which is important for normal development and maintenance of brain function. At present, it is unclear whether additional intake of omega-3 fatty acids improves cognitive performance in children.
    The aim of this thesis was to investigate the role of multiple micronutrients and omega-3 fatty acids on cognitive performance in school-age children living in deprived environments, thereby addressing three main research questions.
    The first query concerned the investigation of the size of effects of multiple micronutrient interventions on different cognitive domains. Findings of our meta-analysis comprising 17 studies in children 5-16 years of age, suggested that multiple micronutrients were beneficial for fluid intelligence (i.e. reasoning abilities) (0.14 SD; 95% CI: -0.02, 0.29) and academic performance (0.30 SD; 95% CI: 0.01, 0.58). Crystallized intelligence (i.e. acquired knowledge) seemed not affected (-0.03 SD; 95% CI: -0.21, 0.15) and for the other cognitive domains data were too limited to draw firm conclusions.
    Secondly, we examined the role of omega-3 fatty acids on children’s cognitive development, for which a literature review was conducted. Associations between omega-3 fatty acid status or dietary intake and cognitive performance were investigated by cross-sectional analysis using baseline data of a randomized controlled trial in 598 Indian schoolchildren (see below for details). We found no evidence for a beneficial effect of additional intake of omega-3 fatty acids, and of DHA in particular, on cognitive development in school-age children. Neither there was a significant relationship between omega-3 fatty acid status and cognitive performance.
    Lastly, we studied the effect of different doses of micronutrients and omega-3 fatty acids, and their interaction, on cognitive performance. For that purpose, a randomized controlled trial in 598 Indian schoolchildren aged 6-10 years was conducted from November 2005 until March 2007. Children received either 15% or 100% of the Recommended Dietary Allowance of micronutrients in combination with either a low (140 mg ALA) or high dose (900 mg ALA plus 100 mg DHA) of omega-3 fatty acids for 12 months. Cognitive function was measured at baseline, 6 and 12 months. Our results showed that with some small differential effects on short term memory at 6 months (0.11 SD; 95% CI: 0.01-0.20) and fluid intelligence at 6 months (-0.10 SD; 95% CI: -0.17, -0.03) and 12 months (-0.12 SD; 95% CI: -0.20, -0.04), the high and low dose of micronutrients were as effective for improving retrieval ability, cognitive speediness and overall cognitive performance. Neither there were differences between the omega-3 fatty acid treatments, nor an interaction between micronutrients and omega-3 fatty acids on cognitive outcomes.
    In conclusion, although multiple micronutrients may benefit intellectual performance of schoolchildren, development of public health guidelines is currently premature. Further investigation on doses and composition of micronutrients would be needed to identify a cost-effective micronutrient supplement to optimize cognitive performance in children. Presently, no evidence exists for a positive effect of omega-3 fatty acids on cognitive performance in healthy children. A final trial using a higher dose and sufficiently long duration would be needed to conclude whether omega-3 fatty acid supplementation improves mental development at school age.
    Very long-chain n-3 polyunsaturated fatty acids: a head start to win some years between the ears?
    Dullemeijer, C. - \ 2009
    Wageningen University. Promotor(en): Frans Kok; R.J. Brummer, co-promotor(en): I.A. Brouwer. - [S.l.] : S.n. - ISBN 9789085853770 - 136
    vetzuren met een lange keten - hersenen - cognitieve ontwikkeling - mentale vaardigheid - visoliën - ouderen - vaatziekten - omega-3 vetzuren - kenvermogen - long chain fatty acids - brain - cognitive development - mental ability - fish oils - elderly - vascular diseases - omega-3 fatty acids - cognition
    Very long-chain n-3 (or omega-3) polyunsaturated fatty acids have attracted considerable public interest during the past few years for their potential beneficial role in cognitive performance. The proposed benefits stretch from advantages in developing brains of infants and children to preventing cognitive decline at old age.
    In this thesis, we first examined the role of very long-chain n-3 PUFA at the beginning of the lifespan. We investigated the effects of dietary very long-chain n-3 PUFA on the fatty acid composition of the several brain lobes in juvenile pigs, and showed that a diet enriched with fish oil resulted in higher proportions of DHA in the frontal, parietal and occipital brain lobes compared with the temporal brain lobe. These findings suggest a region-specific incorporation of DHA in the developing brain, which may guide future research into the mechanism by which very long-chain n-3 PUFA may in involved in brain development and function.
    Subsequently, we investigated the role of very long-chain n-3 PUFA near the end of the lifespan. In a population of older adults, we investigated the association between very long-chain n-3 PUFA and cognitive decline over three years in multiple cognitive domains. We demonstrated that higher plasma proportions of very long-chain n-3 PUFA were associated with less decline in the cognitive domains sensorimotor speed and complex speed, but not in memory, information-processing speed and word fluency, compared with lower plasma proportions of very long-chain n-3 PUFA. These results suggest a beneficial role of very long-chain n-3 PUFA in the speed-related cognitive domains, which justifies future research in this area with sensitive cognitive outcome measurements that provide domain-specific information.
    Finally, we touched upon the role of very long-chain n-3 PUFA in the macrovascular and the microvascular blood supply in the head region. We showed that plasma very long-chain n-3 PUFA were not associated with changes in carotid intima-media thickness and common carotid distension in a healthy older adult population. This may suggest that the role of very long-chain n-3 PUFA in a healthy population extends in particular to the smaller blood vessels. The role of very long-chain n-3 PUFA in the microcirculation of the brain could therefore be an interesting future direction of research. Although we did not directly investigate the role of very long-chain n-3 PUFA in the brain microcirculation, we did investigate whether plasma very long-chain n-3 PUFA were associated with age-related hearing loss over a period of three years in older adults. Since microvascular disease may decrease the blood supply to the highly vascularised cochlea, this may result in age-related hearing loss. We showed that higher plasma proportions of very long-chain n-3 PUFA were indeed associated with less age-related hearing loss compared with lower plasma proportions of very long-chain n-3 PUFA which implies that the hypothesis of improved microcirculation, if proven correct, may have far-reaching consequences.
    In summary, this thesis showed that very long-chain n-3 PUFA have region-specific effects on the developing brain and that higher plasma proportions of very long-chain n-3 PUFA were associated with less decline in the speed-related cognitive domains and less age-related hearing loss. Further research is required to establish the role of very long-chain n-3 PUFA in the developing as well as the aging brain and to investigate the underlying mechanisms.

