Nutrition and brain function: trace elements

Relationship Between a High-Fat Diet, Reduced Mobility, and Trace Element Overload in the Olfactory Bulbs of C57BL/6J and DBA/2J Mice

The dysregulation of trace elements in the brain, which can be caused by genetic or environmental factors, has been associated with disease and compromised mobility. Research regarding trace elements and motor function has focused mainly on the basal ganglia, but few studies have examined the olfactory bulb in this context. Diets high in fat have been shown to have consequences of dysregulated iron and manganese in the brain and disrupted motor activity. The aim of our study was to examine the relationship between mobility and trace element disruption in the olfactory bulb in male and female C57BL/6J and DBA/2J mice fed a high-fat diet. Mobility was significantly reduced in male C57BL/6Js, but the correlation between iron and manganese in the olfactory bulb with velocity, distance travelled, and habituation was not statistically significant. However, there appears to be an overall pattern of a high-fat diet having a statistically significant impact individually on elevated iron and manganese in the olfactory bulb, reduced velocity, reduced distance travelled, and reduced habituation mainly in the male C57BL/6J strain. We found similar trends within the scientific literature to suggest that dysregulated trace element status in the olfactory bulb may be related to motor function in both humans and animals and that males may be more susceptible to the negative outcomes. Our findings contribute new information regarding the impact of diet on the brain, behavior, and potential connection between trace element dysregulation in the olfactory bulb with mobility.

Associations of essential element serum concentrations with autism spectrum disorder

This case-control study explored the associations between autism spectrum disorder (ASD) and the serum concentration of nine chemical elements in children. The study recruited 92 Chinese children with ASD and 103 typically developing individuals. Serum concentrations of nine chemical elements (calcium, iodine, iron, lithium, magnesium, potassium, selenium, strontium, and zinc) were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). An unconditional logistic regression model was used to analyze the associations between the serum concentrations of the elements and the risk of ASD. After adjusting for confounders, the multivariate analysis results showed that zinc ≤ 837.70 ng/mL, potassium > 170.06 μg/mL, and strontium ≤ 52.46 ng/mL were associated with an increased risk of ASD, while selenium > 159.80 ng/mL was associated with a decreased risk of ASD. Furthermore, the degree of lithium and zinc deficiency was associated with ASD severity. The results indicated that metallomic profiles of some specific elements might play important roles in the development of ASD, a finding of scientific significance for understanding the etiology, and providing dietary guidance for certain ASD types.

Why Do Children in Slums Suffer from Anemia, Iron, Zinc, and Vitamin A Deficiency? Results from a Birth Cohort Study in Dhaka

Considering the high burden of micronutrient deficiencies in Bangladeshi children, this analysis aimed to identify the factors associated with micronutrient deficiencies and association of plasma micronutrient concentration trajectories from 7 to 24 months with the concentrations at 60 months of age. Plasma samples were collected at 7, 15, 24, and 60 months of age, and hemoglobin, ferritin, zinc, and retinol concentrations of 155, 153, 154, and 155 children were measured, respectively. A generalized estimating equation was used to identify the factors associated with micronutrient deficiencies, while latent class growth modeling identified the trajectories of plasma micronutrients from 7 to 24 months and its association with the concentrations of micronutrients at 60 months was examined using multiple linear regression modeling. Early (AOR = 2.21, p < 0.05) and late convalescence (AOR = 1.65, p < 0.05) stage of an infection, low ferritin (AOR = 3.04, p < 0.05), and low retinol (AOR = 2.07, p < 0.05) were associated with increased anemia prevalence. Wasting at enrollment was associated with zinc deficiency (AOR = 1.8, p < 0.05) and birth weight was associated with ferritin deficiency (AOR = 0.58, p < 0.05). Treatment of drinking water was found protective against vitamin A deficiency (AOR = 0.57, p < 0.05). Higher trajectories for ferritin and retinol during 7–24 months were positively associated with plasma ferritin (β = 13.72, p < 0.05) and plasma retinol (β = 3.99, p < 0.05) at 60 months.

