Iron homeostasis in older adults: balancing nutritional requirements and health risks

Rola S Zeidan; Matthew Martenson; Javier A Tamargo; Christian McLaren; Armin Ezzati; Yi Lin; Jae Jeong Yang; Hyung-Suk Yoon; Taylor McElroy; James F Collins; Christiaan Leeuwenburgh; Robert T Mankowski; Stephen Anton

doi:10.1016/j.jnha.2024.100212

Iron homeostasis in older adults: balancing nutritional requirements and health risks

J Nutr Health Aging. 2024 Mar 14;28(5):100212. doi: 10.1016/j.jnha.2024.100212. Online ahead of print.

Affiliations

¹ Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL, USA; Department of Health Outcomes and Biomedical Informatics, College of Medicine, University of Florida, Gainesville, Florida, USA.
² Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL, USA.
³ Department of Clinical and Health Psychology, College of Health and Health Professions, University of Florida, Gainesville, Florida, USA.
⁴ Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL, USA; Department of Food, Nutrition, Dietetics and Health, Kansas State University, Manhattan, KS, USA.
⁵ UF Health Cancer Center, Gainesville, FL, USA; Department of Surgery, College of Medicine, University of Florida, Gainesville, FL, USA.
⁶ Department of Food Science & Human Nutrition, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA.
⁷ Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL, USA; Department of Clinical and Health Psychology, College of Health and Health Professions, University of Florida, Gainesville, Florida, USA. Electronic address: santon@ufl.edu.

PMID: 38489995
DOI: 10.1016/j.jnha.2024.100212

Abstract

Iron plays a crucial role in many physiological processes, including oxygen transport, bioenergetics, and immune function. Iron is assimilated from food and also recycled from senescent red blood cells. Iron exists in two dietary forms: heme (animal based) and non-heme (mostly plant based). The body uses iron for metabolic purposes, and stores the excess mainly in splenic and hepatic macrophages. Physiologically, iron excretion in humans is inefficient and not highly regulated, so regulation of intestinal absorption maintains iron homeostasis. Iron losses occur at a steady rate via turnover of the intestinal epithelium, blood loss, and exfoliation of dead skin cells, but overall iron homeostasis is tightly controlled at cellular and systemic levels. Aging can have a profound impact on iron homeostasis and induce a dyshomeostasis where iron deficiency or overload (sometimes both simultaneously) can occur, potentially leading to several disorders and pathologies. To maintain physiologically balanced iron levels, reduce risk of disease, and promote healthy aging, it is advisable for older adults to follow recommended daily intake guidelines and periodically assess iron levels. Clinicians can evaluate body iron status using different techniques but selecting an assessment method primarily depends on the condition being examined. This review provides a comprehensive overview of the forms, sources, and metabolism of dietary iron, associated disorders of iron dyshomeostasis, assessment of iron levels in older adults, and nutritional guidelines and strategies to maintain iron balance in older adults.

Keywords: Aging; Homeostasis; Iron; Nutrition.

Publication types

Review