Alginate inhibits iron absorption from ferrous gluconate in a randomized controlled trial and reduces iron uptake into Caco-2 cells

Previous in vitro results indicated that alginate beads might be a useful vehicle for food iron fortification. A human study was undertaken to test the hypothesis that alginate enhances iron absorption. A randomised, single blinded, cross-over trial was carried out in which iron absorption was measured from serum iron appearance after a test meal. Overnight-fasted volunteers (n=15) were given a test meal of 200g cola-flavoured jelly plus 21 mg iron as ferrous gluconate, either in alginate beads mixed into the jelly or in a capsule. Iron absorption was lower from the alginate beads than from ferrous gluconate (8.5% and 12.6% respectively, p=0.003). Sub-group B (n=9) consumed the test meals together with 600 mg calcium to determine whether alginate modified the inhibitory effect of calcium. Calcium reduced iron absorption from ferrous gluconate by 51%, from 11.5% to 5.6% (p=0.014), and from alginate beads by 37%, from 8.3% to 5.2% (p=0.009). In vitro studies using Caco-2 cells were designed to explore the reasons for the difference between the previous in vitro findings and the human study; confirmed the inhibitory effect of alginate. Beads similar to those used in the human study were subjected to simulated gastrointestinal digestion, with and without cola jelly, and the digestate applied to Caco-2 cells. Both alginate and cola jelly significantly reduced iron uptake into the cells, by 34% (p=0.009) and 35% (p=0.003) respectively. The combination of cola jelly and calcium produced a very low ferritin response, 16.5% (p<0.001) of that observed with ferrous gluconate alone. The results of these studies demonstrate that alginate beads are not a useful delivery system for soluble salts of iron for the purpose of food fortification

Association between consumption of black tea and iron status in adult Africans in the North West Province: The THUSA study

The association between black tea consumption and iron status was investigated in a sample of African adults participating in the cross-sectional THUSA (Transition and Health during Urbanization of South Africans) study in the North West Province, South Africa. Data were analysed from 1605 apparently healthy adults aged 15-65 years by demographic and FFQ, anthropometric measurements and biochemical analyses. The main outcome measures were Hb and serum ferritin concentrations. No associations were seen between black tea consumption and concentrations of serum ferritin (men P=0.059; women P=0.49) or Hb (men P=0.33; women P=0.49). Logistic regression showed that tea consumption did not significantly increase risk for iron deficiency (men: OR 1.36; 95 % CI 0.99, 1.87; women: OR 0.98; 95 % CI 0.84, 1.13) nor for iron deficiency anaemia (men: OR 1.28: 95 % Cl 0.84, 1.96; women: OR 0.93; 95 % Cl 0.78, 1.11). Prevalence of iron deficiency and iron deficiency anaemia was especially high in women: 21.6 and 14.6 %, respectively. However, the likelihood of iron deficiency and iron deficiency anaemia was not significantly explained by tea consumption in sub-populations which were assumed to be at risk for iron deficiency. Regression of serum ferritin levels on tea consumption in women : 40 years, adults with a daily iron intak

Seasonal variation in food pattern but not in energy and nutrient intakes of rural Beninese school-aged children

Background: Inadequate energy and nutrient intakes are a major nutritional problem in developing countries. A recent study in Beninese school-aged children in different seasons revealed a high prevalence of stunting and poor iron status that might be related to the food pattern. Objective: To analyse the food pattern and resulting energy and nutrient intakes of rural Beninese school-aged children in relation to season and school attendance. Subjects and methods: The study was performed in northern Benin in eighty randomly selected children aged 6¿8 years. Dietary intake was assessed using observed weighed records. Food, energy and nutrient intakes were measured in post- and pre-harvest seasons. Complete food consumption data sets were available for seventy-five children. Results: Food pattern showed seasonal variations. Cereals, roots and tubers were the main staple foods. Contributions of animal products to the diet were very small. The food pattern was not different for either boys v. girls or for children attending v. not attending school. Median daily energy intakes were 5?0 and 5?3 MJ in the post- and pre-harvest season, respectively. Only fat and vitamin C showed seasonal differences (P,0?05). Energy and nutrient intakes were different for boys and girls but, unexpectedly, not for children attending v. not attending school. Conclusions: Seasonal variations in food pattern did not result in seasonality in energy and nutrient intakes. Because the children¿s diet was low in animal products, protein, fat and vitamin C and high in fibre, the absorption of fat, fatsoluble vitamins, carotenoids, Fe and Zn might be low. Fe and Zn bioavailability from such a diet needs further investigation

