RESUMEN
BACKGROUND: There is increasing recognition that personalized approaches may be more effective in helping people establish healthier eating patterns and exercise more, and that this approach may be particularly effective in adolescents. OBJECTIVE: The objective of this study was to investigate the use of a smartphone app (FoodWiz2) in supporting healthy lifestyle choices in adolescence. METHODS: Participants (N=34: 11 male, 23 female) aged 16-19 years in full- or part-time education were recruited from sixth form colleges, schools, and other further education establishments in Norfolk and Suffolk, United Kingdom, between February and May 2015. Participants recorded food intake and exercise using a paper diary for 4-5 weeks and then used the app for the same duration. Initial nutrition education and general support were provided during the paper diary use, but the app included personalized messages sent in response to app activity. At the end of each study phase, participants completed an online questionnaire to describe their experience of using the paper diary and app. RESULTS: Record completion declined throughout the study, possibly affected by examination pressure. Food intake data showed increased fruit consumption and significantly reduced consumption of chocolate snacks (P=.01) and fizzy drinks (P=.002) among participants using the app. Questionnaire responses indicated that the app was generally preferred to the paper diary, in particular, the app was seen as less boring to use (P=.03) and more acceptable in social settings (P<.001). CONCLUSIONS: This app-based approach has shown the potential for a more effective approach to improving adolescent diet and exercise levels.
RESUMEN
Preliminary data in the literature indicate that iron absorption from a meal may be increased when consumed with low-pH beverages such as cola, and it is also possible that sugar iron complexes may alter iron availability. A randomized, crossover trial was conducted to compare the bioavailability of nonheme iron from a vegetarian pizza meal when consumed with 3 different beverages (cola, diet cola, and mineral water). Sixteen women with serum ferritin concentrations of 11-54 µg/L were recruited and completed the study. The pizza meal contained native iron and added ferric chloride solution as a stable isotope extrinsic label; the total iron content of the meal was ~5.3 mg. Incorporation of iron from the meal into RBC was not affected by the type of drink (9.9% with cola, 9.4% with diet cola, and 9.6% with water). Serum ferritin and plasma hepcidin were correlated (r = 0.66; P<0.001) and both were significant predictors of iron bioavailability, but their combined effect explained only 30% of the inter-individual variation (P<0.001) and illustrates the current lack of understanding of mechanisms responsible for the fine-tuning of iron absorption. Although there was no effect of low-pH drinks on iron bioavailability in healthy women, their effect on absorption of fortification iron that requires solubilization in dilute acid, such as reduced iron, and in individuals with low gastric acid production, such as older people and individuals with Helicobacter pylori infection, warrants further investigation.
Asunto(s)
Bebidas Gaseosas , Dieta Vegetariana , Absorción Intestinal , Hierro de la Dieta/metabolismo , Adulto , Anciano , Anemia Ferropénica/prevención & control , Péptidos Catiónicos Antimicrobianos/sangre , Bebidas Gaseosas/efectos adversos , Estudios Cruzados , Sacarosa en la Dieta/efectos adversos , Eritrocitos/metabolismo , Femenino , Ferritinas/sangre , Hepcidinas , Humanos , Concentración de Iones de Hidrógeno , Hierro/sangre , Persona de Mediana Edad , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: Iron absorption is proposed to be regulated by circulating hepcidin, but, to date, little data are available to evaluate this relation in humans. OBJECTIVE: Stored samples from a human iron absorption study were used to test the hypothesis that differences in plasma hepcidin explain interindividual variation in iron absorption. DESIGN: Hepcidin-25 concentrations were measured in fasting samples from men aged > or = 40 y (n = 33) recruited to a study investigating the relation between the HFE genotype, iron absorption, and iron status. RESULTS: Log iron absorption was negatively correlated with serum ferritin (r = -0.59, P < 0.001) and with plasma hepcidin (r = -0.55, P < 0.001) but was unaffected by genotype. There was a positive correlation (r = 0.82, P < 0.001) between hepcidin (mean: 2.3; range: 0.1-7.8 nmol/L) and ferritin (mean: 70; range: 9-208 microg/L). Multiple linear regression models showed that plasma hepcidin in isolation significantly predicted 36% of the interindividual variation in iron absorption. CONCLUSIONS: Plasma hepcidin and serum ferritin concentrations are highly correlated, and, in the normal range of plasma hepcidin values, 36% of interindividual differences in iron absorption are explained by differences in circulating plasma hepcidin.