How minerals may influence the development and expression of immunity to endoparasites in livestock

This review attempts to explain how dietary mineral intake may affect the immune system, with particular reference to gastrointestinal nematode infestations of livestock, and considers its significance for other gut infections as well as for other species. Of the 56 minerals found in mammalian tissues, 16 are currently considered to be essential, and a further 13 probably essential, for cell and tissue function. To date, eight of these have been shown to affect the function of the mammalian immune system directly. Nine others have roles in physiological pathways such as neurological or endocrine function, or protein or carbohydrate metabolism, which in turn regulate the immune system. The remainder may in the future be shown to have immunologically specific roles. The pathogenesis of mineral effects on immunity involves a number of pathways and molecular mechanisms. Major areas requiring further investigation are the relationship between deficiency of minerals and in vivo immune-mediated protection against disease, in particular diseases of the mucosa, and the mechanisms by which the minerals or their deficiency exert their effect on immunity. Research is also required into the possibility that animals in the process of acquiring gut immunity have higher requirements for minerals.

Plasma trace elements and cognitive function in older men and women: the Rancho Bernardo study

OBJECTIVE

This study examines the sex-specific associations of plasma concentrations of iron, copper, and zinc with cognitive function in older community-dwelling adults.

DESIGN

Cross-sectional study.

SETTING

1988-92 follow-up clinic visit.

PARTICIPANTS

602 men and 849 women (average age=75 +/- 8 years) who were community-dwelling and not clinically demented.

MEASUREMENTS

Blood samples were assayed for trace elements and 12 cognitive function tests were administered. Sex-specific analyses were adjusted for age, education, alcohol consumption, smoking, exercise, and estrogen use in women.

RESULTS

Men and women differed significantly in education and alcohol intake (p's < 0.001), concentrations of plasma iron, copper and zinc (p's < 0.001) and scores on 11 of 12 cognitive function tests (p=0.04 to < 0.001). Regression analyses showed significant inverted U-shaped associations in men; both low and high iron levels were associated with poor performance on total and long-term recall and Serial 7's (p's=0.018, 0.042 and 0.004, respectively) compared to intermediate concentrations. In women, iron and copper concentrations had inverse linear associations with Buschke total, long and short-term recall and Blessed scores (p's < 0.05). Zinc was positively associated with performance on Blessed Items (p=0.008). Analyses comparing cognitive function using categorically defined mineral concentrations yielded similar sex specific results.

CONCLUSION

Optimal trace element concentrations may exist for optimal cognitive function in older adults, and these levels may differ by sex and cognitive function domain.

The evidence linking zinc deficiency with children's cognitive and motor functioning

The role of zinc in children's cognitive and motor functioning is usually assessed by the response to supplementation in populations thought to be zinc deficient. A review of published zinc-supplementation trials that examined behavior and development identified one trial in fetuses, six trials in infants and toddlers and three trials in school-age children. The three studies that examined activity reported that zinc supplementation was associated with more activity. Of the five studies that examined motor development in infants and toddlers, one found improvements among very low-birth-weight infants, one found improvements in the quality of motor development and three found no impact. Of the four studies that examined mental development in infants and toddlers, three found no impact of zinc supplementation and one found that zinc-supplemented children had lower scores than control children. Among school-age children, one study found no impact of zinc supplementation on cognitive performance and two found a beneficial impact of neuropsychological processes, specifically reasoning. The evidence linking zinc deficiency to children's cognitive and motor functioning suggests a relationship among the most vulnerable children but lacks a clear consensus, highlighting the need for additional research into the timing of zinc deficiency and the co-occurrence with other micronutrient deficiencies.

