ABSTRACT
Reductions in red meat and increases in cereals in the diet may compromise the intake and bioavailability of Zn. In this cross-sectional study of 330 premenopausal New Zealand women aged 18--40 years, we have assessed the inter-relationships among dietary intakes (via computer-administered food-frequency questionnaire), biochemical Zn status, and anthropometric indices, and compared our results with earlier data. Fasting serum (12.00 (sd 1.36) micromol/l) and hair Zn (2.71 (sd 0.36) micromol/g) were lower than those for young Dunedin, New Zealand, women in 1973 (non-fasting serum Zn 18.6 (sd 4.6) micromol/l, hair Zn 2.99 (sd 0.35) micromol/g). Further, our mean serum Zn was at the 25th percentile of the US National Health and Nutrition Examination Survey (NHANES) (1976--1980) reference sample for women aged 20--44 years. Meat-poultry-fish contributed only 28 % total Zn in the present study, a level comparable with that from cereals-nuts-legumes (27 %), compared to about 40 % in 1989. Significant negative correlations existed between serum Zn and dietary [phytate]:[Zn] molar ratios (r -0.163, 35 % had diets with [phytate]:[Zn] >15, a level said to compromise Zn status. Mean serum Zn of a subgroup of non-oral contraceptive users free of infection was higher in the red-meat eaters (n 149) compared with non-red-meat eaters (n 48) (12.2 v. 11.8 micromol/g, In contrast, serum Zn was lower in those with dietary [phytate]:[Zn] ratios >15 v. <15 (i.e. 11.9 v. 12.3 micromol/l, We postulate that the lower biochemical Zn status of these New Zealand women may be associated in part with changes in food selection patterns, which have led to a reduction in the bioavailability of dietary Zn.