    “Very long-chain n-3 polyunsaturated fatty acids: a head start to win some years between the ears?” PhD-thesis by Carla Dullemeijer, Top Institute Food and Nutrition and Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands, May 15, 2009
    Determinants of cognitive decline in older European men
    Gelder, B.M. van - \ 2007
    Wageningen University. Promotor(en): Daan Kromhout, co-promotor(en): M.A.R. Tijhuis; S. Kalmijn. - [S.l.] : S.n. - ISBN 9789085046493 - 157
    cognitieve ontwikkeling - mentale vaardigheid - dieet - ouderen - ouderdom - mannen - europa - kenvermogen - sociale factoren - cognitive development - mental ability - diet - elderly - old age - men - europe - cognition - social factors
    In our ageing population, the number of persons with cognitive impairment, dementia and Alzheimer's disease still increase and cause many problems for the elderly themselves, their relatives and caregivers and for health care. Therefore, the need for preventive action is high. In this thesis we identified social, lifestyle and dietary risk factors for the postponement of cognitive impairment and decline in elderly European men.

    For the results presented in this thesis, data from theFinland,Italyand the Netherlands Elderly (FINE) Study were used. This prospective population-based cohort study was carried out between 1985 and 2000 among 2,285 Finnish, Italian and Dutch men bornbetween 1900 - 1920. Cognitive functioning was measured with the Mini-Mental State Examination (MMSE).

