Nutrient adequacy and food group consumption of Filipino novices and religious sisters over a nine month period

Rice is commonly consumed in the Philippines; however the contribution of other foods to the diet is not well defined. Our aim was to determine the nutrient intake and food group intake of Philippine nuns and compare their intakes to the current estimated average requirements (EAR), and food-based recommendations, respectively, and assess any differences in nutrient adequacy and energy intakes between body mass index (BMI) categories. Body weight was assessed at baseline and at nine months; three-day weighed food intakes were recorded once every fortnight (n=187). At baseline, the mean (SD) age and BMI of the women was: 25.0 (4.6) years and 21.8 (17.3) kg/m2, respectively. Over the nine months, women with an underweight (n=46;<18.5 kg/m2) and acceptable BMI (n=132; 18.5-25 kg/m2) lost 5.0 kg (p=0.005) and 1.5 kg (p=0.047), respectively, whereas overweight women maintained their weight. Irrespective of BMI, 98% of women consumed less than the adequate intake for calcium, and no one met the folate EAR. The intake of all food groups (e.g., rice, vegetables, fruit, meat, dairy) was lower than food-based recommendations. It is evident that the nutrient density of the Philippine diet is poor. In order to meet nutrient requirements, it is recommended that all women increase intake of fruits, vegetables, fish, meat and dairy products, to reduce risk of micronutrient deficiencies. For the overweight women, these nutrient dense foods also are recommended, however it is important that they be substituted for energy dense foods to promote weight loss and prevent weight gain.

CSF proteomic analysis reveals persistent iron deficiency-induced alterations in non-human primate infants

Iron deficiency (ID) anemia during infancy results in long-term neurological consequences, yet the mediating mechanisms remain unclear. Infant monkeys often become naturally anemic during the first 6 months of life, presenting an opportunity to determine the effect of developmental iron deficiency. After weaning, animals were chosen randomly for supplementation with oral iron or, fed a standard commercial chow diet. The control group was never iron deficient. ID anemia was corrected by 12 months in both groups, as indicated by hematological parameters. CSF was collected for proteomic analysis at 12 months of age to assess the impact of developmental ID on the brain. The CSF proteome for both formerly iron deficient groups was similar and revealed 12 proteins with expression levels altered at least twofold. These proteins were identified by matrix assisted laser desorption ionization time-of-flight spectrometry and included prostaglandin D synthase, olfactory receptors and glial fibrillary acidic protein. Thus the proteomic analysis reveals a persistent effect of ID and provides insights into reports of disturbed sleep, hypomyelination and other behavioral alterations associated with ID. Furthermore, alterations in the CSF proteome despite normal hematologic parameters indicate that there is a hierarchical system that prioritizes repletion of red cell mass at the expense of the brain.

Systems genetic analysis of peripheral iron parameters in the mouse

Iron homeostasis is one of the most critical functions in living systems. Too little iron can lead to anemia and tissue-specific disorders, such as splenomegaly. Excessive systemic iron is characteristic of hemochromatosis and is implicated in the brain in Parkinson's disease. With the exception of some single gene diseases like hemochromatosis, we know little about genetic-based, individual differences in iron-related parameters and their impact on biology. To model genetic control of iron homeostasis, we measured liver, spleen, and plasma iron concentrations, hematocrit and hemoglobin, transferrin saturation, and total iron-binding capacity in several BXD/Ty recombinant inbred mouse strains derived from C57BL/6 and DBA/2 progenitors. At 120 days of age, the animals were killed for iron analysis. All measures showed genetic-based variability consistent with polygenic influence. Analysis of principal components of the seven measures revealed three factors that we named availability, transport, and storage. Quantitative trait loci (QTL) analysis revealed one suggestive QTL on chromosome 5 for availability, two suggestive QTL (one on chromosome 1 and the other on chromosome 7) for transport, and one weak QTL on chromosome 2 for storage. The results show that iron homeostasis is a complex trait and is influenced by multiple genes.