Zinc and cognitive development

Cognition is a field of thought processes by which an individual processes information through skills of perception, thinking, memory, learning and attention. Zinc deficiency may affect cognitive development by alterations in attention, activity, neuropsychological behavior and motor development. The exact mechanisms are not clear but it appears that zinc is essential for neurogenesis, neuronal migration, synaptogenesis and its deficiency could interfere with neurotransmission and subsequent neuropsychological behavior. Studies in animals show that zinc deficiency during the time of rapid brain growth, or during the juvenile and adolescent period affects cognitive development by decreasing activity, increasing emotional behavior, impairing memory and the capacity to learn. Evidence from human studies is limited. Low maternal intakes of zinc during pregnancy and lactation were found to be associated with less focused attention in neonates and decreased motor functions at 6 months of age. Zinc supplementation resulted in better motor development and more playfulness in low birth weight infants and increased vigorous and functional activity in infants and toddlers. In older school going children the data is controversial but there is some evidence of improved neuropsychological functions with zinc supplementation. Additional research is required to determine the exact biological mechanisms, the critical periods, the threshold of severity and the long-term effects of zinc deprivation on cognitive development.

Zinc deficiency and child development

Zinc is a trace metal that is present in the brain and contributes to its structure and function. Limited evidence from both animal and human studies suggests that zinc deficiency may lead to delays in cognitive development. Although the mechanisms linking zinc deficiency with cognitive development are unclear, it appears that zinc deficiency may lead to deficits in children's neuropsychologic functioning, activity, or motor development, and thus interfere with cognitive performance. In this article a model is presented that incorporates the influence of social context and the caregiving environment and suggests that the relation between zinc deficiency and cognitive development may vary by age in children and may be mediated by neuropsychologic functioning, activity, and motor development. Suggestions for further research are provided.

Trace element distribution in rat brain following lead and lithium supplementation--a study using an EDXRF spectrometer

Distribution of K, Fe, Cu, Zn, Br and Rb in whole brain samples following combined Pb and Li administration to female Porton rats has been investigated by using the Energy Dispersive x-Ray Fluorescence (EDXRF) technique. Brain K, Cu and Rb levels are diminished, whereas Fe and Br levels are enhanced significantly following short-term (1 month) and long-term (4 months) combined treatment with Li (1.1 g/kg diet) and two doses of Pb (50 and 100 mg/kg body weight). The Zn levels are lowered following combined treatment with Li and both the doses of Pb given for short-term only.

Sucrose and delinquent behavior: coincidence or consequence?

Over the past decade, a number of theories have appeared that are attempts to relate consumption of simple sugars to violent or delinquent behavior. Such claims have been based mainly on anecdotal reports, misinterpretations of scientific literature, or flawed interpretation of questionable data. Thus, these claims remain unsubstantiated. There are data that suggest that a very few individual hyperactive children may respond adversely to a sucrose challenge, but most carefully designed and controlled studies with children offer no convincing evidence that sucrose ingestion exacerbates hyperkinetic behavior. While provocative evidence is beginning to emerge from studies of incarcerated juvenile delinquents, as well as from studies of adult criminals habitually violent under the influence of alcohol, that anomalies in carbohydrate metabolism may in some way be related to expression of antisocial behavior, there is no evidence to suggest that consuming sucrose causes violent behavior. On the contrary, ingestion of foods that contain simple carbohydrates may elicit beneficial responses, at least in behavioral subgroups of adolescent males.

Regional distribution of potassium, calcium, and six trace elements in normal human brain

Eight elements (i.e. K, Ca, Mn, Fe, Cu, Zn, Se, and Rb) were measured in 50 different regions of 12 normal human brains by particle-induced X-ray emission (PIXE) analysis. The dry weight concentrations of K, Fe, Cu, Zn, Se, and Rb were consistently higher for gray than for white matter areas. The K, Zn and Se concentrations for the regions of mixed composition and, to some extent, also the Rb concentrations, were intermediate between the gray and white matter values, and they tended to decrease with decreasing neuron density. The mean dry weight concentrations of K, Ca, Zn, Se, and Rb in the various brain regions were highly correlated with the mean wet-to-dry weight ratios of these regions. For Mn, Fe, and Cu, however, such a correlation was not observed, and these elements exhibited elevated levels in several structures of the basal ganglia. For K, Fe, and Se the concentrations seemed to change with age. A hierarchical cluster analysis indicated that the structures clustered into two large groups, one comprising gray and mixed matter regions, the other white and mixed matter areas. Brain structures involved in the same physiological function or morphologically similar regions often conglomerated in a single subcluster.