    In the FINE Study, cognitive functioning decreased on average with 1.5 points during the 10-year follow-up period. This decline was due to an age effect, but also to a period and birth cohort effect.

    Men who were married or who lived with others during five years had at least a two times smaller subsequent 10-year cognitive decline compared with men who lost a partner, who were unmarried, who started to live alone and who lived alone during these five years.

    Cognitive decline did not differ among men with a high or low duration of physical activity at baseline. However, men who participated in activities with at leasta medium-low intensity had a 1.8 to 3.5 times smaller cognitive decline compared with men who participated in activities with lowest intensity. Moreover, a decrease in duration or intensity of physical activity resulted respectively in a 2.6 or 3.6 times stronger cognitive decline than maintaining duration or intensity.

    Men who consumed coffee had a two times smaller 10-year cognitive decline than non-consumers. In addition, an inverse and J-shaped association between the number of cups of coffee per day consumed and 10-year cognitive decline was present, with the least decline for men consuming three cups of coffee per day.

    Fish consumers had significantly less 5-year subsequent cognitive decline than non-consumers. A linear trend was observed for the relation between the intake of the n-3 fatty acids EPA + DHA and cognitive decline. An average difference of about 380 mg/day in EPA + DHA intake was associated with a 1.1 points difference in cognitive decline.

    Men whose cognition decreased between 1990 and 1995 had a twofold higher risk of dying in the following five years compared with men whose cognition was stable. Mortality risk of men whose cognition improved between 1995 and 2000 was not different from men with a stable cognition.