Iron absorption prediction equations lack agreement and underestimate iron absorption

A number of algorithms have been developed to predict the bioavailability of iron from mixed meals and diets, but their direct validity in predicting change in iron status remains questionable. Throughout the course of conducting a large feeding trial in 10 convents in Manila, we collected weighed food intake data (n = 317) and directly compared the performance of these prediction equations to each other and to the change in serum ferritin (SF). Dietary weighed food intakes were measured on d 3 every 2 wk for each woman and iron status determined at baseline, 4.5 mo, and 9 mo. The Monsen and Balintfy equation predicted higher median absorption efficiency (7.3%) than did the equations of Hallberg and Hulthen (6.1%) and Reddy et al. (5.8%). In contrast, the predictions that used the equations of Bhargava et al. (3.8%), Tseng et al. (2.9%), and Du et al. (2.6%) were significantly lower. The iron absorption efficiencies calculated using the Monsen and Balintfy equation correlated with those using the Hallberg and Hulthen equation (r = 0.91, P < 0.001). This slope did not differ from unity, whereas all other equations underestimated iron absorption efficiency relative to Monsen and Balintfy's equation. The median efficiency of absorption, based on change in SF in 114 subjects, was 17.2%, suggesting that these equations underestimate iron absorption. The inhibitory and enhancing factors in the published prediction equations were quantitatively either too large or perhaps too small to correctly predict apparent iron bioavailability over a 9-mo period. The causes of the lack of agreement between change in iron status estimated by SF change and absorption predicted by algorithms are open to discussion and will need to be resolved.

Variation in the Diets of Filipino Women over 9 Months of Continuous Observation

Background

The variability in habitual intakes of most components in the Philippine diet is unknown.

Objective

To perform a quantitative evaluation of the traditional Philippine diet using data collected over an extended period of time. We sought to identify seasonal variations and within-subject components of variation in nutrient intake.

Methods

A quantitative evaluation of the Philippine diet was conducted in convents in metropolitan Manila as part of an efficacy trial to examine biofortified rice as an approach to improve iron nutritional status. Weighed food intakes were conducted on 54 days in each of more than 300 religious sisters over 9 months in 10 convents. The sisters consumed their habitual diets except for the substitution of one variety of rice for another.

Results

More than 40% of calories were derived from rice, with protein from meat and fish comprising 18% of calories. There were significant variations in macronutri- ent and micronutrient intakes across seasons of the year, with more rice consumed in the wet season and more fruits, eggs, milk, and beverages consumed in the dry season. The day-to-day within-subject variation (CV) in median intake was 23% for energy, 31% for protein, 42% for iron, and 138% for vitamin A.

Conclusions

These novel data show that traditional Filipino dietary patterns have substantial individual variation and are inadequate in certain micronutrients. This quantitative evaluation of diet can provide a reference point for dietary adequacy.

Early postnatal iron repletion overcomes lasting effects of gestational iron deficiency in rats

Iron deficiency anemia in early childhood causes developmental delays and, very likely, irreversible alterations in neurological functioning. One primary goal for the present study was to determine whether the effects of late gestational iron deficiency on brain monoamine metabolism, iron content, and behavioral phenotypes could be repaired with iron intervention in early lactation. Young pregnant rats were provided iron-deficient or control diets from mid-gestation (G15). At postnatal d 4 (P4), pups from iron-deficient dams were out-fostered either to other ID dams or control dams while pups of control dams were similarly fostered to other control dams. Dietary treatments continued to adulthood (P65) when brain iron and regional monoamines were evaluated. P4 iron repletion normalized body iron status, brain iron concentrations, monoamine concentrations, and monoamine transporter and receptor densities in most brain regions. Dopamine transporter densities in caudate and substantia nigra were lower in ID rats but were normalized with iron repletion. Serotonin transporter levels in most brain regions and open-field exploration were also normalized with iron repletion. The success of this approach of early postnatal iron intervention following iron deficiency in utero contrasts to a relative lack of success when the intervention is performed at weaning. These data suggest that a window of opportunity exists for reversing the detrimental effects of iron deficiency in utero in rats and provides strong support of intervention approaches in humans with iron deficiency during pregnancy.

Iron treatment normalizes cognitive functioning in young women

BACKGROUND

Evidence suggests that brain iron deficiency at any time in life may disrupt metabolic processes and subsequently change cognitive and behavioral functioning. Women of reproductive age are among those most vulnerable to iron deficiency and may be at high risk for cognitive alterations due to iron deficiency.