Asunto(s)
Péptidos Catiónicos Antimicrobianos/sangre , Péptidos Catiónicos Antimicrobianos/fisiología , Ferritinas/sangre , Absorción Intestinal/fisiología , Hierro de la Dieta/farmacocinética , Administración Oral , Anciano , Análisis de Varianza , Disponibilidad Biológica , Biomarcadores/sangre , Genotipo , Hemoglobinas/análisis , Hepcidinas , Humanos , Absorción Intestinal/efectos de los fármacos , Isótopos de Hierro , Modelos Lineales , Masculino , Persona de Mediana Edad , Estado NutricionalRESUMEN
BACKGROUND: Food iron fortification is a sustainable and relatively simple strategy to reduce/prevent iron deficiency but is a challenge for the food industry because of possible adverse organoleptic changes caused by the added iron. A micronized dispersible ferric pyrophosphate, trademarked as SunActive Fe, has recently been developed. SunActive Fe has a small particle size, is water soluble and may be suitable for fortifying liquid products. AIM OF THE STUDY: To determine the relative bioavailability of SunActive Fe and its suitability for addition to pure apple juice. METHODS: Iron absorption from SunActive Fe added to pure apple juice (Minute Maid) was compared with absorption from ferrous sulphate, a highly bioavailable form of iron, in 15 women with relatively low iron stores. Both forms of iron were enriched with an iron stable isotope and iron absorption from the apple juice drinks was calculated from the isotopic enrichment of red blood cells 14 days after the last test meal. RESULTS: Although mean absorption of iron from SunActive Fe was significantly lower than from ferrous sulphate (5.5% compared with 9.1%), the mean bioavailability of SunActive Fe iron relative to ferrous sulphate was 0.6, indicating that it is a good source of bioavailable iron. Iron Absorption from SunActive Fe was positively correlated (r = 0.97, P = 0.01) with absorption from ferrous sulphate, and negatively correlated with serum ferritin concentration (ferrous sulphate r = -0.81, P < 0.001; SunActive Fe r = -0.76, P = 0.01). CONCLUSIONS: SunActive Fe was well absorbed from apple juice and is a potentially useful fortificant for liquid food products.
Asunto(s)
Bebidas , Difosfatos/administración & dosificación , Difosfatos/farmacocinética , Compuestos Ferrosos/farmacocinética , Hierro/administración & dosificación , Hierro/farmacocinética , Malus , Absorción , Adolescente , Adulto , Anciano , Disponibilidad Biológica , Proteína C-Reactiva/análisis , Difosfatos/química , Femenino , Ferritinas/sangre , Alimentos Fortificados , Frutas , Hemoglobinas/análisis , Humanos , Hierro/sangre , Hierro/química , Deficiencias de Hierro , Isótopos de Hierro , Persona de Mediana Edad , Tamaño de la PartículaRESUMEN
BACKGROUND: Iron deficiency is a major health problem worldwide, and is associated with diets of low iron bioavailability. Non-heme iron absorption is modulated by dietary constituents, one of which is the so-called "meat factor", present in meat, fish (oily and lean) and poultry, which is an important enhancer of iron absorption in humans. Food processing also affects iron bioavailability. OBJECTIVE: To evaluate the effect of consuming sous vide cooked salmon fish on non-heme iron bioavailability from a bean meal, rich in phytate, in iron-deficient women. DESIGN: Randomized crossover trial in 21 young women with low iron stores (ferritin < 30 microg/L). Two test meals were extrinsically labelled with stable isotopes of iron (Fe-57 or Fe-58). Iron bioavailability was measured as the incorporation of stable isotopes into erythrocytes 14 d after meals consumption. RESULTS: The addition of fish to the bean meal significantly increased (p < 0.001) iron absorption. Serum ferritin concentration and iron absorption were inversely correlated for both the bean meal (R(2) = 0.294, p = 0.011) and the fish and bean meal (R(2) = 0.401, p = 0.002). CONCLUSION: Sous vide cooked salmon fish increases iron absorption from a high phytate bean meal in humans.
