ZINC-ABSORPTION IN ADULT MEN FROM A CHICKEN SANDWICH MADE WITH WHITE OR WHOLEMEAL BREAD, MEASURED BY A DOUBLE-LABEL STABLE-ISOTOPE TECHNIQUE

Eleven fasted adult men consumed a chicken meat sandwich made with white or wholemeal bread, extrinsically labelled with 2 Mg Zn-67, on two different occasions. Immediately after eating the sandwich they were given an intravenous injection of 1.5 mg Zn-70. True Zn absorption (which was approximately 7% higher than apparent absorption) was determined by the faecal balance technique by making an allowance for endogenous excretion from measurements of faecal excretion of Zn-70. There was no significant difference in mean true Zn absorption from the white or wholemeal bread sandwich, 33.6 and 25.4% respectively. It was concluded that the substitution of wholemeal for white bread does not reduce Zn absorption from meat-based sandwiches.