Effects of iron intake on iron stores in elderly men and women: Longitudinal and cross-sectional results

Objective: For middle aged and elderly subjects there is a concern that inc reased iron intake, especially heme iron associated with consumption of red meat, leads to increased iron stores resulting in disturbed glucose homeos tasis and risk for cardiovascular disease and certain types of cancer. The aim of this study was to investigate me influence of heme, non-heme and iro n supplementation on iron stores in healthy elderly men and women. Method: We conducted a 10 year longitudinal study (48 men and 77 women) and a one year cross-sectional study (165 men and 226 women) in healthy elderl y men and women enrolled in the New Mexico Aging process Study. Tron stores were estimated by serum ferritin concentrations and iron intake was determ ined by three-day food records in the longitudinal study and by a food freq uency questionnaire in the cross-sectional study. Results: We found no association between heme iron intake and iron stores i n either the longitudinal or cross sectional study. In the cross-sectional study we found in women, but not in men, that age and supplemental iron int ake were significantly and positively associated with increased iron stores . Conclusion: Iron stores in elderly men are thought to reach steady state le vels where iron absorption is adjusted to a level just sufficient to cover basal iron losses. In elderly women, we speculate that not enough time has elapsed for postmenopausal women to reach steady state levels of iron stere o resulting in increases in iron absorption with age. Another factor is tha t use of hormone replacement therapy could further delay some women in reac hing steady state iron levels due to continued menstrual blood losses.