Asunto(s)
Anemia Ferropénica/dietoterapia , Hierro de la Dieta/farmacocinética , Proteínas de Hierro no Heme/farmacocinética , Salmón , Adolescente , Adulto , Animales , Disponibilidad Biológica , Estudios Cruzados , Eritrocitos/química , Fabaceae/química , Femenino , Ferritinas/sangre , Humanos , Absorción Intestinal , Hierro de la Dieta/administración & dosificación , Persona de Mediana Edad , Proteínas de Hierro no Heme/administración & dosificación , Ácido Fítico/farmacología , Alimentos MarinosRESUMEN
OBJECTIVE: To determine the relative importance of HFE gene, diet, lifestyle, and blood loss characteristics for predicting iron status in a sample of men aged 40 years or over. DESIGN: Iron status (serum ferritin, transferrin saturation, soluble transferrin receptor) was measured in 44 C282Y heterozygote and 85 age- and BMI-matched wildtype men aged 40 years or over. Dietary intake of iron (total, heme and non-heme), and components known to influence iron bioavailability, was determined using a validated Meal-Based Intake Assessment Tool. Information on lifestyle and blood loss was obtained by questionnaire. Height and weight were measured to determine Quetelet's body mass index. Linear mixed models were used to determine the extent to which these variables predicted iron status. RESULTS: C282Y heterozygosity was associated with 17% higher transferrin saturation (95% CI: 6%, 29%) but no difference in serum ferritin or soluble transferrin receptor concentrations. Blood donation was negatively associated with transferrin saturation (-13% (- 3%, -22%)) and serum ferritin (-58% (-44%, -68%)), and had a marginally significant positive association with soluble transferrin receptor concentration. Self-reported fecal blood loss was negatively associated with serum ferritin concentration (-35% (-54%, -7%)). Alcohol was the only dietary variable associated with iron status and was associated with all three of the iron status indices. Serum ferritin concentration was positively associated with body mass index (10% per unit increase (6%, 15%)). CONCLUSIONS: Blood loss was a stronger predictor of iron status than either C282Y heterozygosity or diet in this population of men aged 40 years and over.
Asunto(s)
Donantes de Sangre , Dieta , Hemorragia Gastrointestinal/sangre , Antígenos de Histocompatibilidad Clase I/genética , Hierro/metabolismo , Proteínas de la Membrana/genética , Estado Nutricional , Adulto , Anciano , Índice de Masa Corporal , Ferritinas/sangre , Genotipo , Proteína de la Hemocromatosis , Hemorroides/sangre , Heterocigoto , Humanos , Sobrecarga de Hierro/genética , Sobrecarga de Hierro/metabolismo , Sobrecarga de Hierro/prevención & control , Hierro de la Dieta/administración & dosificación , Hierro de la Dieta/farmacocinética , Estilo de Vida , Modelos Lineales , Masculino , Persona de Mediana Edad , Mutación , Receptores de Transferrina/sangre , Transferrina/metabolismoRESUMEN
To examine the contribution of genetic factors to food choice, we determined dietary patterns from food frequency questionnaires in 3262 UK female twins aged 18 to 79 years. Five distinct dietary patterns were identified (fruit and vegetable, high alcohol, traditional English, dieting, low meat) that accounted for 22% of the total variance. These patterns are similar to those found in other singleton Western populations, and were related to body mass index, smoking status, physical activity and deprivation scores. Older subjects had higher scores on the fruit and vegetable and traditional English patterns, while lower social deprivation was associated with higher scores for fruit and vegetable, and lower scores for traditional English patterns. All 5 patterns were heritable, with estimates ranging from 41% to 48%. Among individual dietary components, a strongly heritable component was identified for garlic (46%), coffee (41%), fruit and vegetable sources (49%), and red meat (39%). Our results indicate that genetic factors have an important influence in determining food choice and dietary habits in Western populations. The relatively high heritability of specific dietary components implicates taste perception as a possible target for future genetic studies.