    The associations between marital status, living situation and physical activity are strong and provide in combination with the existing literature enough evidence for justifying public health recommendations for postponing cognitive decline. However, our findings on coffee and fish consumption and on the intake of the fatty acids EPA + DHA in relation with cognitive functioning need confirmation in other studies.
    Milde vitamine B12 deficiëntie en het cognitief functioneren van ouderen : de effectiviteit van orale supplementen
    Eussen, S.J.P.M. - \ 2006
    Wageningen University. Promotor(en): Wija van Staveren; W.H.L. Hoefnagels, co-promotor(en): Lisette de Groot. - [S.l.] : S.n. - ISBN 9789085044314 - 142
    vitamine b12 - vitaminetekorten - mentale vaardigheid - verstandelijk gehandicapt - vitaminetoevoegingen - bijvoeding - ouderen - ouderdom - kenvermogen - vitamin b12 - vitamin deficiencies - mental ability - mental retardation - vitamin supplements - supplementary feeding - elderly - old age - cognition
    Cobalamin deficiency is common in older people and has been recognised as a possible cause for several clinical manifestations such as anaemia and cognitive impairment. Markers for cobalamin deficiency include increased concentrations of plasma total homocysteine (tHcy) and methylmalonic acid (MMA), and decreased concentrations of holotranscobalamin (holoTC). Cross sectional analysis in this thesis confirmed that impaired cognitive performance was associated with relatively unfavourable concentrations of markers for cobalamin status. These results are in line with findings from previous cross-sectional and prospective studies and suggest a role for cobalamin status in cognitive function, in particular because cobalamin deficiency is highly prevalent in old age. According to our recruitment activities it appeared that 26.6% of the older people had mild cobalamin deficiency, which we defined as low to low-normal cobalamin concentrations in combination with increased MMA concentrations. Normalizing mild cobalamin deficiency, defined as a decrease of respectively 80% to 90% of the estimated maximum reduction in plasma MMA concentrations, could be achieved by supplementing daily oral doses of 647 mg to 1032 mg crystalline cobalamin. The main purpose of our research was to investigate whether daily supplementation with such a high dose of oral cobalamin alone or in combination with folic acid has beneficial effects on cognitive function in people aged 70 years or older with mild cobalamin deficiency. We did this in a double-blind, placebo-controlled trial with a relatively large number of carefully selected participants, and an extensive assessment of cognitive function. In total, 195 individuals were randomized to receive either 1,000 μg cobalamin, or 1,000 μg cobalamin + 400 μg folic acid, or placebo for 24 weeks. Markers for cobalamin status and cognitive function were assessed before and after 24 weeks of treatment. Assessment of cognitive function included the domains of attention, construction, sensomotor speed, memory and executive function. Cobalamin status did not change in the placebo group, whereas oral cobalamin supplementation corrected mild cobalamin deficiency. Improvement in one domain (memory function) was observed in all treatment groups, and was greater in the placebo group than in the group who received cobalamin alone ( P = 0.0036). Oral supplementation with cobalamin alone or in combination with folic acid for 24 weeks was not associated with improvements in other cognitive functions. Blood collection after cessation of oral cobalamin supplementation showed that adequate cobalamin status may maintain for a period of up to 5 months after cessation. Despite the null finding of this trial, recent studies provide clues for future research in improving cognitive function.
    Vitamine B12 en cognitieve functies
    Eussen, S.J.P.M. ; Groot, C.P.G.M. de; Hoefnagels, W.H.L. ; Staveren, W.A. van - \ 2004
    Voeding Nu 4 (2004)4. - ISSN 1389-7608 - p. 29 - 31.
    ouderen - vitamine b12 - vitaminetekorten - voedingsstoffentekorten - voedingstoestand - deficiëntie - cognitieve ontwikkeling - mentale vaardigheid - supplementen - toevoegingen - wetenschappelijk onderzoek - elderly - vitamin b12 - vitamin deficiencies - nutrient deficiencies - nutritional state - deficiency - cognitive development - mental ability - supplements - additives - scientific research
    Vitamine B12-deficiëntie is een relatief veel voorkomend probleem bij ouderen. Wageningen Universiteit onderzoekt wat de optimale hoeveelheid vitamine B12 in capsules zou moeten zijn om een vitamine B12-deficiëntie te behandelen en of deze hoeveelheid B12 gunstige effecten heeft op het cognitief functioneren bij ouderen met een vitamine B12-deficiëntie
    Iodine deficiency and functional performance of schoolchildren in Benin
    Briel-van Ingen, T. van den - \ 2001
    Wageningen University. Promotor(en): J.G.A.J. Hautvast; C.E. West; N. Bleichrodt. - S.l. : S.n. - ISBN 9789058085368 - 160
    jodium - deficiëntie - prestatietests - mentale vaardigheid - gehoorgrens - schildklierfunctietoetsen - schoolkinderen - benin - iodine - deficiency - performance tests - mental ability - auditory threshold - thyroid function tests - school children - benin
    The notion that iodine deficiency may lead not only to goiter and cretinism, but to a much wider range of disorders, from stillbirth and abortions, to hearing problems and mental and physical underdevelopment began to be accepted beyond the research community since the early 1980's. In 1990 it was estimated that these problems, collectively called iodine deficiency disorders (IDD), presented a public health problem in 118 countries and that over 40 million people were affected by some degree of mental impairment. Children who have been exposed to iodine deficiency in the pre- and early post-natal phases of life show varying degrees of mental and psychomotor retardation, depending on the duration and degree of the deficiency. Adequate maternal iodine intake before and during pregnancy prevents such disorders. The question however whether or not deficits in mental and psychomotor performance of iodine deficient children may be reversed by supple-mentation with iodine later in life has not yet been answered unequivocally.

    The research described in this thesis was set up to address this question. A double-blind placebo-controlled intervention was carried out in an iodine deficient area of northern Benin in the period 1995-1996. A single oral dose of iodized oil or placebo was administrated to 2 groups of schoolchildren, aged 7-11 years. The observation period was 10-11 months. However, 3 to 4 months after supple-mentation the population started to have access to iodized salt, in addition to non-iodized salt. Because iodine became available to both groups, the main hypothesis, i.e. that iodine supplementation would improve mental performance had to be modified. It was decided to take children whose iodine status, as measured by different indicators, did not change during the observation period as the "control" group. In addition to mental and psychomotor performance, other aspects associated with iodine deficiency were studied, including behavioral change and hearing thresholds and their relation with mental performance. The suitability of several indicators for measuring iodine status and thyroid function was evaluated.

