Ana M. Pérez-Granados

An oily fish diet increases insulin sensitivity compared to a red meat diet in young iron-deficient women

Beneficial effects of n-3 fatty acids on a variety of physiological functions have been reported, but information related to the effects of oily fish consumed within a varied diet on glucose metabolism and diabetes risk is scarce. The objective of the study was to compare the effects of a diet rich in oily fish to those of a diet rich in red meat on lipid profile, oxidative status, glucose metabolism and insulin sensitivity in young, iron-deficient women. The study was designed attending the CONSORT statement guidelines. It was a randomised crossover dietary intervention study with two 8-week periods. Two diets were designed differing only in their oily fish or red meat content (four portions per week). Twenty-five young iron-deficient women with normal lipid, glucose and insulin levels participated in the assay. Lipid profile (total, LDL- and HDL-cholesterol, TAG), fasting glucose, fasting insulin, and oxidation (lipoperoxides) and inflammation (soluble intercellular adhesion molecule-1 and soluble vascular cell adhesion molecule-1) biomarkers were analysed. Insulin sensitivity was assessed by the Homeostasis Model Assessment (HOMA) and Quantitative Insulin Sensitivity Check Index (QUICKI). Insulin levels significantly decreased and insulin sensitivity significantly increased with the oily fish diet. HDL-cholesterol significantly increased with the oily fish diet. Other parameters did not significantly differ between diets. An increase in oily fish consumption increases insulin sensitivity in young iron-deficient women. This outcome should be considered when giving dietary advice to this population.

Reduction in cardiovascular risk by sodium-bicarbonated mineral water in moderately hypercholesterolemic young adults

The effects of drinking sodium-bicarbonated mineral water on cardiovascular risk in young men and women with moderate cardiovascular risk were studied. Eighteen young volunteers (total cholesterol levels >5.2 mmol/L) without any disease participated. The study consisted of two 8-week intervention periods. Subjects consumed, as supplement to their usual diet, 1 L/day control low mineral water, followed by 1 L/day bicarbonated mineral water (48 mmol/L sodium, 35 mmol/L bicarbonate and 17 mmol/L chloride). Determinations were performed at the end of the control water period and on Weeks 4 and 8 of the bicarbonated water period. Body weight, body mass index (BMI), blood pressure, dietary intake, total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, apolipoprotein (Apo) A-I, Apo B, triacylgycerols, glucose, insulin, adiponectin, high-sensitivity C-reactive protein (hs-CRP), soluble adhesion molecules [soluble intercellular adhesion molecule (sICAM) and soluble vascular adhesion molecule (sVCAM)], sodium and chloride urinary excretion, and urine pH were measured. Dietary intake, body weight and BMI showed no significant variations. Systolic blood pressure decreased significantly after 4 weeks of bicarbonated water consumption, without significant differences between Weeks 4 and 8. After bicarbonated water consumption, significant reductions in total cholesterol (by 6.3%; P=.012), LDL cholesterol (by 10%; P=.001), total/HDL cholesterol (P=.004), LDL/HDL cholesterol (P=.001) and Apo B (P=.017) were observed. Serum triacylglycerol, Apo A-I, sICAM-1, sVCAM-1 and hs-CRP levels did not change. Serum glucose values tended to decrease during the bicarbonated water intervention (P=.056), but insulin levels did not vary. This sodium-bicarbonated mineral water improves lipid profile in moderately hypercholesterolemic young men and women and could therefore be applied in dietary interventions to reduce cardiovascular risk.

Iron status biomarkers in iron deficient women consuming oily fish versus red meat diet