Asunto(s)
Dieta , Preferencias Alimentarias , Carácter Cuantitativo Heredable , Adolescente , Adulto , Anciano , Estudios de Cohortes , Análisis Factorial , Femenino , Humanos , Persona de Mediana Edad , Encuestas y Cuestionarios , Reino UnidoRESUMEN
Hepcidin plays a major role in iron homeostasis, but understanding its role has been hampered by the absence of analytical methods for quantification in blood. A commercial ELISA has been developed for serum prohepcidin, a hepcidin precursor, and there is interest in its potential use in the clinical and research arena. We investigated the association between serum prohepcidin concentration and iron absorption in healthy men, and its relationship with iron status in men carrying HFE mutations, hereditary haemochromatosis patients, and pregnant women. Iron absorption was determined in thirty healthy men (fifteen wild-type, fifteen C282Y heterozygote) using the stable isotope red cell incorporation technique. Iron status was measured in 138 healthy men (ninety-one wild-type, forty-seven C282Y heterozygote), six hereditary haemochromatosis patients, and thirteen pregnant women. Mean serum prohepcidin concentrations were 214 (SD 118) ng/ml [208 (SD 122) ng/ml in wild-type and 225 (SD 109) ng/ml in C282Y heterozygotes] in healthy men, 177 (SD 36) ng/ml in haemochromatosis patients, and 159 (SD 59) ng/ml in pregnant women. There was no relationship between serum prohepcidin concentration and serum ferritin in any subject groups, nor was it associated with efficiency of iron absorption. Serum prohepcidin is not a useful biomarker for clinical or research purposes.
Asunto(s)
Péptidos Catiónicos Antimicrobianos/sangre , Hemocromatosis/sangre , Antígenos de Histocompatibilidad Clase I/genética , Hierro de la Dieta/farmacocinética , Proteínas de la Membrana/genética , Embarazo/sangre , Precursores de Proteínas/sangre , Adolescente , Adulto , Biomarcadores/sangre , Suplementos Dietéticos , Femenino , Ferritinas/sangre , Compuestos Ferrosos/uso terapéutico , Genotipo , Hematínicos/uso terapéutico , Hemocromatosis/genética , Hemocromatosis/cirugía , Proteína de la Hemocromatosis , Hepcidinas , Heterocigoto , Humanos , Absorción Intestinal/fisiología , Masculino , Mutación , Flebotomía , Atención Prenatal/métodos , Método Simple CiegoRESUMEN
BACKGROUND: Iron deficiency anaemia is one of the most important nutritional diseases, with high prevalence worldwide. The G277S transferrin mutation has been implicated as a risk factor for iron deficiency in menstruating women. However, the subject is controversial and there are no data concerning the possible influence of this polymorphism on iron absorption. AIM OF THE STUDY: To undertake a pilot study to investigate the effect of carrying the G277S transferrin mutation on non-haem iron absorption from a meal in young menstruating women compared to wild-type controls. METHODS: Menstruating women with low iron stores (serum ferritin < 30 microg/l) or who had suffered from iron deficiency anaemia or had a family history of anaemia were recruited (n = 162). Haematological parameters were analysed, including haemoglobin, ferritin, total-iron binding capacity and transferrin saturation. Non-haem iron absorption from a meal was measured in 25 non-anaemic women either with the G277S/G277G (n = 10) or the wild type G277G/G277G (n = 15) genotype. The incorporation of stable isotopes of iron into erythrocytes was used to measure absorption. RESULTS AND CONCLUSIONS: There were no significant differences in iron status indices or non-haem iron absorption between genotypes. However, G277S carriers did not show the usual inverse association between iron stores and non-haem iron absorption. Further studies should focus on the effects of a combination of polymorphisms in iron metabolism genes on iron absorption.
Asunto(s)
Anemia Ferropénica/genética , Anemia Ferropénica/metabolismo , Deficiencias de Hierro , Hierro de la Dieta/farmacocinética , Transferrina/genética , Adulto , Femenino , Predisposición Genética a la Enfermedad , Humanos , Persona de Mediana Edad , Mutación , Proyectos Piloto , Polimorfismo Genético , Factores de RiesgoRESUMEN
A computer-based dietary assessment tool, the meal-based intake assessment tool (MBIAT), is described. In the current study, dietary intakes of Fe and Zn fractions (total Fe, non-haem Fe, haem Fe, meat Fe, total Zn) and dietary components that influence Fe and Zn absorption (vitamin C, phytate, Ca, grams of meat/fish/poultry, black tea equivalents, phytate:Zn molar ratio) were assessed. The relative validity of the MBIAT was determined in forty-eight UK men aged 40 years and over by comparing its results with those from weighed diet records collected over 12 d. There was good agreement between the MBIAT and the weighed diet records for median intakes of total, non-haem, haem and meat Fe, Zn, vitamin C, phytate, grams of meat/fish/poultry and phytate:Zn molar ratio. Correlations between the two methods ranged from 0.32 (for Ca) to 0.80 (for haem Fe), with 0.76 for total Fe and 0.75 for Zn. The percentage of participants classified by the MBIAT into the same/opposite weighed diet record quartiles ranged from 56/0 for Fe and 60/0 for Zn to 33/10 for Ca. The questionnaire also showed an acceptable level of agreement between repeat administrations (e.g. a correlation for total Fe of 0.74). In conclusion, the MBIAT is appropriate for assessing group dietary intakes of total Fe and Zn and their absorption modifiers in UK men aged 40 years and over.
