Effect of reduced phytate wheat bran on zinc absorption

The rise in plasma zinc after the ingestion of 765 mumol (50 mg) elemental zinc was measured over 6 h in three groups of healthy subjects who, in a second test, also consumed a standard wheat bran, a reduced phytate, high fibre processed bran or rice-based, low phytate, low fibre breakfast cereal (Rice Krispies). Standard bran, reduced phytate bran and Rice Krispies all significantly decreased the area under the plasma zinc time curve (AUC) compared to the zinc alone test. The AUC obtained with standard bran was significantly lower than that after reduced phytate bran (mean +/- s.e.: -5.9 +/- 2.7 vs 18.5 +/- 4.2 mumol.h/l, P less than 0.001). The percentage reductions in AUC produced by the test meals were: standard bran 106.4 +/- 2.4, reduced phytate bran 75.9 +/- 4.8, Rice Krispies 46.3 +/- 10.4 per cent, P less than 0.01). Histidine, taken with standard bran in a small subgroup of subjects, tended to improve zinc absorption but the difference was not statistically significant.