Zinc status and its association with the health of adolescents: a review of studies in India

Background: Zinc is important in adolescence because of its role in growth and sexual maturation. Adolescents from developing countries such as India may be at high risk of zinc deficiency because of unwholesome food habits and poor bioavailability of zinc from plant-based diets. Objectives: (1) to study zinc status and its association with profile of other micronutrients, (2) to construct a simple tool in the form of Adolescent Micronutrient Quality Index (AMQI) to assess quality of diets of the girls and (3) to examine the effect of zinc supplement on health of adolescent girls. Methods: Girls (10–16 years) from two secondary schools of Pune, Maharashtra state, in Western India were enrolled in a cross-sectional study (n = 630). Data were collected on dietary intake, cognitive performance, taste acuity, haemoglobin, erythrocyte zinc and plasma levels of zinc, vitamin C, β-carotene and retinol. AMQI was developed using age–sex-specific Indian dietary guidelines and healthy foods and habits described in the recent US dietary guidelines. Zinc-rich recipes were developed considering habitual diets of the girls and vegetarian sources of zinc. An intervention trial (n = 180) was conducted to assess the effect of zinc-rich dietary supplements and ayurvedic zinc (Jasad) supplementation. Results: Prevalence of micronutrient deficiencies was high in these girls. Poor cognitive performance was seen in half of the girls, and salt taste perception was affected in 45%. AMQI was correlated with nutrient intakes and blood micronutrient levels (p < 0.01), indicating the potential of AMQI to measure micronutrient quality of diets of adolescent girls. Results of the intervention trial indicated that supplementation of zinc-rich recipes vis-a-vis ayurvedic Jasad zinc has the potential to improve plasma zinc status, cognitive performance and taste acuity in adolescent girls. Conclusion: Review of the studies on Indian adolescent girls demonstrates the necessity of adopting zinc and micronutrient-rich diets for positive health building in adolescents

Zinc intake, status and indices of cognitive function in adults and children: a systematic review and meta-analysis

In developing countries, deficiencies of micronutrients are thought to have a major impact on child development; however, a consensus on the specific relationship between dietary zinc intake and cognitive function remains elusive. The aim of this systematic review was to examine the relationship between zinc intake, status and indices of cognitive function in children and adults. A systematic literature search was conducted using EMBASE, MEDLINE and Cochrane Library databases from inception to March 2014. Included studies were those that supplied zinc as supplements or measured dietary zinc intake. A meta-analysis of the extracted data was performed where sufficient data were available. Of all of the potentially relevant papers, 18 studies met the inclusion criteria, 12 of which were randomised controlled trials (RCTs; 11 in children and 1 in adults) and 6 were observational studies (2 in children and 4 in adults). Nine of the 18 studies reported a positive association between zinc intake or status with one or more measure of cognitive function. Meta-analysis of data from the adult’s studies was not possible because of limited number of studies. A meta-analysis of data from the six RCTs conducted in children revealed that there was no significant overall effect of zinc intake on any indices of cognitive function: intelligence, standard mean difference of <0.001 (95% confidence interval (CI) –0.12, 0.13) P=0.95; executive function, standard mean difference of 0.08 (95% CI, –0.06, 022) P=0.26; and motor skills standard mean difference of 0.11 (95% CI –0.17, 0.39) P=0.43. Heterogeneity in the study designs was a major limitation, hence only a small number (n=6) of studies could be included in the meta-analyses. Meta-analysis failed to show a significant effect of zinc supplementation on cognitive functioning in children though, taken as a whole, there were some small indicators of improvement on aspects of executive function and motor development following supplementation but high-quality RCTs are necessary to investigate this further

The importance of Antarctic krill in biogeochemical cycles

Antarctic krill (Euphausia superba) are swarming, oceanic crustaceans, up to two inches long, and best known as prey for whales and penguins – but they have another important role. With their large size, high biomass and daily vertical migrations they transport and transform essential nutrients, stimulate primary productivity and influence the carbon sink. Antarctic krill are also fished by the Southern Ocean’s largest fishery. Yet how krill fishing impacts nutrient fertilisation and the carbon sink in the Southern Ocean is poorly understood. Our synthesis shows fishery management should consider the influential biogeochemical role of both adult and larval Antarctic krill

Aspectos psicobiológicos do comportamento alimentar Psychobiological aspects of feeding behavior

Esta revisão aborda alguns aspectos psicobiológicos ligados à manifestação do comportamento alimentar, e tem como objetivo evidenciar a relação entre os principais processos neuropsicológicos e a neurociência nutricional. Algumas estruturas neurais estão associadas ao controle alimentar por mecanismos distintos e correlatos que ocorrem no hipotálamo, hipocampo e em outras áreas como no cerebelo, bulbo olfatório, glândulas pituitária e pineal que exercem funções distintas, porém influênciam o comportamento alimentar, intermediadas geralmente por neurotransmissores comuns. Os precursores dos neuroquímicos apresentam funções específicas, sendo a influência na alimentação relevante no contexto comportamental da escolha de alimentos. Os processos sensoriais na alimentação como paladar, olfato, visão e audição interagem entre si e com outras estruturas e vias neurais, participando também do controle do apetite e da saciedade, que culminam na iniciação e no término da alimentação. A interação entre aspectos neurais no processo de consumo de alimento promove a manifestação do comportamento alimentar específico para cada espécie em seu ambiente.<br>This review shows how some psychobiological aspects are related to feeding behavior manifestation, and has as it objective to provide evidence as to the relation between neuropsychological processes and nutritional neuroscience. Several neural structures are associated with alimentary controls, which are distinct but correlated mechanisms; for example: hypothalamus, hypocampus, cerebellum, olfactory bulb, pituitary and pineal glands, all presenting distinct functions, but affecting feeding behavior directly or indirectly through common neurotransmitters. Neurochemical precursors present specific functions and their influence on feeding is evident in behavioral food selection. The sensory processes in feeding, principally taste, olfaction, vision and hearing, interact with other neural structures and pathways, thus participating in appetite and satiety, which results in the beginning and end of feeding. The interaction between neural aspects concerning food consumption promotes the manifestation of specific feeding behavior for each specie in their environment