Long-Term Dose-Response Condensed Tannin Supplementation Does Not Affect Iron Status or Bioavailability

Citation: Delimont, N. M., Fiorentino, N. M., Kimmel, K. A., Haub, M. D., Rosenkranz, S. K., & Lindshield, B. L. (2017). Long-Term Dose-Response Condensed Tannin Supplementation Does Not Affect Iron Status or Bioavailability. Current Developments in Nutrition, 1(10), e001081. https://doi.org/10.3945/cdn.117.001081Background: Repeated phytic acid consumption leads to iron absorption adaptation but, to the best of our knowledge, the impact of repeated tannin consumption has not yet been established. Salivary proline-rich proteins (PRPs) may improve iron absorption by precipitating tannins. Objectives: This study aimed to determine the effect of long-term, dose-response condensed tannin supplementation on iron bioavailability and status and to assess the effect of salivary proteins on iron bioavailability during prolonged condensed tannin consumption. A secondary objective was to assess astringency as a potential marker for adaptation to tannins and iron bioavailability. Methods: Eleven nonanemic women were enrolled in a double-blind 3-dose crossover trial. Three (1.5, 0.25, or 0.03 g) condensed tannin supplements were consumed 3 times/d for 4 wk in random order, with 2-wk washouts in between. Meal challenges were employed before and after supplementation to assess iron bioavailability, iron status, salivary PRP changes, and astringency. Results: Tannin supplementation in any dose did not change iron bioavailability at any dose (P . 0.82) from weeks 0 to 4. Hemoglobin (P = 0.126) and serum ferritin (P = 0.83) were unchanged by tannin dose from weeks 0 to 4. There were significant correlations among tannin supplementation and iron bioavailability, basic proline-rich proteins (bPRPs) (r = 0.366, P = 0.003), and cystatin production (r = 0.27, P = 0.03). Astringency ratings did not change significantly within or between tannin doses (P . 0.126), but there were negative relations among bPRP (r , 20.32, P , 0.21), cystatin production (r , 20.2, P , 0.28), and astringency ratings. Conclusions: Condensed tannin consumption did not affect iron bioavailability or status regardless of the supplementation period in premenopausal nonanemic women. Correlation analyses suggest that bPRPs and cystatins are associated with improved iron bioavailability and that lower ratings of astringency may predict improved iron absorption with repeated tannin consumption. Curr Dev Nutr 2017;1:e001081

Factors affecting sorghum protein digestibility

In the semi-arid tropics worldwide, sorghum (Sorghum bicolor (L.) Moench) is cultivated by farmers on a subsistence level and consumed as food by humans. A nutritional limitation to its use is the poor digestibility of sorghum protein when wet cooked. The factors affecting wet cooked sorghum protein digestibility may be categorised into two main groups: exogenous factors (grain organisational structure, polyphenols, phytic acid, starch and non-starch polysaccharides) and endogenous factors (disulphide and non-disulphide crosslinking, kafirin hydrophobicity and changes in protein secondary structure). All these factors have been shown to influence sorghum protein digestibility. More than one factor may be at play at any time depending on the nature or the state in which the sorghum grain is; that is whether whole grain, endosperm, protein body preparation, high-tannin or condensed-tannin-free. It is proposed that protein crosslinking may be the greatest factor that influences sorghum protein digestibility. This may be between ?- and ß-kafirin proteins at the protein body periphery, which may impede digestion of the centrally located major storage protein, a-kafirin, or between ?- or ß-kafirin and a-kafiri