OBJECTIVE

We aimed to examine the relation between iron status and cognitive abilities in young women.

DESIGN

A blinded, placebo-controlled, stratified intervention study was conducted in women aged 18-35 y of varied iron status who were randomly assigned to receive iron supplements or a placebo. Cognition was assessed by using 8 cognitive performance tasks (from Detterman's Cognitive Abilities Test) at baseline (n = 149) and after 16 wk of treatment (n = 113).

RESULTS

At baseline, the iron-sufficient women (n = 42) performed better on cognitive tasks (P = 0.011) and completed them faster (P = 0.038) than did the women with iron deficiency anemia (n = 34). Factors representing performance accuracy and the time needed to complete the tasks by the iron-deficient but nonanemic women (n = 73) were intermediate between the 2 extremes of iron status. After treatment, a significant improvement in serum ferritin was associated with a 5-7-fold improvement in cognitive performance, whereas a significant improvement in hemoglobin was related to improved speed in completing the cognitive tasks.

CONCLUSIONS

Iron status is a significant factor in cognitive performance in women of reproductive age. Severity of anemia primarily affects processing speed, and severity of iron deficiency affects accuracy of cognitive function over a broad range of tasks. Thus, the effects of iron deficiency on cognition are not limited to the developing brain.

Iron bioavailability: UK Food Standards Agency workshop report

The UK Food Standards Agency convened a group of expert scientists to review current research investigating factors affecting iron status and the bioavailability of dietary iron. Results presented at the workshop show menstrual blood loss to be the major determinant of body iron stores in premenopausal women. In the presence of abundant and varied food supplies, the health consequences of lower iron bioavailability are unclear and require further investigation.

Early iron deficiency alters sensorimotor development and brain monoamines in rats

Iron deficiency in human infancy reportedly leads to developmental delays and changes in neurobiology that may be irreversible. Using a rodent model, the present study examined whether dietary iron deficiency late in pregnancy and during lactation alters sensorimotor development and brain monoaminergic systems. Rats were assigned to 1 of 4 dietary treatments during gestation and lactation: 1) iron sufficient control; 2) prenatal iron deficiency beginning on gestational d 15 (G15); 3) postnatal iron deficiency beginning on postnatal d 4 (P4); 4) iron deficiency beginning on G15 followed by an iron sufficient diet on P4. Developmental milestones, open field behavior, brain iron and proteins, monoamines, and their transporters were evaluated between P6 and P21. Only G15 iron deficient rats had greater dopaminergic activity than controls as indicated by increased tyrosine hydroxylase levels, phosphorylated tyrosine hydroxylase levels, and cellular dopamine in prefrontal cortex and striatum at P15. These rats also showed delayed eye opening, ear development, and reduced locomotor activity. Iron repletion at P4 returned most measures to control levels by the time of weaning. Postnatal iron deficiency reduced striatal and ventral midbrain iron as well as cellular dopamine levels in prefrontal cortex and striatum at P21. Developmental delays in ear development and achievement in bar holding and surface righting also resulted from postnatal iron deficiency. These results indicate that iron deficiency begun at G15 affects early dopamine neurobiology, the development of specific developmental milestones, and behavior in preweaned rats.

Down-regulation of dopamine transporter by iron chelationin vitrois mediated by altered trafficking, not synthesis

Neurological development and functioning of dopamine (DA) neurotransmission is adversely affected by iron deficiency in early life. Iron-deficient rats demonstrate significant elevations in extracellular DA and a reduction in dopamine transporter (DAT) densities in the caudate putamen and nucleus accumbens. To explore possible mechanisms by which cellular iron concentrations control DAT functioning, endogenous DAT-expressing PC12 cells were used to determine the effect of iron chelation on DAT protein and mRNA expression patterns. In addition, we used human DAT (hDAT)-transfected Neuro2a (N2A) cells to examine DAT degradation and trafficking patterns. A 50 microM treatment for 24 h with the iron chelator, desferrioxamine (DFO), significantly decreased dopamine uptake in a dose-dependent manner, with no apparent change in K(m), in both PC12 and N2A cells. Reduced DA uptake was accompanied by concentration- and time-dependent reductions in total DAT protein levels in both cell lines. Exposure to increasing concentrations of DFO did not significantly alter DAT mRNA in either PC12 or N2A cells. However, DAT degradation rates increased three-fivefold in both cell types exposed to 50 microM DFO for 24 h. Biotinylation studies in N2A cells indicate a more dramatic loss of DAT in the membrane fraction, while OptiPrep fractionation experiments revealed an increase in lysosomal DAT with iron chelation. Inhibition of protein kinase C activation with staurosporin prevented the effect of iron chelation on DAT function, suggesting that in vitro iron chelation affects DAT primarily through the effects on trafficking rather than on synthesis.

