Objective:
This review explores how aging alters monocyte function, contributing to chronic inflammation (inflammaging), and evaluates how exercise training—especially in older adults—may restore immune balance by modulating monocyte activity, phenotype, and inflammatory output.
Key Findings:
1. Monocyte Subtypes Shift With Age
· Aging increases CD16+ monocytes (intermediate & non-classical), which are more pro-inflammatory.
· These subtypes are associated with diseases like atherosclerosis, arthritis, and cognitive decline.
· Intermediate monocytes produce high levels of TNF-α and IL-1β and increase significantly with age.
2. Aging Microenvironment Promotes Inflammation
· Older adults show elevated mitochondrial DNA, TNF-α, IL-6, and LPS, which overstimulate monocytes and reinforce the inflammatory cycle.
· These changes promote a skew toward the M1 (pro-inflammatory) phenotype and upregulate CD11b, a marker linked to atherosclerosis.
3. Exercise Reduces Pro-Inflammatory Monocytes
· Chronic exercise reduces CD16+ monocytes in older adults, especially intermediate subsets.
· Aerobic and resistance training both showed reductions, although more research using modern monocyte classification is needed.
4. Exercise Decreases Inflammatory Receptor Expression
· Exercise training lowers TLR4 and CD14 expression on monocytes, especially in the elderly.
· This is significant because TLR4 is a key pattern recognition receptor tied to systemic inflammation.
5. Exercise Diminishes Cytokine Release & Improves Function
· Regular training decreases TNF-α, IL-6, IL-1β production in response to stimulation.
· Some studies also show increases in IL-10, an anti-inflammatory cytokine.
· Results vary based on training mode, intensity, and population.
6. Exercise May Improve Monocyte Mitochondrial Function
· Aging impairs mitochondrial respiration in monocytes.
· Exercise has been shown to improve mitochondrial efficiency in immune cells, possibly rejuvenating monocyte function—though more research is needed.
Conclusion:
Monocytes become more inflammatory and dysfunctional with age, contributing to chronic diseases. Exercise, both aerobic and resistance, appears to reverse many of these changes by:
· Reducing pro-inflammatory monocytes (CD16+)
· Lowering receptor expression (TLR4, CD14)
· Improving cytokine profiles and potentially mitochondrial function
These findings position exercise as a powerful immune-modulating therapy for healthy aging.
Disclaimer:
This summary is for educational purposes only and does not constitute medical advice. The research described is based on published peer-reviewed findings. Please consult a healthcare professional before making lifestyle or exercise changes, especially if you have a medical condition or are undergoing treatment.
References Monocytes in Aging and Exercise Johnathan R. Yarbro1, Brandt D. Pence1,2,* 1School of Health Studies, University of Memphis, Memphis, TN, USA 2Center for Nutraceutical and Dietary Supplement Research, University of Memphis, Memphis, TN, USA https://doi.org/10.26644/em.2018.015