Specific recommendations for anemic individuals consist in increasing red meat intake, but the population at large is advised to reduce consumption of red meat and increase that of fish, in order to prevent the risk of developing cardiovascular disease. This study aimed to determine the effects of consuming an oily fish compared to a red meat diet on iron status in women with low iron stores. The study was designed attending the Consolidated Standards of Reporting Trials (CONSORT) statement guidelines. It was a randomised crossover dietary intervention study of two 8-week periods. Twenty-five young women with low iron stores completed the study. Two diets containing a total of 8 portions of fish, meat and poultry per week were designed differing only in their oily fish or red meat content (5 portions per week). At the beginning and the end of each period blood samples were taken and hemoglobin, hematocrit, serum ferritin, serum iron, serum transferrin, serum transferrin receptor-2 and the Zn-protoporphyrin/free-protoporphyrin ratio were determined. Food intake and body weight were monitored. During the oily fish diet, PUFA intake was significantly higher (p=0.010) and iron intake lower (mean±SD, 11.5±3.4 mg/dayvs. 13.9±0.1 mg/day, p=0.008), both diets providing lower mean daily iron intake than recommended for menstruating women. Although there were no significant differences after 16 weeks, serum ferritin moderately decreased and soluble transferrin receptor increased with the oily fish, while changes with the red meat diet were the opposite. In conclusion, an oily fish diet compared to a red meat diet does not decrease iron status after 8 weeks in iron deficient women.ResumenLas recomendaciones nutricionales dirigidas a personas con anemia consisten generalmente en aumentar el consumo de carne roja, mientras que las recomendaciones para la población general están enfocadas a la reducción del consumo de esta carne y aumentar el consumo de pescado, con el fin de reducir el riesgo de desarrollar enfermedades cardiovasculares. El presente estudio se diseñó para investigar los efectos del consumo de una dieta basada en pescado azul frente a una de carne roja sobre el estado de hierro de mujeres con bajas reservas de hierro. Este estudio se planteó de acuerdo con la guía CONSORT (patrones consolidados para la publicación de ensayos). Se trató de una intervención nutricional cruzada, aleatorizada, con 2 periodos de 8 semanas cada uno. Veinticinco mujeres finalizaron el estudio. Se diseñaron dos dietas que contenían 8 raciones de pescado, carne y aves a la semana. Sólo se diferenciaban en el contenido de pescado azul o carne roja (4 raciones semanales). Al inicio y final de cada periodo se obtuvieron muestras de sangre y se analizó la concentración de hemoglobina, hematocrito, ferritina, hierro sérico, transferrina, receptor-2 de la transferrina y el cociente Zn-protoporfirina/ protoporfirina libre. El peso y la ingesta de alimentos se controlaron durante el estudio. Durante la dieta de pescado azul la ingesta de ácidos grasos poliinsturados (AGP) fue significativamente mayor (p=0,010) y la ingesta de hierro se redujo (media±SD, 11,5±3,4 frente a 13,9±0,1 mg/día, p=0.008), siendo el aporte de hierro menor al recomendado para esta población. Aunque no se encontraron diferencias significativas durante 16 semanas, la ferritina descendió ligeramente y la concentración del receptor de transferrina aumentó con la dieta de pescado azul, mientras que los cambios observados con la dieta rica en carne roja fueron los opuestos. En conclusión, una dieta basada en pescado azul comparada con una dieta rica en carne roja, no provoca un descenso en el estado de hierro de mujeres con deficiencia de hierro después de 8 semanas.

Oily Fish Increases Iron Bioavailability of a Phytate Rich Meal in Young Iron Deficient Women

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 μg/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 (R2 = 0.294, p = 0.011) and the fish and bean meal (R2 = 0.401, p = 0.002). Conclusion: Sous vide cooked salmon fish increases iron absorption from a high phytate bean meal in humans.

Efficacy of a microencapsulated iron pyrophosphate-fortified fruit juice: a randomised, double-blind, placebo-controlled study in Spanish iron-deficient women.

Fe-deficiency anaemia is a worldwide health problem. We studied the influence of consuming an Fe-fortified fruit juice on Fe status in menstruating women. A randomised, double-blind, placebo-controlled study of 16 weeks of duration was performed. Subjects were randomised into two groups: the P group (n 58) or the F group (n 64), and consumed, as a supplement to their usual diet, 500 ml/d of a placebo fruit juice or an Fe-fortified fruit juice, respectively. The Fe-fortified fruit juice, containing microencapsulated iron pyrophosphate, provided 18 mg Fe/d (100 % of the RDA). At baseline and monthly, dietary intake, body weight and Fe parameters were determined: total erythrocytes, haematocrit, mean corpuscular volume (MCV), red blood cell distribution width (RDW), Hb, serum Fe, serum ferritin, serum transferrin, transferrin saturation, soluble transferrin receptor (sTfR) and zinc protoporphyrin (ZnPP). The fruit juice consumption involved increased intake of carbohydrates and vitamin C, and increased BMI within normal limits. Ferritin was higher in the F group after week 4 (P < 0·05) and became 80 % higher than in the P group after week 16 (P < 0·001), and transferrin decreased in the F group compared with the P group after week 4 (P < 0·001). RDW was higher at weeks 4 and 8 in the F group compared with the P group (P < 0·05). Transferrin saturation increased after week 8, and haematocrit, MCV and Hb increased after week 12, in the F group compared with the P group. Serum Fe did not change. sTfR and ZnPP decreased in the F group at week 16 (P < 0·05). Iron pyrophosphate-fortified fruit juice improves Fe status and may be used to prevent Fe-deficiency anaemia.