Interpretation of serum ferritin concentrations as indicators of total-body iron stores in survey populations: the role of biomarkers for the acute phase response

BACKGROUND

Nutritional surveys use acute phase protein (APP) biomarkers such as C-reactive protein (CRP) and alpha1-acid glycoprotein (AGP) to identify the influence of inflammation on the distribution of iron status biomarkers. Few, however, have examined which biomarker better identifies persons with spurious elevations in iron status markers.

OBJECTIVE

We explored the relations of APP biomarkers to iron-status biomarkers in infants and school-age children.

DESIGN

In screening surveys, we identified a sample of African American infants (n = 351) and Guatemalan school-age children (n = 375). We used a common set of APP and iron-status biomarkers to examine the association between the 2 sets of markers (laboratory variables).

RESULTS

The overall prevalence of either inflammation or iron deficiency was <10% in both samples. The log AGP and CRP values were significantly correlated (r = 0.70), but the unexplained variance still was >50%. Serum ferritin-but not transferrin receptor, transferrin receptor index, or serum iron-was related to APP concentrations, but poor positive predictive value (<72%) and low kappa scores were found. Ferritin concentrations >1 geometric SD above the geometric mean were poorly predicted by either elevated AGP or CRP. Qualitative CRP analysis was not effective in identifying persons who had other indications of mild inflammation.

CONCLUSIONS

These analyses show that a low prevalence of inflammation has little influence on the distribution of ferritin, and 2 common indicators of inflammation do not perform equally well in identifying persons who may have elevations in ferritin due to inflammation.

Quantitative genetic analysis of brain copper and zinc in BXD recombinant inbred mice

Copper and zinc are trace nutrients essential for normal brain function, yet an excess of these elements can be toxic. It is important therefore that these metals be closely regulated. We recently conducted a quantitative trait loci (QTL) analysis to identify chromosomal regions in the mouse containing possible regulatory genes. The animals came from 15 strains of the BXD/Ty recombinant inbred (RI) strain panel and the brain regions analyzed were frontal cortex, caudate-putamen, nucleus accumbens and ventral midbrain. Several QTL were identified for copper and/or zinc, most notably on chromosomes 1, 8, 16 and 17. Genetic correlational analysis also revealed associations between these metals and dopamine, cocaine responses, saccharine preference, immune response and seizure susceptibility. Notably, the QTL on chromosome 17 is also associated with seizure susceptibility and contains the histocompatibility H2 complex. This work shows that regulation of zinc and copper is under polygenic influence and is intimately related to CNS function. Future work will reveal genes underlying the QTL and how they interact with other genes and the environment. More importantly, revelation of the genetic underpinnings of copper and zinc brain homeostasis will aid our understanding of neurological diseases that are related to copper and zinc imbalance.

Persistent neurochemical and behavioral abnormalities in adulthood despite early iron supplementation for perinatal iron deficiency anemia in rats

BACKGROUND

Iron deficiency anemia (IDA) has been associated with altered cognitive, motor, and social-emotional outcomes in human infants. We recently reported that rats with chronic perinatal IDA, had altered regional brain iron, monoamines, and sensorimotor skill emergence during early development.

OBJECTIVE

To examine the long-term consequences of chronic perinatal IDA on behavior, brain iron and monoamine systems after dietary iron treatment in rats.