    Results showed that an improvement in iodine status as measured by urinary iodine concentration, was reflected in a significantly improved performance on the combination of mental tests, 10 months after supplementation. Moreover, children with better iodine status could hear better than their peers with a poorer iodine status, while hearing thresholds were negatively correlated with performance on all mental tests, but one. The serum concentration of thyroglobulin and the urinary iodine concentration were found to be indicators most suitable for measuring change in iodine status in this age group. Although the influx of iodine into the area precludes the drawing of "hard" conclusions, the results presented suggest that iodine supplementation is likely to promote a catch-up process in functional performance of iodine deficient schoolchildren.

    Gerontotechnologie aan de Technische Universiteit Delft.
    Steenbekkers, L.P.A. ; Beijsterveldt, C.E.M. van; Dirken, J.M. ; Houtkamp, J.J. ; Molenbroek, J.F.M. ; Voorbij, A.I.M. - \ 1998
    Tijdschrift voor Ergonomie 23 (1998)4. - ISSN 0921-4348 - p. 98 - 105.
    ergonomie - aangepaste technologie - huishoudelijke uitrusting - ouderen - fysische eigenschappen - mentale vaardigheid - nederland - ergonomics - appropriate technology - household equipment - elderly - physical properties - mental ability - netherlands
    Omdat voor het ontwerpen van dagelijkse gebruiksgoederen gegevens nodig zijn over capaciteiten en karakteristieken van toekomstige gebruikers, zijn 79 fysieke, psychomotorische, sensorische en cognitieve variabelen gemeten bij 627 Nederlanders tussen 50 en 94 jaar
    Wat ga jij nu doen? Leren voor oordeelsvorming en besluitvaardigheid.
    Haarlem, R. van - \ 1996
    Agrarisch Onderwijs 38 (1996)18. - ISSN 0925-837X - p. 8 - 10.
    besluitvorming - scholen - samenwerking - relaties - organisaties - genetische modificatie - recombinant dna - ethiek - onderwijs - mentale vaardigheid - duurzaamheid (sustainability) - projecten - agrarisch onderwijs - hoger onderwijs - beroepsopleiding - colleges - universiteiten - onderwijsmethoden - moraal - utilisme - probleemgestuurd onderwijs - decision making - schools - cooperation - relationships - organizations - genetic engineering - recombinant dna - ethics - education - mental ability - sustainability - projects - agricultural education - higher education - vocational training - colleges - universities - teaching methods - moral - utilitarianism - problem-based learning
    Agrarisch ondernemerschap in psychologisch perspectief.
    Defares, P.B. - \ 1986
    Wageningen : Wageningen Universiteit - 28
    cognitieve ontwikkeling - agrarische bedrijfsvoering - mentale vaardigheid - ontwikkelingspsychologie - cognitive development - farm management - mental ability - developmental psychology
    Selectieve migratie : een empirische studie van de samenhang tussen plattelandsmigratie en selectie naar intelligentie in Nederland
    Lijfering, J.H.W. - \ 1968
    Wageningen : Veenman (Mededelingen / Landbouwhogeschool Wageningen 68-3) - 138
    ontwerp - mentale vaardigheid - migratie - nederland - vragenlijsten - plattelandsgemeenschappen - sociologie - karteringen - creativiteit - design - mental ability - migration - netherlands - questionnaires - rural communities - sociology - surveys - creativity
    Wetenschappelijke creativiteit
    Leent, J.A.A. van - \ 1963
    Wageningen : Unknown Publisher - 19
    kennis - mentale vaardigheid - psychologie - creativiteit - wetenschap - knowledge - mental ability - psychology - creativity - science
    Rede Wageningen
    Specialisatie en algemene vorming
    Hofstee, E.W. - \ 1955
    Den Haag : [s.n.] - 36
    hoger onderwijs - mentale vaardigheid - nederland - persoonlijkheid - higher education - mental ability - netherlands - personality
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