Iron absorption from meat pate fortified with ferric pyrophosphate in iron-deficient women

OBJECTIVE Preventing iron deficiency has been a main target of the World Health Organization since 1992. Difficulties to reach dietary recommended iron intakes and to enhance iron absorption should be overcome. We compared in iron-deficient women the bioavailability of iron of three meat pate products enriched with ferrous sulfate, ferric pyrophosphate encapsulated in liposomes, or ferric pyrophosphate encapsulated in liposomes plus a hemoglobin-based meat pigment. METHODS Seventeen women with low iron stores (ferritin <30 microg/L) took part in a three-way, randomized, crossover, double-blind postprandial intervention. Test meals consisted of 80 g of the three different enriched meat pate products, which were spread on two slices of white bread. The pate composition was 13.5 g of protein/100 g, 30 g of fat/100 g (49% monounsaturated fatty acids, 35% saturated fatty acids, 16% polyunsaturated fatty acids), 1 g of carbohydrates/100 g, and 19 mg of total iron (including 15 mg of iron from the test fortificants). Blood samples were taken at baseline and each hour for 6 h after eating the meal and serum iron was determined. RESULTS Serum iron concentration evolution during the postprandial study was similar with the three meals, and maximum concentrations were obtained between hours 2 and 4. The effect of type of fortificant was not significant. CONCLUSION Consumption of meat pate fortified with ferric pyrophosphate encapsulated in liposomes can be part of a dietary strategy for preventing iron deficiency in humans. The addition of larger amounts of a meat pigment rich in heme iron should be further studied.

Sodium bicarbonated mineral water decreases postprandial lipaemia in postmenopausal women compared to a low mineral water

The role of bicarbonated mineral waters on lipid metabolism and lipoprotein concentrations in man has scarcely been investigated. The present study aimed to investigate whether drinking sodium bicarbonated mineral water affects postprandial cholesterol and triacylglycerol metabolism in postmenopausal women. In a three-way, randomised, crossover study, eighteen healthy postmenopausal women consumed two sodium bicarbonated mineral waters (bicarbonated mineral water 1 and bicarbonated mineral water 2) and a low mineral water (500 ml of each) with a standard fat-rich meal (4552 kJ; 75.3 g fat). The bicarbonated waters were rich in sodium and bicarbonate and bicarbonated mineral water 1 contained 5.7 times more fluoride than bicarbonated mineral water 2. Fasting blood samples and postprandial blood samples were taken at 30, 60, 120, 240, 360 and 420 min after the end of the meal consumption. Cholesterol and triacylglycerols were determined in serum and chylomicrons. A significant water consumption effect was observed in the total area under the curve (TAUC) of serum and chylomicron triacylglycerols (ANOVA, P=0.008 and P=0.027, respectively). TAUC of serum triacylglycerols for bicarbonated mineral water 2 was significantly lower compared to low mineral water (Bonferroni, P=0.039). Peak concentration of serum triacylglycerols showed a significant water effect (P=0.025). Changes in chylomicron cholesterol were not significantly affected by the type of water. Bicarbonated mineral waters 1 and 2 did not show any significant differences. Drinking sodium bicarbonate-rich mineral waters reduces postprandial lipaemia in healthy postmenopausal women compared to drinking a low mineral water.

