Increased iron bioavailability from lactic-fermented vegetables is likely an effect of promoting the formation of ferric iron (Fe(3+)).

BACKGROUND: Lactic fermentation of foods increases the availability of iron as shown in a number of studies throughout the years. Several explanations have been provided such as decreased content of inhibitory phytate, increased solubility of iron, and increased content of lactic acid in the fermented product. However, to our knowledge, there are no data to support that the bioavailability of iron is affected by lactic fermentation. OBJECTIVES: The objective of the present study was to investigate whether the bioavailability of iron from a vegetable mix was affected by lactic fermentation and to propose a mechanism for such an event, by conducting human and cell (Caco-2, HepG2) studies and iron speciation measurements (voltammetry). We also investigated whether the absorption of zinc was affected by the lactic fermentation. RESULTS: In human subjects, we observed that lactic-fermented vegetables served with both a high-phytate and low-phytate meal increased the absorption of iron, but not zinc. In vitro digested fermented vegetables were able to provoke a greater hepcidin response per ng Fe than fresh vegetables, indicating that Fe in the fermented mixes was more bioavailable, independent on the soluble Fe content. We measured that hydrated Fe(3+) species were increased after the lactic fermentation, while there was no significant change in hydrated Fe(2+). Furthermore, lactate addition to Caco-2 cells did not affect ferritin formation in response to Fe nor did lactate affect the hepcidin response in the Caco-2/HepG2 cell system. CONCLUSIONS: The mechanism for the increased bioavailability of iron from lactic-fermented vegetables is likely an effect of the increase in ferric iron (Fe(3+)) species caused by the lactic fermentation. No effect on zinc bioavailability was observed.

Weight and length at birth and their relationship to diabetes incidence and all-cause mortality--a 32-year follow-up of the population study of women in Gothenburg, Sweden.

OBJECTIVE: The purpose of the study was to explore the relationship of weight and length at birth to diabetes in adult life and to all-cause mortality. Special attention was taken to potential confounding factors as age, family history, education, socio-economic group, physical inactivity, smoking, blood pressure, serum lipids and obesity. RESEARCH DESIGN AND METHODS: A longitudinal population study consisting of a representative sample of 1381 women aged 38-54 started in Gothenburg, Sweden, in 1968-1969 monitoring for diabetes mellitus and overall mortality over 32 years. Original delivery records were retrieved for 61.2% of the women. Death certificates were obtained for 99.3% the women who died during the 32-year follow-up period. RESULTS: We observed an inverse statistically significant relationship between birth weight and 32-year diabetes incidence independent of age, the highest incidence 16.3% in the lowest quartile of birth weight compared to 9.2% in the highest quartile. The relationship remained when controlling for the following covariates: education, socio-economic group, physical activity, smoking, systolic blood pressure, adult body mass index (BMI), waist-hip ratio, serum triglycerides and cholesterol. When overweight women (BMI> or =25) were excluded from the statistical analyses birth weight was even stronger related to the incidence of diabetes, 12.8% in lowest quartile and 5.7% in the highest quartile of birth weight independent of birth length, education, socio-economic group, physical activity, smoking, systolic blood pressure, body mass index, waist-hip ratio, blood glucose, serum triglycerides and cholesterol. Length at birth was a predictor for diabetes independent of age plus adult body mass index (BMI) and smoking but not independent of age only. No significant associations were observed between birth factors as birth weight and birth length and overall mortality during the 32-year of follow-up. CONCLUSIONS: A low birth weight seems to be a risk factor for diabetes in adult women independent of age and most of the established risk factors for diabetes.

No enhancing effect of vitamin A on iron absorption in humans.

BACKGROUND: Vitamin A and beta-carotene were recently reported to enhance iron absorption by counteracting the inhibitory effect of phytic acid in cereal-based meals and of polyphenol-containing beverages on nonheme-iron absorption in humans. OBJECTIVE: Our objective was to further evaluate the influence of vitamin A on iron absorption. DESIGN: Iron absorption from corn bread with or without added vitamin A (retinyl palmitate) was determined in 5 studies in young adult human subjects by using either a stable-isotope method (2 studies) or a radioisotope technique (3 studies). Iron absorption was measured by erythrocyte incorporation of the isotopic labels and by whole-body retention of (59)Fe. Corn bread was served with water (studies 1 and 3) or coffee (studies 2, 4, and 5). The studies differed in the amounts and chemical forms of added tracer and fortification iron. The possibility of methodologic artifacts in earlier investigations was evaluated. RESULTS: No effect of vitamin A on iron absorption from the test meals was identified in the individual studies by using paired Student's t test. A slightly negative effect of vitamin A on iron absorption was found with the use of analysis of variance. CONCLUSIONS: The previously reported findings of a positive effect of vitamin A on nonheme-iron absorption in humans was not confirmed. Incomplete isotopic equilibration of the tracer with native iron in the meal or with fortification iron cannot explain the previous findings. However, the present study does not exclude the possibility that suboptimal vitamin A status influences the effect of dietary vitamin A on iron absorption.