Professor Ann-Sofie Sandberg
Asst. professor Nathalie Scheers
Nils-Gunnar Carlsson, research engineer
Annette Almgren, research engineer
An area which has been in focus in the unit for many years is the bioavailability of minerals and most importantly, factors that stimulate or inhibit the absorption of iron and zinc. We are also concerned with the improvement of bioavailability by evaluating methods such as fermentation, malting, hydro-thermal treatment, and addition of enzymes. The mineral absorption inhibitor Phytic acid (inositol hexaphosphate) which is abundant in cereals and legumes is one of the research areas. We have previously identified inositol pentaphosphate as an inhibitor of iron and zinc absorption in human and animal studies and developed several methods for analyzing minerals and inositol phosphate and their positional isomeres. We have also showed that iron and zinc absorption from a meal can be dramatically increased by controlled degradation of mineral absorption inhibitors. In a collaboration with Sahlgrenska academy (Lena Hulthén), we are investigating how long-term intake of whole-grain bread affects iron status in women of child-bearing age and if the iron status can be improved by the degradation of phytic acid in the breads.
Nowadays we are also interested in the regulation of iron absorption. The studies are carried out in a human cell model (Caco-2) where we are investigating the expression of iron transport proteins in response to different stimuli. We have for instance shown that ascorbate (vitamin C) has direct effects on the expression of several important proteins involved in transmembrane transport of iron. Additional studies have also shown that this regulation is bi-directional; iron affects the cellular uptake of ascorbate via up-regulation of the ascorbate transporter SVCT1. We are also concerned with the development of a new, improved cell model for iron absorption studies.