What Is Inflammaging? How the Immune System Changes With Age

Inflammaging describes the persistent, low-level inflammatory activity that can develop as the immune system changes with age.

When we think about ageing, we often notice changes in our skin, energy, strength or memory. But ageing also takes place inside the immune system—and these internal changes may influence how effectively the body responds, repairs and returns to balance.

What Is Inflammaging?

Inflammation is a normal and essential part of the body’s defence system. It helps the body respond to infection or injury, clear damaged material and begin the repair process.

Normally, this response should settle once its work is complete. With age, however, low-level inflammatory signalling may remain active even when there is no immediate infection or injury. Researchers refer to this persistent, age-associated pattern as inflammaging.

The term was introduced to describe how ageing may be accompanied by a gradual increase in inflammatory activity. Inflammaging does not refer to one specific disease, and it does not mean that all inflammation is harmful. It describes a broader biological pattern being investigated in healthy-ageing research.

Immunosenescence: How the Immune System Changes with Age

Another term frequently discussed alongside inflammaging is immunosenescence.

Immunosenescence refers to age-related changes in immune function. These changes do not simply make the immune system “weaker.” Different parts of the immune system may become less coordinated, slower to respond or more likely to maintain inflammatory signalling for longer than necessary.

Researchers increasingly view immunosenescence and inflammaging as closely connected processes. Changes in immune regulation may contribute to persistent inflammation, while prolonged inflammatory activity may place further pressure on immune cells and tissues.

A healthy immune system must be able not only to switch on, but also to switch off when its work is complete.

Why Immune Balance Matters

Healthy immunity is not about maintaining maximum immune activity at all times. An effective immune system needs to:

• Recognise when a response is required
• Coordinate communication between immune cells
• Remove pathogens, damaged cells and cellular debris
• Support tissue repair and recovery
• Allow inflammatory activity to settle afterwards

This is why immune balance is different from simply “boosting” immunity. The goal is not constant stimulation. It is an appropriate response followed by a return towards balance.

The Role of Macrophages in Inflammaging

Macrophages are immune cells involved in defence, inflammatory signalling, cellular clean-up and tissue repair.

They help identify and remove unwanted microorganisms, dead cells and damaged material. They also communicate with other immune cells through signalling molecules, including cytokines.

As macrophages age, their behaviour and metabolism may change. Research suggests that ageing macrophages may become less efficient at clearing cellular debris or resolving inflammatory responses. In some circumstances, they may also produce inflammatory signals for longer than necessary.

This does not mean that macrophage activation is inherently harmful. Macrophages are essential to normal immunity. The important issue is regulation: activating an appropriate response, carrying out the required work and helping that response resolve.

Chronic Inflammation and Inflammaging: What Is the Difference?

Chronic inflammation is a broad term for inflammatory activity that continues over an extended period. It may be influenced by infection, injury, metabolic factors, environmental exposure or other biological processes.

Inflammaging is more specific. It describes the persistent, low-grade inflammatory state associated with the ageing process.

• Acute inflammation: a short-term response that supports defence and repair.
• Chronic inflammation: inflammatory activity that persists over time for a range of possible reasons.
• Inflammaging: chronic, low-level inflammatory activity associated specifically with ageing.

How Inflammaging Connects with Healthy Ageing

Healthy ageing is influenced by multiple interconnected systems. Immune regulation, cellular repair, metabolism, brain function and the body’s response to stress do not operate independently.

Researchers are investigating how inflammaging may connect with wider areas of ageing biology, including cellular senescence, mitochondrial function, telomere biology and longevity-associated proteins such as α-Klotho.

These relationships are complex and are still being studied. Inflammaging should not be understood as a single cause of ageing, nor can it be measured or changed through one simple intervention. Instead, it provides a useful framework for understanding how immune regulation may influence the body’s long-term resilience.

The Story So Far

Our latest Research Hub articles explain this progression step by step:

1. Immune Balance vs. Immune Boosting—why stronger immune activity is not always better.
2. What Are Macrophages?—the immune cells involved in defence, communication, clean-up and repair.
3. What Is Chronic Inflammation?—what may happen when an inflammatory response continues longer than necessary.
4. What Is Inflammaging?—how immune regulation and persistent low-level inflammation connect with ageing.

Together, these topics reveal an important principle: healthy immunity is not defined by constant activation. It depends on the ability to respond appropriately, coordinate repair and return towards balance.

Explore all articles in the Saisei Australia Research Hub →

The Next Chapter: Telomeres and α-Klotho

Immune balance is one part of the healthy-ageing story. The next step is understanding how immune-related pathways may connect with cellular ageing, telomere maintenance and α-Klotho—a protein widely studied in longevity research.

Explore telomeres, α-Klotho and longevity science →