Asunto(s)
Dieta/estadística & datos numéricos , Hierro de la Dieta/administración & dosificación , Zinc/administración & dosificación , Anciano , Ácido Ascórbico/administración & dosificación , Calcio de la Dieta/administración & dosificación , Registros de Dieta , Humanos , Absorción Intestinal , Hierro de la Dieta/farmacocinética , Masculino , Carne/análisis , Persona de Mediana Edad , Ácido Fítico/administración & dosificación , Encuestas y Cuestionarios , Zinc/farmacocinéticaRESUMEN
BACKGROUND: The suggestion that carriers of the HFE C282Y mutation absorb nonheme iron more efficiently than do carriers of the wild type has public health implications for countries where the C282Y mutation is common and foods are fortified with iron. OBJECTIVE: We investigated the effect of C282Y heterozygosity on nonheme-iron absorption from a diet high in bioavailable iron and from iron-fortified cereals. DESIGN: The subjects were recruited from a parallel study investigating the relation between HFE mutations, habitual diet, and iron status. Iron absorption was measured in 15 wild-type carriers and 15 C282Y heterozygotes aged >/=40 y. Each subject consumed 3 meals of high iron bioavailability (labeled with Fe-57) for 2 d and 2 meals with fortified cereal products (labeled with Fe-54) for the next 3 d. Iron absorption was measured from isotope incorporation into red blood cells 14 d after the last labeled meal and was corrected for utilization of absorbed iron by means of an intravenous infusion of Fe-58. RESULTS: Absorption of Fe-57 with the high-iron-bioavailability diet was 6.8 +/- 6.8% (0.6 +/- 0.6 mg/d) in the wild-type carriers and 7.6 +/- 3.2% (0.7 +/- 0.3 mg/d) in the C282Y heterozygotes. Absorption of Fe-54 with cereal products was 4.9 +/- 2.0% (0.7 +/- 0.3 mg/d) in the wild-type carriers and 5.3 +/- 1.3% (0.8 +/- 0.2 mg/d) in the C282Y heterozygotes. CONCLUSIONS: There was no overall significant difference between C282Y heterozygotes and wild-type men in iron absorption from either dietary nonheme iron or fortified cereal products.
Asunto(s)
Dieta , Heterocigoto , Absorción Intestinal/genética , Hierro de la Dieta/farmacocinética , Disponibilidad Biológica , Ferritinas/sangre , Genotipo , Humanos , Hierro de la Dieta/sangre , Masculino , Persona de Mediana EdadRESUMEN
A method for measuring unlabelled Fe absorption has been investigated in a pilot study using a simple mathematical model. The metabolism of newly absorbed Fe can be approximated as a single-compartment model with the sampled compartment being the plasma pool. Five female volunteers (aged 30-55 years) were recruited to participate in the pilot study. After a 10 mg oral dose of unlabelled ferrous sulfate, the change in plasma Fe concentration over the following 6 h was used to estimate the quantity of absorbed Fe from the mathematical model. To assess the accuracy of the new technique, a 1 mg oral dose of (57)Fe-labelled iron sulfate was given simultaneously with a 225 microg intravenous dose of (58)Fe as iron citrate. The plasma appearance of the labelled Fe was used to estimate the absorption of the oral label from the traditional area under the curve method. There was no significant difference (P=0.61) between the geometric mean absorption of the unlabelled (19 (-1 sd 12, +1 sd 28) %) and the labelled Fe (17 (-1 sd 10, +1 sd 29) %). These initial results are encouraging, but further work needs to be undertaken with smaller doses, as typically found in meals. The effect of diurnal variation in serum Fe concentration on the estimation of unlabelled Fe absorption needs further assessment.