Iron and Zinc Status of Women and Men who Followed Cholesterol-Lowering Diets

Abstract

Objective To determine if men and women taught the National Cholesterol Education Program step 2 diet experienced diminished iron or zinc status after 2 years of consuming the diet. Design Subjects attended 8 weeks of diet classes and follow-up counseling. Four-day food records, zinc protoporphyrin/heme (ZPP/H, a measure of iron stores), hematocrit, and plasma zinc values were collected at baseline, 1 year, and 2 years. Subjects Participants in a study of the efficacy of the step 2 diet (213 men and 151 women) who had low-density lipoprotein cholesterol levels above the 75th percentile, and who were not taking lipid-altering medication. Statistical analyses Paired t tests to compare preintervention and postintervention test results. Two-sample t tests to compare gender, menopause status, and hormone-use groups. Analysis of variance was performed to compare plasma zinc levels among diet-adherence subgroups. Individual evaluation of outlying values and backward stepwise regression to determine the independent effects of variables were also completed. Results Mean dietary intake approached or exceeded step 2 guidelines. Density of iron intake increased. Density of zinc intake was unchanged, but mean intake was low. Mean ZPP/H and hematocrit did not change for premenopausal or postmenopausal women with or without supplemental hormones; men's values changed only slightly. Abnormal ZPP/H and hematocrit occurred sporadically. Mean plasma zinc levels did not differ from baseline for women, increased slightly for men, and did not differ by level of dietary adherence. No plasma zinc concentrations were below normal. Application In this large-scale, 2-year prospective study of women and men, no adverse effects on intake or plasma indicators of iron and zinc were detected as a result of subjects being taught the NCEP step 2 diet. J Am Diet Assoc. 1998;98:149-154.