Four variants in transferrin and HFE genes as potential markers of iron deficiency anaemia risk: an association study in menstruating women

BackgroundIron deficiency anaemia is a worldwide health problem in which environmental, physiologic and genetic factors play important roles. The associations between iron status biomarkers and single nucleotide polymorphisms (SNPs) known to be related to iron metabolism were studied in menstruating women.MethodsA group of 270 Caucasian menstruating women, a population group at risk of iron deficiency anaemia, participated in the study. Haematological and biochemical parameters were analysed and 10 selected SNPs were genotyped by minisequencing assay. The associations between genetic and biochemical data were analysed by Bayesian Model Averaging (BMA) test and decision trees. Dietary intake of a representative subgroup of these volunteers (n = 141) was assessed, and the relationship between nutrients and iron biomarkers was also determined by linear regression.ResultsFour variants, two in the transferrin gene (rs3811647, rs1799852) and two in the HFE gene (C282Y, H63D), explain 35% of the genetic variation or heritability of serum transferrin in menstruating women. The minor allele of rs3811647 was associated with higher serum transferrin levels and lower transferrin saturation, while the minor alleles of rs1799852 and the C282Y and H63D mutations of HFE were associated with lower serum transferrin levels. No association between nutrient intake and iron biomarkers was found.ConclusionsIn contrast to dietary intake, these four SNPs are strongly associated with serum transferrin. Carriers of the minor allele of rs3811647 present a reduction in iron transport to tissues, which might indicate higher iron deficiency anaemia risk, although the simultaneous presence of the minor allele of rs1799852 and HFE mutations appear to have compensatory effects. Therefore, it is suggested that these genetic variants might potentially be used as markers of iron deficiency anaemia risk.

Effects of an Iron or Iron and Vitamin D–Fortified Flavored Skim Milk on Iron Metabolism: A Randomized Controlled Double-Blind Trial in Iron-Deficient Women

Objectives: Iron deficiency anemia and vitamin D deficiency are considered global pandemics. The aim of this study was to determine whether the consumption of a dairy product fortified with iron and vitamin D, compared to the equivalent with only added iron, exerts an additional effect on iron metabolism in iron-deficient menstruating women. Methods: The design was a randomized, placebo-controlled, double-blind, parallel-group trial of 16 weeks’ duration. Subjects were randomized into 2 groups that consumed, as part of their usual diet, 500 mL/day of an iron (n = 54) or iron- and vitamin D–fortified (n = 55) flavored skim milk. At baseline and monthly, dietary intake, body weight, and hematological and iron metabolism biomarkers were determined. Serum 25-hydroxyvitamin D was analyzed at baseline and weeks 8 and 16. Data were analyzed by analysis of variance (ANOVA) of repeated measures for time and Time×Group interaction effects. Results: A total of 109 volunteers completed the study. Calcium and iron intakes increased during the intervention (p < 0.001 for both groups). Serum 25-hydroxyvitamin D significantly increased in Fe + D group during the assay (p < 0.001) and at week 16 it was higher compared to the Fe group (p < 0.05). Serum ferritin, serum transferrin, mean corpuscular volume, mean corpuscular hemoglobin, and red blood cell distribution width showed significant time effects but no Time×Group interaction. Higher values of erythrocytes (p = 0.01), hematocrit (p = 0.05), and hemoglobin (p = 0.03) at week 8 were observed in the Fe + D group compared to the Fe group. Conclusion: Iron-fortified flavored skim milk does not improve iron status in iron-deficient menstruating women. However, vitamin D fortification slightly enhances erythropoiesis and iron status.

A Comparative Study of Iron Bioavailability from Cocoa Supplemented with Ferric Pyrophosphate or Ferrous Fumarate in Rats

Background: Food iron fortification can be a good strategy to prevent iron deficiency. Iron bioavailability from cocoa powder enriched with ferric pyrophosphate encapsulated in liposomes or ferrous fumarate was assessed in rats. Methods: Three groups of rats consumed during 28 days either a control diet or two diets prepared with ferric pyrophosphate- or ferrous fumarate-enriched cocoa powder as the unique source of iron. Body weight and food intake were monitored and last-week feces were collected. On day 28, animals were sacrificed and livers and spleens were removed. Hemoglobin and total iron binding capacity (TIBC) were determined. Results: There were no significant differences in body weight and food intake. Apparent iron absorption and % absorption/intake were significantly lower in rats consuming enriched cocoa compared to the control group, without significant differences due to the iron form. Enriched cocoa groups showed significantly lower spleen iron content and concentration than the control. Liver iron was lower in the ferric pyrophosphate group compared to the other two groups. Hemoglobin and TIBC values showed a deficient iron status in ferric pyrophosphate rats. Conclusion: Cocoa powder is a good vehicle for iron fortification when enriched with ferrous fumarate compared to ferric pyrophosphate encapsulated in liposomes.