METHODS

Sixty dams were randomly assigned to iron-sufficient (CN) or low-iron (EID) diets during gestation and lactation. Thereafter, all offspring were fed the iron-sufficient diet, assessed for hematology and behavior after weaning and into adulthood and for brain measures as adults (regional brain iron, monoamines, dopamine and serotonin transporters, and dopamine receptor). Behavioral assessments included sensorimotor function, general activity, response to novelty, spatial alternation, and spatial water maze performance.

RESULTS

Hematology and growth were similar for EID and CN rats by postnatal day 35. In adulthood, EID thalamic iron content was lower. Monoamines, dopamine transporter, and dopamine receptor concentrations did not differ from CN. EID serotonin transporter concentration was reduced in striatum and related regions. EID rats had persisting sensorimotor deficits (delayed vibrissae-evoked forelimb placing, longer sticker removal time, and more imperfect grooming chains), were more hesitant in novel settings, and had poorer spatial water maze performance than CN. General activity and spatial alternation were similar for EID and CN.

CONCLUSION

Rats that had chronic perinatal IDA showed behavioral impairments that suggest persistent striatal dopamine and hippocampal dysfunction despite normalization of hematology, growth and most brain measures.

Moderate iron deficiency in infancy: Biology and behavior in young rats

Iron deficiency anemia in early childhood is associated with developmental delays and perhaps, irreversible alterations in neurological functioning. The goals were to determine if dietary induced gestational and lactational iron deficiency alters brain monoamine metabolism and behaviors dependent on that neurotransmitter system. Young pregnant rats were provided iron deficient or control diets from early in gestation through to weaning of pups and brain iron concentration, regional monoamine variables and achievement of specific developmental milestones were determined throughout lactation. Despite anemia during lactation, most brain iron concentrations did not fall significantly until P25, and well after significant changes in monoamine levels, transporter levels, and D2R density changed in terminal fields. The changes in D2R density were far smaller than previously observed models that utilized severe dietary restriction during lactation or after weaning. Iron deficient pups had normal birth weight, but were delayed in the attainment of a number of milestones (bar holding, vibrissae-evoked forelimb placing). This approach of iron deficiency in utero and during lactation sufficient to cause moderate anemia but not stunt growth demonstrates that monaminergic metabolism changes occur prior to profound declines in brain iron concentration and is associated with developmental delays. Similar developmental delays in iron deficient human infants suggest to us that alterations in iron status during this developmental period likely affects developing brain monaminergic systems in these infants.

Acoustic startle response is disrupted in iron-deficient rats

Diurnal effects on motor control are evident in the human disease of Restless Leg Syndrome (RLS), which is purported to be linked to brain iron deficiency as well as alterations in dopaminergic systems. Thus, we explored the relationship between daily rhythms, the onset of motor dysregulation and brain iron deficiency in an animal model of iron deficiency. Male and female weanling Sprague-Dawley rats consuming control (CN) or iron-deficient (ID) diets were examined weekly for acoustic startle response (ASR) and prepulse inhibition (PPI) for a 5-week period. Iron deficiency reduced the magnitude, but not timing, of the ASR at specific time points. ASR was elevated 60% at the onset of the dark cycle relative to the median of the light cycle in male CN and ID rats. The respective elevation was 400% and 150% in female CN and ID rats during the first 2 weeks of testing. The diurnal cycle of ASR response was attenuated by 3 weeks of testing in both dietary treatment groups. PPI was not affected by iron deficiency, sex, diurnal cycle or the interaction between these factors. These results thus demonstrate that iron deficiency moderately alters ASR signaling although the inhibitory pathways of ASR do not appear to be affected.

