A systematic review of red blood cells biomarkers in human aging.

Red blood cells (RBCs) have emerged as biomarkers of the aging process as they undergo several changes in human aging and age-related diseases. The objectives of our study are to explore the effect of human aging on red blood cell indices, the strengths, therapeutic interventions, challenges, and future directions for using RBCs as a biomarker. Two online databases, PubMed and ScienceDirect, were used to search relevant studies using 'RBCs as biomarkers of human aging', 'red blood cells [MeSH Terms] AND biomarkers [MeSH Terms] AND human aging [MeSH Terms]', and 'erythrocytes and human aging' as keywords. A total of 474 studies were identified, and after the removal of duplicates, excluding studies based on title, abstract, or full text, 74 studies and 48 additional studies found through cross-referencing were included in this systematic review. Based on the evidence, we concluded that RBC indices such as hemoglobin concentration, mean corpuscular volume, red blood cell distribution width, RBC membrane, oxidative stress, and metabolism change with human aging. Several studies have applied therapeutic interventions to RBCs, including dietary supplementation, phytochemicals, nanoparticles, and physical activity, to mitigate aging and related outcomes. Hence, the quality of life for older people and healthy aging can be improved by further investigating the RBC parameters, molecular mechanisms, and their implications for age-related health consequences.