Factors Associated with Iron Status in a Hutterite Population

Several factors are known to influence the absorption of dietary iron. The type of dietary iron consumed, what foods or supplements are consumed with dietary iron can all influence iron absorption. Understanding these factors can lead to better knowledge of what may or may not influence iron absorption. Obtaining accurate dietary data is important in nutrition research. Food frequency questionnaires can be used to estimate intake over a year time period, however, validation of a food frequency questionnaire against the 24 hour recall is essential for assessing the accuracy of the food frequency questionnaire. The following chapters of this dissertation present papers that have added to work in the field of iron nutrition. It will also add to the studies of the use of food frequency questionnaires in a rural setting. Factors associated with iron status of a Hutterite population, the contribution of tea to iron status in a rural female population and the validation of a food frequency questionnaire for assessment of calcium and bone related nutrient intake in rural populations are presented

Sodium iron EDTA and ascorbic acid, but not polyphenol oxidase treatment, counteract the strong inhibitory effect of polyphenols from brown sorghum on the absorption of fortification iron in young women

In addition to phytate, polyphenols (PP) might contribute to low Fe bioavailability from sorghum-based foods. To investigate the inhibitory effects of sorghum PP on Fe absorption and the potential enhancing effects of ascorbic acid (AA), NaFeEDTA and the PP oxidase enzyme laccase, we carried out three Fe absorption studies in fifty young women consuming dephytinised Fe-fortified test meals based on white and brown sorghum varieties with different PP concentrations. Fe absorption was measured as the incorporation of stable Fe isotopes into erythrocytes. In study 1, Fe absorption from meals with 17mg PP (8·5%) was higher than that from meals with 73mg PP (3·2%) and 167mg PP (2·7%; P<0·001). Fe absorption from meals containing 73 and 167mg PP did not differ (P=0·9). In study 2, Fe absorption from NaFeEDTA-fortified meals (167mg PP) was higher than that from the same meals fortified with FeSO4 (4·6 v. 2·7%; P<0·001), but still it was lower than that from FeSO4-fortified meals with 17mg PP (10·7%; P<0·001). In study 3, laccase treatment decreased the levels of PP from 167 to 42mg, but it did not improve absorption compared with that from meals with 167mg PP (4·8 v. 4·6%; P=0·4), whereas adding AA increased absorption to 13·6% (P<0·001). These findings suggest that PP from brown sorghum contribute to low Fe bioavailability from sorghum foods and that AA and, to a lesser extent, NaFeEDTA, but not laccase, have the potential to overcome the inhibitory effect of PP and improve Fe absorption from sorghum food

Potential Health Benefits and Adverse Effects Associated with Phytate in Foods

Phytate (myo-inositol (1,2,3,4,5,6) hexakisphosphate), a naturally compound formed during maturation of plant seeds and grains is a common constituent of plant-derived foods. This paper is aimed to review the scientific information concerning the potential health benefits and adverse effects associated with phytate in foods. The adverse health effects of phytate in the diet is its effect on mineral uptake. Minerals of concern in this regard would include Zn2+, Fe2+/3+, Ca2+, Mg2+, Mn2+, and Cu2+. Especially zinc and iron deficiencies were reported as a consequence of high phytate intakes. In addition, a the adverse effect on the nutritional value of protein by dietary phytate is discussed. Consumption of phytate, however, seems not to have only adverse health effects but also potential benefits on human health. Dietary phytate was reported to prevent kidney stone formation, protect against diabetes mellitus, caries, atherosclerosis and coronary heart disease as well as against a variety of cancers. Keywords: Antinutrient, Phytate, Health Benefits, Health Effects, Human Nutritio

Fytinsyrenedbrydning ved fytase

Antallet af komplekst bundne fosfatgrupper til fytinsyre i korn til foder og brødfremstilling er afgørende for biotilgængeligheden af mineraler. 31P NMR kombineret med multivariat data analyse er en unik metode at undersøge fytinsyrenedbrydningen på