Ferritin subunits in CSF are decreased in restless legs syndrome

Restless legs syndrome (RLS) is a neurological disorder that may be related to iron misregulation at the level of the central nervous system. Evidence that iron is involved in RLS comes from magnetic resonance imaging data, autopsy studies, analyses of cerebrospinal fluid (CSF), and correlations of symptoms with serum ferritin. To further examine the possibility that brain iron status is insufficient in RLS, we determined ferritin levels in the CSF. Specifically, we differentiated between the H- and L-subunits of ferritin, because these peptides are expressed from different chromosomes and have different functions. We measured H- and L-ferritin subunit levels in control and RLS human CSF using immunoblot analysis and found that both H- and L-ferritin are significantly decreased in early but not late-onset RLS. Additionally, we quantified total protein in each CSF sample to establish that the decrease in ferritin subunits in RLS did not reflect a decrease in total protein in CSF. Furthermore, we used equal amounts of total CSF protein in the immunoblot analyses, in contrast to previously published studies that provided only volumetric data, to determine which approach was more accurate for quantifying the amount of ferritin relative to other proteins in CSF. Our results establish a protein standard in RLS, provide a comparative analysis of protein-controlled versus volumetric immunoblot techniques, and argue for a profound loss of iron storage capacity in the brain in RLS, specifically in the early onset RLS phenotype. These data suggest that CSF ferritin levels may provide a biomarker for assisting in the diagnosis of RLS.

Cellular iron concentrations directly affect the expression levels of norepinephrine transporter in PC12 cells and rat brain tissue

Neurological development and functioning are adversely affected by iron deficiency in early life. Iron-deficient rats are known to have elevations in extracellular DA and NE, suggesting alterations in reuptake of these monoamines. To explore possible mechanisms by which cellular iron concentrations may alter NE transporter functioning, we utilized NET expressing PC12 cells and iron-deficient rats to explore the relationship between NET protein and mRNA expression patterns and iron concentrations. Treatment of PC12 with the iron chelator, desferrioxamine mesylate (DFO, 50 microM for 24 h), significantly decreased [3H] NE uptake by more than 35% with no apparent change in Km. PC12 cells exposed to increasing concentrations of DFO (25-100 microM) exhibited a dose response decrease in [3H] NE uptake within 24 h (38-73% of control) that paralleled a decrease in cellular NET protein content. Inhibition of protein synthesis with cycloheximide resulted in NET disappearance rates from DFO-treated cells greatly exceeding the rate of loss from control cells. RT-PCR analysis revealed only a modest decrease in NET mRNA levels. Rat brain locus ceruleus and thalamus NET mRNA levels were also only modestly decreased (10-15%) despite a 40% reduction in regional brain iron. In contrast, NET proteins levels in thalamus and locus ceruleus were strongly affected by regional iron deficiency with high correlations with iron concentrations (r > 0.94 and r > 0.80 respectively). The present findings demonstrate that NET protein concentrations and functioning are dramatically reduced with iron deficiency; the modest effect on mRNA levels suggests a stronger influence on NET trafficking and degradation than on protein synthesis.

Iron deficiency affects acoustic startle response and latency, but not prepulse inhibition in young adult rats

Iron deficiency is associated with alterations in dopamine and serotonin transporters as well as changes in dopamine receptor (DR) density, monoamine concentrations, and in vivo extracellular contents of monoamines in terminal fields. Human infants with iron deficiency have both delayed maturation as well as lengthened central conduction times in auditory evoked potential studies. The current study utilizes the magnitude of the acoustic startle response (ASR), prepulse inhibition (PPI), and mean latency to maximum startle response (T(max)), to examine the functional integrity of response to environmental cues. Male and female rats consumed iron deficient (ID) or iron adequate (CN) diets from weaning until adulthood. ID rats of both sexes had 20-60% reductions in ASR when compared to CN rats but there was no effect on PPI. T(max) was significantly longer by 10-20% in females, but not males. Dopamine transporter density was significantly lower in putamen, nucleus accumbens, and olfactory tubercle in males, but not female rats while the serotonin transporter was significantly different from control animal density in five of 14 brain regions. Norepinephrine transporter density was lower in the locus ceruleus of ID male rats but was unaffected in ID female rats. Regression modeling of ASR with brain monoamine transporters and receptors showed hematocrit, norepinephrine transporter (NET) in dentate gyrus, and D1R in the nucleus accumbens account for nearly 49% of the variance in ASR. T(max) was not significantly associated with any of the independent variables. We conclude that iron deficiency affects the startle response, but not the inhibitory circuits involved in prepulse inhibition. Importantly, sex also strongly influenced these behavioral responses. Future studies, perhaps pharmacologic in nature, are necessary to ascertain whether iron deficiency modifies the contribution of monoaminergic systems to responses to environmental stimuli.